Custom View handling improvements

First and foremost, allow custom views to accept children such that
you can drag & drop children into the custom view in the outline.

Second, prevent an NPE which can occur if you drag into a layout where
the root element is a custom view.

Third, handle <view> (not <View>) better: provide a custom icon, and
inline the view class name in the outline label.

Fourth, allow double clicks (in addition to ctrl-click which is already
supported) on the custom views in the palette to allow jumping to the
custom view code.

Change-Id: I13c2bf2f4169185c9fcc893ce487f2abdac46802

8 files changed, 66 insertions, 12 deletions

diff --git a/eclipse/plugins/com.android.ide.eclipse.adt/icons/view.png b/eclipse/plugins/com.android.ide.eclipse.adt/icons/view.png
new file mode 100644
index 0000000..35c4d8f
--- /dev/null
+++ b/eclipse/plugins/com.android.ide.eclipse.adt/icons/view.png
diff --git a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/common/layout/ViewRule.java b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/common/layout/ViewRule.java
index 470b6a4..a7b23ab 100755
--- a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/common/layout/ViewRule.java
+++ b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/common/layout/ViewRule.java
@@ -24,7 +24,7 @@ import com.android.ide.common.api.IViewRule;
  * apply.
  * <p/>
  * There is no customization here, everything that is common to all views is
- * simply implemented in BaseView.
+ * simply implemented in BaseViewRule.
  */
 public class ViewRule extends BaseViewRule {
 
diff --git a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/descriptors/CustomViewDescriptorService.java b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/descriptors/CustomViewDescriptorService.java
index db72ac6..be9fe34 100644
--- a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/descriptors/CustomViewDescriptorService.java
+++ b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/descriptors/CustomViewDescriptorService.java
@@ -16,6 +16,8 @@
 
 package com.android.ide.eclipse.adt.internal.editors.layout.descriptors;
 
+import static com.android.sdklib.SdkConstants.CLASS_VIEWGROUP;
+
 import com.android.ide.common.resources.platform.ViewClassInfo;
 import com.android.ide.eclipse.adt.internal.editors.descriptors.AttributeDescriptor;
 import com.android.ide.eclipse.adt.internal.editors.descriptors.DescriptorsUtils;
@@ -164,7 +166,8 @@ public final class CustomViewDescriptorService {
 
                         String name = DescriptorsUtils.getBasename(fqcn);
                         ViewElementDescriptor descriptor = new CustomViewDescriptor(name, fqcn,
-                                getAttributeDescriptor(type, parentDescriptor));
+                                getAttributeDescriptor(type, parentDescriptor),
+                                parentDescriptor.hasChildren());
                         descriptor.setSuperClass(parentDescriptor);
 
                         synchronized (mCustomDescriptorMap) {
@@ -241,8 +244,14 @@ public final class CustomViewDescriptorService {
                 // parent class is a valid View class with a descriptor, so we create one
                 // for this class.
                 String name = DescriptorsUtils.getBasename(fqcn);
+                // A custom view accepts children if its parent descriptor also does.
+                // The only exception to this is ViewGroup, which accepts children even though
+                // its parent does not.
+                boolean isViewGroup = fqcn.equals(CLASS_VIEWGROUP);
+                boolean hasChildren = isViewGroup || parentDescriptor.hasChildren();
                 ViewElementDescriptor descriptor = new CustomViewDescriptor(name, fqcn,
-                        getAttributeDescriptor(type, parentDescriptor));
+                        getAttributeDescriptor(type, parentDescriptor),
+                        hasChildren);
                 descriptor.setSuperClass(parentDescriptor);
 
                 // add it to the map
@@ -283,7 +292,10 @@ public final class CustomViewDescriptorService {
     }
 
     private class CustomViewDescriptor extends ViewElementDescriptor {
-        public CustomViewDescriptor(String name, String fqcn, AttributeDescriptor[] attributes) {
+        private boolean mHasChildren;
+
+        public CustomViewDescriptor(String name, String fqcn, AttributeDescriptor[] attributes,
+                boolean hasChildren) {
             super(
                     fqcn, // xml name
                     name, // ui name
@@ -295,8 +307,21 @@ public final class CustomViewDescriptorService {
                     null, // children
                     false // mandatory
             );
+            mHasChildren = hasChildren;
+        }
+
+        /**
+         * {@inheritDoc}
+         * <p>
+         * Custom views can accept children even if we have no information about
+         * allowed children.
+         */
+        @Override
+        public boolean hasChildren() {
+            return mHasChildren;
         }
 
+
         @Override
         public Image getGenericIcon() {
             // Java source file icon. We could use the Java class icon here
diff --git a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/descriptors/LayoutDescriptors.java b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/descriptors/LayoutDescriptors.java
index 4613492..24aea33 100644
--- a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/descriptors/LayoutDescriptors.java
+++ b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/descriptors/LayoutDescriptors.java
@@ -63,6 +63,15 @@ public final class LayoutDescriptors implements IDescriptorProvider {
     public static final String REQUEST_FOCUS = "requestFocus";//$NON-NLS-1$
 
     /**
+     * The XML name of the special {@code <view>} layout tag. This is used to add generic
+     * views with a class attribute to specify the view.
+     * <p>
+     * TODO: We should add a synthetic descriptor for this, similar to our descriptors for
+     * include, merge and requestFocus.
+     */
+    public static final String VIEW_VIEWTAG = "view";           //$NON-NLS-1$
+
+    /**
      * The attribute name of the include tag's url naming the resource to be inserted
      * <p>
      * <b>NOTE</b>: The layout attribute is NOT in the Android namespace!
@@ -353,7 +362,7 @@ public final class LayoutDescriptors implements IDescriptorProvider {
     }
 
     /**
-     * Creates and return a new {@code <merge>} descriptor.
+     * Creates and returns a new {@code <merge>} descriptor.
      * @param knownLayouts  A list of all known layout view descriptors, used to find the
      *   FrameLayout descriptor and extract its layout attributes.
      */
@@ -379,9 +388,7 @@ public final class LayoutDescriptors implements IDescriptorProvider {
     }
 
     /**
-     * Creates and return a new {@code <requestFocus>} descriptor.
-     * @param knownLayouts  A list of all known layout view descriptors, used to find the
-     *   FrameLayout descriptor and extract its layout attributes.
+     * Creates and returns a new {@code <requestFocus>} descriptor.
      */
     private ViewElementDescriptor createRequestFocus() {
         String xml_name = REQUEST_FOCUS;
diff --git a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/MoveGesture.java b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/MoveGesture.java
index a2cdbe6..a56eb16 100644
--- a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/MoveGesture.java
+++ b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/MoveGesture.java
@@ -674,7 +674,7 @@ public class MoveGesture extends DropGesture {
         // Update outline to show the target node there
         OutlinePage outline = mCanvas.getOutlinePage();
         TreeSelection newSelection = TreeSelection.EMPTY;
-        if (mCurrentView != null) {
+        if (mCurrentView != null && mTargetNode != null) {
             // Find the view corresponding to the target node. The current view can be a leaf
             // view whereas the target node is always a parent layout.
             if (mCurrentView.getUiViewNode() != mTargetNode.getNode()) {
diff --git a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/PaletteControl.java b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/PaletteControl.java
index 2227531..4b4bf96 100755
--- a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/PaletteControl.java
+++ b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/PaletteControl.java
@@ -23,14 +23,14 @@ import static com.android.ide.common.layout.LayoutConstants.ATTR_TEXT;
 import static com.android.ide.common.layout.LayoutConstants.VALUE_WRAP_CONTENT;
 
 import com.android.ide.common.api.InsertType;
-import com.android.ide.common.api.MenuAction.Toggle;
 import com.android.ide.common.api.Rect;
+import com.android.ide.common.api.MenuAction.Toggle;
 import com.android.ide.common.rendering.LayoutLibrary;
 import com.android.ide.common.rendering.api.Capability;
 import com.android.ide.common.rendering.api.LayoutLog;
 import com.android.ide.common.rendering.api.RenderSession;
-import com.android.ide.common.rendering.api.SessionParams.RenderingMode;
 import com.android.ide.common.rendering.api.ViewInfo;
+import com.android.ide.common.rendering.api.SessionParams.RenderingMode;
 import com.android.ide.eclipse.adt.AdtPlugin;
 import com.android.ide.eclipse.adt.internal.editors.IconFactory;
 import com.android.ide.eclipse.adt.internal.editors.descriptors.DescriptorsUtils;
@@ -572,10 +572,16 @@ public class PaletteControl extends Composite {
             Control item = createItem(parent, desc);
 
             // Add control-click listener on custom view items to you can warp to
+            // (and double click listener too -- the more discoverable, the better.)
             if (item instanceof IconTextItem) {
                 IconTextItem it = (IconTextItem) item;
                 it.addMouseListener(new MouseAdapter() {
                     @Override
+                    public void mouseDoubleClick(MouseEvent e) {
+                        AdtPlugin.openJavaClass(mEditor.getProject(), fqcn);
+                    }
+
+                    @Override
                     public void mouseDown(MouseEvent e) {
                         if ((e.stateMask & SWT.MOD1) != 0) {
                             AdtPlugin.openJavaClass(mEditor.getProject(), fqcn);
diff --git a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gre/ViewMetadataRepository.java b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gre/ViewMetadataRepository.java
index cf6acba..42b4a16 100644
--- a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gre/ViewMetadataRepository.java
+++ b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gre/ViewMetadataRepository.java
@@ -343,13 +343,17 @@ public class ViewMetadataRepository {
                 String fqcn = view.getFcqn();
                 ViewElementDescriptor descriptor = fqcnToDescriptor.get(fqcn);
                 if (descriptor != null) {
+                    remaining.remove(descriptor);
+                    if (view.getSkip()) {
+                        continue;
+                    }
+
                     if (view.getDisplayName() != null || view.getInitString().length() > 0) {
                         categoryItems.add(new PaletteMetadataDescriptor(descriptor,
                                 view.getDisplayName(), view.getInitString(), view.getIconName()));
                     } else {
                         categoryItems.add(descriptor);
                     }
-                    remaining.remove(descriptor);
 
                     if (view.hasVariations()) {
                         for (ViewData variation : view.getVariations()) {
diff --git a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/uimodel/UiElementNode.java b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/uimodel/UiElementNode.java
index 93b6baf..e2b6ccf 100644
--- a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/uimodel/UiElementNode.java
+++ b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/uimodel/UiElementNode.java
@@ -17,6 +17,7 @@
 package com.android.ide.eclipse.adt.internal.editors.uimodel;
 
 import static com.android.ide.common.layout.LayoutConstants.ANDROID_NS_NAME;
+import static com.android.ide.common.layout.LayoutConstants.ATTR_CLASS;
 import static com.android.ide.common.layout.LayoutConstants.ID_PREFIX;
 import static com.android.ide.common.layout.LayoutConstants.NEW_ID_PREFIX;
 import static com.android.ide.eclipse.adt.internal.editors.descriptors.XmlnsAttributeDescriptor.XMLNS;
@@ -288,6 +289,17 @@ public class UiElementNode implements IPropertySource {
     public StyledString getStyledDescription() {
         String uiName = mDescriptor.getUiName();
 
+        // Special case: for <view>, show the class attribute value instead.
+        // This is done here rather than in the descriptor since this depends on
+        // node instance data.
+        if (LayoutDescriptors.VIEW_VIEWTAG.equals(uiName) && mXmlNode instanceof Element) {
+            Element element = (Element) mXmlNode;
+            String cls = element.getAttribute(ATTR_CLASS);
+            if (cls != null) {
+                uiName = cls.substring(cls.lastIndexOf('.') + 1);
+            }
+        }
+
         StyledString styledString = new StyledString();
         String attr = getDescAttribute();
         if (attr != null) {