Processes {@code AWTEvent}s for {@code JLayer}and
all its descendants to this {@code LayerUI} instance.
To enable the {@code AWTEvent}s of a particular type, you call {@link JLayer#setLayerEventMask}in {@link #installUI(javax.swing.JComponent)}and set the layer event mask to {@code 0}in {@link #uninstallUI(javax.swing.JComponent)} after that.By default this method calls the appropriate {@code process<event type>Event}method for the given class of event.
Note: Events are processed only for displayable {@code JLayer}s.
@param e the event to be dispatched
@param l the layer this LayerUI is set to
@see JLayer#setLayerEventMask(long)
@see Component#isDisplayable()
@see #processComponentEvent
@see #processFocusEvent
@see #processKeyEvent
@see #processMouseEvent
@see #processMouseMotionEvent
@see #processInputMethodEvent
@see #processHierarchyEvent
@see #processMouseWheelEvent