utility classes to create custom tree models

platform/util/src/com/intellij/util/ui/tree/TreeModelAdapter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2009 JetBrains s.r.o.
+ * Copyright 2000-2016 JetBrains s.r.o.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,21 +20,61 @@ import javax.swing.event.TreeModelListener;
 
 /**
  * @author dyoma
+ * @author Sergey.Malenkov
  */
 public abstract class TreeModelAdapter implements TreeModelListener {
-  @Override
-  public void treeNodesChanged(TreeModelEvent e) {
+  public enum EventType {StructureChanged, NodesChanged, NodesInserted, NodesRemoved}
+
+  /**
+   * Invoked after a tree has changed.
+   *
+   * @param event the event object specifying changed nodes
+   * @param type  the event type specifying a kind of changes
+   */
+  protected void process(TreeModelEvent event, EventType type) {
   }
 
+  /**
+   * Invoked after a tree hierarchy has changed.
+   * By default, it calls the {@link #process} method with the corresponding event type.
+   *
+   * @param event the event object specifying a node with changed hierarchy
+   */
   @Override
-  public void treeNodesInserted(TreeModelEvent e) {
+  public void treeStructureChanged(TreeModelEvent event) {
+    if (event != null) process(event, EventType.StructureChanged);
   }
 
+  /**
+   * Invoked after some nodes have been changed.
+   * By default, it calls the {@link #process} method with the corresponding event type.
+   *
+   * @param event the event object specifying changed nodes
+   */
   @Override
-  public void treeNodesRemoved(TreeModelEvent e) {
+  public void treeNodesChanged(TreeModelEvent event) {
+    if (event != null) process(event, EventType.NodesChanged);
   }
 
+  /**
+   * Invoked after some nodes have been inserted.
+   * By default, it calls the {@link #process} method with the corresponding event type.
+   *
+   * @param event the event object specifying inserted nodes
+   */
   @Override
-  public void treeStructureChanged(TreeModelEvent e) {
+  public void treeNodesInserted(TreeModelEvent event) {
+    if (event != null) process(event, EventType.NodesInserted);
+  }
+
+  /**
+   * Invoked after some nodes have been removed.
+   * By default, it calls the {@link #process} method with the corresponding event type.
+   *
+   * @param event the event object specifying removed nodes
+   */
+  @Override
+  public void treeNodesRemoved(TreeModelEvent event) {
+    if (event != null) process(event, EventType.NodesRemoved);
   }
 }

platform/util/src/com/intellij/util/ui/tree/TreeModelListenerList.java

@@ -0,0 +1,127 @@
+/*
+ * Copyright 2000-2016 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.intellij.util.ui.tree;
+
+import javax.swing.event.TreeModelEvent;
+import javax.swing.event.TreeModelListener;
+import java.util.ArrayDeque;
+
+/**
+ * @author Sergey.Malenkov
+ */
+public final class TreeModelListenerList implements TreeModelListener {
+  private final ArrayDeque<TreeModelListener> myDeque = new ArrayDeque<TreeModelListener>();
+
+  /**
+   * Adds a listener for changes in a tree model.
+   * This method is safe for use by multiple concurrent threads.
+   *
+   * @param listener a listener to add
+   */
+  public void add(TreeModelListener listener) {
+    if (listener != null) {
+      synchronized (myDeque) {
+        myDeque.addFirst(listener);
+      }
+    }
+  }
+
+  /**
+   * Removes a previously added listener.
+   * This method is safe for use by multiple concurrent threads.
+   *
+   * @param listener a listener to remove
+   */
+  public void remove(TreeModelListener listener) {
+    if (listener != null) {
+      synchronized (myDeque) {
+        myDeque.remove(listener);
+      }
+    }
+  }
+
+  /**
+   * Returns {@code true} if no listeners have been added.
+   * This method is safe for use by multiple concurrent threads.
+   *
+   * @return {@code true} if no listeners have been added, or {@code false} otherwise
+   */
+  public boolean isEmpty() {
+    synchronized (myDeque) {
+      return myDeque.isEmpty();
+    }
+  }
+
+  /**
+   * Returns all added listeners or an empty array if no listeners have been added.
+   * This method is safe for use by multiple concurrent threads.
+   *
+   * @return all added listeners
+   */
+  public TreeModelListener[] get() {
+    synchronized (myDeque) {
+      return myDeque.toArray(new TreeModelListener[0]);
+    }
+  }
+
+  /**
+   * Notifies all added listeners that a tree hierarchy was changed.
+   *
+   * @param event the event object specifying a node with changed hierarchy
+   */
+  @Override
+  public void treeStructureChanged(TreeModelEvent event) {
+    for (TreeModelListener listener : get()) {
+      listener.treeStructureChanged(event);
+    }
+  }
+
+  /**
+   * Notifies all added listeners that some nodes were changed.
+   *
+   * @param event the event object specifying changed nodes
+   */
+  @Override
+  public void treeNodesChanged(TreeModelEvent event) {
+    for (TreeModelListener listener : get()) {
+      listener.treeNodesChanged(event);
+    }
+  }
+
+  /**
+   * Notifies all added listeners that some nodes were inserted.
+   *
+   * @param event the event object specifying inserted nodes
+   */
+  @Override
+  public void treeNodesInserted(TreeModelEvent event) {
+    for (TreeModelListener listener : get()) {
+      listener.treeNodesInserted(event);
+    }
+  }
+
+  /**
+   * Notifies all added listeners that some nodes were removed.
+   *
+   * @param event the event object specifying removed nodes
+   */
+  @Override
+  public void treeNodesRemoved(TreeModelEvent event) {
+    for (TreeModelListener listener : get()) {
+      listener.treeNodesRemoved(event);
+    }
+  }
+}