Have position listener only call when interesting

Test: it compiled; HwAccelTest looked fine
Change-Id: I193028791749811d5709d078f32efdebd7173d13
Fixes: 123656149

core/jni/android_view_RenderNode.cpp

@@ -507,15 +507,15 @@ jmethodID gPositionListener_PositionChangedMethod;
 jmethodID gPositionListener_PositionLostMethod;
 
 static void android_view_RenderNode_requestPositionUpdates(JNIEnv* env, jobject,
-        jlong renderNodePtr, jobject surfaceview) {
-    class SurfaceViewPositionUpdater : public RenderNode::PositionListener {
+        jlong renderNodePtr, jobject listener) {
+    class PositionListenerTrampoline : public RenderNode::PositionListener {
     public:
-        SurfaceViewPositionUpdater(JNIEnv* env, jobject surfaceview) {
+        PositionListenerTrampoline(JNIEnv* env, jobject listener) {
             env->GetJavaVM(&mVm);
-            mWeakRef = env->NewWeakGlobalRef(surfaceview);
+            mWeakRef = env->NewWeakGlobalRef(listener);
         }
 
-        virtual ~SurfaceViewPositionUpdater() {
+        virtual ~PositionListenerTrampoline() {
             jnienv()->DeleteWeakGlobalRef(mWeakRef);
             mWeakRef = nullptr;
         }
@@ -539,9 +539,14 @@ static void android_view_RenderNode_requestPositionUpdates(JNIEnv* env, jobject,
                 bounds.roundOut();
             }
 
+            if (mPreviousPosition == bounds) {
+                return;
+            }
+            mPreviousPosition = bounds;
+
             incStrong(0);
             auto functor = std::bind(
-                std::mem_fn(&SurfaceViewPositionUpdater::doUpdatePositionAsync), this,
+                std::mem_fn(&PositionListenerTrampoline::doUpdatePositionAsync), this,
                 (jlong) info.canvasContext.getFrameNumber(),
                 (jint) bounds.left, (jint) bounds.top,
                 (jint) bounds.right, (jint) bounds.bottom);
@@ -552,6 +557,11 @@ static void android_view_RenderNode_requestPositionUpdates(JNIEnv* env, jobject,
         virtual void onPositionLost(RenderNode& node, const TreeInfo* info) override {
             if (CC_UNLIKELY(!mWeakRef || (info && !info->updateWindowPositions))) return;
 
+            if (mPreviousPosition.isEmpty()) {
+                return;
+            }
+            mPreviousPosition.setEmpty();
+
             ATRACE_NAME("SurfaceView position lost");
             JNIEnv* env = jnienv();
             jobject localref = env->NewLocalRef(mWeakRef);
@@ -561,6 +571,7 @@ static void android_view_RenderNode_requestPositionUpdates(JNIEnv* env, jobject,
                 return;
             }
 
+            // TODO: Remember why this is synchronous and then make a comment
             env->CallVoidMethod(localref, gPositionListener_PositionLostMethod,
                     info ? info->canvasContext.getFrameNumber() : 0);
             env->DeleteLocalRef(localref);
@@ -596,10 +607,11 @@ static void android_view_RenderNode_requestPositionUpdates(JNIEnv* env, jobject,
 
         JavaVM* mVm;
         jobject mWeakRef;
+        uirenderer::Rect mPreviousPosition;
     };
 
     RenderNode* renderNode = reinterpret_cast<RenderNode*>(renderNodePtr);
-    renderNode->setPositionListener(new SurfaceViewPositionUpdater(env, surfaceview));
+    renderNode->setPositionListener(new PositionListenerTrampoline(env, listener));
 }
 
 // ----------------------------------------------------------------------------

tests/HwAccelerationTest/AndroidManifest.xml

@@ -1027,5 +1027,15 @@
             </intent-filter>
         </activity>
 
+        <activity
+            android:name="PositionListenerActivity"
+            android:label="RenderNode/PositionListener"
+            android:screenOrientation="fullSensor">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="com.android.test.hwui.TEST" />
+            </intent-filter>
+        </activity>
+
     </application>
 </manifest>

tests/HwAccelerationTest/src/com/android/test/hwui/PositionListenerActivity.java

@@ -0,0 +1,98 @@
+/*
+ * Copyright (C) 2010 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.test.hwui;
+
+import android.app.Activity;
+import android.content.Context;
+import android.graphics.Canvas;
+import android.graphics.RenderNode;
+import android.os.Bundle;
+import android.widget.LinearLayout;
+import android.widget.ProgressBar;
+import android.widget.ScrollView;
+import android.widget.TextView;
+
+@SuppressWarnings({"UnusedDeclaration"})
+public class PositionListenerActivity extends Activity {
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        final LinearLayout layout = new LinearLayout(this);
+        layout.setOrientation(LinearLayout.VERTICAL);
+
+        ProgressBar spinner = new ProgressBar(this, null, android.R.attr.progressBarStyleLarge);
+        layout.addView(spinner);
+
+        ScrollView scrollingThing = new ScrollView(this);
+        scrollingThing.addView(new MyPositionReporter(this));
+        layout.addView(scrollingThing);
+
+        setContentView(layout);
+    }
+
+    static class MyPositionReporter extends TextView implements RenderNode.PositionUpdateListener {
+        RenderNode mNode;
+        int mCurrentCount = 0;
+        int mTranslateY = 0;
+
+        MyPositionReporter(Context c) {
+            super(c);
+            mNode = new RenderNode("positionListener");
+            mNode.requestPositionUpdates(this);
+            setTextAlignment(TEXT_ALIGNMENT_VIEW_START);
+        }
+
+        @Override
+        protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
+            setMeasuredDimension(getMeasuredWidth(), 10000);
+        }
+
+        @Override
+        protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
+            mNode.setLeftTopRightBottom(left, top, right, bottom);
+        }
+
+        @Override
+        protected void onDraw(Canvas canvas) {
+            ScrollView parent = (ScrollView) getParent();
+            canvas.translate(0, parent.getScrollY());
+            super.onDraw(canvas);
+            canvas.translate(0, -parent.getScrollY());
+            // Inject our listener proxy
+            canvas.drawRenderNode(mNode);
+        }
+
+        @Override
+        public void positionChanged(long frameNumber, int left, int top, int right, int bottom) {
+            post(() -> {
+                mCurrentCount++;
+                setText(String.format("%d: Position [%d, %d, %d, %d]", mCurrentCount,
+                        left, top, right, bottom));
+            });
+        }
+
+        @Override
+        public void positionLost(long frameNumber) {
+            post(() -> {
+                mCurrentCount++;
+                setText(mCurrentCount + " No position");
+            });
+        }
+    }
+}