LayoutLib: add implementation of Bridge.renderDrawable()

Change-Id: Ic4d96488fd1a2e5b7d24353bebc8fdb24262c1d1
diff --git a/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/Bridge.java b/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/Bridge.java
index dff7ff1..c01962d 100644
--- a/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/Bridge.java
+++ b/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/Bridge.java
@@ -20,12 +20,14 @@
 import static com.android.ide.common.rendering.api.Result.Status.SUCCESS;
 
 import com.android.ide.common.rendering.api.Capability;
+import com.android.ide.common.rendering.api.DrawableParams;
 import com.android.ide.common.rendering.api.LayoutLog;
 import com.android.ide.common.rendering.api.RenderSession;
 import com.android.ide.common.rendering.api.Result;
 import com.android.ide.common.rendering.api.SessionParams;
 import com.android.layoutlib.bridge.android.BridgeAssetManager;
 import com.android.layoutlib.bridge.impl.FontLoader;
+import com.android.layoutlib.bridge.impl.RenderDrawable;
 import com.android.layoutlib.bridge.impl.RenderSessionImpl;
 import com.android.ninepatch.NinePatchChunk;
 import com.android.resources.ResourceType;
@@ -332,6 +334,33 @@
     }
 
     @Override
+    public Result renderDrawable(DrawableParams params) {
+        try {
+            Result lastResult = SUCCESS.createResult();
+            RenderDrawable action = new RenderDrawable(params);
+            try {
+                prepareThread();
+                lastResult = action.init(params.getTimeout());
+                if (lastResult.isSuccess()) {
+                    lastResult = action.render();
+                }
+            } finally {
+                action.release();
+                cleanupThread();
+            }
+
+            return lastResult;
+        } catch (Throwable t) {
+            // get the real cause of the exception.
+            Throwable t2 = t;
+            while (t2.getCause() != null) {
+                t2 = t.getCause();
+            }
+            return ERROR_UNKNOWN.createResult(t2.getMessage(), t);
+        }
+    }
+
+    @Override
     public void clearCaches(Object projectKey) {
         if (projectKey != null) {
             sProjectBitmapCache.remove(projectKey);
diff --git a/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/impl/RenderAction.java b/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/impl/RenderAction.java
index 82ac176..8e80c21 100644
--- a/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/impl/RenderAction.java
+++ b/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/impl/RenderAction.java
@@ -35,16 +35,18 @@
 import java.util.concurrent.locks.ReentrantLock;
 
 /**
- * Class implementing the render session.
+ * Base class for rendering action.
  *
- * A session is a stateful representation of a layout file. It is initialized with data coming
- * through the {@link Bridge} API to inflate the layout. Further actions and rendering can then
- * be done on the layout.
+ * It provides life-cycle methods to init and stop the rendering.
+ * The most important methods are:
+ * {@link #init(long)} and {@link #acquire(long)} to start a rendering and {@link #release()}
+ * after the rendering.
+ *
  *
  * @param <T> the {@link RenderParams} implementation
  *
  */
-public class RenderAction<T extends RenderParams> extends FrameworkResourceIdProvider {
+public abstract class RenderAction<T extends RenderParams> extends FrameworkResourceIdProvider {
 
     /**
      * The current context being rendered. This is set through {@link #acquire(long)} and
@@ -65,7 +67,7 @@
      * @param params the RenderParams. This must be a copy that the action can keep
      *
      */
-    public RenderAction(T params) {
+    protected RenderAction(T params) {
         mParams = params;
     }
 
diff --git a/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/impl/RenderDrawable.java b/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/impl/RenderDrawable.java
new file mode 100644
index 0000000..953d8cf
--- /dev/null
+++ b/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/impl/RenderDrawable.java
@@ -0,0 +1,141 @@
+/*
+ * Copyright (C) 2011 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.layoutlib.bridge.impl;
+
+import static com.android.ide.common.rendering.api.Result.Status.ERROR_UNKNOWN;
+
+import com.android.ide.common.rendering.api.DrawableParams;
+import com.android.ide.common.rendering.api.ResourceValue;
+import com.android.ide.common.rendering.api.Result;
+import com.android.ide.common.rendering.api.Result.Status;
+import com.android.layoutlib.bridge.android.BridgeContext;
+import com.android.layoutlib.bridge.android.BridgeWindow;
+import com.android.layoutlib.bridge.android.BridgeWindowSession;
+import com.android.resources.ResourceType;
+
+import android.graphics.Bitmap;
+import android.graphics.Bitmap_Delegate;
+import android.graphics.Canvas;
+import android.graphics.drawable.Drawable;
+import android.os.Handler;
+import android.view.View;
+import android.view.View.AttachInfo;
+import android.view.View.MeasureSpec;
+import android.widget.FrameLayout;
+
+import java.awt.AlphaComposite;
+import java.awt.Color;
+import java.awt.Graphics2D;
+import java.awt.image.BufferedImage;
+import java.io.IOException;
+
+/**
+ * Action to render a given Drawable provided through {@link DrawableParams#getDrawable()}.
+ *
+ * The class only provides a simple {@link #render()} method, but the full life-cycle of the
+ * action must be respected.
+ *
+ * @see RenderAction
+ *
+ */
+public class RenderDrawable extends RenderAction<DrawableParams> {
+
+    public RenderDrawable(DrawableParams params) {
+        super(new DrawableParams(params));
+    }
+
+    public Result render() {
+        checkLock();
+        try {
+            // get the drawable resource value
+            DrawableParams params = getParams();
+            ResourceValue drawableResource = params.getDrawable();
+
+            // resolve it
+            BridgeContext context = getContext();
+            drawableResource = context.getRenderResources().resolveResValue(drawableResource);
+
+            if (drawableResource == null ||
+                    drawableResource.getResourceType() != ResourceType.DRAWABLE) {
+                return Status.ERROR_NOT_A_DRAWABLE.createResult();
+            }
+
+            // create a simple FrameLayout
+            FrameLayout content = new FrameLayout(context);
+
+            // get the actual Drawable object to draw
+            Drawable d = ResourceHelper.getDrawable(drawableResource, context);
+            content.setBackgroundDrawable(d);
+
+            // set the AttachInfo on the root view.
+            AttachInfo info = new AttachInfo(new BridgeWindowSession(), new BridgeWindow(),
+                    new Handler(), null);
+            info.mHasWindowFocus = true;
+            info.mWindowVisibility = View.VISIBLE;
+            info.mInTouchMode = false; // this is so that we can display selections.
+            info.mHardwareAccelerated = false;
+            content.dispatchAttachedToWindow(info, 0);
+
+
+            // measure
+            int w = params.getScreenWidth();
+            int h = params.getScreenHeight();
+            int w_spec = MeasureSpec.makeMeasureSpec(w, MeasureSpec.EXACTLY);
+            int h_spec = MeasureSpec.makeMeasureSpec(h, MeasureSpec.EXACTLY);
+            content.measure(w_spec, h_spec);
+
+            // now do the layout.
+            content.layout(0, 0, w, h);
+
+            // preDraw setup
+            content.mAttachInfo.mTreeObserver.dispatchOnPreDraw();
+
+            // draw into a new image
+            BufferedImage image = getImage(w, h);
+
+            // create an Android bitmap around the BufferedImage
+            Bitmap bitmap = Bitmap_Delegate.createBitmap(image,
+                    true /*isMutable*/, params.getDensity());
+
+            // create a Canvas around the Android bitmap
+            Canvas canvas = new Canvas(bitmap);
+            canvas.setDensity(params.getDensity().getDpiValue());
+
+            // and draw
+            content.draw(canvas);
+
+            return Status.SUCCESS.createResult(image);
+        } catch (IOException e) {
+            return ERROR_UNKNOWN.createResult(e.getMessage(), e);
+        }
+    }
+
+    protected BufferedImage getImage(int w, int h) {
+        BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
+        Graphics2D gc = image.createGraphics();
+        gc.setComposite(AlphaComposite.Src);
+
+        gc.setColor(new Color(0x00000000, true));
+        gc.fillRect(0, 0, w, h);
+
+        // done
+        gc.dispose();
+
+        return image;
+    }
+
+}