platform/platform-impl/src/com/intellij/ui/SelectionSaver.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.ui;
  17
  18 import javax.swing.*;
  19 import javax.swing.event.TreeModelEvent;
  20 import javax.swing.event.TreeModelListener;
  21 import javax.swing.event.TreeSelectionEvent;
  22 import javax.swing.event.TreeSelectionListener;
  23 import javax.swing.tree.TreeModel;
  24 import javax.swing.tree.TreeNode;
  25 import javax.swing.tree.TreePath;
  26 import java.beans.PropertyChangeEvent;
  27 import java.beans.PropertyChangeListener;
  28 import java.util.ArrayList;
  29 import java.util.Collection;
  30
  31 public class SelectionSaver implements TreeSelectionListener, TreeModelListener, PropertyChangeListener{
  32
  33   private final JTree myTree;
  34   private Collection<TreeNode> myCurrentSelection = new ArrayList<TreeNode>();
  35
  36
  37   private SelectionSaver(JTree tree) {
  38     myTree = tree;
  39   }
  40
  41   public static void installOn(JTree tree){
  42     new SelectionSaver(tree).install();
  43   }
  44
  45   private void install(){
  46     myTree.getModel().addTreeModelListener(this);
  47     myTree.getSelectionModel().addTreeSelectionListener(this);
  48     myTree.addPropertyChangeListener(this);
  49   }
  50
  51   public void propertyChange(PropertyChangeEvent evt) {
  52     if (evt.getPropertyName().equals(JTree.TREE_MODEL_PROPERTY)){
  53       ((TreeModel)evt.getOldValue()).removeTreeModelListener(this);
  54       ((TreeModel)evt.getNewValue()).addTreeModelListener(this);
  55     }
  56   }
  57
  58   public void treeNodesRemoved(TreeModelEvent treeModelEvent) {
  59     TreePath pathToDelete = treeModelEvent.getTreePath();
  60     Object[] children = treeModelEvent.getChildren();
  61
  62     for (int i = 0; i < children.length; i++) {
  63       Object nodeToDelete = children[i];
  64       if (myCurrentSelection.contains(nodeToDelete)){
  65         int deletedRow = myTree.getRowForPath(pathToDelete.pathByAddingChild(nodeToDelete));
  66         if (deletedRow == 0) return;
  67         TreePath treePath = new TreePath(myTree.getPathForRow(deletedRow - 1));
  68         myTree.getSelectionModel().addSelectionPath((TreePath)treePath.getLastPathComponent());
  69       }
  70     }
  71
  72   }
  73
  74   public void valueChanged(TreeSelectionEvent e) {
  75     myCurrentSelection = new ArrayList<TreeNode>();
  76     TreePath[] selection = myTree.getSelectionModel().getSelectionPaths();
  77     if (selection == null) return;
  78     for (int i = 0; i < selection.length; i++) {
  79       TreePath treePath = selection[i];
  80       myCurrentSelection.add((TreeNode)treePath.getLastPathComponent());
  81     }
  82   }
  83
  84   public void treeNodesChanged(TreeModelEvent e) {
  85
  86   }
  87
  88   public void treeNodesInserted(TreeModelEvent e) {
  89
  90   }
  91
  92   public void treeStructureChanged(TreeModelEvent e) {
  93
  94   }
  95 }