Detects a drag and drop gesture. This method is used
to detect a drag gesture when called from within a mouse
down listener.
<p>By default, a drag is detected when the gesture
occurs anywhere within the client area of a control.
Some controls, such as tables and trees, override this
behavior. In addition to the operating system specific
drag gesture, they require the mouse to be inside an
item. Custom widget writers can use <code>setDragDetect</code>
to disable the default detection, listen for mouse down,
and then call <code>dragDetect()</code> from within the
listener to conditionally detect a drag.
</p>
@param event the mouse down event
@return <code>true</code> if the gesture occurred, and <code>false</code> otherwise.
@exception IllegalArgumentException <ul>
<li>ERROR_NULL_ARGUMENT when the event is null</li>
</ul>
@exception SWTException <ul>
<li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
<li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
</ul>
Detects a drag and drop gesture. This method is used to detect a drag gesture when called from within a mouse down listener.
<p>By default, a drag is detected when the gesture occurs anywhere within the client area of a control. Some controls, such as tables and trees, override this behavior. In addition to the operating system specific drag gesture, they require the mouse to be inside an item. Custom widget writers can use <code>setDragDetect</code> to disable the default detection, listen for mouse down, and then call <code>dragDetect()</code> from within the listener to conditionally detect a drag. </p>
@param event the mouse down event
@return <code>true</code> if the gesture occurred, and <code>false</code> otherwise.
@exception IllegalArgumentException <ul> <li>ERROR_NULL_ARGUMENT when the event is null</li> </ul> @exception SWTException <ul> <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> </ul>
@see DragDetectListener @see #addDragDetectListener
@see #getDragDetect @see #setDragDetect
@since 3.3