[Remoting Android] Refactor GlDesktopView

remoting/android/java/src/org/chromium/chromoting/Desktop.java

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.chromoting;
 
 import android.annotation.SuppressLint;
 import android.os.Build;
 import android.os.Bundle;
 import android.os.Handler;
 import android.support.v7.app.ActionBar.OnMenuVisibilityListener;
 import android.support.v7.app.AppCompatActivity;
 import android.support.v7.widget.Toolbar;
 import android.view.KeyEvent;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.view.MotionEvent;
 import android.view.View;
 import android.view.View.OnLayoutChangeListener;
 import android.view.View.OnTouchListener;
-import android.view.ViewGroup;
 import android.view.inputmethod.InputMethodManager;
 
 import org.chromium.chromoting.help.HelpContext;
 import org.chromium.chromoting.help.HelpSingleton;
 import org.chromium.chromoting.jni.Client;
 
 import java.util.List;
 
 /**
  * A simple screen that does nothing except display a DesktopView and notify it of rotations.
+ * It may be recreated for multiple times when the screen is rotated or the app is brought to the
+ * background.

[joedow, 2016/09/13 00:08:50]

Since you removed the attach/detach methods and this class has the same lifetime
as the activity, I don't think the additional comment is needed now.

[Yuwei, 2016/09/13 01:42:26]

Removed.

Actually this is the activity class...

  */
 public class Desktop
         extends AppCompatActivity implements View.OnSystemUiVisibilityChangeListener,
                                              CapabilityManager.CapabilitiesChangedListener {
     /** Used to set/store the selected input mode. */
     public enum InputMode {
         UNKNOWN,
         TRACKPAD,
         TOUCH;
 
@@ skipping 28 matching lines @@
     /** The Toolbar instance backing our SupportActionBar. */
     private Toolbar mToolbar;
 
     /** Tracks the current input mode (e.g. trackpad/touch). */
     private InputMode mInputMode = InputMode.UNKNOWN;
 
     /** Indicates whether the remote host supports touch injection. */
     private CapabilityManager.HostCapability mHostTouchCapability =
             CapabilityManager.HostCapability.UNKNOWN;
 
+    private DesktopView mRemoteHostDesktop;
+
     /** Called when the activity is first created. */
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.desktop);
 
         mClient = Client.getInstance();
         mInjector = new InputEventSender(mClient);
 
+        Preconditions.notNull(mClient);
+
         mToolbar = (Toolbar) findViewById(R.id.toolbar);
         setSupportActionBar(mToolbar);
 
-        DesktopView remoteHostDesktop = mClient.createDesktopView(this, mClient);
-        remoteHostDesktop.setLayoutParams(new ViewGroup.LayoutParams(
-                ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
-        ((ViewGroup) findViewById(R.id.desktop_view_placeholder)).addView(remoteHostDesktop);
+        mRemoteHostDesktop = (DesktopView) findViewById(R.id.desktop_view);
+        mRemoteHostDesktop.init(mClient, this, mClient.getRenderStub());
 
         getSupportActionBar().setDisplayShowTitleEnabled(false);
         getSupportActionBar().setDisplayHomeAsUpEnabled(true);
 
         // For this Activity, the home button in the action bar acts as a Disconnect button, so
         // set the description for accessibility/screen readers.
         getSupportActionBar().setHomeActionContentDescription(R.string.disconnect_myself_button);
 
         // The action bar is already shown when the activity is started however calling the
         // function below will set our preferred system UI flags which will adjust the layout
@@ skipping 27 matching lines @@
             getSupportActionBar().addOnMenuVisibilityListener(new OnMenuVisibilityListener() {
                 public void onMenuVisibilityChanged(boolean isVisible) {
                     if (isVisible) {
                         stopActionBarAutoHideTimer();
                     } else {
                         startActionBarAutoHideTimer();
                     }
                 }
             });
         } else {
-            remoteHostDesktop.setFitsSystemWindows(true);
+            mRemoteHostDesktop.setFitsSystemWindows(true);
         }
     }
 
     @Override
     protected void onStart() {
         super.onStart();
         mActivityLifecycleListener.onActivityStarted(this);
         mClient.enableVideoChannel(true);
         mClient.getCapabilityManager().addListener(this);
     }
@@ skipping 379 matching lines @@
     @Override
     public boolean dispatchKeyEvent(KeyEvent event) {
         if (event.getKeyCode() == KeyEvent.KEYCODE_BACK) {
             mClient.destroy();
             return super.dispatchKeyEvent(event);
         }
 
         return mInjector.sendKeyEvent(event);
     }
 }