Refactor Chromoting JNI code to use jni/Client (Java changes only).

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.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;
 
-    public void init() {
+    // 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.
+    public Client() {
+        if (sClient != null) {
+            throw new RuntimeException("Client instance already created.");
+        }
+
+        sClient = this;
         mNativeJniClient = nativeInit();
     }
 
     private native long nativeInit();
 
+    // 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() {
-        nativeDestroy(mNativeJniClient);
+        if (sClient != null) {
+            disconnectFromHost();
+            nativeDestroy(mNativeJniClient);
+            sClient = null;
+        }
     }
 
     private native void nativeDestroy(long nativeJniClient);
+
+    /** 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;
+        JniInterface.nativeConnect(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;
+        }
+
+        JniInterface.nativeDisconnect();
+        mConnectionListener = null;
+        mConnected = false;
+        mCapabilityManager.onHostDisconnect();
+
+        // Drop the reference to free the Bitmap for GC.
+        synchronized (mFrameLock) {
+            mFrameBitmap = null;
+        }
+    }
+
+    /** Called by native code whenever the connection status changes. Called on the UI thread. */
+    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,
+            // it will try to disconnect, triggering an incorrect status notification.
+
+            // TODO(lambroslambrou): Connection state notifications for separate sessions should
+            // go to separate Client instances. Once this is true, we can remove this line and
+            // simplify the disconnectFromHost() code.
+            disconnectFromHostWithoutNotification();
+        }
+    }
+
+    /**
+     * Called by JniInterface (from native code) to prompt the user to enter a PIN. Called on the
+     * UI thread.
+     */
+    void displayAuthenticationPrompt(boolean pairingSupported) {
+        mAuthenticator.displayAuthenticationPrompt(pairingSupported);
+    }
+
+    /**
+     * Called by the SessionAuthenticator after the user enters a PIN.
+     * @param pin The entered PIN.
+     * @param createPair Whether to create a new pairing for this client.
+     * @param deviceName The device name to appear in the pairing registry. Only used if createPair
+     *                   is true.
+     */
+    public void handleAuthenticationResponse(
+            String pin, boolean createPair, String deviceName) {
+        assert mConnected;
+        JniInterface.nativeAuthenticationResponse(pin, createPair, deviceName);
+    }
+
+    /**
+     * Called by JniInterface (from native code), to save newly-received pairing credentials to
+     * permanent storage. Called on the UI thread.
+     */
+    void commitPairingCredentials(String host, String id, String secret) {
+        mAuthenticator.commitPairingCredentials(host, id, secret);
+    }
+
+    /**
+     * Moves the mouse cursor, possibly while clicking the specified (nonnegative) button. Called
+     * on the UI thread.
+     */
+    public void sendMouseEvent(int x, int y, int whichButton, boolean buttonDown) {
+        if (!mConnected) {
+            return;
+        }
+
+        JniInterface.nativeSendMouseEvent(x, y, whichButton, buttonDown);
+    }
+
+    /** Injects a mouse-wheel event with delta values. Called on the UI thread. */
+    public void sendMouseWheelEvent(int deltaX, int deltaY) {
+        if (!mConnected) {
+            return;
+        }
+
+        JniInterface.nativeSendMouseWheelEvent(deltaX, deltaY);
+    }
+
+    /**
+     * Presses or releases the specified key. Called on the UI thread. If scanCode is not zero then
+     * keyCode is ignored.
+     */
+    public boolean sendKeyEvent(int scanCode, int keyCode, boolean keyDown) {
+        if (!mConnected) {
+            return false;
+        }
+
+        return JniInterface.nativeSendKeyEvent(scanCode, keyCode, keyDown);
+    }
+
+    /** Sends TextEvent to the host. Called on the UI thread. */
+    public void sendTextEvent(String text) {
+        if (!mConnected) {
+            return;
+        }
+
+        JniInterface.nativeSendTextEvent(text);
+    }
+
+    /** Sends an array of TouchEvents to the host. Called on the UI thread. */
+    public void sendTouchEvent(TouchEventData.EventType eventType, TouchEventData[] data) {
+        if (!mConnected) {
+            return;
+        }
+
+        JniInterface.nativeSendTouchEvent(eventType.value(), data);
+    }
+
+    /**
+     * Enables or disables the video channel. Called on the UI thread in response to Activity
+     * lifecycle events.
+     */
+    public void enableVideoChannel(boolean enable) {
+        if (!mConnected) {
+            return;
+        }
+
+        JniInterface.nativeEnableVideoChannel(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;
+
+        JniInterface.nativeScheduleRedraw();
+        return true;
+    }
+
+    /**
+     * Called by JniInterface to perform the redrawing callback requested by
+     * {@link #redrawGraphics}. This is a no-op if the window isn't visible (the callback is null).
+     * Called on the graphics thread.
+     */
+    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;
+        }
+    }
+
+    /**
+     * Called by JniInterface (from native code) to set a new video frame. Called on the native
+     * graphics thread when a new frame is allocated.
+     */
+    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. Called by JniInterface (from native code),
+     * and the returned Bitmap is referenced by native code which writes the decoded frame pixels
+     * to it.
+     */
+    static Bitmap newBitmap(int width, int height) {
+        return Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
+    }
+
+    /**
+     * Called by JniInterface (from native code) to update the cursor shape. This is called on the
+     * graphics thread when receiving a new cursor shape from the host.
+     */
+    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
+    //
+
+    /**
+     * Called by JniInterface (from native code), to pop up a third party login page to fetch the
+     * token required for authentication.
+     */
+    void fetchThirdPartyToken(String tokenUrl, String clientId, String scope) {
+        mAuthenticator.fetchThirdPartyToken(tokenUrl, clientId, scope);
+    }
+
+    /**
+     * Called by the SessionAuthenticator to pass the |token| and |sharedSecret| to native code to
+     * continue authentication.
+     */
+    public void onThirdPartyTokenFetched(String token, String sharedSecret) {
+        if (!mConnected) {
+            return;
+        }
+
+        JniInterface.nativeOnThirdPartyTokenFetched(token, sharedSecret);
+    }
+
+    //
+    // Host and Client Capabilities
+    //
+
+    /**
+     * Called by JniInterface (from native code) to set the list of negotiated capabilities between
+     * host and client. Called on the UI thread.
+     */
+    void setCapabilities(String capabilities) {
+        mCapabilityManager.setNegotiatedCapabilities(capabilities);
+    }
+
+    //
+    // Extension Message Handling
+    //
+
+    /**
+     * Called by JniInterface (from native code), to pass on the deconstructed ExtensionMessage to
+     * the app. Called on the UI thread.
+     */
+    void handleExtensionMessage(String type, String data) {
+        mCapabilityManager.onExtensionMessage(type, data);
+    }
+
+    /** Sends an extension message to the Chromoting host. Called on the UI thread. */
+    public void sendExtensionMessage(String type, String data) {
+        if (!mConnected) {
+            return;
+        }
+
+        JniInterface.nativeSendExtensionMessage(type, data);
+    }
 }