A Tooltip provides additional information for widgets when the user hovers over a widget.    This information can consist in plain text, but also include an icon and complex HTML code.       Example       Here is a little example of how to use the widget.       <pre class='javascript'>    var widget = new qx.ui.form.Button("save");       var tooltip = new qx.ui.tooltip.ToolTip("Save the opened file");    widget.setToolTip(tooltip);    <pre>       This example creates a ToolTip and assigns it to a button. When the user hovers the    button the tooltip is shown.       External Documentation       <a href='http:manual.qooxdoo.org${qxversion}pageswidgettooltip.html' target='_blank'>    Documentation of this widget in the qooxdoo manual.<a>