Draw the mouse cursor in Chromoting Android client

remoting/android/java/src/org/chromium/chromoting/jni/JniInterface.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.jni;
 
 import android.app.Activity;
 import android.app.AlertDialog;
 import android.app.ProgressDialog;
 import android.content.Context;
 import android.content.DialogInterface;
 import android.content.SharedPreferences;
 import android.graphics.Bitmap;
+import android.graphics.Point;
 import android.os.Looper;
 import android.text.InputType;
 import android.util.Log;
 import android.view.KeyEvent;
 import android.view.View;
 import android.view.inputmethod.EditorInfo;
 import android.widget.CheckBox;
 import android.widget.TextView;
 import android.widget.Toast;
 
@@ skipping 92 matching lines @@
         sConnected = false;
     }
 
     /** Performs the native portion of the connection. */
     private static native void connectNative(String username, String authToken, String hostJid,
             String hostId, String hostPubkey, String pairId, String pairSecret);
 
     /** Performs the native portion of the cleanup. */
     private static native void disconnectNative();
 
+    /** Position of cursor hotspot within cursor image. */
+    public static Point getCursorHotspot() { return sCursorHotspot; }
+
+    /** Returns the current cursor shape. */
+    public static Bitmap getCursorBitmap() { return sCursorBitmap; }
+
     /*
      * Entry points *from* the native code.
      */
     /** Callback to signal whenever we need to redraw. */
     private static Runnable sRedrawCallback = null;
 
     /** Screen width of the video feed. */
     private static int sWidth = 0;
 
     /** Screen height of the video feed. */
     private static int sHeight = 0;
 
     /** Buffer holding the video feed. */
     private static ByteBuffer sBuffer = null;
 
+    /** Position of cursor hot-spot. */
+    private static Point sCursorHotspot = new Point();
+
+    /** Bitmap holding the cursor shape. */
+    private static Bitmap sCursorBitmap = null;
+
     /** Reports whenever the connection status changes. */
     private static void reportConnectionStatus(int state, int error) {
         if (state < SUCCESSFUL_CONNECTION && error == 0) {
             // The connection is still being established, so we'll report the current progress.
             synchronized (JniInterface.class) {
                 if (sProgressIndicator == null) {
                     sProgressIndicator = ProgressDialog.show(sContext, sContext.
                             getString(R.string.progress_title), sContext.getResources().
                             getStringArray(R.array.protoc_states)[state], true, true,
                             new DialogInterface.OnCancelListener() {
@@ skipping 147 matching lines @@
         }
 
         int[] frame = new int[sWidth * sHeight];
 
         sBuffer.order(ByteOrder.LITTLE_ENDIAN);
         sBuffer.asIntBuffer().get(frame, 0, frame.length);
 
         return Bitmap.createBitmap(frame, 0, sWidth, sWidth, sHeight, Bitmap.Config.ARGB_8888);
     }
 
+    /**
+     * Updates the cursor shape. This is called from native code on the graphics thread when
+     * receiving a new cursor shape from the host.
+     */
+    public static void updateCursorShape(int width, int height, int hotspotX, int hotspotY,
+                                         ByteBuffer buffer) {
+        sCursorHotspot.x = hotspotX;

[Sergey Ulanov, 2013/09/14 02:21:29]

it's better to create a new Point instance here instead of mutating it in-place.
Problem is that caller or getCursorHotspot() may store result and wouldn't
expect it to be change.

Also you can use Point.set() to set x and y at the same time.

[solb, 2013/09/14 03:44:42]

I think Sergey brings up a good point here.

[Lambros, 2013/09/16 21:52:58]

Done.

+        sCursorHotspot.y = hotspotY;
+
+        int[] data = new int[width * height];
+        buffer.order(ByteOrder.LITTLE_ENDIAN);
+        buffer.asIntBuffer().get(data, 0, data.length);
+        sCursorBitmap = Bitmap.createBitmap(data, width, height, Bitmap.Config.ARGB_8888);
+    }
+
     /** Moves the mouse cursor, possibly while clicking the specified (nonnegative) button. */
     public static void mouseAction(int x, int y, int whichButton, boolean buttonDown) {
         if (!sConnected) {
             return;
         }
 
         mouseActionNative(x, y, whichButton, buttonDown);
     }
 
     /** Presses and releases the specified (nonnegative) key. */
@@ skipping 10 matching lines @@
 
     /** Schedules a redraw on the native graphics thread. */
     private static native void scheduleRedrawNative();
 
     /** Passes mouse information to the native handling code. */
     private static native void mouseActionNative(int x, int y, int whichButton, boolean buttonDown);
 
     /** Passes key press information to the native handling code. */
     private static native void keyboardActionNative(int keyCode, boolean keyDown);
 }