ToolTips are a standard feature of many desktop applications. They make the application easier to use by displaying messages when the user moves the mouse pointer over an onscreen element, such as a Button control.

The following image shows ToolTip text that appears when the user hovers the mouse pointer over a button:

When the user moves the mouse pointer away from the component or clicks the mouse button, the ToolTip disappears. If the mouse pointer remains over the component, the ToolTip eventually disappears. The default behavior is to display only one ToolTip at a time.

You can set the time it takes for the ToolTip to appear when a user moves the mouse pointer over the component. You can also set the amount of time it takes for the ToolTip to disappear.

If you define a ToolTip on a container, the ToolTipManager displays the parent's ToolTip for the children if the child does not have one.

Flex ToolTips support style sheets and the dynamic loading of ToolTip text. ToolTip text does not support embedded HTML. For more information on using style sheets and dynamic loading of text, see Setting styles in ToolTips and Using dynamic ToolTip text.

Some Flex components have their own ToolTip-like "data tips." These components include the List control, most chart controls, and DataGrid control. For more information, see that component's documentation.

ToolTips are the basis for the accessibility implementation within Flex. All controls that support accessibility do so by making their ToolTip text readable by screen readers such as JAWS. For more information on accessibility, see Creating Accessible Applications.