platform/platform-impl/src/com/intellij/ui/TreeExpandCollapse.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.tree.TreeModel;
  20 import javax.swing.tree.TreePath;
  21
  22 public class TreeExpandCollapse {
  23   public static void collapse(JTree tree) {
  24     TreePath selectionPath = tree.getSelectionPath();
  25     tree.collapsePath(selectionPath);
  26   }
  27
  28   public static void expand(JTree tree) {
  29     TreePath selectionPath = tree.getSelectionPath();
  30     tree.expandPath(selectionPath);
  31   }
  32
  33   public static void expandAll(JTree tree) {
  34     TreePath path = tree.getSelectionPath();
  35     if (path == null) path = new TreePath(tree.getModel().getRoot());
  36     new ExpandContext(300, 10).expand(tree, path);
  37   }
  38
  39   private static class ExpandContext {
  40     private final int myLevelsLeft;
  41     private int myExpansionLimit;
  42
  43     public ExpandContext(int expansionLimit, int levelsLeft) {
  44       myExpansionLimit = expansionLimit;
  45       myLevelsLeft = levelsLeft;
  46     }
  47
  48     public int expand(JTree tree, TreePath path) {
  49       if (myLevelsLeft == 0) return myExpansionLimit;
  50       TreeModel model = tree.getModel();
  51       Object node = path.getLastPathComponent();
  52       int levelDecrement = 0;
  53       if (!tree.isExpanded(path) && !model.isLeaf(node)) {
  54         tree.expandPath(path);
  55         levelDecrement = 1;
  56         myExpansionLimit--;
  57       }
  58       for (int i = 0; i < model.getChildCount(node); i++) {
  59         Object child = model.getChild(node, i);
  60         if (model.isLeaf(child)) continue;
  61         ExpandContext childContext = new ExpandContext(myExpansionLimit, myLevelsLeft - levelDecrement);
  62         myExpansionLimit = childContext.expand(tree, path.pathByAddingChild(child));
  63         if (myExpansionLimit <= 0) return 0;
  64       }
  65       return myExpansionLimit;
  66     }
  67   }
  68 }