完美解决desktop图标换行问题

最近看到不少人询问关于在4.0中实现desktop图标换行的问题，现在把我修改的实现方法分享出来，帮助大家完善desktop。此方法能随浏览器的大小自动排列图标

在desktop.js中扩展一个函数

initShortcut : function() {
        var btnHeight = 64;
        var btnWidth = 64;
        var btnPadding = 30;
        var col = {index : 1,x : btnPadding};
        var row = {index : 1,y : btnPadding};
        var bottom;
        var numberOfItems = 0;
        var taskBarHeight = Ext.query(".ux-taskbar")[0].clientHeight + 40;
        var bodyHeight = Ext.getBody().getHeight() - taskBarHeight;
        var items = Ext.query(".ux-desktop-shortcut");

        for (var i = 0, len = items.length; i < len; i++) {
            numberOfItems += 1;
            bottom = row.y + btnHeight;
            if (((bodyHeight < bottom) ? true : false) && bottom > (btnHeight + btnPadding)) {
                numberOfItems = 0;
                col = {index : col.index++,x : col.x + btnWidth + btnPadding};
                row = {index : 1,y : btnPadding};
            }
            Ext.fly(items[i]).setXY([col.x, row.y]);
            row.index++;
            row.y = row.y + btnHeight + btnPadding;
        }
    }

但是我在4.0.7中测试 Ext.query(".ux-taskbar")undefined 所以附上另一个initShortcut

initShortcut : function() {
        var btnHeight = 80;
        var btnWidth = 80;
        var btnPadding = 8;
        var col = null;
        var row = null;
        var bottom;
        var bodyHeight = Ext.getBody().getHeight();
	
        function initColRow() {
            col = {
               index : 1,
               x : btnPadding
            };
            row = {
               index : 1,
               y : btnPadding + 27
            };
        }
        this.setXY = function(item) {
            bottom = row.y + btnHeight;
            if (bottom > bodyHeight && bottom > (btnHeight + btnPadding)) {
               col = {
                   index : col.index++,
                   x : col.x + btnWidth + btnPadding
               };
               row = {
                   index : 1,
                   y : btnPadding + 27
               };
            }
            Ext.fly(item).setXY([col.x, row.y]);
            row.y = row.y + btnHeight + btnPadding + 4;

        } 
	       
 	    this.handleUpdate = function() {
            initColRow(); 
            var items = Ext.query(".ux-desktop-shortcut"); 
            for (var i = 0, len = items.length; i < len; i++) { 
                this.setXY(items[i]); 
            } 
        }; 
        this.handleUpdate();
	}

在createDataView添加一个监听器

createDataView: function () {
        var me = this;
        return {
            xtype: 'dataview',
            overItemCls: 'x-view-over',
            trackOver: true,
            itemSelector: me.shortcutItemSelector,
            store: me.shortcuts,
            tpl: new Ext.XTemplate(me.shortcutTpl),
            listeners:{
                resize:me.initShortcut
            }
        };
    }

在afterRender渲染结束时调用函数

afterRender: function () {
        var me = this;
        me.callParent();
        me.el.on('contextmenu', me.onDesktopMenu, me);
        Ext.Function.defer(me.initShortcut,1);
    }