[Remoting Android] Refactor GlDesktopView

remoting/android/java/src/org/chromium/chromoting/jni/Client.java

 // Copyright 2015 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.jni;
 
-import android.content.Context;
-
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.annotations.JNINamespace;
 import org.chromium.base.annotations.SuppressFBWarnings;
 import org.chromium.chromoting.CapabilityManager;
-import org.chromium.chromoting.Desktop;
-import org.chromium.chromoting.DesktopView;
-import org.chromium.chromoting.DesktopViewFactory;
 import org.chromium.chromoting.InputStub;
-import org.chromium.chromoting.Preconditions;
+import org.chromium.chromoting.RenderStub;
 import org.chromium.chromoting.SessionAuthenticator;
 
 /**
  * Class to manage a client connection to the host. This class controls the lifetime of the
  * corresponding C++ object which implements the connection. A new object should be created for
  * each connection to the host, so that notifications from a connection are always sent to the
  * right object.
  * This class is used entirely on the UI thread.
  */
 @JNINamespace("remoting")
 public class Client implements InputStub {
     // Pointer to the C++ object, cast to a |long|.
-    private long mNativeJniClient;
+    private final long mNativeJniClient;
 
-    // The factory to create implementation-dependent desktop view.
-    private DesktopViewFactory mDesktopViewFactory;
+    private RenderStub mRenderStub;
 
     // The global Client instance (may be null). This needs to be a global singleton so that the
     // Client can be passed between Activities.
     private static Client sClient;
 
     public Client() {
         if (sClient != null) {
             throw new RuntimeException("Client instance already created.");
         }
 
         sClient = this;
         mNativeJniClient = nativeInit();
     }
 
-    /**
-     * Sets the desktop view factory to be used by {@link Client#createDesktopView(Context)}.
-     * @param factory The factory to create implementation-dependent desktop view.
-     */
-    public void setDesktopViewFactory(DesktopViewFactory factory) {
-        mDesktopViewFactory = factory;
-    }
-
-    /**
-     * Creates an implementation specific {@link DesktopView} using the
-     * {@link DesktopViewFactory} set by {@link Client#setDesktopViewFactory(DesktopViewFactory)}.
-     */
-    public DesktopView createDesktopView(Desktop desktop, Client client) {
-        Preconditions.notNull(mDesktopViewFactory);
-        return mDesktopViewFactory.createDesktopView(desktop, client);
-    }
-
     // Suppress FindBugs warning, since |sClient| is only used on the UI thread.
     @SuppressFBWarnings("LI_LAZY_INIT_STATIC")
     public void destroy() {
         if (sClient != null) {
             disconnectFromHost();
             nativeDestroy(mNativeJniClient);
             sClient = null;
         }
     }
 
+    public void setRenderStub(RenderStub stub) {
+        mRenderStub = stub;

[Hzj_jie, 2016/09/10 02:06:32]

Add Preconditions here. If I have made a mistake, this is an one-off function.

[Yuwei, 2016/09/12 18:56:14]

Done.

BTW why is the Precondition implemented by throwing exceptions instead of doing
asserts?

[Hzj_jie, 2016/09/12 21:28:04]

In Java, assertions take effect only with -ea option on java command, or
debug.assert == 1 in Android. Otherwise it won't evaluate the expression.
http://stackoverflow.com/questions/2364910/can-i-use-assert-on-android-devices
But throwing exceptions is a safer way to ensure the expression always being
evaluated.
This implementation is copied from guava, a Google java library, @
https://github.com/google/guava/blob/master/guava/src/com/google/common/base/....

[Yuwei, 2016/09/12 21:50:04]

Acknowledged.

+    }
+
+    public RenderStub getRenderStub() {

[Hzj_jie, 2016/09/10 02:06:32]

And here.

[Yuwei, 2016/09/12 18:56:14]

Done.

+        return mRenderStub;
+    }
+
     /** Returns the current Client instance, or null. */
     public static Client getInstance() {

[Hzj_jie, 2016/09/10 02:06:32]

Suggest to add a Preconditions.notNull here, and update the comment. Consumer
(Desktop activity) always assumes it returns a valid instance.

[Yuwei, 2016/09/12 18:56:13]

I think it may make more sense to check it in Desktop, since this function might
be useful in the future for checking whether the instance has been created.

[Hzj_jie, 2016/09/12 21:28:04]

Yes, both OK.

         return sClient;
     }
 
     /** Used for authentication-related UX during connection. */
     private SessionAuthenticator mAuthenticator;
 
     /** Whether the native code is attempting a connection. */
     private boolean mConnected;
 
     /** Notified upon successful connection or disconnection. */
@@ skipping 251 matching lines @@
     /** Passes touch event information to the native handling code. */
     private native void nativeSendTouchEvent(
             long nativeJniClient, int eventType, TouchEventData[] data);
 
     /** Native implementation of Client.enableVideoChannel() */
     private native void nativeEnableVideoChannel(long nativeJniClient, boolean enable);
 
     /** Passes extension message to the native code. */
     private native void nativeSendExtensionMessage(long nativeJniClient, String type, String data);
 }