Tweak some RenderNode API surfaces

* no-arg #start()
* remove no-op #destroy method
* fix a Java-imposed quirk that you can't draw a
  currently invalid RenderNode, forcing bottom-up
  recording for no particular reason

Test: builds
Change-Id: I28b41c83b4f7f9ddced843b0d57e9ac510d40ae5

5 files changed, 21 insertions, 25 deletions

diff --git a/core/java/android/view/DisplayListCanvas.java b/core/java/android/view/DisplayListCanvas.java
index 671532c90bc8..df4d5c415b98 100644
--- a/core/java/android/view/DisplayListCanvas.java
+++ b/core/java/android/view/DisplayListCanvas.java
@@ -180,13 +180,12 @@ public final class DisplayListCanvas extends RecordingCanvas {
     ///////////////////////////////////////////////////////////////////////////
 
     /**
-     * Draws the specified display list onto this canvas. The display list can only
-     * be drawn if {@link android.view.RenderNode#isValid()} returns true.
+     * Draws the specified display list onto this canvas.
      *
      * @param renderNode The RenderNode to draw.
      */
     public void drawRenderNode(RenderNode renderNode) {
-        nDrawRenderNode(mNativeCanvasWrapper, renderNode.getNativeDisplayList());
+        nDrawRenderNode(mNativeCanvasWrapper, renderNode.mNativeRenderNode);
     }
 
     ///////////////////////////////////////////////////////////////////////////
diff --git a/core/java/android/view/RenderNode.java b/core/java/android/view/RenderNode.java
index 7c25fac3974e..e10eeb0457be 100644
--- a/core/java/android/view/RenderNode.java
+++ b/core/java/android/view/RenderNode.java
@@ -139,7 +139,9 @@ public class RenderNode {
                 RenderNode.class.getClassLoader(), nGetNativeFinalizer(), 1024);
     }
 
-    // Do not access directly unless you are ThreadedRenderer
+    /** Not for general use; use only if you are ThreadedRenderer or DisplayListCanvas.
+     * @hide
+     */
     final long mNativeRenderNode;
     private final View mOwningView;
 
@@ -159,15 +161,6 @@ public class RenderNode {
     }
 
     /**
-     * Immediately destroys the RenderNode
-     * Only suitable for testing/benchmarking where waiting for the GC/finalizer
-     * is not feasible.
-     */
-    public void destroy() {
-        // TODO: Removed temporarily
-    }
-
-    /**
      * Creates a new RenderNode that can be used to record batches of
      * drawing operations, and store / apply render properties when drawn.
      *
@@ -219,6 +212,14 @@ public class RenderNode {
     }
 
     /**
+     * Same as {@link #start(int, int)} but with the RenderNode's width & height
+     */
+    public DisplayListCanvas start() {
+        return DisplayListCanvas.obtain(this,
+                nGetWidth(mNativeRenderNode), nGetHeight(mNativeRenderNode));
+    }
+
+    /**
      * Ends the recording for this display list. A display list cannot be
      * replayed if recording is not finished. Calling this method marks
      * the display list valid and {@link #isValid()} will return true.
@@ -251,13 +252,6 @@ public class RenderNode {
         return nIsValid(mNativeRenderNode);
     }
 
-    long getNativeDisplayList() {
-        if (!isValid()) {
-            throw new IllegalStateException("The display list is not valid.");
-        }
-        return mNativeRenderNode;
-    }
-
     ///////////////////////////////////////////////////////////////////////////
     // Matrix manipulation
     ///////////////////////////////////////////////////////////////////////////
@@ -463,7 +457,6 @@ public class RenderNode {
      * @see #setHasOverlappingRendering(boolean)
      */
     public boolean hasOverlappingRendering() {
-        //noinspection SimplifiableIfStatement
         return nHasOverlappingRendering(mNativeRenderNode);
     }
 
@@ -1009,4 +1002,8 @@ public class RenderNode {
     private static native float nGetPivotX(long renderNode);
     @CriticalNative
     private static native float nGetPivotY(long renderNode);
+    @CriticalNative
+    private static native int nGetWidth(long renderNode);
+    @CriticalNative
+    private static native int nGetHeight(long renderNode);
 }
diff --git a/core/java/android/view/ThreadedRenderer.java b/core/java/android/view/ThreadedRenderer.java
index aa1e4079f91f..2f975b68b985 100644
--- a/core/java/android/view/ThreadedRenderer.java
+++ b/core/java/android/view/ThreadedRenderer.java
@@ -850,7 +850,9 @@ public final class ThreadedRenderer {
 
 
     void buildLayer(RenderNode node) {
-        nBuildLayer(mNativeProxy, node.getNativeDisplayList());
+        if (node.isValid()) {
+            nBuildLayer(mNativeProxy, node.mNativeRenderNode);
+        }
     }
 
 
@@ -928,7 +930,7 @@ public final class ThreadedRenderer {
      * not the RenderNode from a View.
      **/
     public static Bitmap createHardwareBitmap(RenderNode node, int width, int height) {
-        return nCreateHardwareBitmap(node.getNativeDisplayList(), width, height);
+        return nCreateHardwareBitmap(node.mNativeRenderNode, width, height);
     }
 
     /**
diff --git a/core/java/android/view/ViewDebug.java b/core/java/android/view/ViewDebug.java
index 276f50a51e66..e4c595b4f53b 100644
--- a/core/java/android/view/ViewDebug.java
+++ b/core/java/android/view/ViewDebug.java
@@ -531,7 +531,6 @@ public class ViewDebug {
             throws IOException {
         RenderNode node = RenderNode.create("ViewDebug", null);
         profileViewAndChildren(view, node, out, true);
-        node.destroy();
     }
 
     private static void profileViewAndChildren(View view, RenderNode node, BufferedWriter out,
diff --git a/core/java/android/widget/Magnifier.java b/core/java/android/widget/Magnifier.java
index 929496f2d237..11054c81f342 100644
--- a/core/java/android/widget/Magnifier.java
+++ b/core/java/android/widget/Magnifier.java
@@ -611,7 +611,6 @@ public final class Magnifier {
                 mRenderer.destroy();
                 mSurfaceControl.destroy();
                 mSurfaceSession.kill();
-                mBitmapRenderNode.destroy();
                 mHandler.removeCallbacks(mMagnifierUpdater);
                 if (mBitmap != null) {
                     mBitmap.recycle();