js_mind修改了支持单节点是否可编辑属性editable

/**
 * @license BSD
 * @copyright 2014-2023 hizzgdev@163.com
 *
 * Project Home:
 *   https://github.com/hizzgdev/jsmind/
 */

; (function ($w) {
    'use strict';
    console.warn("The version is outdated. see details: https://hizzgdev.github.io/jsmind/es6/")
    // set 'jsMind' as the library name.
    // __name__ should be a const value, Never try to change it easily.
    var __name__ = 'jsMind';
    // library version
    var __version__ = '0.5.7';
    // author
    var __author__ = 'hizzgdev@163.com';

    // an noop function define
    var _noop = function () { };
    var logger = (typeof console === 'undefined') ? {
        log: _noop, debug: _noop, error: _noop, warn: _noop, info: _noop
    } : console;

    // check global variables
    if (typeof module === 'undefined' || !module.exports) {
        if (typeof $w[__name__] != 'undefined') {
            logger.log(__name__ + ' has been already exist.');
            return;
        }
    }

    // shortcut of methods in dom
    var $d = $w.document;
    var $g = function (id) { return $d.getElementById(id); };
    var $c = function (tag) { return $d.createElement(tag); };
    var $t = function (n, t) { if (n.hasChildNodes()) { n.firstChild.nodeValue = t; } else { n.appendChild($d.createTextNode(t)); } };

    var $h = function (n, t) {
        if (t instanceof HTMLElement) {
            n.innerHTML = '';
            n.appendChild(t);
        } else {
            n.innerHTML = t;
        }
    };
    // detect isElement
    var $i = function (el) { return !!el && (typeof el === 'object') && (el.nodeType === 1) && (typeof el.style === 'object') && (typeof el.ownerDocument === 'object'); };
    if (typeof String.prototype.startsWith != 'function') { String.prototype.startsWith = function (p) { return this.slice(0, p.length) === p; }; }

    var DEFAULT_OPTIONS = {
        container: '',   // id of the container
        editable: false, // you can change it in your options
        theme: null,
        mode: 'full',    // full or side
        support_html: true,

        view: {
            engine: 'canvas',
            hmargin: 100,
            vmargin: 50,
            line_width: 2,
            line_color: '#555',
            draggable: false, // drag the mind map with your mouse, when it's larger that the container
            hide_scrollbars_when_draggable: false, // hide container scrollbars, when mind map is larger than container and draggable option is true.
            node_overflow: 'hidden' // hidden or wrap
        },
        layout: {
            hspace: 30,
            vspace: 20,
            pspace: 13,
            cousin_space: 0
        },
        default_event_handle: {
            enable_mousedown_handle: true,
            enable_click_handle: true,
            enable_dblclick_handle: true,
            enable_mousewheel_handle: true
        },
        shortcut: {
            enable: true,
            handles: {
            },
            mapping: {
                addchild: [45, 4096 + 13], // Insert, Ctrl+Enter
                addbrother: 13, // Enter
                editnode: 113,// F2
                delnode: 46, // Delete
                toggle: 32, // Space
                left: 37, // Left
                up: 38, // Up
                right: 39, // Right
                down: 40, // Down
            }
        },
    };

    // core object
    var jm = function (options) {
        jm.current = this;

        this.version = __version__;
        var opts = {};
        jm.util.json.merge(opts, DEFAULT_OPTIONS);
        jm.util.json.merge(opts, options);

        if (!opts.container) {
            logger.error('the options.container should not be null or empty.');
            return;
        }
        this.options = opts;
        this.initialized = false;
        this.mind = null;
        this.event_handles = [];
        this.init();
    };

    // ============= static object =============================================
    jm.direction = {
        left: -1, center: 0, right: 1, of: function (dir) {
            if (!dir || dir === -1 || dir === 0 || dir === 1) {
                return dir;
            }
            if (dir === '-1' || dir === '0' || dir === '1') {
                return parseInt(dir);
            }
            if (dir.toLowerCase() === 'left') {
                return this.left;
            }
            if (dir.toLowerCase() === 'right') {
                return this.right;
            }
            if (dir.toLowerCase() === 'center') {
                return this.center;
            }
        }
    };
    jm.event_type = { show: 1, resize: 2, edit: 3, select: 4 };
    jm.key = { meta: 1 << 13, ctrl: 1 << 12, alt: 1 << 11, shift: 1 << 10 };

    jm.node = function (sId, iIndex, sTopic, oData, bIsRoot, oParent, eDirection, bExpanded) {
        if (!sId) { logger.error('invalid node id'); return; }
        if (typeof iIndex != 'number') { logger.error('invalid node index'); return; }
        if (typeof bExpanded === 'undefined') { bExpanded = true; }
        this.id = sId;
        this.index = iIndex;
        this.topic = sTopic;
        this.data = oData || {};
        this.isroot = bIsRoot;
        this.parent = oParent;
        this.direction = eDirection;
        this.expanded = !!bExpanded;
        this.children = [];
        this._data = {};
    };

    jm.node.compare = function (node1, node2) {
        // '-1' is alwary the last
        var r = 0;
        var i1 = node1.index;
        var i2 = node2.index;
        if (i1 >= 0 && i2 >= 0) {
            r = i1 - i2;
        } else if (i1 == -1 && i2 == -1) {
            r = 0;
        } else if (i1 == -1) {
            r = 1;
        } else if (i2 == -1) {
            r = -1;
        } else {
            r = 0;
        }
        //logger.debug(i1+' <> '+i2+'  =  '+r);
        return r;
    };

    jm.node.inherited = function (pnode, node) {
        if (!!pnode && !!node) {
            if (pnode.id === node.id) {
                return true;
            }
            if (pnode.isroot) {
                return true;
            }
            var pid = pnode.id;
            var p = node;
            while (!p.isroot) {
                p = p.parent;
                if (p.id === pid) {
                    return true;
                }
            }
        }
        return false;
    };

    jm.node.is_node = function (n) {
        return !!n && n instanceof jm.node;
    };

    jm.node.prototype = {
        get_location: function () {
            var vd = this._data.view;
            return {
                x: vd.abs_x,
                y: vd.abs_y
            };
        },
        get_size: function () {
            var vd = this._data.view;
            return {
                w: vd.width,
                h: vd.height
            }
        }
    };


    jm.mind = function () {
        this.name = null;
        this.author = null;
        this.version = null;
        this.root = null;
        this.selected = null;
        this.nodes = {};
    };

    jm.mind.prototype = {
        get_node: function (nodeid) {
            if (nodeid in this.nodes) {
                return this.nodes[nodeid];
            } else {
                logger.warn('the node[id=' + nodeid + '] can not be found');
                return null;
            }
        },

        set_root: function (nodeid, topic, data) {
            if (this.root == null) {
                this.root = new jm.node(nodeid, 0, topic, data, true);
                this._put_node(this.root);
                return this.root;
            } else {
                logger.error('root node is already exist');
                return null;
            }
        },

        add_node: function (parent_node, nodeid, topic, data, direction, expanded, idx) {
            if (!jm.util.is_node(parent_node)) {
                logger.error('the parent_node ' + parent_node + ' is not a node.');
                return null;
            }
            var node_index = idx || -1;
            var node = new jm.node(nodeid, node_index, topic, data, false, parent_node, parent_node.direction, expanded);
            if (parent_node.isroot) {
                node.direction = direction || jm.direction.right;
            }
            if (this._put_node(node)) {
                parent_node.children.push(node);
                this._reindex(parent_node);
            } else {
                logger.error('fail, the nodeid \'' + node.id + '\' has been already exist.');
                node = null;
            }
            return node;
        },

        insert_node_before: function (node_before, nodeid, topic, data, direction) {
            if (!jm.util.is_node(node_before)) {
                logger.error('the node_before ' + node_before + ' is not a node.');
                return null;
            }
            var node_index = node_before.index - 0.5;
            return this.add_node(node_before.parent, nodeid, topic, data, direction, true, node_index);
        },

        get_node_before: function (node) {
            if (!jm.util.is_node(node)) {
                var the_node = this.get_node(node);
                if (!the_node) {
                    logger.error('the node[id=' + node + '] can not be found.');
                    return null;
                } else {
                    return this.get_node_before(the_node);
                }
            }
            if (node.isroot) { return null; }
            var idx = node.index - 2;
            if (idx >= 0) {
                return node.parent.children[idx];
            } else {
                return null;
            }
        },

        insert_node_after: function (node_after, nodeid, topic, data, direction) {
            if (!jm.util.is_node(node_after)) {
                logger.error('the node_after ' + node_after + ' is not a node.');
                return null;
            }
            var node_index = node_after.index + 0.5;
            return this.add_node(node_after.parent, nodeid, topic, data, direction, true, node_index);
        },

        get_node_after: function (node) {
            if (!jm.util.is_node(node)) {
                var the_node = this.get_node(node);
                if (!the_node) {
                    logger.error('the node[id=' + node + '] can not be found.');
                    return null;
                } else {
                    return this.get_node_after(the_node);
                }
            }
            if (node.isroot) { return null; }
            var idx = node.index;
            var brothers = node.parent.children;
            if (brothers.length > idx) {
                return node.parent.children[idx];
            } else {
                return null;
            }
        },

        move_node: function (node, before_id, parent_id, direction) {
            if (!jm.util.is_node(node)) {
                logger.error('the parameter node ' + node + ' is not a node.');
                return null;
            }
            if (!parent_id) {
                parent_id = node.parent.id;
            }
            return this._move_node(node, before_id, parent_id, direction);
        },

        _flow_node_direction: function (node, direction) {
            if (typeof direction === 'undefined') {
                direction = node.direction;
            } else {
                node.direction = direction;
            }
            var len = node.children.length;
            while (len--) {
                this._flow_node_direction(node.children[len], direction);
            }
        },

        _move_node_internal: function (node, beforeid) {
            if (!!node && !!beforeid) {
                if (beforeid == '_last_') {
                    node.index = -1;
                    this._reindex(node.parent);
                } else if (beforeid == '_first_') {
                    node.index = 0;
                    this._reindex(node.parent);
                } else {
                    var node_before = (!!beforeid) ? this.get_node(beforeid) : null;
                    if (node_before != null && node_before.parent != null && node_before.parent.id == node.parent.id) {
                        node.index = node_before.index - 0.5;
                        this._reindex(node.parent);
                    }
                }
            }
            return node;
        },

        _move_node: function (node, beforeid, parentid, direction) {
            if (!!node && !!parentid) {
                var parent_node = this.get_node(parentid)
                if (jm.node.inherited(node, parent_node)) {
                    logger.error('can not move a node to its children');
                    return null;
                }
                if (node.parent.id != parentid) {
                    // remove from parent's children
                    var sibling = node.parent.children;
                    var si = sibling.length;
                    while (si--) {
                        if (sibling[si].id == node.id) {
                            sibling.splice(si, 1);
                            break;
                        }
                    }
                    node.parent = parent_node;
                    parent_node.children.push(node);
                }

                if (node.parent.isroot) {
                    if (direction == jm.direction.left) {
                        node.direction = direction;
                    } else {
                        node.direction = jm.direction.right;
                    }
                } else {
                    node.direction = node.parent.direction;
                }
                this._move_node_internal(node, beforeid);
                this._flow_node_direction(node);
            }
            return node;
        },

        remove_node: function (node) {
            if (!jm.util.is_node(node)) {
                logger.error('the parameter node ' + node + ' is not a node.');
                return false;
            }
            if (node.isroot) {
                logger.error('fail, can not remove root node');
                return false;
            }
            if (this.selected != null && this.selected.id == node.id) {
                this.selected = null;
            }
            // clean all subordinate nodes
            var children = node.children;
            var ci = children.length;
            while (ci--) {
                this.remove_node(children[ci]);
            }
            // clean all children
            children.length = 0;
            // remove from parent's children
            var sibling = node.parent.children;
            var si = sibling.length;
            while (si--) {
                if (sibling[si].id == node.id) {
                    sibling.splice(si, 1);
                    break;
                }
            }
            // remove from global nodes
            delete this.nodes[node.id];
            // clean all properties
            for (var k in node) {
                delete node[k];
            }
            // remove it's self
            node = null;
            //delete node;
            return true;
        },

        _put_node: function (node) {
            if (node.id in this.nodes) {
                logger.warn('the nodeid \'' + node.id + '\' has been already exist.');
                return false;
            } else {
                this.nodes[node.id] = node;
                return true;
            }
        },

        _reindex: function (node) {
            if (node instanceof jm.node) {
                node.children.sort(jm.node.compare);
                for (var i = 0; i < node.children.length; i++) {
                    node.children[i].index = i + 1;
                }
            }
        },
    };

    jm.format = {
        node_tree: {
            example: {
                "meta": {
                    "name": __name__,
                    "author": __author__,
                    "version": __version__
                },
                "format": "node_tree",
                "data": { "id": "root", "topic": "jsMind Example" }
            },
            get_mind: function (source) {
                var df = jm.format.node_tree;
                var mind = new jm.mind();
                mind.name = source.meta.name;
                mind.author = source.meta.author;
                mind.version = source.meta.version;
                df._parse(mind, source.data);
                return mind;
            },
            get_data: function (mind) {
                var df = jm.format.node_tree;
                var json = {};
                json.meta = {
                    name: mind.name,
                    author: mind.author,
                    version: mind.version
                };
                json.format = 'node_tree';
                json.data = df._buildnode(mind.root);
                return json;
            },

            _parse: function (mind, node_root) {
                var df = jm.format.node_tree;
                var data = df._extract_data(node_root);
                mind.set_root(node_root.id, node_root.topic, data);
                if ('children' in node_root) {
                    var children = node_root.children;
                    for (var i = 0; i < children.length; i++) {
                        df._extract_subnode(mind, mind.root, children[i]);
                    }
                }
            },

            _extract_data: function (node_json) {
                var data = {};
                for (var k in node_json) {
                    if (k == 'id' || k == 'topic' || k == 'children' || k == 'direction' || k == 'expanded') {
                        continue;
                    }
                    data[k] = node_json[k];
                }
                return data;
            },

            _extract_subnode: function (mind, node_parent, node_json) {
                var df = jm.format.node_tree;
                var data = df._extract_data(node_json);
                var d = null;
                if (node_parent.isroot) {
                    d = node_json.direction == 'left' ? jm.direction.left : jm.direction.right;
                }
                var node = mind.add_node(node_parent, node_json.id, node_json.topic, data, d, node_json.expanded);
                if (!!node_json['children']) {
                    var children = node_json.children;
                    for (var i = 0; i < children.length; i++) {
                        df._extract_subnode(mind, node, children[i]);
                    }
                }
            },

            _buildnode: function (node) {
                var df = jm.format.node_tree;
                if (!(node instanceof jm.node)) { return; }
                var o = {
                    id: node.id,
                    topic: node.topic,
                    expanded: node.expanded
                };
                if (!!node.parent && node.parent.isroot) {
                    o.direction = node.direction == jm.direction.left ? 'left' : 'right';
                }
                if (node.data != null) {
                    var node_data = node.data;
                    for (var k in node_data) {
                        o[k] = node_data[k];
                    }
                }
                var children = node.children;
                if (children.length > 0) {
                    o.children = [];
                    for (var i = 0; i < children.length; i++) {
                        o.children.push(df._buildnode(children[i]));
                    }
                }
                return o;
            }
        },

        node_array: {
            example: {
                "meta": {
                    "name": __name__,
                    "author": __author__,
                    "version": __version__
                },
                "format": "node_array",
                "data": [
                    { "id": "root", "topic": "jsMind Example", "isroot": true }
                ]
            },

            get_mind: function (source) {
                var df = jm.format.node_array;
                var mind = new jm.mind();
                mind.name = source.meta.name;
                mind.author = source.meta.author;
                mind.version = source.meta.version;
                df._parse(mind, source.data);
                return mind;
            },

            get_data: function (mind) {
                var df = jm.format.node_array;
                var json = {};
                json.meta = {
                    name: mind.name,
                    author: mind.author,
                    version: mind.version
                };
                json.format = 'node_array';
                json.data = [];
                df._array(mind, json.data);
                return json;
            },

            _parse: function (mind, node_array) {
                var df = jm.format.node_array;
                var narray = node_array.slice(0);
                // reverse array for improving looping performance
                narray.reverse();
                var root_node = df._extract_root(mind, narray);
                if (!!root_node) {
                    df._extract_subnode(mind, root_node, narray);
                } else {
                    logger.error('root node can not be found');
                }
            },

            _extract_root: function (mind, node_array) {
                var df = jm.format.node_array;
                var i = node_array.length;
                while (i--) {
                    if ('isroot' in node_array[i] && node_array[i].isroot) {
                        var root_json = node_array[i];
                        var data = df._extract_data(root_json);
                        var node = mind.set_root(root_json.id, root_json.topic, data);
                        node_array.splice(i, 1);
                        return node;
                    }
                }
                return null;
            },

            _extract_subnode: function (mind, parent_node, node_array) {
                var df = jm.format.node_array;
                var i = node_array.length;
                var node_json = null;
                var data = null;
                var extract_count = 0;
                while (i--) {
                    node_json = node_array[i];
                    if (node_json.parentid == parent_node.id) {
                        data = df._extract_data(node_json);
                        var d = null;
                        var node_direction = node_json.direction;
                        if (!!node_direction) {
                            d = node_direction == 'left' ? jm.direction.left : jm.direction.right;
                        }
                        var node = mind.add_node(parent_node, node_json.id, node_json.topic, data, d, node_json.expanded);
                        node_array.splice(i, 1);
                        extract_count++;
                        var sub_extract_count = df._extract_subnode(mind, node, node_array);
                        if (sub_extract_count > 0) {
                            // reset loop index after extract subordinate node
                            i = node_array.length;
                            extract_count += sub_extract_count;
                        }
                    }
                }
                return extract_count;
            },

            _extract_data: function (node_json) {
                var data = {};
                for (var k in node_json) {
                    if (k == 'id' || k == 'topic' || k == 'parentid' || k == 'isroot' || k == 'direction' || k == 'expanded') {
                        continue;
                    }
                    data[k] = node_json[k];
                }
                return data;
            },

            _array: function (mind, node_array) {
                var df = jm.format.node_array;
                df._array_node(mind.root, node_array);
            },

            _array_node: function (node, node_array) {
                var df = jm.format.node_array;
                if (!(node instanceof jm.node)) { return; }
                var o = {
                    id: node.id,
                    topic: node.topic,
                    expanded: node.expanded
                };
                if (!!node.parent) {
                    o.parentid = node.parent.id;
                }
                if (node.isroot) {
                    o.isroot = true;
                }
                if (!!node.parent && node.parent.isroot) {
                    o.direction = node.direction == jm.direction.left ? 'left' : 'right';
                }
                if (node.data != null) {
                    var node_data = node.data;
                    for (var k in node_data) {
                        o[k] = node_data[k];
                    }
                }
                node_array.push(o);
                var ci = node.children.length;
                for (var i = 0; i < ci; i++) {
                    df._array_node(node.children[i], node_array);
                }
            },
        },

        freemind: {
            example: {
                "meta": {
                    "name": __name__,
                    "author": __author__,
                    "version": __version__
                },
                "format": "freemind",
                "data": "<map version=\"1.0.1\"><node ID=\"root\" TEXT=\"freemind Example\"/></map>"
            },
            get_mind: function (source) {
                var df = jm.format.freemind;
                var mind = new jm.mind();
                mind.name = source.meta.name;
                mind.author = source.meta.author;
                mind.version = source.meta.version;
                var xml = source.data;
                var xml_doc = df._parse_xml(xml);
                var xml_root = df._find_root(xml_doc);
                df._load_node(mind, null, xml_root);
                return mind;
            },

            get_data: function (mind) {
                var df = jm.format.freemind;
                var json = {};
                json.meta = {
                    name: mind.name,
                    author: mind.author,
                    version: mind.version
                };
                json.format = 'freemind';
                var xmllines = [];
                xmllines.push('<map version=\"1.0.1\">');
                df._buildmap(mind.root, xmllines);
                xmllines.push('</map>');
                json.data = xmllines.join(' ');
                return json;
            },

            _parse_xml: function (xml) {
                var xml_doc = null;
                if (window.DOMParser) {
                    var parser = new DOMParser();
                    xml_doc = parser.parseFromString(xml, 'text/xml');
                } else { // Internet Explorer
                    xml_doc = new ActiveXObject('Microsoft.XMLDOM');
                    xml_doc.async = false;
                    xml_doc.loadXML(xml);
                }
                return xml_doc;
            },

            _find_root: function (xml_doc) {
                var nodes = xml_doc.childNodes;
                var node = null;
                var root = null;
                var n = null;
                for (var i = 0; i < nodes.length; i++) {
                    n = nodes[i];
                    if (n.nodeType == 1 && n.tagName == 'map') {
                        node = n;
                        break;
                    }
                }
                if (!!node) {
                    var ns = node.childNodes;
                    node = null;
                    for (var i = 0; i < ns.length; i++) {
                        n = ns[i];
                        if (n.nodeType == 1 && n.tagName == 'node') {
                            node = n;
                            break;
                        }
                    }
                }
                return node;
            },

            _load_node: function (mind, parent_node, xml_node) {
                var df = jm.format.freemind;
                var node_id = xml_node.getAttribute('ID');
                var node_topic = xml_node.getAttribute('TEXT');
                // look for richcontent
                if (node_topic == null) {
                    var topic_children = xml_node.childNodes;
                    var topic_child = null;
                    for (var i = 0; i < topic_children.length; i++) {
                        topic_child = topic_children[i];
                        //logger.debug(topic_child.tagName);
                        if (topic_child.nodeType == 1 && topic_child.tagName === 'richcontent') {
                            node_topic = topic_child.textContent;
                            break;
                        }
                    }
                }
                var node_data = df._load_attributes(xml_node);
                var node_expanded = ('expanded' in node_data) ? (node_data.expanded == 'true') : true;
                delete node_data.expanded;

                var node_position = xml_node.getAttribute('POSITION');
                var node_direction = null;
                if (!!node_position) {
                    node_direction = node_position == 'left' ? jm.direction.left : jm.direction.right;
                }
                //logger.debug(node_position +':'+ node_direction);
                var node = null;
                if (!!parent_node) {
                    node = mind.add_node(parent_node, node_id, node_topic, node_data, node_direction, node_expanded);
                } else {
                    node = mind.set_root(node_id, node_topic, node_data);
                }
                var children = xml_node.childNodes;
                var child = null;
                for (var i = 0; i < children.length; i++) {
                    child = children[i];
                    if (child.nodeType == 1 && child.tagName == 'node') {
                        df._load_node(mind, node, child);
                    }
                }
            },

            _load_attributes: function (xml_node) {
                var children = xml_node.childNodes;
                var attr = null;
                var attr_data = {};
                for (var i = 0; i < children.length; i++) {
                    attr = children[i];
                    if (attr.nodeType == 1 && attr.tagName === 'attribute') {
                        attr_data[attr.getAttribute('NAME')] = attr.getAttribute('VALUE');
                    }
                }
                return attr_data;
            },

            _buildmap: function (node, xmllines) {
                var df = jm.format.freemind;
                var pos = null;
                if (!!node.parent && node.parent.isroot) {
                    pos = node.direction === jm.direction.left ? 'left' : 'right';
                }
                xmllines.push('<node');
                xmllines.push('ID=\"' + node.id + '\"');
                if (!!pos) {
                    xmllines.push('POSITION=\"' + pos + '\"');
                }
                xmllines.push('TEXT=\"' + node.topic + '\">');

                // store expanded status as an attribute
                xmllines.push('<attribute NAME=\"expanded\" VALUE=\"' + node.expanded + '\"/>');

                // for attributes
                var node_data = node.data;
                if (node_data != null) {
                    for (var k in node_data) {
                        xmllines.push('<attribute NAME=\"' + k + '\" VALUE=\"' + node_data[k] + '\"/>');
                    }
                }

                // for children
                var children = node.children;
                for (var i = 0; i < children.length; i++) {
                    df._buildmap(children[i], xmllines);
                }

                xmllines.push('</node>');
            },
        },
    };

    // ============= utility object =============================================

    jm.util = {
        is_node: function (node) {
            return !!node && node instanceof jm.node;
        },
        ajax: {
            request: function (url, param, method, callback, fail_callback) {
                var a = jm.util.ajax;
                var p = null;
                var tmp_param = [];
                for (var k in param) {
                    tmp_param.push(encodeURIComponent(k) + '=' + encodeURIComponent(param[k]));
                }
                if (tmp_param.length > 0) {
                    p = tmp_param.join('&');
                }
                var xhr = new XMLHttpRequest();
                if (!xhr) { return; }
                xhr.onreadystatechange = function () {
                    if (xhr.readyState == 4) {
                        if (xhr.status == 200 || xhr.status == 0) {
                            if (typeof callback === 'function') {
                                var data = jm.util.json.string2json(xhr.responseText);
                                if (data != null) {
                                    callback(data);
                                } else {
                                    callback(xhr.responseText);
                                }
                            }
                        } else {
                            if (typeof fail_callback === 'function') {
                                fail_callback(xhr);
                            } else {
                                logger.error('xhr request failed.', xhr);
                            }
                        }
                    }
                }
                method = method || 'GET';
                xhr.open(method, url, true);
                xhr.setRequestHeader('If-Modified-Since', '0');
                if (method == 'POST') {
                    xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded;charset=utf-8');
                    xhr.send(p);
                } else {
                    xhr.send();
                }
            },
            get: function (url, callback) {
                return jm.util.ajax.request(url, {}, 'GET', callback);
            },
            post: function (url, param, callback) {
                return jm.util.ajax.request(url, param, 'POST', callback);
            }
        },

        dom: {
            //target,eventType,handler
            add_event: function (t, e, h) {
                if (!!t.addEventListener) {
                    t.addEventListener(e, h, false);
                } else {
                    t.attachEvent('on' + e, h);
                }
            }
        },

        file: {
            read: function (file_data, fn_callback) {
                var reader = new FileReader();
                reader.onload = function () {
                    if (typeof fn_callback === 'function') {
                        fn_callback(this.result, file_data.name);
                    }
                };
                reader.readAsText(file_data);
            },

            save: function (file_data, type, name) {
                var blob;
                if (typeof $w.Blob === 'function') {
                    blob = new Blob([file_data], { type: type });
                } else {
                    var BlobBuilder = $w.BlobBuilder || $w.MozBlobBuilder || $w.WebKitBlobBuilder || $w.MSBlobBuilder;
                    var bb = new BlobBuilder();
                    bb.append(file_data);
                    blob = bb.getBlob(type);
                }
                if (navigator.msSaveBlob) {
                    navigator.msSaveBlob(blob, name);
                } else {
                    var URL = $w.URL || $w.webkitURL;
                    var bloburl = URL.createObjectURL(blob);
                    var anchor = $c('a');
                    if ('download' in anchor) {
                        anchor.style.visibility = 'hidden';
                        anchor.href = bloburl;
                        anchor.download = name;
                        $d.body.appendChild(anchor);
                        var evt = $d.createEvent('MouseEvents');
                        evt.initEvent('click', true, true);
                        anchor.dispatchEvent(evt);
                        $d.body.removeChild(anchor);
                    } else {
                        location.href = bloburl;
                    }
                }
            }
        },

        json: {
            json2string: function (json) {
                return JSON.stringify(json);
            },
            string2json: function (json_str) {
                return JSON.parse(json_str);
            },
            merge: function (b, a) {
                for (var o in a) {
                    if (o in b) {
                        if (typeof b[o] === 'object' &&
                            Object.prototype.toString.call(b[o]).toLowerCase() == '[object object]' &&
                            !b[o].length) {
                            jm.util.json.merge(b[o], a[o]);
                        } else {
                            b[o] = a[o];
                        }
                    } else {
                        b[o] = a[o];
                    }
                }
                return b;
            }
        },

        uuid: {
            newid: function () {
                return (new Date().getTime().toString(16) + Math.random().toString(16).substring(2)).substring(2, 18);
            }
        },

        text: {
            is_empty: function (s) {
                if (!s) { return true; }
                return s.replace(/\s*/, '').length == 0;
            }
        }
    };

    jm.prototype = {
        init: function () {
            if (this.initialized) { return; }
            this.initialized = true;

            var opts = this.options;

            var opts_layout = {
                mode: opts.mode,
                hspace: opts.layout.hspace,
                vspace: opts.layout.vspace,
                pspace: opts.layout.pspace,
                cousin_space: opts.layout.cousin_space
            }
            var opts_view = {
                container: opts.container,
                support_html: opts.support_html,
                engine: opts.view.engine,
                hmargin: opts.view.hmargin,
                vmargin: opts.view.vmargin,
                line_width: opts.view.line_width,
                line_color: opts.view.line_color,
                draggable: opts.view.draggable,
                hide_scrollbars_when_draggable: opts.view.hide_scrollbars_when_draggable,
                node_overflow: opts.view.node_overflow
            };
            // create instance of function provider
            this.data = new jm.data_provider(this);
            this.layout = new jm.layout_provider(this, opts_layout);
            this.view = new jm.view_provider(this, opts_view);
            this.shortcut = new jm.shortcut_provider(this, opts.shortcut);

            this.data.init();
            this.layout.init();
            this.view.init();
            this.shortcut.init();

            this._event_bind();

            jm.init_plugins(this);
        },

        enable_edit: function () {
            this.options.editable = true;
        },

        disable_edit: function () {
            this.options.editable = false;
        },

        // call enable_event_handle('dblclick')
        // options are 'mousedown', 'click', 'dblclick'
        enable_event_handle: function (event_handle) {
            this.options.default_event_handle['enable_' + event_handle + '_handle'] = true;
        },

        // call disable_event_handle('dblclick')
        // options are 'mousedown', 'click', 'dblclick'
        disable_event_handle: function (event_handle) {
            this.options.default_event_handle['enable_' + event_handle + '_handle'] = false;
        },

        get_editable: function () {
            return this.options.editable;
        },

        set_theme: function (theme) {
            var theme_old = this.options.theme;
            this.options.theme = (!!theme) ? theme : null;
            if (theme_old != this.options.theme) {
                this.view.reset_theme();
                this.view.reset_custom_style();
            }
        },
        _event_bind: function () {
            this.view.add_event(this, 'mousedown', this.mousedown_handle);
            this.view.add_event(this, 'click', this.click_handle);
            this.view.add_event(this, 'dblclick', this.dblclick_handle);
            this.view.add_event(this, "mousewheel", this.mousewheel_handle)
        },

        mousedown_handle: function (e) {
            if (!this.options.default_event_handle['enable_mousedown_handle']) {
                return;
            }
            var element = e.target || event.srcElement;
            var nodeid = this.view.get_binded_nodeid(element);
            if (!!nodeid) {
                if (this.view.is_node(element)) {
                    this.select_node(nodeid);
                }
            } else {
                this.select_clear();
            }
        },

        click_handle: function (e) {
            if (!this.options.default_event_handle['enable_click_handle']) {
                return;
            }
            var element = e.target || event.srcElement;
            var is_expander = this.view.is_expander(element);
            if (is_expander) {
                var nodeid = this.view.get_binded_nodeid(element);
                if (!!nodeid) {
                    this.toggle_node(nodeid);
                }
            }
        },

        dblclick_handle: function (e) {
            if (!this.options.default_event_handle['enable_dblclick_handle']) {
                return;
            }
            if (this.get_editable()) {
                var element = e.target || event.srcElement;
                var is_node = this.view.is_node(element);
                if (is_node) {
                    var nodeid = this.view.get_binded_nodeid(element);
                    if (!!nodeid) {
                        this.begin_edit(nodeid);
                    }
                }
            }
        },

        // Use [Ctrl] + Mousewheel, to zoom in/out.
        mousewheel_handle: function (event) {
            // Test if mousewheel option is enabled and Ctrl key is pressed.
            if (!this.options.default_event_handle["enable_mousewheel_handle"] || !window.event.ctrlKey) {
                return
            }
            // Avoid default page scrolling behavior.
            event.preventDefault()

            if (event.deltaY < 0) {
                this.view.zoomIn()
            } else {
                this.view.zoomOut()
            }
        },

        begin_edit: function (node) {
            if (!jm.util.is_node(node)) {
                var the_node = this.get_node(node);
                if (!the_node) {
                    logger.error('the node[id=' + node + '] can not be found.');
                    return false;
                } else {
                    return this.begin_edit(the_node);
                }
            }
            if (this.get_editable()) {
                if (!node.data["editable"]) {
                    return;
                }
                this.view.edit_node_begin(node);
            } else {
                logger.error('fail, this mind map is not editable.');
                return;
            }
        },

        end_edit: function () {
            this.view.edit_node_end();
        },

        toggle_node: function (node) {
            if (!jm.util.is_node(node)) {
                var the_node = this.get_node(node);
                if (!the_node) {
                    logger.error('the node[id=' + node + '] can not be found.');
                    return;
                } else {
                    return this.toggle_node(the_node);
                }
            }
            if (node.isroot) { return; }
            this.view.save_location(node);
            this.layout.toggle_node(node);
            this.view.relayout();
            this.view.restore_location(node);
        },

        expand_node: function (node) {
            if (!jm.util.is_node(node)) {
                var the_node = this.get_node(node);
                if (!the_node) {
                    logger.error('the node[id=' + node + '] can not be found.');
                    return;
                } else {
                    return this.expand_node(the_node);
                }
            }
            if (node.isroot) { return; }
            this.view.save_location(node);
            this.layout.expand_node(node);
            this.view.relayout();
            this.view.restore_location(node);
        },

        collapse_node: function (node) {
            if (!jm.util.is_node(node)) {
                var the_node = this.get_node(node);
                if (!the_node) {
                    logger.error('the node[id=' + node + '] can not be found.');
                    return;
                } else {
                    return this.collapse_node(the_node);
                }
            }
            if (node.isroot) { return; }
            this.view.save_location(node);
            this.layout.collapse_node(node);
            this.view.relayout();
            this.view.restore_location(node);
        },

        expand_all: function () {
            this.layout.expand_all();
            this.view.relayout();
        },

        collapse_all: function () {
            this.layout.collapse_all();
            this.view.relayout();
        },

        expand_to_depth: function (depth) {
            this.layout.expand_to_depth(depth);
            this.view.relayout();
        },

        _reset: function () {
            this.view.reset();
            this.layout.reset();
            this.data.reset();
        },

        _show: function (mind) {
            var m = mind || jm.format.node_array.example;

            this.mind = this.data.load(m);
            if (!this.mind) {
                logger.error('data.load error');
                return;
            } else {
                logger.debug('data.load ok');
            }

            this.view.load();
            logger.debug('view.load ok');

            this.layout.layout();
            logger.debug('layout.layout ok');

            this.view.show(true);
            logger.debug('view.show ok');

            this.invoke_event_handle(jm.event_type.show, { data: [mind] });
        },

        show: function (mind) {
            this._reset();
            this._show(mind);
        },

        get_meta: function () {
            return {
                name: this.mind.name,
                author: this.mind.author,
                version: this.mind.version
            };
        },

        get_data: function (data_format) {
            var df = data_format || 'node_tree';
            return this.data.get_data(df);
        },

        get_root: function () {
            return this.mind.root;
        },

        get_node: function (node) {
            if (jm.util.is_node(node)) {
                return node;
            }
            return this.mind.get_node(node);
        },

        add_node: function (parent_node, nodeid, topic, data, direction) {
            if (this.get_editable()) {
                var the_parent_node = this.get_node(parent_node);
                var dir = jm.direction.of(direction)
                if (dir === undefined) {
                    dir = this.layout.calculate_next_child_direction(the_parent_node);
                }
                var node = this.mind.add_node(the_parent_node, nodeid, topic, data, dir);
                if (!!node) {
                    this.view.add_node(node);
                    this.layout.layout();
                    this.view.show(false);
                    this.view.reset_node_custom_style(node);
                    this.expand_node(the_parent_node);
                    this.invoke_event_handle(jm.event_type.edit, { evt: 'add_node', data: [the_parent_node.id, nodeid, topic, data, dir], node: nodeid });
                }
                return node;
            } else {
                logger.error('fail, this mind map is not editable');
                return null;
            }
        },

        insert_node_before: function (node_before, nodeid, topic, data, direction) {
            if (this.get_editable()) {
                var the_node_before = this.get_node(node_before);
                var dir = jm.direction.of(direction)
                if (dir === undefined) {
                    dir = this.layout.calculate_next_child_direction(the_node_before.parent);
                }
                var node = this.mind.insert_node_before(the_node_before, nodeid, topic, data, dir);
                if (!!node) {
                    this.view.add_node(node);
                    this.layout.layout();
                    this.view.show(false);
                    this.invoke_event_handle(jm.event_type.edit, { evt: 'insert_node_before', data: [the_node_before.id, nodeid, topic, data, dir], node: nodeid });
                }
                return node;
            } else {
                logger.error('fail, this mind map is not editable');
                return null;
            }
        },

        insert_node_after: function (node_after, nodeid, topic, data, direction) {
            if (this.get_editable()) {
                var the_node_after = this.get_node(node_after);
                var dir = jm.direction.of(direction)
                if (dir === undefined) {
                    dir = this.layout.calculate_next_child_direction(the_node_after.parent);
                }
                var node = this.mind.insert_node_after(the_node_after, nodeid, topic, data, dir);
                if (!!node) {
                    this.view.add_node(node);
                    this.layout.layout();
                    this.view.show(false);
                    this.invoke_event_handle(jm.event_type.edit, { evt: 'insert_node_after', data: [the_node_after.id, nodeid, topic, data, dir], node: nodeid });
                }
                return node;
            } else {
                logger.error('fail, this mind map is not editable');
                return null;
            }
        },

        remove_node: function (node) {
            if (!jm.util.is_node(node)) {
                var the_node = this.get_node(node);
                if (!the_node) {
                    logger.error('the node[id=' + node + '] can not be found.');
                    return false;
                } else {
                    return this.remove_node(the_node);
                }
            }
            if (this.get_editable()) {
                if (node.isroot) {
                    logger.error('fail, can not remove root node');
                    return false;
                }
                var nodeid = node.id;
                var parentid = node.parent.id;
                var parent_node = this.get_node(parentid);
                this.view.save_location(parent_node);
                this.view.remove_node(node);
                this.mind.remove_node(node);
                this.layout.layout();
                this.view.show(false);
                this.view.restore_location(parent_node);
                this.invoke_event_handle(jm.event_type.edit, { evt: 'remove_node', data: [nodeid], node: parentid });
                return true;
            } else {
                logger.error('fail, this mind map is not editable');
                return false;
            }
        },

        update_node: function (nodeid, topic) {
            if (this.get_editable()) {
                if (jm.util.text.is_empty(topic)) {
                    logger.warn('fail, topic can not be empty');
                    return;
                }
                var node = this.get_node(nodeid);
                if (!node.data["editable"]) {
                    return;
                }
                if (!!node) {
                    if (node.topic === topic) {
                        logger.info('nothing changed');
                        this.view.update_node(node);
                        return;
                    }
                    node.topic = topic;
                    this.view.update_node(node);
                    this.layout.layout();
                    this.view.show(false);
                    this.invoke_event_handle(jm.event_type.edit, { evt: 'update_node', data: [nodeid, topic], node: nodeid });
                }
            } else {
                logger.error('fail, this mind map is not editable');
                return;
            }
        },

        move_node: function (nodeid, beforeid, parentid, direction) {
            if (this.get_editable()) {
                var node = this.get_node(nodeid);
                if (!node.data["editable"]) {
                    return;
                }
                var updated_node = this.mind.move_node(node, beforeid, parentid, direction);
                if (!!updated_node) {
                    this.view.update_node(updated_node);
                    this.layout.layout();
                    this.view.show(false);
                    this.invoke_event_handle(jm.event_type.edit, { evt: 'move_node', data: [nodeid, beforeid, parentid, direction], node: nodeid });
                }
            } else {
                logger.error('fail, this mind map is not editable');
                return;
            }
        },

        select_node: function (node) {
            if (!jm.util.is_node(node)) {
                var the_node = this.get_node(node);
                if (!the_node) {
                    logger.error('the node[id=' + node + '] can not be found.');
                    return;
                } else {
                    return this.select_node(the_node);
                }
            }
            if (!this.layout.is_visible(node)) {
                return;
            }
            this.mind.selected = node;
            this.view.select_node(node);
            this.invoke_event_handle(jm.event_type.select, { evt: 'select_node', data: [], node: node.id });
        },

        get_selected_node: function () {
            if (!!this.mind) {
                return this.mind.selected;
            } else {
                return null;
            }
        },

        select_clear: function () {
            if (!!this.mind) {
                this.mind.selected = null;
                this.view.select_clear();
            }
        },

        is_node_visible: function (node) {
            return this.layout.is_visible(node);
        },

        find_node_before: function (node) {
            if (!jm.util.is_node(node)) {
                var the_node = this.get_node(node);
                if (!the_node) {
                    logger.error('the node[id=' + node + '] can not be found.');
                    return;
                } else {
                    return this.find_node_before(the_node);
                }
            }
            if (node.isroot) { return null; }
            var n = null;
            if (node.parent.isroot) {
                var c = node.parent.children;
                var prev = null;
                var ni = null;
                for (var i = 0; i < c.length; i++) {
                    ni = c[i];
                    if (node.direction === ni.direction) {
                        if (node.id === ni.id) {
                            n = prev;
                        }
                        prev = ni;
                    }
                }
            } else {
                n = this.mind.get_node_before(node);
            }
            return n;
        },

        find_node_after: function (node) {
            if (!jm.util.is_node(node)) {
                var the_node = this.get_node(node);
                if (!the_node) {
                    logger.error('the node[id=' + node + '] can not be found.');
                    return;
                } else {
                    return this.find_node_after(the_node);
                }
            }
            if (node.isroot) { return null; }
            var n = null;
            if (node.parent.isroot) {
                var c = node.parent.children;
                var getthis = false;
                var ni = null;
                for (var i = 0; i < c.length; i++) {
                    ni = c[i];
                    if (node.direction === ni.direction) {
                        if (getthis) {
                            n = ni;
                            break;
                        }
                        if (node.id === ni.id) {
                            getthis = true;
                        }
                    }
                }
            } else {
                n = this.mind.get_node_after(node);
            }
            return n;
        },

        set_node_color: function (nodeid, bgcolor, fgcolor) {
            if (this.get_editable()) {
                var node = this.mind.get_node(nodeid);
                if (!node.data["editable"]) {
                    return;
                }
                if (!!node) {
                    if (!!bgcolor) {
                        node.data['background-color'] = bgcolor;
                    }
                    if (!!fgcolor) {
                        node.data['foreground-color'] = fgcolor;
                    }
                    this.view.reset_node_custom_style(node);
                }
            } else {
                logger.error('fail, this mind map is not editable');
                return null;
            }
        },

        set_node_font_style: function (nodeid, size, weight, style) {
            if (this.get_editable()) {
                var node = this.mind.get_node(nodeid);
                if (!node.data["editable"]) {
                    return;
                }
                if (!!node) {
                    if (!!size) {
                        node.data['font-size'] = size;
                    }
                    if (!!weight) {
                        node.data['font-weight'] = weight;
                    }
                    if (!!style) {
                        node.data['font-style'] = style;
                    }
                    this.view.reset_node_custom_style(node);
                    this.view.update_node(node);
                    this.layout.layout();
                    this.view.show(false);
                }
            } else {
                logger.error('fail, this mind map is not editable');
                return null;
            }
        },

        set_node_background_image: function (nodeid, image, width, height, rotation) {
            if (this.get_editable()) {
                var node = this.mind.get_node(nodeid);
                if (!node.data["editable"]) {
                    return;
                }
                if (!!node) {
                    if (!!image) {
                        node.data['background-image'] = image;
                    }
                    if (!!width) {
                        node.data['width'] = width;
                    }
                    if (!!height) {
                        node.data['height'] = height;
                    }
                    if (!!rotation) {
                        node.data['background-rotation'] = rotation;
                    }
                    this.view.reset_node_custom_style(node);
                    this.view.update_node(node);
                    this.layout.layout();
                    this.view.show(false);
                }
            } else {
                logger.error('fail, this mind map is not editable');
                return null;
            }
        },

        set_node_background_rotation: function (nodeid, rotation) {
            if (this.get_editable()) {
                var node = this.mind.get_node(nodeid);
                if (!!node) {
                    if (!node.data['background-image']) {
                        logger.error('fail, only can change rotation angle of node with background image');
                        return null;
                    }
                    node.data['background-rotation'] = rotation;
                    this.view.reset_node_custom_style(node);
                    this.view.update_node(node);
                    this.layout.layout();
                    this.view.show(false);
                }
            } else {
                logger.error('fail, this mind map is not editable');
                return null;
            }
        },

        resize: function () {
            this.view.resize();
        },

        // callback(type ,data)
        add_event_listener: function (callback) {
            if (typeof callback === 'function') {
                this.event_handles.push(callback);
            }
        },

        clear_event_listener: function () {
            this.event_handles = [];
        },

        invoke_event_handle: function (type, data) {
            var j = this;
            $w.setTimeout(function () {
                j._invoke_event_handle(type, data);
            }, 0);
        },

        _invoke_event_handle: function (type, data) {
            var l = this.event_handles.length;
            for (var i = 0; i < l; i++) {
                this.event_handles[i](type, data);
            }
        },

    };

    // ============= data provider =============================================

    jm.data_provider = function (jm) {
        this.jm = jm;
    };

    jm.data_provider.prototype = {
        init: function () {
            logger.debug('data.init');
        },

        reset: function () {
            logger.debug('data.reset');
        },

        load: function (mind_data) {
            var df = null;
            var mind = null;
            if (typeof mind_data === 'object') {
                if (!!mind_data.format) {
                    df = mind_data.format;
                } else {
                    df = 'node_tree';
                }
            } else {
                df = 'freemind';
            }

            if (df == 'node_array') {
                mind = jm.format.node_array.get_mind(mind_data);
            } else if (df == 'node_tree') {
                mind = jm.format.node_tree.get_mind(mind_data);
            } else if (df == 'freemind') {
                mind = jm.format.freemind.get_mind(mind_data);
            } else {
                logger.warn('unsupported format');
            }
            return mind;
        },

        get_data: function (data_format) {
            var data = null;
            if (data_format == 'node_array') {
                data = jm.format.node_array.get_data(this.jm.mind);
            } else if (data_format == 'node_tree') {
                data = jm.format.node_tree.get_data(this.jm.mind);
            } else if (data_format == 'freemind') {
                data = jm.format.freemind.get_data(this.jm.mind);
            } else {
                logger.error('unsupported ' + data_format + ' format');
            }
            return data;
        },
    };

    // ============= layout provider ===========================================

    jm.layout_provider = function (jm, options) {
        this.opts = options;
        this.jm = jm;
        this.isside = (this.opts.mode == 'side');
        this.bounds = null;

        this.cache_valid = false;
    };

    jm.layout_provider.prototype = {
        init: function () {
            logger.debug('layout.init');
        },

        reset: function () {
            logger.debug('layout.reset');
            this.bounds = { n: 0, s: 0, w: 0, e: 0 };
        },

        calculate_next_child_direction: function (node) {
            if (this.isside) {
                return jm.direction.right;
            }
            var children = node.children || [];
            var children_len = children.length;
            var r = 0;
            for (var i = 0; i < children_len; i++) { if (children[i].direction === jm.direction.left) { r--; } else { r++; } }
            return (children_len > 1 && r > 0) ? jm.direction.left : jm.direction.right;
        },

        layout: function () {
            logger.debug('layout.layout');
            this.layout_direction();
            this.layout_offset();
        },

        layout_direction: function () {
            this._layout_direction_root();
        },

        _layout_direction_root: function () {
            var node = this.jm.mind.root;
            // logger.debug(node);
            var layout_data = null;
            if ('layout' in node._data) {
                layout_data = node._data.layout;
            } else {
                layout_data = {};
                node._data.layout = layout_data;
            }
            var children = node.children;
            var children_count = children.length;
            layout_data.direction = jm.direction.center;
            layout_data.side_index = 0;
            if (this.isside) {
                var i = children_count;
                while (i--) {
                    this._layout_direction_side(children[i], jm.direction.right, i);
                }
            } else {
                var i = children_count;
                var subnode = null;
                while (i--) {
                    subnode = children[i];
                    if (subnode.direction == jm.direction.left) {
                        this._layout_direction_side(subnode, jm.direction.left, i);
                    } else {
                        this._layout_direction_side(subnode, jm.direction.right, i);
                    }
                }
                /*
                var boundary = Math.ceil(children_count/2);
                var i = children_count;
                while(i--){
                    if(i>=boundary){
                        this._layout_direction_side(children[i],jm.direction.left, children_count-i-1);
                    }else{
                        this._layout_direction_side(children[i],jm.direction.right, i);
                    }
                }*/

            }
        },

        _layout_direction_side: function (node, direction, side_index) {
            var layout_data = null;
            if ('layout' in node._data) {
                layout_data = node._data.layout;
            } else {
                layout_data = {};
                node._data.layout = layout_data;
            }
            var children = node.children;
            var children_count = children.length;

            layout_data.direction = direction;
            layout_data.side_index = side_index;
            var i = children_count;
            while (i--) {
                this._layout_direction_side(children[i], direction, i);
            }
        },

        layout_offset: function () {
            var node = this.jm.mind.root;
            var layout_data = node._data.layout;
            layout_data.offset_x = 0;
            layout_data.offset_y = 0;
            layout_data.outer_height = 0;
            var children = node.children;
            var i = children.length;
            var left_nodes = [];
            var right_nodes = [];
            var subnode = null;
            while (i--) {
                subnode = children[i];
                if (subnode._data.layout.direction == jm.direction.right) {
                    right_nodes.unshift(subnode);
                } else {
                    left_nodes.unshift(subnode);
                }
            }
            layout_data.left_nodes = left_nodes;
            layout_data.right_nodes = right_nodes;
            layout_data.outer_height_left = this._layout_offset_subnodes(left_nodes);
            layout_data.outer_height_right = this._layout_offset_subnodes(right_nodes);
            this.bounds.e = node._data.view.width / 2;
            this.bounds.w = 0 - this.bounds.e;
            //logger.debug(this.bounds.w);
            this.bounds.n = 0;
            this.bounds.s = Math.max(layout_data.outer_height_left, layout_data.outer_height_right);
        },

        // layout both the x and y axis
        _layout_offset_subnodes: function (nodes) {
            var total_height = 0;
            var nodes_count = nodes.length;
            var i = nodes_count;
            var node = null;
            var node_outer_height = 0;
            var layout_data = null;
            var base_y = 0;
            var pd = null; // parent._data
            while (i--) {
                node = nodes[i];
                layout_data = node._data.layout;
                if (pd == null) {
                    pd = node.parent._data;
                }

                node_outer_height = this._layout_offset_subnodes(node.children);
                if (!node.expanded) {
                    node_outer_height = 0;
                    this.set_visible(node.children, false);
                }
                node_outer_height = Math.max(node._data.view.height, node_outer_height);
                if (node.children.length > 1) {
                    node_outer_height += this.opts.cousin_space;
                }

                layout_data.outer_height = node_outer_height;
                layout_data.offset_y = base_y - node_outer_height / 2;
                layout_data.offset_x = this.opts.hspace * layout_data.direction + pd.view.width * (pd.layout.direction + layout_data.direction) / 2;
                if (!node.parent.isroot) {
                    layout_data.offset_x += this.opts.pspace * layout_data.direction;
                }

                base_y = base_y - node_outer_height - this.opts.vspace;
                total_height += node_outer_height;
            }
            if (nodes_count > 1) {
                total_height += this.opts.vspace * (nodes_count - 1);
            }
            i = nodes_count;
            var middle_height = total_height / 2;
            while (i--) {
                node = nodes[i];
                node._data.layout.offset_y += middle_height;
            }
            return total_height;
        },

        // layout the y axis only, for collapse/expand a node
        _layout_offset_subnodes_height: function (nodes) {
            var total_height = 0;
            var nodes_count = nodes.length;
            var i = nodes_count;
            var node = null;
            var node_outer_height = 0;
            var layout_data = null;
            var base_y = 0;
            var pd = null; // parent._data
            while (i--) {
                node = nodes[i];
                layout_data = node._data.layout;
                if (pd == null) {
                    pd = node.parent._data;
                }

                node_outer_height = this._layout_offset_subnodes_height(node.children);
                if (!node.expanded) {
                    node_outer_height = 0;
                }
                node_outer_height = Math.max(node._data.view.height, node_outer_height);
                if (node.children.length > 1) {
                    node_outer_height += this.opts.cousin_space;
                }

                layout_data.outer_height = node_outer_height;
                layout_data.offset_y = base_y - node_outer_height / 2;
                base_y = base_y - node_outer_height - this.opts.vspace;
                total_height += node_outer_height;
            }
            if (nodes_count > 1) {
                total_height += this.opts.vspace * (nodes_count - 1);
            }
            i = nodes_count;
            var middle_height = total_height / 2;
            while (i--) {
                node = nodes[i];
                node._data.layout.offset_y += middle_height;
                //logger.debug(node.topic);
                //logger.debug(node._data.layout.offset_y);
            }
            return total_height;
        },

        get_node_offset: function (node) {
            var layout_data = node._data.layout;
            var offset_cache = null;
            if (('_offset_' in layout_data) && this.cache_valid) {
                offset_cache = layout_data._offset_;
            } else {
                offset_cache = { x: -1, y: -1 };
                layout_data._offset_ = offset_cache;
            }
            if (offset_cache.x == -1 || offset_cache.y == -1) {
                var x = layout_data.offset_x;
                var y = layout_data.offset_y;
                if (!node.isroot) {
                    var offset_p = this.get_node_offset(node.parent);
                    x += offset_p.x;
                    y += offset_p.y;
                }
                offset_cache.x = x;
                offset_cache.y = y;
            }
            return offset_cache;
        },

        get_node_point: function (node) {
            var view_data = node._data.view;
            var offset_p = this.get_node_offset(node);
            //logger.debug(offset_p);
            var p = {};
            p.x = offset_p.x + view_data.width * (node._data.layout.direction - 1) / 2;
            p.y = offset_p.y - view_data.height / 2;
            //logger.debug(p);
            return p;
        },

        get_node_point_in: function (node) {
            var p = this.get_node_offset(node);
            return p;
        },

        get_node_point_out: function (node) {
            var layout_data = node._data.layout;
            var pout_cache = null;
            if (('_pout_' in layout_data) && this.cache_valid) {
                pout_cache = layout_data._pout_;
            } else {
                pout_cache = { x: -1, y: -1 };
                layout_data._pout_ = pout_cache;
            }
            if (pout_cache.x == -1 || pout_cache.y == -1) {
                if (node.isroot) {
                    pout_cache.x = 0;
                    pout_cache.y = 0;
                } else {
                    var view_data = node._data.view;
                    var offset_p = this.get_node_offset(node);
                    pout_cache.x = offset_p.x + (view_data.width + this.opts.pspace) * node._data.layout.direction;
                    pout_cache.y = offset_p.y;
                    //logger.debug('pout');
                    //logger.debug(pout_cache);
                }
            }
            return pout_cache;
        },

        get_expander_point: function (node) {
            var p = this.get_node_point_out(node);
            var ex_p = {};
            if (node._data.layout.direction == jm.direction.right) {
                ex_p.x = p.x - this.opts.pspace;
            } else {
                ex_p.x = p.x;
            }
            ex_p.y = p.y - Math.ceil(this.opts.pspace / 2);
            return ex_p;
        },

        get_min_size: function () {
            var nodes = this.jm.mind.nodes;
            var node = null;
            var pout = null;
            for (var nodeid in nodes) {
                node = nodes[nodeid];
                pout = this.get_node_point_out(node);
                if (pout.x > this.bounds.e) { this.bounds.e = pout.x; }
                if (pout.x < this.bounds.w) { this.bounds.w = pout.x; }
            }
            return {
                w: this.bounds.e - this.bounds.w,
                h: this.bounds.s - this.bounds.n
            }
        },

        toggle_node: function (node) {
            if (node.isroot) {
                return;
            }
            if (node.expanded) {
                this.collapse_node(node);
            } else {
                this.expand_node(node);
            }
        },

        expand_node: function (node) {
            node.expanded = true;
            this.part_layout(node);
            this.set_visible(node.children, true);
            this.jm.invoke_event_handle(jm.event_type.show, { evt: 'expand_node', data: [], node: node.id });
        },

        collapse_node: function (node) {
            node.expanded = false;
            this.part_layout(node);
            this.set_visible(node.children, false);
            this.jm.invoke_event_handle(jm.event_type.show, { evt: 'collapse_node', data: [], node: node.id });
        },

        expand_all: function () {
            var nodes = this.jm.mind.nodes;
            var c = 0;
            var node;
            for (var nodeid in nodes) {
                node = nodes[nodeid];
                if (!node.expanded) {
                    node.expanded = true;
                    c++;
                }
            }
            if (c > 0) {
                var root = this.jm.mind.root;
                this.part_layout(root);
                this.set_visible(root.children, true);
            }
        },

        collapse_all: function () {
            var nodes = this.jm.mind.nodes;
            var c = 0;
            var node;
            for (var nodeid in nodes) {
                node = nodes[nodeid];
                if (node.expanded && !node.isroot) {
                    node.expanded = false;
                    c++;
                }
            }
            if (c > 0) {
                var root = this.jm.mind.root;
                this.part_layout(root);
                this.set_visible(root.children, true);
            }
        },

        expand_to_depth: function (target_depth, curr_nodes, curr_depth) {
            if (target_depth < 1) { return; }
            var nodes = curr_nodes || this.jm.mind.root.children;
            var depth = curr_depth || 1;
            var i = nodes.length;
            var node = null;
            while (i--) {
                node = nodes[i];
                if (depth < target_depth) {
                    if (!node.expanded) {
                        this.expand_node(node);
                    }
                    this.expand_to_depth(target_depth, node.children, depth + 1);
                }
                if (depth == target_depth) {
                    if (node.expanded) {
                        this.collapse_node(node);
                    }
                }
            }
        },

        part_layout: function (node) {
            var root = this.jm.mind.root;
            if (!!root) {
                var root_layout_data = root._data.layout;
                if (node.isroot) {
                    root_layout_data.outer_height_right = this._layout_offset_subnodes_height(root_layout_data.right_nodes);
                    root_layout_data.outer_height_left = this._layout_offset_subnodes_height(root_layout_data.left_nodes);
                } else {
                    if (node._data.layout.direction == jm.direction.right) {
                        root_layout_data.outer_height_right = this._layout_offset_subnodes_height(root_layout_data.right_nodes);
                    } else {
                        root_layout_data.outer_height_left = this._layout_offset_subnodes_height(root_layout_data.left_nodes);
                    }
                }
                this.bounds.s = Math.max(root_layout_data.outer_height_left, root_layout_data.outer_height_right);
                this.cache_valid = false;
            } else {
                logger.warn('can not found root node');
            }
        },

        set_visible: function (nodes, visible) {
            var i = nodes.length;
            var node = null;
            var layout_data = null;
            while (i--) {
                node = nodes[i];
                layout_data = node._data.layout;
                if (node.expanded) {
                    this.set_visible(node.children, visible);
                } else {
                    this.set_visible(node.children, false);
                }
                if (!node.isroot) {
                    node._data.layout.visible = visible;
                }
            }
        },

        is_expand: function (node) {
            return node.expanded;
        },

        is_visible: function (node) {
            var layout_data = node._data.layout;
            if (('visible' in layout_data) && !layout_data.visible) {
                return false;
            } else {
                return true;
            }
        }
    };

    jm.graph_canvas = function (view) {
        this.opts = view.opts;
        this.e_canvas = $c('canvas');
        this.e_canvas.className = 'jsmind';
        this.canvas_ctx = this.e_canvas.getContext('2d');
        this.size = { w: 0, h: 0 };
    };

    jm.graph_canvas.prototype = {
        element: function () {
            return this.e_canvas;
        },

        set_size: function (w, h) {
            this.size.w = w;
            this.size.h = h;
            this.e_canvas.width = w;
            this.e_canvas.height = h;
        },

        clear: function () {
            this.canvas_ctx.clearRect(0, 0, this.size.w, this.size.h);
        },

        draw_line: function (pout, pin, offset) {
            var ctx = this.canvas_ctx;
            ctx.strokeStyle = this.opts.line_color;
            ctx.lineWidth = this.opts.line_width;
            ctx.lineCap = 'round';

            // this._bezier_to(ctx,
            //     pin.x + offset.x,
            //     pin.y + offset.y,
            //     pout.x + offset.x,
            //     pout.y + offset.y);
            this._brokenline_to(ctx,
                pin.x + offset.x,
                pin.y + offset.y,
                pout.x + offset.x,
                pout.y + offset.y);
        },

        copy_to: function (dest_canvas_ctx, callback) {
            dest_canvas_ctx.drawImage(this.e_canvas, 0, 0);
            !!callback && callback();
        },

        _bezier_to: function (ctx, x1, y1, x2, y2) {
            ctx.beginPath();
            ctx.moveTo(x1, y1);
            ctx.bezierCurveTo(x1 + (x2 - x1) * 2 / 3, y1, x1, y2, x2, y2);
            ctx.stroke();
        },
        //用直角画线方式 取得是两点中间的距离
        _brokenline_to: function (ctx, x1, y1, x2, y2) {
            ctx.beginPath();
            ctx.moveTo(x1, y1);
            ctx.lineTo(x1 + (x2 - x1) / 2, y1);
            ctx.lineTo(x1 + (x2 - x1) / 2, y2);//延长了一半 
            ctx.lineTo(x2, y2);
            ctx.stroke();
        },

        _line_to: function (ctx, x1, y1, x2, y2) {
            ctx.beginPath();
            ctx.moveTo(x1, y1);
            ctx.lineTo(x2, y2);
            ctx.stroke();
        }
    };

    jm.graph_svg = function (view) {
        this.view = view;
        this.opts = view.opts;
        this.e_svg = jm.graph_svg.c('svg');
        this.e_svg.setAttribute('class', 'jsmind');
        this.size = { w: 0, h: 0 };
        this.lines = [];
    };

    jm.graph_svg.c = function (tag) {
        return $d.createElementNS('http://www.w3.org/2000/svg', tag);
    };

    jm.graph_svg.prototype = {
        element: function () {
            return this.e_svg;
        },

        set_size: function (w, h) {
            this.size.w = w;
            this.size.h = h;
            this.e_svg.setAttribute('width', w);
            this.e_svg.setAttribute('height', h);
        },

        clear: function () {
            var len = this.lines.length;
            while (len--) {
                this.e_svg.removeChild(this.lines[len]);
            }
            this.lines.length = 0;
        },

        draw_line: function (pout, pin, offset) {
            var line = jm.graph_svg.c('path');
            line.setAttribute('stroke', this.opts.line_color);
            line.setAttribute('stroke-width', this.opts.line_width);
            line.setAttribute('fill', 'transparent');
            this.lines.push(line);
            this.e_svg.appendChild(line);
            this._bezier_to(line, pin.x + offset.x, pin.y + offset.y, pout.x + offset.x, pout.y + offset.y);
        },

        copy_to: function (dest_canvas_ctx, callback) {
            var img = new Image();
            img.onload = function () {
                dest_canvas_ctx.drawImage(img, 0, 0);
                !!callback && callback();
            }
            img.src = 'data:image/svg+xml;base64,' + btoa(new XMLSerializer().serializeToString(this.e_svg));
        },

        _bezier_to: function (path, x1, y1, x2, y2) {
            path.setAttribute('d', 'M' + x1 + ' ' + y1 + ' C ' + (x1 + (x2 - x1) * 2 / 3) + ' ' + y1 + ', ' + x1 + ' ' + y2 + ', ' + x2 + ' ' + y2);
        },

        _line_to: function (path, x1, y1, x2, y2) {
            path.setAttribute('d', 'M ' + x1 + ' ' + y1 + ' L ' + x2 + ' ' + y2);
        }
    };

    // view provider
    jm.view_provider = function (jm, options) {
        this.opts = options;
        this.jm = jm;
        this.layout = jm.layout;

        this.container = null;
        this.e_panel = null;
        this.e_nodes = null;

        this.size = { w: 0, h: 0 };

        this.selected_node = null;
        this.editing_node = null;

        this.graph = null;
    };

    jm.view_provider.prototype = {
        init: function () {
            logger.debug('view.init');

            this.container = $i(this.opts.container) ? this.opts.container : $g(this.opts.container);
            if (!this.container) {
                logger.error('the options.view.container was not be found in dom');
                return;
            }
            this.e_panel = $c('div');
            this.e_nodes = $c('jmnodes');
            this.e_editor = $c('input');

            this.graph = this.opts.engine.toLowerCase() === 'svg' ? new jm.graph_svg(this) : new jm.graph_canvas(this);
            this.e_panel.className = 'jsmind-inner jmnode-overflow-' + this.opts.node_overflow;
            this.e_panel.tabIndex = 1;
            this.e_panel.appendChild(this.graph.element());
            this.e_panel.appendChild(this.e_nodes);

            this.e_editor.className = 'jsmind-editor';
            this.e_editor.type = 'text';

            this.actualZoom = 1;
            this.zoomStep = 0.1;
            this.minZoom = 0.5;
            this.maxZoom = 2;

            var v = this;
            jm.util.dom.add_event(this.e_editor, 'keydown', function (e) {
                var evt = e || event;
                if (evt.keyCode == 13) { v.edit_node_end(); evt.stopPropagation(); }
            });
            jm.util.dom.add_event(this.e_editor, 'blur', function (e) {
                v.edit_node_end();
            });

            this.container.appendChild(this.e_panel);

            // Used to avoid dragging, while editing node.
            this.dragging_enabled = true

            this.draggable_canvas()
        },

        add_event: function (obj, event_name, event_handle) {
            jm.util.dom.add_event(this.e_nodes, event_name, function (e) {
                var evt = e || event;
                event_handle.call(obj, evt);
            });
        },

        get_binded_nodeid: function (element) {
            if (element == null) {
                return null;
            }
            var tagName = element.tagName.toLowerCase();
            if (tagName == 'jmnode' || tagName == 'jmexpander') {
                return element.getAttribute('nodeid');
            } else if (tagName == 'jmnodes' || tagName == 'body' || tagName == 'html') {
                return null;
            } else {
                return this.get_binded_nodeid(element.parentElement);
            }
        },

        is_node: function (element) {
            if (element == null) {
                return false;
            }
            var tagName = element.tagName.toLowerCase();
            if (tagName == 'jmnode') {
                return true;
            } else if (tagName == 'jmnodes' || tagName == 'body' || tagName == 'html') {
                return false;
            } else {
                return this.is_node(element.parentElement);
            }
        },

        is_expander: function (element) {
            return (element.tagName.toLowerCase() == 'jmexpander');
        },

        reset: function () {
            logger.debug('view.reset');
            this.selected_node = null;
            this.clear_lines();
            this.clear_nodes();
            this.reset_theme();
        },

        reset_theme: function () {
            var theme_name = this.jm.options.theme;
            if (!!theme_name) {
                this.e_nodes.className = 'theme-' + theme_name;
            } else {
                this.e_nodes.className = '';
            }
        },

        reset_custom_style: function () {
            var nodes = this.jm.mind.nodes;
            for (var nodeid in nodes) {
                this.reset_node_custom_style(nodes[nodeid]);
            }
        },

        load: function () {
            logger.debug('view.load');
            this.init_nodes();
        },

        expand_size: function () {
            var min_size = this.layout.get_min_size();
            var min_width = min_size.w + this.opts.hmargin * 2;
            var min_height = min_size.h + this.opts.vmargin * 2;
            var client_w = this.e_panel.clientWidth;
            var client_h = this.e_panel.clientHeight;
            if (client_w < min_width) { client_w = min_width; }
            if (client_h < min_height) { client_h = min_height; }
            this.size.w = client_w;
            this.size.h = client_h;
        },

        init_nodes_size: function (node) {
            var view_data = node._data.view;
            view_data.width = view_data.element.clientWidth;
            view_data.height = view_data.element.clientHeight;
        },

        init_nodes: function () {
            var nodes = this.jm.mind.nodes;
            var doc_frag = $d.createDocumentFragment();
            for (var nodeid in nodes) {
                this.create_node_element(nodes[nodeid], doc_frag);
            }
            this.e_nodes.appendChild(doc_frag);
            for (var nodeid in nodes) {
                this.init_nodes_size(nodes[nodeid]);
            }
        },

        add_node: function (node) {
            this.create_node_element(node, this.e_nodes);
            this.init_nodes_size(node);
        },

        create_node_element: function (node, parent_node) {
            var GUIDPattern = /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i;
            if (!GUIDPattern.test(node.id))//是GUID
            {
                node.data.editable = true;
            }
            var view_data = null;
            if ('view' in node._data) {
                view_data = node._data.view;
            } else {
                view_data = {};
                node._data.view = view_data;
            }

            var d = $c('jmnode');
            if (node.isroot) {
                d.className = 'root';
            } else {
                var d_e = $c('jmexpander');
                $t(d_e, '-');
                d_e.setAttribute('nodeid', node.id);
                d_e.style.visibility = 'hidden';
                parent_node.appendChild(d_e);
                view_data.expander = d_e;
            }
            if (!!node.topic) {
                if (this.opts.support_html) {
                    $h(d, node.topic);
                } else {
                    $t(d, node.topic);
                }
            }
            d.setAttribute('nodeid', node.id);
            d.style.visibility = 'hidden';
            this._reset_node_custom_style(d, node.data);

            parent_node.appendChild(d);
            view_data.element = d;
        },

        remove_node: function (node) {
          
            if (this.selected_node != null && this.selected_node.id == node.id) {
                this.selected_node = null;
            }
            if (this.editing_node != null && this.editing_node.id == node.id) {
                node._data.view.element.removeChild(this.e_editor);
                this.editing_node = null;
            }
            var children = node.children;
            var i = children.length;
            while (i--) {
                this.remove_node(children[i]);
            }
            if (node._data.view) {
                var element = node._data.view.element;
                var expander = node._data.view.expander;
                this.e_nodes.removeChild(element);
                this.e_nodes.removeChild(expander);
                node._data.view.element = null;
                node._data.view.expander = null;
            }
        },

        update_node: function (node) {
            var view_data = node._data.view;
            var element = view_data.element;
            if (!!node.topic) {
                if (this.opts.support_html) {
                    $h(element, node.topic);
                } else {
                    $t(element, node.topic);
                }
            }
            if (this.layout.is_visible(node)) {
                view_data.width = element.clientWidth;
                view_data.height = element.clientHeight;
            } else {
                let origin_style = element.getAttribute('style');
                element.style = 'visibility: visible; left:0; top:0;';
                view_data.width = element.clientWidth;
                view_data.height = element.clientHeight;
                element.style = origin_style;
            }
        },

        select_node: function (node) {
            if (!!this.selected_node) {
                this.selected_node._data.view.element.className =
                    this.selected_node._data.view.element.className.replace(/\s*selected\b/i, '');
                this.reset_node_custom_style(this.selected_node);
            }
            if (!!node) {
                this.selected_node = node;
                node._data.view.element.className += ' selected';
                this.clear_node_custom_style(node);
            }
        },

        select_clear: function () {
            this.select_node(null);
        },

        get_editing_node: function () {
            return this.editing_node;
        },

        is_editing: function () {
            return (!!this.editing_node);
        },

        edit_node_begin: function (node) {
            if (!node.topic) {
                logger.warn("don't edit image nodes");
                return;
            }
            if (this.editing_node != null) {
                this.edit_node_end();
            }
            this.editing_node = node;
            var view_data = node._data.view;
            var element = view_data.element;
            var topic = node.topic;
            var ncs = getComputedStyle(element);
            this.e_editor.value = topic;
            this.e_editor.style.width = (element.clientWidth - parseInt(ncs.getPropertyValue('padding-left')) - parseInt(ncs.getPropertyValue('padding-right'))) + 'px';
            element.innerHTML = '';
            element.appendChild(this.e_editor);
            element.style.zIndex = 5;
            this.e_editor.focus();
            this.e_editor.select();
        },

        edit_node_end: function () {
            if (this.editing_node != null) {
                var node = this.editing_node;
                this.editing_node = null;
                var view_data = node._data.view;
                var element = view_data.element;
                var topic = this.e_editor.value;
                element.style.zIndex = 'auto';
                element.removeChild(this.e_editor);
                if (jm.util.text.is_empty(topic) || node.topic === topic) {
                    if (this.opts.support_html) {
                        $h(element, node.topic);
                    } else {
                        $t(element, node.topic);
                    }
                } else {
                    this.jm.update_node(node.id, topic);
                }
            }
            this.e_panel.focus();
        },

        get_view_offset: function () {
            var bounds = this.layout.bounds;
            var _x = (this.size.w - bounds.e - bounds.w) / 2;
            var _y = this.size.h / 2;
            return { x: _x, y: _y };
        },

        resize: function () {
            this.graph.set_size(1, 1);
            this.e_nodes.style.width = '1px';
            this.e_nodes.style.height = '1px';

            this.expand_size();
            this._show();
        },

        _show: function () {
            this.graph.set_size(this.size.w, this.size.h);
            this.e_nodes.style.width = this.size.w + 'px';
            this.e_nodes.style.height = this.size.h + 'px';
            this.show_nodes();
            this.show_lines();
            //this.layout.cache_valid = true;
            this.jm.invoke_event_handle(jm.event_type.resize, { data: [] });
        },

        zoomIn: function () {
            return this.setZoom(this.actualZoom + this.zoomStep);
        },

        zoomOut: function () {
            return this.setZoom(this.actualZoom - this.zoomStep);
        },

        setZoom: function (zoom) {
            if ((zoom < this.minZoom) || (zoom > this.maxZoom)) {
                return false;
            }
            this.actualZoom = zoom;
            for (var i = 0; i < this.e_panel.children.length; i++) {
                this.e_panel.children[i].style.zoom = zoom;
            };
            this.show(true);
            return true;

        },

        _center_root: function () {
            // center root node
            var outer_w = this.e_panel.clientWidth;
            var outer_h = this.e_panel.clientHeight;
            if (this.size.w > outer_w) {
                var _offset = this.get_view_offset();
                this.e_panel.scrollLeft = _offset.x * this.actualZoom - outer_w / 2;
            }
            if (this.size.h > outer_h) {
                this.e_panel.scrollTop = (this.size.h * this.actualZoom - outer_h) / 2;
            }
        },

        show: function (keep_center) {
            logger.debug('view.show');
            this.expand_size();
            this._show();
            if (!!keep_center) {
                this._center_root();
            }
        },

        relayout: function () {
            this.expand_size();
            this._show();
        },

        save_location: function (node) {
            var vd = node._data.view;
            vd._saved_location = {
                x: parseInt(vd.element.style.left) - this.e_panel.scrollLeft,
                y: parseInt(vd.element.style.top) - this.e_panel.scrollTop,
            };
        },

        restore_location: function (node) {
            var vd = node._data.view;
            this.e_panel.scrollLeft = parseInt(vd.element.style.left) - vd._saved_location.x;
            this.e_panel.scrollTop = parseInt(vd.element.style.top) - vd._saved_location.y;
        },

        clear_nodes: function () {
            var mind = this.jm.mind;
            if (mind == null) {
                return;
            }
            var nodes = mind.nodes;
            var node = null;
            for (var nodeid in nodes) {
                node = nodes[nodeid];
                node._data.view.element = null;
                node._data.view.expander = null;
            }
            this.e_nodes.innerHTML = '';
        },

        show_nodes: function () {
            var nodes = this.jm.mind.nodes;
            var node = null;
            var node_element = null;
            var expander = null;
            var p = null;
            var p_expander = null;
            var expander_text = '-';
            var view_data = null;
            var _offset = this.get_view_offset();
            for (var nodeid in nodes) {
                node = nodes[nodeid];
                view_data = node._data.view;
                node_element = view_data.element;
                expander = view_data.expander;
                if (!this.layout.is_visible(node)) {
                    node_element.style.display = 'none';
                    expander.style.display = 'none';
                    continue;
                }
                this.reset_node_custom_style(node);
                p = this.layout.get_node_point(node);
                view_data.abs_x = _offset.x + p.x;
                view_data.abs_y = _offset.y + p.y;
                node_element.style.left = (_offset.x + p.x) + 'px';
                node_element.style.top = (_offset.y + p.y) + 'px';
                node_element.style.display = '';
                node_element.style.visibility = 'visible';
                if (!node.isroot && node.children.length > 0) {
                    expander_text = node.expanded ? '-' : '+';
                    p_expander = this.layout.get_expander_point(node);
                    expander.style.left = (_offset.x + p_expander.x) + 'px';
                    expander.style.top = (_offset.y + p_expander.y) + 'px';
                    expander.style.display = '';
                    expander.style.visibility = 'visible';
                    $t(expander, expander_text);
                }
                // hide expander while all children have been removed
                if (!node.isroot && node.children.length == 0) {
                    expander.style.display = 'none';
                    expander.style.visibility = 'hidden';
                }
            }
        },

        reset_node_custom_style: function (node) {
            this._reset_node_custom_style(node._data.view.element, node.data);
        },

        _reset_node_custom_style: function (node_element, node_data) {
            if ('background-color' in node_data) {
                node_element.style.backgroundColor = node_data['background-color'];
            }
            if ('foreground-color' in node_data) {
                node_element.style.color = node_data['foreground-color'];
            }
            if ('width' in node_data) {
                node_element.style.width = node_data['width'] + 'px';
            }
            if ('height' in node_data) {
                node_element.style.height = node_data['height'] + 'px';
            }
            if ('font-size' in node_data) {
                node_element.style.fontSize = node_data['font-size'] + 'px';
            }
            if ('font-weight' in node_data) {
                node_element.style.fontWeight = node_data['font-weight'];
            }
            if ('font-style' in node_data) {
                node_element.style.fontStyle = node_data['font-style'];
            }
            if ('background-image' in node_data) {
                var backgroundImage = node_data['background-image'];
                if (backgroundImage.startsWith('data') && node_data['width'] && node_data['height']) {
                    var img = new Image();

                    img.onload = function () {
                        var c = $c('canvas');
                        c.width = node_element.clientWidth;
                        c.height = node_element.clientHeight;
                        var img = this;
                        if (c.getContext) {
                            var ctx = c.getContext('2d');
                            ctx.drawImage(img, 2, 2, node_element.clientWidth, node_element.clientHeight);
                            var scaledImageData = c.toDataURL();
                            node_element.style.backgroundImage = 'url(' + scaledImageData + ')';
                        }
                    };
                    img.src = backgroundImage;

                } else {
                    node_element.style.backgroundImage = 'url(' + backgroundImage + ')';
                }
                node_element.style.backgroundSize = '99%';

                if ('background-rotation' in node_data) {
                    node_element.style.transform = 'rotate(' + node_data['background-rotation'] + 'deg)';
                }
            }
        },

        clear_node_custom_style: function (node) {
            var node_element = node._data.view.element;
            node_element.style.backgroundColor = "";
            node_element.style.color = "";
        },

        clear_lines: function () {
            this.graph.clear();
        },

        show_lines: function () {
            this.clear_lines();
            var nodes = this.jm.mind.nodes;
            var node = null;
            var pin = null;
            var pout = null;
            var _offset = this.get_view_offset();
            for (var nodeid in nodes) {
                node = nodes[nodeid];
                if (!!node.isroot) { continue; }
                if (('visible' in node._data.layout) && !node._data.layout.visible) { continue; }
                pin = this.layout.get_node_point_in(node);
                pout = this.layout.get_node_point_out(node.parent);
                this.graph.draw_line(pout, pin, _offset);
            }
        },

        // Drag the whole mind map with your mouse (usefull when it's larger that the container).
        draggable_canvas: function () {
            // If draggable option is true.
            if (this.opts.draggable) {
                // Dragging disabled by default.
                let dragging = false
                let x, y
                if (this.opts.hide_scrollbars_when_draggable) {
                    // Avoid scrollbars when mind map is larger than the container (e_panel = id jsmind-inner)
                    this.e_panel.style = 'overflow: hidden'
                }
                // Move the whole mind map with mouse moves, while button is down.
                jm.util.dom.add_event(this.container, 'mousedown', (eventDown) => {
                    dragging = true
                    // Record current mouse position.
                    x = eventDown.clientX
                    y = eventDown.clientY
                })
                // Stop moving mind map once mouse button is released.
                jm.util.dom.add_event(this.container, 'mouseup', () => {
                    dragging = false
                })
                // Follow current mouse position and move mind map accordingly.
                jm.util.dom.add_event(this.container, 'mousemove', (eventMove) => {
                    if (this.dragging_enabled && dragging) {
                        this.e_panel.scrollBy(x - eventMove.clientX, y - eventMove.clientY)
                        // Record new current position.
                        x = eventMove.clientX
                        y = eventMove.clientY
                    }
                })
            }
        },

        get_draggable_canvas: function () {
            return this.opts.draggable
        },

        enable_draggable_canvas: function () {
            this.dragging_enabled = true
        },

        disable_draggable_canvas: function () {
            this.dragging_enabled = false
        },

    };

    // shortcut provider
    jm.shortcut_provider = function (jm, options) {
        this.jm = jm;
        this.opts = options;
        this.mapping = options.mapping;
        this.handles = options.handles;
        this._newid = null;
        this._mapping = {};
    };

    jm.shortcut_provider.prototype = {
        init: function () {
            jm.util.dom.add_event(this.jm.view.e_panel, 'keydown', this.handler.bind(this));

            this.handles['addchild'] = this.handle_addchild;
            this.handles['addbrother'] = this.handle_addbrother;
            this.handles['editnode'] = this.handle_editnode;
            this.handles['delnode'] = this.handle_delnode;
            this.handles['toggle'] = this.handle_toggle;
            this.handles['up'] = this.handle_up;
            this.handles['down'] = this.handle_down;
            this.handles['left'] = this.handle_left;
            this.handles['right'] = this.handle_right;

            for (var handle in this.mapping) {
                if (!!this.mapping[handle] && (handle in this.handles)) {
                    var keys = this.mapping[handle];
                    if (!Array.isArray(keys)) {
                        keys = [keys]
                    }
                    for (let key of keys) {
                        this._mapping[key] = this.handles[handle];
                    }
                }
            }

            if (typeof this.opts.id_generator === 'function') {
                this._newid = this.opts.id_generator;
            } else {
                this._newid = jm.util.uuid.newid;
            }
        },

        enable_shortcut: function () {
            this.opts.enable = true;
        },

        disable_shortcut: function () {
            this.opts.enable = false;
        },

        handler: function (e) {
            if (e.which == 9) { e.preventDefault(); } //prevent tab to change focus in browser
            if (this.jm.view.is_editing()) { return; }
            var evt = e || event;
            if (!this.opts.enable) { return true; }
            var kc = evt.keyCode + (evt.metaKey << 13) + (evt.ctrlKey << 12) + (evt.altKey << 11) + (evt.shiftKey << 10);
            if (kc in this._mapping) {
                this._mapping[kc].call(this, this.jm, e);
            }
        },

        handle_addchild: function (_jm, e) {
            var selected_node = _jm.get_selected_node();
            if (!!selected_node) {
                var nodeid = this._newid();
                var node = _jm.add_node(selected_node, nodeid, 'New Node');
                if (!!node) {
                    _jm.select_node(nodeid);
                    _jm.begin_edit(nodeid);
                }
            }
        },
        handle_addbrother: function (_jm, e) {
            var selected_node = _jm.get_selected_node();
            if (!selected_node.data["editable"]) {
                return;
            }
            if (!!selected_node && !selected_node.isroot) {
                var nodeid = this._newid();
                var node = _jm.insert_node_after(selected_node, nodeid, 'New Node');
                if (!!node) {
                    _jm.select_node(nodeid);
                    _jm.begin_edit(nodeid);
                }
            }
        },
        handle_editnode: function (_jm, e) {
            var selected_node = _jm.get_selected_node();
            if (!!selected_node) {
                _jm.begin_edit(selected_node);
            }
        },
        handle_delnode: function (_jm, e) {
            var selected_node = _jm.get_selected_node();
            if (!!selected_node && !selected_node.isroot) {
                if(!selected_node.data.editable)
                {
                    return;
                }
                _jm.select_node(selected_node.parent);
                
                _jm.remove_node(selected_node);
            }
        },
        handle_toggle: function (_jm, e) {
            var evt = e || event;
            var selected_node = _jm.get_selected_node();
            if (!!selected_node) {
                _jm.toggle_node(selected_node.id);
                evt.stopPropagation();
                evt.preventDefault();
            }
        },
        handle_up: function (_jm, e) {
            var evt = e || event;
            var selected_node = _jm.get_selected_node();
            if (!!selected_node) {
                var up_node = _jm.find_node_before(selected_node);
                if (!up_node) {
                    var np = _jm.find_node_before(selected_node.parent);
                    if (!!np && np.children.length > 0) {
                        up_node = np.children[np.children.length - 1];
                    }
                }
                if (!!up_node) {
                    _jm.select_node(up_node);
                }
                evt.stopPropagation();
                evt.preventDefault();
            }
        },

        handle_down: function (_jm, e) {
            var evt = e || event;
            var selected_node = _jm.get_selected_node();
            if (!!selected_node) {
                var down_node = _jm.find_node_after(selected_node);
                if (!down_node) {
                    var np = _jm.find_node_after(selected_node.parent);
                    if (!!np && np.children.length > 0) {
                        down_node = np.children[0];
                    }
                }
                if (!!down_node) {
                    _jm.select_node(down_node);
                }
                evt.stopPropagation();
                evt.preventDefault();
            }
        },

        handle_left: function (_jm, e) {
            this._handle_direction(_jm, e, jm.direction.left);
        },
        handle_right: function (_jm, e) {
            this._handle_direction(_jm, e, jm.direction.right);
        },
        _handle_direction: function (_jm, e, d) {
            var evt = e || event;
            var selected_node = _jm.get_selected_node();
            var node = null;
            if (!!selected_node) {
                if (selected_node.isroot) {
                    var c = selected_node.children;
                    var children = [];
                    for (var i = 0; i < c.length; i++) {
                        if (c[i].direction === d) {
                            children.push(i);
                        }
                    }
                    node = c[children[Math.floor((children.length - 1) / 2)]];
                }
                else if (selected_node.direction === d) {
                    var children = selected_node.children;
                    var childrencount = children.length;
                    if (childrencount > 0) {
                        node = children[Math.floor((childrencount - 1) / 2)];
                    }
                } else {
                    node = selected_node.parent;
                }
                if (!!node) {
                    _jm.select_node(node);
                }
                evt.stopPropagation();
                evt.preventDefault();
            }
        },
    };


    // plugin
    jm.plugin = function (name, init) {
        this.name = name;
        this.init = init;
    };

    jm.plugins = [];

    jm.register_plugin = function (plugin) {
        if (plugin instanceof jm.plugin) {
            jm.plugins.push(plugin);
        }
    };

    jm.init_plugins = function (sender) {
        $w.setTimeout(function () {
            jm._init_plugins(sender);
        }, 0);
    };

    jm._init_plugins = function (sender) {
        var l = jm.plugins.length;
        var fn_init = null;
        for (var i = 0; i < l; i++) {
            fn_init = jm.plugins[i].init;
            if (typeof fn_init === 'function') {
                fn_init(sender);
            }
        }
    };

    jm.show = function (options, mind) {
        logger.warn('`jsMind.show(options, mind)` is deprecated, please use `jm = new jsMind(options); jm.show(mind);` instead')
        var _jm = new jm(options);
        _jm.show(mind);
        return _jm;
    };

    // export jsmind
    if (typeof module !== 'undefined' && typeof exports === 'object') {
        module.exports = jm;
    } else if (typeof define === 'function' && (define.amd || define.cmd)) {
        define(function () { return jm; });
    } else {
        $w[__name__] = jm;
    }
})(typeof window !== 'undefined' ? window : global);