[Remoting Android] Support for resizing host to fit client resolution

This CL adds support for Android client to resize host to fit client
resolution.

Bug: 874626
Change-Id: I9c3c8139eab20834e79deb2ce662a8ab1234b09c
Reviewed-on: https://chromium-review.googlesource.com/1182187Reviewed-by: Joe Downing <joedow@chromium.org>
Commit-Queue: Yuwei Huang <yuweih@chromium.org>
Cr-Commit-Position: refs/heads/master@{#585358}

remoting/android/java/res/menu/desktop_actionbar.xml

@@ -27,6 +27,10 @@
     <item android:id="@+id/actionbar_send_ctrl_alt_del"
             android:title="@string/send_ctrl_alt_del"
             app:showAsAction="withText"/>
+    <item android:id="@+id/resize_to_client"
+        android:checkable="true"
+        android:title="@string/resize_to_client"
+        app:showAsAction="never|withText"/>
     <item android:id="@+id/actionbar_disconnect"
             android:title="@string/disconnect_myself_button"
             app:showAsAction="withText"/>

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

@@ -12,6 +12,7 @@ import android.graphics.PorterDuff;
 import android.graphics.drawable.Drawable;
 import android.net.Uri;
 import android.support.v4.content.ContextCompat;
+import android.util.DisplayMetrics;
 import android.util.TypedValue;
 import android.view.Menu;
 import android.view.MenuItem;
@@ -93,4 +94,16 @@ public abstract class ChromotingUtil {
     public static boolean openUrl(Activity parentActivity, Uri uri) {
         return startActivitySafely(parentActivity, new Intent(Intent.ACTION_VIEW, uri));
     }
+
+    /**
+     * Converts a measurement in px to dp (density independent pixel).
+     *
+     * @param metrics The metrics used for conversion.
+     * @param value The value in px to be converted.
+     * @return The converted result in dp.
+     */
+    public static int pxToDp(DisplayMetrics metrics, int value) {
+        // +0.5f to round up the result.
+        return (int) (value / metrics.density + 0.5f);
+    }
 }

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

@@ -15,6 +15,7 @@ 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.util.DisplayMetrics;
 import android.view.DisplayCutout;
 import android.view.KeyEvent;
 import android.view.Menu;
@@ -55,6 +56,7 @@ public class Desktop
 
     /** Preference used to track the last input mode selected by the user. */
     private static final String PREFERENCE_INPUT_MODE = "input_mode";
+    private static final String PREFERENCE_RESIZE_TO_CLIENT = "resize_to_client";
 
     /** The amount of time to wait to hide the ActionBar after user input is seen. */
     private static final int ACTIONBAR_AUTO_HIDE_DELAY_MS = 3000;
@@ -76,6 +78,9 @@ public class Desktop
     /** Indicates whether a Soft Input UI (such as a keyboard) is visible. */
     private boolean mSoftInputVisible = false;
 
+    /** Indicates whether resize-to-client is enabled. */
+    private boolean mResizeToClientEnabled = false;
+
     /** Holds the scheduled task object which will be called to hide the ActionBar. */
     private Runnable mActionBarAutoHideTask;
 
@@ -154,6 +159,7 @@ public class Desktop
         mActivityLifecycleListener.onActivityCreated(this, savedInstanceState);
 
         mInputMode = getInitialInputModeValue();
+        mResizeToClientEnabled = getStoredResizeToClientEnabled();
 
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
             attachSystemUiResizeListener();
@@ -283,6 +289,8 @@ public class Desktop
         // Wait to set the input mode until after the default tinting has been applied.
         setInputMode(mInputMode);
 
+        setResizeToClientEnabled(mResizeToClientEnabled);
+
         // Keyboard state must be set after the keyboard icon has been added to the menu.
         setKeyboardState(getResources().getConfiguration());
 
@@ -352,6 +360,26 @@ public class Desktop
                 new InputModeChangedEventParameter(mInputMode, mHostTouchCapability));
     }
 
+    private boolean getStoredResizeToClientEnabled() {
+        return getPreferences(MODE_PRIVATE).getBoolean(PREFERENCE_RESIZE_TO_CLIENT, false);
+    }
+
+    private void setResizeToClientEnabled(boolean resizeToClientEnabled) {
+        mResizeToClientEnabled = resizeToClientEnabled;
+        Menu menu = mToolbar.getMenu();
+        MenuItem resizeToClientMenuItem = menu.findItem(R.id.resize_to_client);
+        resizeToClientMenuItem.setChecked(mResizeToClientEnabled);
+        if (mResizeToClientEnabled != getStoredResizeToClientEnabled()) {
+            getPreferences(MODE_PRIVATE)
+                    .edit()
+                    .putBoolean(PREFERENCE_RESIZE_TO_CLIENT, mResizeToClientEnabled)
+                    .apply();
+        }
+        if (mResizeToClientEnabled) {
+            sendPreferredHostResolution();
+        }
+    }
+
     @Override
     public void onCapabilitiesChanged(List<String> newCapabilities) {
         if (newCapabilities.contains(Capabilities.TOUCH_CAPABILITY)) {
@@ -600,6 +628,9 @@ public class Desktop
             mInjector.sendCtrlAltDel();
             return true;
         }
+        if (id == R.id.resize_to_client) {
+            setResizeToClientEnabled(!item.isChecked());
+        }
         if (id == R.id.actionbar_help) {
             HelpSingleton.getInstance().launchHelp(this, HelpContext.DESKTOP);
             return true;
@@ -669,6 +700,25 @@ public class Desktop
         });
     }
 
+    /**
+     * Sends preferred resolution to the host that matches the aspect ratio of the screen. This is
+     * calculated by the size of the DesktopView minus the safe insets.
+     * This method does nothing if resize-to-client has not been enabled by the user.
+     */
+    public void sendPreferredHostResolution() {
+        if (!mResizeToClientEnabled) {
+            return;
+        }
+
+        Rect safeInsets = getSafeInsets();
+        int safeAreaWidth = mRemoteHostDesktop.getWidth() - safeInsets.left - safeInsets.right;
+        int safeAreaHeight = mRemoteHostDesktop.getHeight() - safeInsets.top - safeInsets.bottom;
+        DisplayMetrics metrics = getResources().getDisplayMetrics();
+        safeAreaWidth = ChromotingUtil.pxToDp(metrics, safeAreaWidth);
+        safeAreaHeight = ChromotingUtil.pxToDp(metrics, safeAreaHeight);
+        mClient.sendClientResolution(safeAreaWidth, safeAreaHeight, metrics.density);
+    }
+
     /**
      * Called once when a keyboard key is pressed, then again when that same key is released. This
      * is not guaranteed to be notified of all soft keyboard events: certain keyboards might not

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

@@ -173,6 +173,9 @@ public class DesktopCanvas {
             return;
         }
 
+        // Reset to identity so that screen dimensions and image dimensions match up.
+        mRenderData.transform.reset();
+
         float widthRatio = getSafeScreenWidth() / mRenderData.imageWidth;
         float heightRatio = getSafeScreenHeight() / mRenderData.imageHeight;
         float screenToImageScale = Math.max(widthRatio, heightRatio);

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

@@ -389,6 +389,8 @@ public class TouchInputHandler {
         mPanGestureBounds = new Rect(
                 mEdgeSlopInPx, mEdgeSlopInPx, width - mEdgeSlopInPx, height - mEdgeSlopInPx);
         resizeImageToFitScreen();
+
+        mDesktop.sendPreferredHostResolution();
     }
 
     private void handleHostSizeChanged(int width, int height) {

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

@@ -292,6 +292,22 @@ public class Client implements InputStub {
         nativeSendExtensionMessage(mNativeJniClient, type, data);
     }
 
+    /**
+     * Sends client resolution to the host so that the host can resize itself to fit the client
+     * without showing letterboxes.
+     *
+     * @param dipsWidth The width of the screen in density independent pixels.
+     * @param dipsHeight The height of the screen in density independent pixels.
+     * @param density The pixel density of the screen.
+     */
+    public void sendClientResolution(int dipsWidth, int dipsHeight, float density) {
+        if (!mConnected) {
+            return;
+        }
+
+        nativeSendClientResolution(mNativeJniClient, dipsWidth, dipsHeight, density);
+    }
+
     private native long nativeInit();
 
     private native void nativeDestroy(long nativeJniClient);
@@ -336,4 +352,8 @@ public class Client implements InputStub {
 
     /** Passes extension message to the native code. */
     private native void nativeSendExtensionMessage(long nativeJniClient, String type, String data);
+
+    /** Sends client resolution to the host. */
+    private native void nativeSendClientResolution(
+            long nativeJniClient, int dipsWidth, int dipsHeight, float scale);
 }

remoting/client/chromoting_session.cc

@@ -100,7 +100,7 @@ class ChromotingSession::Core : public ClientUserInterface,
   void SendKeyEvent(int usb_key_code, bool key_down);
   void SendTextEvent(const std::string& text);
   void SendTouchEvent(const protocol::TouchEvent& touch_event);
-  void SendClientResolution(int dips_width, int dips_height, int scale);
+  void SendClientResolution(int dips_width, int dips_height, float scale);
   void EnableVideoChannel(bool enable);
   void SendClientMessage(const std::string& type, const std::string& data);
 
@@ -275,7 +275,7 @@ void ChromotingSession::Core::SendTouchEvent(
 
 void ChromotingSession::Core::SendClientResolution(int dips_width,
                                                    int dips_height,
-                                                   int scale) {
+                                                   float scale) {
   DCHECK(network_task_runner()->BelongsToCurrentThread());
   protocol::ClientResolution client_resolution;
   client_resolution.set_dips_width(dips_width);
@@ -708,7 +708,7 @@ void ChromotingSession::SendTouchEvent(
 
 void ChromotingSession::SendClientResolution(int dips_width,
                                              int dips_height,
-                                             int scale) {
+                                             float scale) {
   RunCoreTaskOnNetworkThread(FROM_HERE, &Core::SendClientResolution, dips_width,
                              dips_height, scale);
 }

remoting/client/chromoting_session.h

@@ -118,7 +118,7 @@ class ChromotingSession : public ClientInputInjector {
   // Sends the provided touch event payload to the host.
   void SendTouchEvent(const protocol::TouchEvent& touch_event);
 
-  void SendClientResolution(int dips_width, int dips_height, int scale);
+  void SendClientResolution(int dips_width, int dips_height, float scale);
 
   // Enables or disables the video channel.
   void EnableVideoChannel(bool enable);

remoting/client/jni/jni_client.cc

@@ -287,6 +287,15 @@ void JniClient::SendExtensionMessage(
                               ConvertJavaStringToUTF8(env, data));
 }
 
+void JniClient::SendClientResolution(
+    JNIEnv* env,
+    const base::android::JavaParamRef<jobject>& caller,
+    jint dips_width,
+    jint dips_height,
+    jfloat scale) {
+  session_->SendClientResolution(dips_width, dips_height, scale);
+}
+
 void JniClient::Destroy(JNIEnv* env, const JavaParamRef<jobject>& caller) {
   delete this;
 }

remoting/client/jni/jni_client.h

@@ -145,6 +145,12 @@ class JniClient : public ChromotingSession::Delegate {
                             const base::android::JavaParamRef<jstring>& type,
                             const base::android::JavaParamRef<jstring>& data);
 
+  void SendClientResolution(JNIEnv* env,
+                            const base::android::JavaParamRef<jobject>& caller,
+                            jint dips_width,
+                            jint dips_height,
+                            jfloat scale);
+
   // Deletes this object.
   void Destroy(JNIEnv* env, const base::android::JavaParamRef<jobject>& caller);
 

remoting/resources/remoting_strings.grd

@@ -1166,7 +1166,7 @@ General fixes and stability improvements.
       <message desc="Label for button to reconnect to the previous Me2Me host. This button appears on the 'session-finished' page." name="IDS_RECONNECT">
         Reconnect
       </message>
-      <message desc="Button for enabling or disabling the 'resize-to-client' functionality, whereby the host desktop is resized to match the client size as closely as possible." name="IDS_RESIZE_TO_CLIENT">
+      <message desc="Button for enabling or disabling the 'resize-to-client' functionality, whereby the host desktop is resized to match the client size as closely as possible." name="IDS_RESIZE_TO_CLIENT" formatter_data="android_java">
         Resize desktop to fit
       </message>
       <message desc="Label for button to retry connecting to a Me2Me host, after failing to connect to that host. This button appears on the 'session-finished' page." name="IDS_RETRY">