AppRTCDemo(android): run in full-screen & immersive mode.

Also:
- Only show stats HUD on demand
- Only collect stats when HUD is showing
- Don't render solid green frame when video is not present in either direction

R=glaznev@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/12639004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6275 4adac7df-926f-26a2-2b94-8c16560cd09d

talk/examples/android/src/org/appspot/apprtc/AppRTCDemoActivity.java

@@ -109,7 +109,7 @@ public class AppRTCDemoActivity extends Activity
     getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
 
     Point displaySize = new Point();
-    getWindowManager().getDefaultDisplay().getSize(displaySize);
+    getWindowManager().getDefaultDisplay().getRealSize(displaySize);
     vsv = new VideoStreamsView(this, displaySize);
     vsv.setOnClickListener(new View.OnClickListener() {
         @Override public void onClick(View v) {
@@ -117,11 +117,14 @@ public class AppRTCDemoActivity extends Activity
         }
       });
     setContentView(vsv);
+    logAndToast("Tap the screen to toggle stats visibility");
+
     hudView = new TextView(this);
     hudView.setTextColor(Color.BLACK);
     hudView.setBackgroundColor(Color.WHITE);
     hudView.setAlpha(0.4f);
     hudView.setTextSize(TypedValue.COMPLEX_UNIT_PT, 5);
+    hudView.setVisibility(View.INVISIBLE);
     addContentView(hudView, hudLayout);
 
     if (!factoryStaticInitialized) {
@@ -189,9 +192,6 @@ public class AppRTCDemoActivity extends Activity
 
   // Update the heads-up display with information from |reports|.
   private void updateHUD(StatsReport[] reports) {
-    if (hudView.getText().length() == 0) {
-      logAndToast("Tap the screen to toggle stats visibility");
-    }
     StringBuilder builder = new StringBuilder();
     for (StatsReport report : reports) {
       if (!report.id.equals("bweforvideo")) {
@@ -264,6 +264,10 @@ public class AppRTCDemoActivity extends Activity
                 return;
               }
               final Runnable runnableThis = this;
+              if (hudView.getVisibility() == View.INVISIBLE) {
+                vsv.postDelayed(runnableThis, 1000);
+                return;
+              }
               boolean success = finalPC.getStats(new StatsObserver() {
                   public void onComplete(final StatsReport[] reports) {
                     runOnUiThread(new Runnable() {

talk/examples/android/src/org/appspot/apprtc/VideoStreamsView.java

@@ -40,6 +40,7 @@ import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
 import java.nio.FloatBuffer;
 import java.util.EnumMap;
+import java.util.EnumSet;
 
 import javax.microedition.khronos.egl.EGLConfig;
 import javax.microedition.khronos.opengles.GL10;
@@ -64,6 +65,8 @@ public class VideoStreamsView
   private Point screenDimensions;
   // [0] are local Y,U,V, [1] are remote Y,U,V.
   private int[][] yuvTextures = { { -1, -1, -1}, {-1, -1, -1 }};
+  private EnumSet<Endpoint> seenFrameInDirection =
+      EnumSet.noneOf(Endpoint.class);
   private int posLocation = -1;
   private long lastFPSLogTime = System.nanoTime();
   private long numFramesSinceLastLog = 0;
@@ -115,10 +118,12 @@ public class VideoStreamsView
       remoteFrame = framesToRender.remove(Endpoint.REMOTE);
     }
     if (localFrame != null) {
+      seenFrameInDirection.add(Endpoint.LOCAL);
       texImage2D(localFrame, yuvTextures[0]);
       framePool.returnFrame(localFrame);
     }
     if (remoteFrame != null) {
+      seenFrameInDirection.add(Endpoint.REMOTE);
       texImage2D(remoteFrame, yuvTextures[1]);
       framePool.returnFrame(remoteFrame);
     }
@@ -167,8 +172,12 @@ public class VideoStreamsView
   @Override
   public void onDrawFrame(GL10 unused) {
     GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
+    if (seenFrameInDirection.contains(Endpoint.REMOTE)) {
       drawRectangle(yuvTextures[1], remoteVertices);
+    }
+    if (seenFrameInDirection.contains(Endpoint.LOCAL)) {
       drawRectangle(yuvTextures[0], localVertices);
+    }
     ++numFramesSinceLastLog;
     long now = System.nanoTime();
     if (lastFPSLogTime == -1 || now - lastFPSLogTime > 1e9) {
@@ -210,6 +219,13 @@ public class VideoStreamsView
     checkNoGLES2Error();
   }
 
+  @Override
+  protected void onAttachedToWindow() {
+    super.onAttachedToWindow();
+    setSystemUiVisibility(SYSTEM_UI_FLAG_HIDE_NAVIGATION |
+        SYSTEM_UI_FLAG_FULLSCREEN | SYSTEM_UI_FLAG_IMMERSIVE_STICKY);
+  }
+
   // Wrap a float[] in a direct FloatBuffer using native byte order.
   private static FloatBuffer directNativeFloatBuffer(float[] array) {
     FloatBuffer buffer = ByteBuffer.allocateDirect(array.length * 4).order(