platform/platform-impl/src/com/intellij/openapi/wm/impl/VisibilityWatcher.java

   1 /*
   2  * Copyright 2000-2009 JetBrains s.r.o.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 package com.intellij.openapi.wm.impl;
  17
  18 import org.jetbrains.annotations.NonNls;
  19
  20 import java.awt.*;
  21 import java.awt.event.ComponentAdapter;
  22 import java.awt.event.ComponentEvent;
  23 import java.beans.PropertyChangeEvent;
  24 import java.beans.PropertyChangeListener;
  25
  26 /**
  27  * @author Anton Katilin
  28  * @author Vladimir Kondratyev
  29  */
  30 public abstract class VisibilityWatcher extends ComponentAdapter implements PropertyChangeListener{
  31   @NonNls protected static final String ANCESTOR_PROPERTY_NAME = "ancestor";
  32
  33   public final void componentHidden(final ComponentEvent e){
  34     visibilityChanged();
  35   }
  36
  37   public final void componentShown(final ComponentEvent e){
  38     visibilityChanged();
  39   }
  40
  41   public final void propertyChange(final PropertyChangeEvent e){
  42     if(ANCESTOR_PROPERTY_NAME.equals(e.getPropertyName())){
  43       final Component oldAncestor=(Component)e.getOldValue();
  44       deinstall(oldAncestor);
  45       final Component newAncestor=(Component)e.getNewValue();
  46       install(newAncestor);
  47       visibilityChanged();
  48     }else{
  49       throw new IllegalArgumentException("unknown propertyName: "+e.getPropertyName());
  50     }
  51   }
  52
  53   public final void install(Component component){
  54     while(component!=null){
  55       component.removePropertyChangeListener(ANCESTOR_PROPERTY_NAME,this); // it prevent double registering
  56       component.addPropertyChangeListener(ANCESTOR_PROPERTY_NAME,this);
  57
  58       component.removeComponentListener(this); // it prevent double registering
  59       component.addComponentListener(this);
  60       component=component.getParent();
  61     }
  62   }
  63
  64   public void deinstall(Component component){
  65     while(component!=null){
  66       component.removePropertyChangeListener(ANCESTOR_PROPERTY_NAME,this);
  67       component.removeComponentListener(this);
  68       component=component.getParent();
  69     }
  70   }
  71
  72   /**
  73    * Invokes every time component changes its visibility. It means one of parent component
  74    * change visibility or hierarchy is connected/disconnected to/from peer.
  75    */
  76   public abstract void visibilityChanged();
  77 }