[Android Client] Break down multi-threaded classes by thread

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.graphics.Bitmap;
-import android.graphics.Point;
-import android.os.Looper;
-
-import org.chromium.base.Log;
 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.SessionAuthenticator;
 
-import java.nio.ByteBuffer;
-import java.nio.ByteOrder;
-
 /**
  * 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.
  */
 @JNINamespace("remoting")
 public class Client {
-    private static final String TAG = "Chromoting";
-
     // Pointer to the C++ object, cast to a |long|.
     private long mNativeJniClient;
 
+    // Reference has to be kept until the lifecycle of Client ends. Code may use getDisplay()
+    // without doing a null check.
+    private Display mDisplay;
+
     // 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;
 
     // Called on the UI thread.

[Lambros, 2016/05/28 00:43:05]

If everything is called on the UI thread, you can remove all these comments
about UI thread, and instead just have a single comment near the top saying this
class is used on the UI thread.

[Yuwei, 2016/06/01 21:30:10]

Done.

     public Client() {
         if (sClient != null) {
             throw new RuntimeException("Client instance already created.");
         }
 
         sClient = this;
         mNativeJniClient = nativeInit();
     }
 
+    /**
+     *

[Lambros, 2016/05/28 00:43:05]

Better to provide a JavaDoc one-sentence summary, even if it is just:
Returns the display object.

[Yuwei, 2016/06/01 21:30:10]

Done.

+     * @return the display object. It will be null before calling connectToHost() but won't be null
+     *          after calling disconnectFromHost().
+     */
+    public Display getDisplay() {
+        return mDisplay;
+    }
+
     // Called on the UI thread. 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;
         }
     }
 
     /** Returns the current Client instance, or null. */
     public static Client getInstance() {
         return sClient;
     }
 
     /** Used for authentication-related UX during connection. Accessed on the UI thread. */
     private SessionAuthenticator mAuthenticator;
 
     /** Whether the native code is attempting a connection. Accessed on the UI thread. */
     private boolean mConnected;
 
     /** Notified upon successful connection or disconnection. Accessed on the UI thread. */
     private ConnectionListener mConnectionListener;
 
-    /**
-     * Callback invoked on the graphics thread to repaint the desktop. Accessed on the UI and
-     * graphics threads.
-     */
-    private Runnable mRedrawCallback;
-
-    /** Bitmap holding a copy of the latest video frame. Accessed on the UI and graphics threads. */
-    private Bitmap mFrameBitmap;
-
-    /** Protects access to {@link mFrameBitmap}. */
-    private final Object mFrameLock = new Object();
-
-    /** Position of cursor hot-spot. Accessed on the graphics thread. */
-    private Point mCursorHotspot = new Point();
-
-    /** Bitmap holding the cursor shape. Accessed on the graphics thread. */
-    private Bitmap mCursorBitmap;
-
     /** Capability Manager through which capabilities and extensions are handled. */
     private CapabilityManager mCapabilityManager = new CapabilityManager();
 
     public CapabilityManager getCapabilityManager() {
         return mCapabilityManager;
     }
 
     /** Returns whether the client is connected. */
     public boolean isConnected() {
         return mConnected;
     }
 
     /** Attempts to form a connection to the user-selected host. Called on the UI thread. */
     public void connectToHost(String username, String authToken, String hostJid,
             String hostId, String hostPubkey, SessionAuthenticator authenticator, String flags,
             ConnectionListener listener) {
         disconnectFromHost();
 
         mConnectionListener = listener;
         mAuthenticator = authenticator;
-        nativeConnect(mNativeJniClient, username, authToken, hostJid, hostId, hostPubkey,
-                mAuthenticator.getPairingId(hostId), mAuthenticator.getPairingSecret(hostId),
-                mCapabilityManager.getLocalCapabilities(), flags);
+        mDisplay = new Display();
+        nativeConnect(mNativeJniClient, mDisplay.getNativePointer(), username, authToken, hostJid,
+                hostId, hostPubkey, mAuthenticator.getPairingId(hostId),
+                mAuthenticator.getPairingSecret(hostId), mCapabilityManager.getLocalCapabilities(),
+                flags);
         mConnected = true;
     }
 
     /** Severs the connection and cleans up. Called on the UI thread. */
     public void disconnectFromHost() {
         if (!mConnected) {
             return;
         }
 
         mConnectionListener.onConnectionState(
                 ConnectionListener.State.CLOSED, ConnectionListener.Error.OK);
 
         disconnectFromHostWithoutNotification();
     }
 
     /** Same as disconnectFromHost() but without notifying the ConnectionListener. */
     private void disconnectFromHostWithoutNotification() {
         if (!mConnected) {
             return;
         }
 
         nativeDisconnect(mNativeJniClient);
         mConnectionListener = null;
         mConnected = false;
         mCapabilityManager.onHostDisconnect();
 
-        // Drop the reference to free the Bitmap for GC.
-        synchronized (mFrameLock) {
-            mFrameBitmap = null;
-        }
+        mDisplay.destroy();
     }
 
     /** Called on the UI thread whenever the connection status changes. */
     @CalledByNative
     void onConnectionState(int stateCode, int errorCode) {
         ConnectionListener.State state = ConnectionListener.State.fromValue(stateCode);
         ConnectionListener.Error error = ConnectionListener.Error.fromValue(errorCode);
         mConnectionListener.onConnectionState(state, error);
         if (state == ConnectionListener.State.FAILED || state == ConnectionListener.State.CLOSED) {
             // Disconnect from the host here, otherwise the next time connectToHost() is called,
@@ skipping 91 matching lines @@
      * lifecycle events.
      */
     public void enableVideoChannel(boolean enable) {
         if (!mConnected) {
             return;
         }
 
         nativeEnableVideoChannel(mNativeJniClient, enable);
     }
 
-    /**
-     * Sets the redraw callback to the provided functor. Provide a value of null whenever the
-     * window is no longer visible so that we don't continue to draw onto it. Called on the UI
-     * thread.
-     */
-    public void provideRedrawCallback(Runnable redrawCallback) {
-        mRedrawCallback = redrawCallback;
-    }
-
-    /** Forces the native graphics thread to redraw to the canvas. Called on the UI thread. */
-    public boolean redrawGraphics() {
-        if (!mConnected || mRedrawCallback == null) return false;
-
-        nativeScheduleRedraw(mNativeJniClient);
-        return true;
-    }
-
-    /**
-     * Called on the graphics thread to perform the redrawing callback requested by
-     * {@link #redrawGraphics}. This is a no-op if the window isn't visible (the callback is null).
-     */
-    @CalledByNative
-    void redrawGraphicsInternal() {
-        Runnable callback = mRedrawCallback;
-        if (callback != null) {
-            callback.run();
-        }
-    }
-
-    /**
-     * Returns a bitmap of the latest video frame. Called on the native graphics thread when
-     * DesktopView is repainted.
-     */
-    public Bitmap getVideoFrame() {
-        if (Looper.myLooper() == Looper.getMainLooper()) {
-            Log.w(TAG, "Canvas being redrawn on UI thread");
-        }
-
-        synchronized (mFrameLock) {
-            return mFrameBitmap;
-        }
-    }
-
-    /**
-     * Set a new video frame. Called on the native graphics thread when a new frame is allocated.
-     */
-    @CalledByNative
-    void setVideoFrame(Bitmap bitmap) {
-        if (Looper.myLooper() == Looper.getMainLooper()) {
-            Log.w(TAG, "Video frame updated on UI thread");
-        }
-
-        synchronized (mFrameLock) {
-            mFrameBitmap = bitmap;
-        }
-    }
-
-    /**
-     * Creates a new Bitmap to hold video frame pixels. The returned Bitmap is referenced by native
-     * code which writes the decoded frame pixels to it.
-     */
-    @CalledByNative
-    static Bitmap newBitmap(int width, int height) {
-        return Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
-    }
-
-    /**
-     * Updates the cursor shape. This is called on the graphics thread when receiving a new cursor
-     * shape from the host.
-     */
-    @CalledByNative
-    void updateCursorShape(int width, int height, int hotspotX, int hotspotY, ByteBuffer buffer) {
-        mCursorHotspot = new Point(hotspotX, hotspotY);
-
-        int[] data = new int[width * height];
-        buffer.order(ByteOrder.LITTLE_ENDIAN);
-        buffer.asIntBuffer().get(data, 0, data.length);
-        mCursorBitmap = Bitmap.createBitmap(data, width, height, Bitmap.Config.ARGB_8888);
-    }
-
-    /** Position of cursor hotspot within cursor image. Called on the graphics thread. */
-    public Point getCursorHotspot() {
-        return mCursorHotspot;
-    }
-
-    /** Returns the current cursor shape. Called on the graphics thread. */
-    public Bitmap getCursorBitmap() {
-        return mCursorBitmap;
-    }
-
     //
     // Third Party Authentication
     //
 
     /**
      * Pops up a third party login page to fetch the token required for authentication.
      */
     @CalledByNative
     void fetchThirdPartyToken(String tokenUrl, String clientId, String scope) {
         mAuthenticator.fetchThirdPartyToken(tokenUrl, clientId, scope);
@@ skipping 42 matching lines @@
         }
 
         nativeSendExtensionMessage(mNativeJniClient, type, data);
     }
 
     private native long nativeInit();
 
     private native void nativeDestroy(long nativeJniClient);
 
     /** Performs the native portion of the connection. */
-    private native void nativeConnect(long nativeJniClient, String username, String authToken,
-            String hostJid, String hostId, String hostPubkey, String pairId, String pairSecret,
-            String capabilities, String flags);
+    private native void nativeConnect(long nativeJniClient, long nativeJniDisplayHandler,
+            String username, String authToken, String hostJid, String hostId, String hostPubkey,
+            String pairId, String pairSecret, String capabilities, String flags);
 
     /** Native implementation of Client.handleAuthenticationResponse(). */
     private native void nativeAuthenticationResponse(
             long nativeJniClient, String pin, boolean createPair, String deviceName);
 
     /** Performs the native portion of the cleanup. */
     private native void nativeDisconnect(long nativeJniClient);
 
-    /** Schedules a redraw on the native graphics thread. */
-    private native void nativeScheduleRedraw(long nativeJniClient);
-
     /** Passes authentication data to the native handling code. */
     private native void nativeOnThirdPartyTokenFetched(
             long nativeJniClient, String token, String sharedSecret);
 
     /** Passes mouse information to the native handling code. */
     private native void nativeSendMouseEvent(
             long nativeJniClient, int x, int y, int whichButton, boolean buttonDown);
 
     /** Passes mouse-wheel information to the native handling code. */
     private native void nativeSendMouseWheelEvent(long nativeJniClient, int deltaX, int deltaY);
 
     /** Passes key press information to the native handling code. */
     private native boolean nativeSendKeyEvent(
             long nativeJniClient, int scanCode, int keyCode, boolean keyDown);
 
     /** Passes text event information to the native handling code. */
     private native void nativeSendTextEvent(long nativeJniClient, String text);
 
     /** 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);
 }