SwingDisposeObservable.java 文件源码

public SwingDisposeObservable(final Component component) {
    Assert.paramNotNull(component, "component");

    this.wasDisplayable = component.isDisplayable();
    component.addHierarchyListener(new HierarchyListener() {
        @Override
        public void hierarchyChanged(final HierarchyEvent e) {
            if ((e.getChangeFlags() & HierarchyEvent.DISPLAYABILITY_CHANGED) != 0) {
                if (wasDisplayable && !component.isDisplayable()) {
                    fireAfterDispose();
                }
                else if (!wasDisplayable && component.isDisplayable()) {
                    wasDisplayable = true;
                }
            }
        }
    });
}