/*!
 * Ext JS Library 3.3.0
 * Copyright(c) 2006-2010 Ext JS, Inc.
 * licensing@extjs.com
 * http://www.extjs.com/license
 */
/**
 * @class Ext.tree.ColumnResizer
 * @extends Ext.util.Observable
 */
Ext.tree.ColumnResizer = Ext.extend(Ext.util.Observable, {
    
/**
     * @cfg {Number} minWidth The minimum width the column can be dragged to.
     * Defaults to 14.
     */
    minWidth: 14,

    constructor: function(config){
        Ext.apply(this, config);
        Ext.tree.ColumnResizer.superclass.constructor.call(this);
    },

    init : function(tree){
        this.tree = tree;
        tree.on('render', this.initEvents, this);
    },

    initEvents : function(tree){
        tree.mon(tree.innerHd, 'mousemove', this.handleHdMove, this);
        this.tracker = new Ext.dd.DragTracker({
            onBeforeStart: this.onBeforeStart.createDelegate(this),
            onStart: this.onStart.createDelegate(this),
            onDrag: this.onDrag.createDelegate(this),
            onEnd: this.onEnd.createDelegate(this),
            tolerance: 3,
            autoStart: 300
        });
        this.tracker.initEl(tree.innerHd);
        tree.on('beforedestroy', this.tracker.destroy, this.tracker);
    },

    handleHdMove : function(e, t){
        var hw = 5,
            x = e.getPageX(),
            hd = e.getTarget('.x-treegrid-hd', 3, true);
        
        if(hd){                                 
            var r = hd.getRegion(),
                ss = hd.dom.style,
                pn = hd.dom.parentNode;
            
            if(x - r.left <= hw && hd.dom !== pn.firstChild) {
                var ps = hd.dom.previousSibling;
                while(ps && Ext.fly(ps).hasClass('x-treegrid-hd-hidden')) {
                    ps = ps.previousSibling;
                }
                if(ps) {                    
                    this.activeHd = Ext.get(ps);
    				ss.cursor = Ext.isWebKit ? 'e-resize' : 'col-resize';
                }
            } else if(r.right - x <= hw) {
                var ns = hd.dom;
                while(ns && Ext.fly(ns).hasClass('x-treegrid-hd-hidden')) {
                    ns = ns.previousSibling;
                }
                if(ns) {
                    this.activeHd = Ext.get(ns);
    				ss.cursor = Ext.isWebKit ? 'w-resize' : 'col-resize';                    
                }
            } else{
                delete this.activeHd;
                ss.cursor = '';
            }
        }
    },

    onBeforeStart : function(e){
        this.dragHd = this.activeHd;
        return !!this.dragHd;
    },

    onStart : function(e){
        this.dragHeadersDisabled = this.tree.headersDisabled;
        this.tree.headersDisabled = true;
        this.proxy = this.tree.body.createChild({cls:'x-treegrid-resizer'});
        this.proxy.setHeight(this.tree.body.getHeight());

        var x = this.tracker.getXY()[0];

        this.hdX = this.dragHd.getX();
        this.hdIndex = this.tree.findHeaderIndex(this.dragHd);

        this.proxy.setX(this.hdX);
        this.proxy.setWidth(x-this.hdX);

        this.maxWidth = this.tree.outerCt.getWidth() - this.tree.innerBody.translatePoints(this.hdX).left;
    },

    onDrag : function(e){
        var cursorX = this.tracker.getXY()[0];
        this.proxy.setWidth((cursorX-this.hdX).constrain(this.minWidth, this.maxWidth));
    },

    onEnd : function(e){
        var nw = this.proxy.getWidth(),
            tree = this.tree,
            disabled = this.dragHeadersDisabled;
        
        this.proxy.remove();
        delete this.dragHd;
        
        tree.columns[this.hdIndex].width = nw;
        tree.updateColumnWidths();
        
        setTimeout(function(){
            tree.headersDisabled = disabled;
        }, 100);
    }
});