/**
* Sets a specified <code>Component</code> to be the glass pane for this root pane. The glass pane
* should normally be a lightweight, transparent component, because it will be made visible when
* ever the root pane needs to grab input events.
*
* <p>The new glass pane's visibility is changed to match that of the current glass pane. An
* implication of this is that care must be taken when you want to replace the glass pane and make
* it visible. Either of the following will work:
*
* <pre>
* root.setGlassPane(newGlassPane);
* newGlassPane.setVisible(true);
* </pre>
*
* or:
*
* <pre>
* root.getGlassPane().setVisible(true);
* root.setGlassPane(newGlassPane);
* </pre>
*
* @param glass the <code>Component</code> to use as the glass pane for this <code>JRootPane
* </code>
* @exception NullPointerException if the <code>glass</code> parameter is <code>null</code>
*/
public void setGlassPane(Component glass) {
if (glass == null) {
throw new NullPointerException("glassPane cannot be set to null.");
}
AWTAccessor.getComponentAccessor().setMixingCutoutShape(glass, new Rectangle());
boolean visible = false;
if (glassPane != null && glassPane.getParent() == this) {
this.remove(glassPane);
visible = glassPane.isVisible();
}
glass.setVisible(visible);
glassPane = glass;
this.add(glassPane, 0);
if (visible) {
repaint();
}
}
/**
* The <code>glassPane</code> and <code>contentPane</code> have the same bounds, which means
* <code>JRootPane</code> does not tiles its children and this should return false. On the other
* hand, the <code>glassPane</code> is normally not visible, and so this can return true if the
* <code>glassPane</code> isn't visible. Therefore, the return value here depends upon the
* visibility of the <code>glassPane</code>.
*
* @return true if this component's children don't overlap
*/
public boolean isOptimizedDrawingEnabled() {
return !glassPane.isVisible();
}