Question

I really like the anchor and mousetrackign and the basic tooltps
http://www.extjs.com/examples/explorer.html#tooltips

How can I go about adding the extjs tooltip /data-qtip on the renderer code below?

var listView = Ext.create('Ext.grid.Panel', {
        store: mystore,
        multiSelect: true,
        viewConfig: {
            emptyText: 'No images to display'
        },
        //reserveScrollOffset: true,
    renderTo: containerEl,

        columns: [
{
            text: 'Class',
            flex: 10,
            dataIndex: 'ClassName',
            renderer: function(value, metaData, record) {
   return Ext.String.format('<a href="#" class="tooltip2">{0}<span>{0}</span></a>', value);
        }

   ]     
    });

Answer 1

Add Ext.QuickTips.init(); after Ext.onReady() call and in your renderer add:

metaData.attr = 'ext:qtip="your tooltip here"';