Nele: Create component tree (pure restructure).

As a preparation for adding drag and drop to the structure pane,
create a class for controlling the tree separate from the structure
pane that also controls the properties panel.

Change-Id: I8696eefce9a56bc087ae6140ba609601f03f3371
(cherry picked from commit 6879840782a434d166924d9f48b04da257ccc1a1)

3 files changed, 355 insertions, 322 deletions

diff --git a/designer/src/com/android/tools/idea/uibuilder/structure/NlComponentTree.java b/designer/src/com/android/tools/idea/uibuilder/structure/NlComponentTree.java
new file mode 100644
index 00000000000..b28d470dff8
--- /dev/null
+++ b/designer/src/com/android/tools/idea/uibuilder/structure/NlComponentTree.java
@@ -0,0 +1,336 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * 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.android.tools.idea.uibuilder.structure;
+
+import com.android.SdkConstants;
+import com.android.annotations.NonNull;
+import com.android.annotations.Nullable;
+import com.android.tools.idea.uibuilder.model.*;
+import com.android.tools.idea.uibuilder.surface.DesignSurface;
+import com.android.tools.idea.uibuilder.surface.DesignSurfaceListener;
+import com.android.tools.idea.uibuilder.surface.ScreenView;
+import com.intellij.openapi.Disposable;
+import com.intellij.openapi.application.ApplicationManager;
+import com.intellij.psi.xml.XmlTag;
+import com.intellij.ui.ColoredTreeCellRenderer;
+import com.intellij.ui.treeStructure.Tree;
+import com.intellij.util.IJSwingUtilities;
+import com.intellij.util.ui.UIUtil;
+import com.intellij.util.ui.tree.TreeUtil;
+import com.intellij.util.ui.update.MergingUpdateQueue;
+import com.intellij.util.ui.update.Update;
+
+import javax.swing.*;
+import javax.swing.border.EmptyBorder;
+import javax.swing.event.TreeSelectionEvent;
+import javax.swing.event.TreeSelectionListener;
+import javax.swing.tree.DefaultMutableTreeNode;
+import javax.swing.tree.DefaultTreeModel;
+import javax.swing.tree.TreePath;
+import javax.swing.tree.TreeSelectionModel;
+import java.awt.Insets;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import static com.android.SdkConstants.*;
+import static com.android.tools.idea.uibuilder.property.NlPropertiesPanel.UPDATE_DELAY_MSECS;
+import static com.intellij.util.Alarm.ThreadToUse.SWING_THREAD;
+
+public class NlComponentTree extends Tree implements Disposable, DesignSurfaceListener, ModelListener, SelectionListener {
+  private static final Insets INSETS = new Insets(0, 6, 0, 6);
+
+  private final StructureTreeDecorator myDecorator;
+  private final Map<XmlTag, DefaultMutableTreeNode> myTag2Node;
+  private final AtomicBoolean mySelectionIsUpdating;
+  private final MergingUpdateQueue myUpdateQueue;
+
+  private NlModel myModel;
+  private boolean myWasExpanded;
+
+  public NlComponentTree() {
+    myDecorator = StructureTreeDecorator.get();
+    myTag2Node = new HashMap<XmlTag, DefaultMutableTreeNode>();
+    mySelectionIsUpdating = new AtomicBoolean(false);
+    myUpdateQueue = new MergingUpdateQueue("android.layout.structure-pane", UPDATE_DELAY_MSECS, true, null, this, null, SWING_THREAD);
+    DefaultMutableTreeNode rootNode = new DefaultMutableTreeNode(null);
+    DefaultTreeModel treeModel = new DefaultTreeModel(rootNode);
+    setModel(treeModel);
+    getSelectionModel().setSelectionMode(TreeSelectionModel.DISCONTIGUOUS_TREE_SELECTION);
+    setBorder(new EmptyBorder(INSETS));
+    setRootVisible(false);
+    setShowsRootHandles(false);
+    setToggleClickCount(1);
+    ToolTipManager.sharedInstance().registerComponent(this);
+    TreeUtil.installActions(this);
+    createCellRenderer();
+    addTreeSelectionListener(new StructurePaneSelectionListener());
+//todo:    new StructureSpeedSearch(myTree);
+//todo:    enableDnD(myTree);
+  }
+
+  public void setDesignSurface(@Nullable DesignSurface designSurface) {
+    setModel(designSurface != null && designSurface.getCurrentScreenView() != null ? designSurface.getCurrentScreenView().getModel() : null);
+  }
+
+  private void setModel(@Nullable NlModel model) {
+    if (myModel != null) {
+      myModel.removeListener(this);
+      myModel.getSelectionModel().removeListener(this);
+    }
+    myModel = model;
+    if (myModel != null) {
+      myModel.addListener(this);
+      myModel.getSelectionModel().addListener(this);
+    }
+    loadData();
+  }
+
+  @Override
+  public void dispose() {
+    if (myModel != null) {
+      myModel.removeListener(this);
+      myModel.getSelectionModel().removeListener(this);
+    }
+  }
+
+  private void createCellRenderer() {
+    setCellRenderer(new ColoredTreeCellRenderer() {
+      @Override
+      public void customizeCellRenderer(@NonNull JTree tree,
+                                        Object value,
+                                        boolean selected,
+                                        boolean expanded,
+                                        boolean leaf,
+                                        int row,
+                                        boolean hasFocus) {
+        DefaultMutableTreeNode node = (DefaultMutableTreeNode)value;
+        NlComponent component = (NlComponent)node.getUserObject();
+        if (component == null) {
+          return;
+        }
+        myDecorator.decorate(component, this, true);
+      }
+    });
+  }
+
+  private void loadData() {
+    updateHierarchy(true);
+  }
+
+  private void invalidateUI() {
+    IJSwingUtilities.updateComponentTreeUI(this);
+  }
+
+  private void updateHierarchy(final boolean firstLoad) {
+    ApplicationManager.getApplication().assertIsDispatchThread();
+    setPaintBusy(true);
+    myUpdateQueue.queue(new Update("updateComponentStructure") {
+      @Override
+      public void run() {
+        try {
+          mySelectionIsUpdating.set(true);
+          if (firstLoad) {
+            myWasExpanded = false;
+            myTag2Node.clear();
+          }
+          DefaultMutableTreeNode rootNode = (DefaultMutableTreeNode)getModel().getRoot();
+          List<NlComponent> components = myModel != null ? myModel.getComponents() : null;
+          replaceChildNodes(rootNode, components);
+          expandOnce();
+          invalidateUI();
+        } finally {
+          setPaintBusy(false);
+          mySelectionIsUpdating.set(false);
+        }
+        if (firstLoad) {
+          updateSelection();
+        }
+      }
+    });
+  }
+
+  private void replaceChildNodes(@NonNull DefaultMutableTreeNode node, @Nullable List<NlComponent> subComponents) {
+    node.removeAllChildren();
+    if (subComponents != null) {
+      for (NlComponent child : subComponents) {
+        node.add(makeNode(child));
+      }
+    }
+  }
+
+  @NonNull
+  private DefaultMutableTreeNode makeNode(@NonNull NlComponent component) {
+    DefaultMutableTreeNode node = myTag2Node.get(component.getTag());
+    if (node == null) {
+      node = new DefaultMutableTreeNode(component);
+      myTag2Node.put(component.getTag(), node);
+    } else {
+      node.setUserObject(component);
+    }
+    replaceChildNodes(node, component.children);
+    return node;
+  }
+
+  private void expandOnce() {
+    if (myWasExpanded) {
+      return;
+    }
+    final DefaultMutableTreeNode rootNode = (DefaultMutableTreeNode)getModel().getRoot();
+    if (rootNode.isLeaf()) {
+      return;
+    }
+    ApplicationManager.getApplication().invokeLater(new Runnable() {
+      @Override
+      public void run() {
+        DefaultMutableTreeNode nodeToExpand = rootNode;
+        NlComponent component = findComponentToExpandTo();
+        if (component != null) {
+          nodeToExpand = myTag2Node.get(component.getTag());
+          if (nodeToExpand == null) {
+            nodeToExpand = rootNode;
+          }
+        }
+        TreePath path = new TreePath(nodeToExpand.getPath());
+        expandPath(path);
+        while (path != null) {
+          path = path.getParentPath();
+          expandPath(path);
+        }
+        myWasExpanded = true;
+      }
+    });
+  }
+
+  // Find a component that it would be interesting to expand to when a new file is viewed.
+  // If the file has an App Bar lookup something that may be user content.
+  @Nullable
+  private NlComponent findComponentToExpandTo() {
+    if (myModel == null || myModel.getComponents().isEmpty()) {
+      return null;
+    }
+    NlComponent root = myModel.getComponents().get(0);
+    NlComponent childOfInterest = root;
+    if (root.getTagName().equals(COORDINATOR_LAYOUT)) {
+      // Find first child that is not an AppBarLayout and not anchored to anything.
+      for (NlComponent child : root.getChildren()) {
+        if (!child.getTagName().equals(APP_BAR_LAYOUT) &&
+            child.getTag().getAttribute(ATTR_LAYOUT_ANCHOR, AUTO_URI) == null) {
+          // If this is a NestedScrollView look inside:
+          if (child.getTagName().equals(SdkConstants.CLASS_NESTED_SCROLL_VIEW) && child.children != null && !child.children.isEmpty()) {
+            child = child.getChild(0);
+          }
+          childOfInterest = child;
+          break;
+        }
+      }
+    }
+
+    if (childOfInterest == null || childOfInterest.children == null || childOfInterest.children.isEmpty()) {
+      return childOfInterest;
+    }
+    return childOfInterest.children.get(childOfInterest.children.size() - 1);
+  }
+
+  private void updateSelection() {
+    if (!mySelectionIsUpdating.compareAndSet(false, true)) {
+      return;
+    }
+    try {
+      clearSelection();
+      if (myModel != null) {
+        for (NlComponent component : myModel.getSelectionModel().getSelection()) {
+          DefaultMutableTreeNode node = myTag2Node.get(component.getTag());
+          if (node != null) {
+            TreePath path = new TreePath(node.getPath());
+            expandPath(path);
+            addSelectionPath(path);
+          }
+        }
+      }
+    } finally {
+      mySelectionIsUpdating.set(false);
+    }
+  }
+
+  // ---- Implemented SelectionListener ----
+  @Override
+  public void selectionChanged(@NonNull SelectionModel model, @NonNull List<NlComponent> selection) {
+    UIUtil.invokeLaterIfNeeded(new Runnable() {
+      @Override
+      public void run() {
+        updateSelection();
+      }
+    });
+  }
+
+  // ---- Implemented ModelListener ----
+  @Override
+  public void modelChanged(@NonNull NlModel model) {
+  }
+
+  @Override
+  public void modelRendered(@NonNull NlModel model) {
+    UIUtil.invokeLaterIfNeeded(new Runnable() {
+      @Override
+      public void run() {
+        updateHierarchy(false);
+      }
+    });
+  }
+
+  // ---- Implemented DesignSurfaceListener ----
+
+  @Override
+  public void componentSelectionChanged(@NonNull DesignSurface surface, @NonNull List<NlComponent> newSelection) {
+  }
+
+  @Override
+  public void screenChanged(@NonNull DesignSurface surface, @Nullable ScreenView screenView) {
+    setModel(screenView != null ? screenView.getModel() : null);
+  }
+
+  @Override
+  public void modelChanged(@NonNull DesignSurface surface, @Nullable NlModel model) {
+    if (model != null) {
+      modelRendered(model);
+    }
+  }
+
+  private class StructurePaneSelectionListener implements TreeSelectionListener {
+    @Override
+    public void valueChanged(TreeSelectionEvent treeSelectionEvent) {
+      if (!mySelectionIsUpdating.compareAndSet(false, true)) {
+        return;
+      }
+      try {
+        List<NlComponent> selected = new ArrayList<NlComponent>();
+        TreePath[] paths = getSelectionPaths();
+        if (paths != null) {
+          for (TreePath path : paths) {
+            DefaultMutableTreeNode node = (DefaultMutableTreeNode)path.getLastPathComponent();
+            selected.add((NlComponent)node.getUserObject());
+          }
+        }
+        myModel.getSelectionModel().setSelection(selected);
+      } finally {
+        mySelectionIsUpdating.set(false);
+      }
+    }
+  }
+}
diff --git a/designer/src/com/android/tools/idea/uibuilder/structure/NlStructurePanel.java b/designer/src/com/android/tools/idea/uibuilder/structure/NlStructurePanel.java
index fc91009ec97..23b31c81490 100644
--- a/designer/src/com/android/tools/idea/uibuilder/structure/NlStructurePanel.java
+++ b/designer/src/com/android/tools/idea/uibuilder/structure/NlStructurePanel.java
@@ -15,97 +15,40 @@
  */
 package com.android.tools.idea.uibuilder.structure;
 
-import com.android.SdkConstants;
 import com.android.annotations.NonNull;
 import com.android.annotations.Nullable;
 import com.android.annotations.VisibleForTesting;
-import com.android.tools.idea.uibuilder.model.*;
 import com.android.tools.idea.uibuilder.property.NlPropertiesPanel;
 import com.android.tools.idea.uibuilder.surface.DesignSurface;
-import com.android.tools.idea.uibuilder.surface.DesignSurfaceListener;
-import com.android.tools.idea.uibuilder.surface.ScreenView;
 import com.intellij.designer.LightToolWindowContent;
-import com.intellij.ide.dnd.aware.DnDAwareTree;
-import com.intellij.openapi.application.ApplicationManager;
 import com.intellij.openapi.ui.Splitter;
-import com.intellij.psi.xml.XmlTag;
-import com.intellij.ui.ColoredTreeCellRenderer;
 import com.intellij.ui.ScrollPaneFactory;
-import com.intellij.util.IJSwingUtilities;
-import com.intellij.util.ui.UIUtil;
-import com.intellij.util.ui.tree.TreeUtil;
-import com.intellij.util.ui.update.MergingUpdateQueue;
-import com.intellij.util.ui.update.Update;
 
 import javax.swing.*;
-import javax.swing.border.EmptyBorder;
-import javax.swing.event.TreeSelectionEvent;
-import javax.swing.event.TreeSelectionListener;
-import javax.swing.tree.DefaultMutableTreeNode;
-import javax.swing.tree.DefaultTreeModel;
-import javax.swing.tree.TreePath;
-import javax.swing.tree.TreeSelectionModel;
 import java.awt.*;
-import java.awt.Insets;
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.concurrent.atomic.AtomicBoolean;
 
-import static com.android.SdkConstants.*;
-import static com.android.tools.idea.uibuilder.property.NlPropertiesPanel.UPDATE_DELAY_MSECS;
-import static com.intellij.util.Alarm.ThreadToUse.SWING_THREAD;
 import static javax.swing.ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER;
 import static javax.swing.ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED;
 
-public class NlStructurePanel extends JPanel implements LightToolWindowContent, DesignSurfaceListener, ModelListener, SelectionListener {
-  private static final Insets INSETS = new Insets(0, 6, 0, 6);
-
-  private final DnDAwareTree myTree;
-  private final StructureTreeDecorator myDecorator;
-  private final Map<XmlTag, DefaultMutableTreeNode> myTag2Node;
-  private final AtomicBoolean mySelectionIsUpdating;
+public class NlStructurePanel extends JPanel implements LightToolWindowContent {
+  private final NlComponentTree myTree;
   private final NlPropertiesPanel myPropertiesPanel;
-  private final MergingUpdateQueue myUpdateQueue;
-
-  private NlModel myModel;
-  private boolean myWasExpanded;
 
   public NlStructurePanel(@NonNull DesignSurface designSurface) {
-    myDecorator = StructureTreeDecorator.get();
-    myTree = new DnDAwareTree();
-    myTag2Node = new HashMap<XmlTag, DefaultMutableTreeNode>();
-    mySelectionIsUpdating = new AtomicBoolean(false);
+    myTree = new NlComponentTree();
     JScrollPane pane = ScrollPaneFactory.createScrollPane(myTree, VERTICAL_SCROLLBAR_AS_NEEDED, HORIZONTAL_SCROLLBAR_NEVER);
     myPropertiesPanel = new NlPropertiesPanel(designSurface);
-    myUpdateQueue = new MergingUpdateQueue(
-      "android.layout.structure-pane", UPDATE_DELAY_MSECS, true, null, designSurface, null, SWING_THREAD);
     Splitter splitter = new Splitter(true, 0.4f);
     splitter.setFirstComponent(pane);
     splitter.setSecondComponent(myPropertiesPanel);
-    initTree();
     setLayout(new BorderLayout());
     add(splitter, BorderLayout.CENTER);
     setDesignSurface(designSurface);
   }
 
   public void setDesignSurface(@Nullable DesignSurface designSurface) {
+    myTree.setDesignSurface(designSurface);
     myPropertiesPanel.setDesignSurface(designSurface);
-    setModel(designSurface != null && designSurface.getCurrentScreenView() != null ? designSurface.getCurrentScreenView().getModel() : null);
-  }
-
-  private void setModel(@Nullable NlModel model) {
-    if (myModel != null) {
-      myModel.removeListener(this);
-      myModel.getSelectionModel().removeListener(this);
-    }
-    myModel = model;
-    if (myModel != null) {
-      myModel.addListener(this);
-      myModel.getSelectionModel().addListener(this);
-    }
-    loadData();
   }
 
   public JComponent getPanel() {
@@ -114,256 +57,11 @@ public class NlStructurePanel extends JPanel implements LightToolWindowContent,
 
   @Override
   public void dispose() {
-    if (myModel != null) {
-      myModel.removeListener(this);
-      myModel.getSelectionModel().removeListener(this);
-    }
+    myTree.dispose();
   }
 
   @VisibleForTesting
-  JTree getTree() {
+  JTree getTree2() {
     return myTree;
   }
-
-  private void initTree() {
-    DefaultMutableTreeNode rootNode = new DefaultMutableTreeNode(null);
-    DefaultTreeModel treeModel = new DefaultTreeModel(rootNode);
-    myTree.setModel(treeModel);
-    myTree.getSelectionModel().setSelectionMode(TreeSelectionModel.DISCONTIGUOUS_TREE_SELECTION);
-    myTree.setBorder(new EmptyBorder(INSETS));
-    myTree.setRootVisible(false);
-    myTree.setShowsRootHandles(false);
-    myTree.setToggleClickCount(1);
-    ToolTipManager.sharedInstance().registerComponent(myTree);
-    TreeUtil.installActions(myTree);
-    createCellRenderer(myTree);
-    myTree.addTreeSelectionListener(new StructurePaneSelectionListener());
-//todo:    new StructureSpeedSearch(myTree);
-//todo:    enableDnD(myTree);
-  }
-
-  private void createCellRenderer(@NonNull JTree tree) {
-    tree.setCellRenderer(new ColoredTreeCellRenderer() {
-      @Override
-      public void customizeCellRenderer(@NonNull JTree tree,
-                                        Object value,
-                                        boolean selected,
-                                        boolean expanded,
-                                        boolean leaf,
-                                        int row,
-                                        boolean hasFocus) {
-        DefaultMutableTreeNode node = (DefaultMutableTreeNode)value;
-        NlComponent component = (NlComponent)node.getUserObject();
-        if (component == null) {
-          return;
-        }
-        myDecorator.decorate(component, this, true);
-      }
-    });
-  }
-
-  private void loadData() {
-    updateHierarchy(true);
-  }
-
-  private void invalidateUI() {
-    IJSwingUtilities.updateComponentTreeUI(myTree);
-  }
-
-  private void updateHierarchy(final boolean firstLoad) {
-    ApplicationManager.getApplication().assertIsDispatchThread();
-    myTree.setPaintBusy(true);
-    myUpdateQueue.queue(new Update("updateComponentStructure") {
-      @Override
-      public void run() {
-        try {
-          mySelectionIsUpdating.set(true);
-          if (firstLoad) {
-            myWasExpanded = false;
-            myTag2Node.clear();
-          }
-          DefaultMutableTreeNode rootNode = (DefaultMutableTreeNode)myTree.getModel().getRoot();
-          List<NlComponent> components = myModel != null ? myModel.getComponents() : null;
-          replaceChildNodes(rootNode, components);
-          expandOnce();
-          invalidateUI();
-        } finally {
-          myTree.setPaintBusy(false);
-          mySelectionIsUpdating.set(false);
-        }
-        if (firstLoad) {
-          updateSelection();
-        }
-      }
-    });
-  }
-
-  private void replaceChildNodes(@NonNull DefaultMutableTreeNode node, @Nullable List<NlComponent> subComponents) {
-    node.removeAllChildren();
-    if (subComponents != null) {
-      for (NlComponent child : subComponents) {
-        node.add(makeNode(child));
-      }
-    }
-  }
-
-  @NonNull
-  private DefaultMutableTreeNode makeNode(@NonNull NlComponent component) {
-    DefaultMutableTreeNode node = myTag2Node.get(component.getTag());
-    if (node == null) {
-      node = new DefaultMutableTreeNode(component);
-      myTag2Node.put(component.getTag(), node);
-    } else {
-      node.setUserObject(component);
-    }
-    replaceChildNodes(node, component.children);
-    return node;
-  }
-
-  private void expandOnce() {
-    if (myWasExpanded) {
-      return;
-    }
-    final DefaultMutableTreeNode rootNode = (DefaultMutableTreeNode)myTree.getModel().getRoot();
-    if (rootNode.isLeaf()) {
-      return;
-    }
-    ApplicationManager.getApplication().invokeLater(new Runnable() {
-      @Override
-      public void run() {
-        DefaultMutableTreeNode nodeToExpand = rootNode;
-        NlComponent component = findComponentToExpandTo();
-        if (component != null) {
-          nodeToExpand = myTag2Node.get(component.getTag());
-          if (nodeToExpand == null) {
-            nodeToExpand = rootNode;
-          }
-        }
-        TreePath path = new TreePath(nodeToExpand.getPath());
-        myTree.expandPath(path);
-        while (path != null) {
-          path = path.getParentPath();
-          myTree.expandPath(path);
-        }
-        myWasExpanded = true;
-      }
-    });
-  }
-
-  // Find a component that it would be interesting to expand to when a new file is viewed.
-  // If the file has an App Bar lookup something that may be user content.
-  @Nullable
-  private NlComponent findComponentToExpandTo() {
-    if (myModel == null || myModel.getComponents().isEmpty()) {
-      return null;
-    }
-    NlComponent root = myModel.getComponents().get(0);
-    NlComponent childOfInterest = root;
-    if (root.getTagName().equals(COORDINATOR_LAYOUT)) {
-      // Find first child that is not an AppBarLayout and not anchored to anything.
-      for (NlComponent child : root.getChildren()) {
-        if (!child.getTagName().equals(APP_BAR_LAYOUT) &&
-            child.getTag().getAttribute(ATTR_LAYOUT_ANCHOR, AUTO_URI) == null) {
-          // If this is a NestedScrollView look inside:
-          if (child.getTagName().equals(SdkConstants.CLASS_NESTED_SCROLL_VIEW) && child.children != null && !child.children.isEmpty()) {
-            child = child.getChild(0);
-          }
-          childOfInterest = child;
-          break;
-        }
-      }
-    }
-
-    if (childOfInterest == null || childOfInterest.children == null || childOfInterest.children.isEmpty()) {
-      return childOfInterest;
-    }
-    return childOfInterest.children.get(childOfInterest.children.size() - 1);
-  }
-
-  private void updateSelection() {
-    if (!mySelectionIsUpdating.compareAndSet(false, true)) {
-      return;
-    }
-    try {
-      myTree.clearSelection();
-      if (myModel != null) {
-        for (NlComponent component : myModel.getSelectionModel().getSelection()) {
-          DefaultMutableTreeNode node = myTag2Node.get(component.getTag());
-          if (node != null) {
-            TreePath path = new TreePath(node.getPath());
-            myTree.expandPath(path);
-            myTree.addSelectionPath(path);
-          }
-        }
-      }
-    } finally {
-      mySelectionIsUpdating.set(false);
-    }
-  }
-
-  // ---- Implemented SelectionListener ----
-  @Override
-  public void selectionChanged(@NonNull SelectionModel model, @NonNull List<NlComponent> selection) {
-    UIUtil.invokeLaterIfNeeded(new Runnable() {
-      @Override
-      public void run() {
-        updateSelection();
-      }
-    });
-  }
-
-  // ---- Implemented ModelListener ----
-  @Override
-  public void modelChanged(@NonNull NlModel model) {
-  }
-
-  @Override
-  public void modelRendered(@NonNull NlModel model) {
-    UIUtil.invokeLaterIfNeeded(new Runnable() {
-      @Override
-      public void run() {
-        updateHierarchy(false);
-      }
-    });
-  }
-
-  // ---- Implemented DesignSurfaceListener ----
-
-  @Override
-  public void componentSelectionChanged(@NonNull DesignSurface surface, @NonNull List<NlComponent> newSelection) {
-  }
-
-  @Override
-  public void screenChanged(@NonNull DesignSurface surface, @Nullable ScreenView screenView) {
-    setModel(screenView != null ? screenView.getModel() : null);
-  }
-
-  @Override
-  public void modelChanged(@NonNull DesignSurface surface, @Nullable NlModel model) {
-    if (model != null) {
-      modelRendered(model);
-    }
-  }
-
-  private class StructurePaneSelectionListener implements TreeSelectionListener {
-    @Override
-    public void valueChanged(TreeSelectionEvent treeSelectionEvent) {
-      if (!mySelectionIsUpdating.compareAndSet(false, true)) {
-        return;
-      }
-      try {
-        List<NlComponent> selected = new ArrayList<NlComponent>();
-        TreePath[] paths = myTree.getSelectionPaths();
-        if (paths != null) {
-          for (TreePath path : myTree.getSelectionPaths()) {
-            DefaultMutableTreeNode node = (DefaultMutableTreeNode)path.getLastPathComponent();
-            selected.add((NlComponent)node.getUserObject());
-          }
-        }
-        myModel.getSelectionModel().setSelection(selected);
-      } finally {
-        mySelectionIsUpdating.set(false);
-      }
-    }
-  }
 }
diff --git a/designer/testSrc/com/android/tools/idea/uibuilder/structure/NlStructurePanelTest.java b/designer/testSrc/com/android/tools/idea/uibuilder/structure/NlComponentTreeTest.java
index b9ef57d6a63..db9a8ca92bf 100644
--- a/designer/testSrc/com/android/tools/idea/uibuilder/structure/NlStructurePanelTest.java
+++ b/designer/testSrc/com/android/tools/idea/uibuilder/structure/NlComponentTreeTest.java
@@ -25,7 +25,6 @@ import com.android.tools.idea.uibuilder.surface.ScreenView;
 import org.jetbrains.annotations.NotNull;
 import org.mockito.Mock;
 
-import javax.swing.*;
 import javax.swing.tree.DefaultMutableTreeNode;
 import javax.swing.tree.TreePath;
 import java.util.Iterator;
@@ -34,13 +33,13 @@ import static com.android.SdkConstants.*;
 import static org.mockito.Mockito.when;
 import static org.mockito.MockitoAnnotations.initMocks;
 
-public class NlStructurePanelTest  extends LayoutTestCase {
+public class NlComponentTreeTest extends LayoutTestCase {
   @Mock
   private DesignSurface mySurface;
   @Mock
   private ScreenView myScreen;
   private NlModel myModel;
-  private NlStructurePanel myPanel;
+  private NlComponentTree myTree;
 
   @Override
   public void setUp() throws Exception {
@@ -50,13 +49,13 @@ public class NlStructurePanelTest  extends LayoutTestCase {
     when(myScreen.getModel()).thenReturn(myModel);
     when(myScreen.getSelectionModel()).thenReturn(myModel.getSelectionModel());
     when(mySurface.getCurrentScreenView()).thenReturn(myScreen);
-    myPanel = new NlStructurePanel(mySurface);
+    myTree = new NlComponentTree();
+    myTree.setDesignSurface(mySurface);
   }
 
   public void testTreeStructure() {
-    JTree tree = myPanel.getTree();
     NlComponent expectedRoot = myModel.getComponents().get(0);
-    DefaultMutableTreeNode hidden = (DefaultMutableTreeNode)tree.getModel().getRoot();
+    DefaultMutableTreeNode hidden = (DefaultMutableTreeNode)myTree.getModel().getRoot();
     assertEquals(1, hidden.getChildCount());
     DefaultMutableTreeNode root = (DefaultMutableTreeNode)hidden.getFirstChild();
     assertEquals("Unexpected root", expectedRoot, root.getUserObject());
@@ -68,16 +67,15 @@ public class NlStructurePanelTest  extends LayoutTestCase {
   }
 
   public void testSelectionInTreeIsPropagatedToModel() {
-    JTree tree = myPanel.getTree();
-    assertNull(tree.getSelectionPaths());
+    assertNull(myTree.getSelectionPaths());
     assertFalse(myModel.getSelectionModel().getSelection().iterator().hasNext());
 
-    DefaultMutableTreeNode hidden = (DefaultMutableTreeNode)tree.getModel().getRoot();
+    DefaultMutableTreeNode hidden = (DefaultMutableTreeNode)myTree.getModel().getRoot();
     DefaultMutableTreeNode root = (DefaultMutableTreeNode)hidden.getFirstChild();
     DefaultMutableTreeNode node1 = (DefaultMutableTreeNode)root.getChildAt(1);
     DefaultMutableTreeNode node2 = (DefaultMutableTreeNode)root.getChildAt(2);
-    tree.addSelectionPath(new TreePath(node1.getPath()));
-    tree.addSelectionPath(new TreePath(node2.getPath()));
+    myTree.addSelectionPath(new TreePath(node1.getPath()));
+    myTree.addSelectionPath(new TreePath(node2.getPath()));
 
     Iterator<NlComponent> selected = myModel.getSelectionModel().getSelection().iterator();
     assertEquals(node1.getUserObject(), selected.next());
@@ -86,17 +84,18 @@ public class NlStructurePanelTest  extends LayoutTestCase {
   }
 
   public void testSelectionInModelIsShownInTree() {
-    JTree tree = myPanel.getTree();
-    assertNull(tree.getSelectionPaths());
+    assertNull(myTree.getSelectionPaths());
     assertFalse(myModel.getSelectionModel().getSelection().iterator().hasNext());
 
     NlComponent layout = myModel.getComponents().get(0);
     NlComponent text = layout.getChild(0);
     NlComponent button = layout.getChild(1);
+    assert text != null;
+    assert button != null;
     myModel.getSelectionModel().toggle(text);
     myModel.getSelectionModel().toggle(button);
 
-    TreePath[] selection = tree.getSelectionPaths();
+    TreePath[] selection = myTree.getSelectionPaths();
     assertEquals(2, selection.length);
     assertEquals(text, ((DefaultMutableTreeNode)selection[0].getLastPathComponent()).getUserObject());
     assertEquals(button, ((DefaultMutableTreeNode)selection[1].getLastPathComponent()).getUserObject());