Implement Virtual Display class for Android.

ui/android/java/src/org/chromium/ui/display/DisplayAndroidImpl.java

Index: ui/android/java/src/org/chromium/ui/display/DisplayAndroidImpl.java
diff --git a/ui/android/java/src/org/chromium/ui/display/DisplayAndroid.java b/ui/android/java/src/org/chromium/ui/display/DisplayAndroidImpl.java
similarity index 54%
copy from ui/android/java/src/org/chromium/ui/display/DisplayAndroid.java
copy to ui/android/java/src/org/chromium/ui/display/DisplayAndroidImpl.java
index fc17ef77548ab1e562913d10993dd28720278112..c00113be54f7b5851ddf4c4f0ef13ad3743aa51a 100644
--- a/ui/android/java/src/org/chromium/ui/display/DisplayAndroid.java
+++ b/ui/android/java/src/org/chromium/ui/display/DisplayAndroidImpl.java
@@ -5,53 +5,22 @@
 package org.chromium.ui.display;
 
 import android.annotation.TargetApi;
-import android.content.Context;
 import android.graphics.PixelFormat;
 import android.graphics.Point;
 import android.os.Build;
 import android.util.DisplayMetrics;
 import android.view.Display;
-import android.view.Surface;
 
 import org.chromium.base.CommandLine;
 import org.chromium.base.Log;
 
-import java.util.WeakHashMap;
-
 /**
- * Chromium's object for android.view.Display. Instances of this object should be obtained
- * from WindowAndroid.
- * This class is designed to avoid leaks. It is ok to hold a strong ref of this class from
- * anywhere, as long as the corresponding WindowAndroids are destroyed. The observers are
- * held weakly so to not lead to leaks.
+ * A DisplayAndroid implementation tied to a physical Display.
  */
-public class DisplayAndroid {
-    /**
-     * DisplayAndroidObserver interface for changes to this Display.
-     */
-    public interface DisplayAndroidObserver {
-        /**
-         * Called whenever the screen orientation changes.
-         *
-         * @param orientation One of Surface.ROTATION_* values.
-         */
-        void onRotationChanged(int rotation);
-
-        /**
-         * Called whenever the screen density changes.
-         *
-         * @param screen density, aka Density Independent Pixel scale.
-         */
-        void onDIPScaleChanged(float dipScale);
-    }
-
+public class DisplayAndroidImpl extends DisplayAndroid {

[boliu, 2016/11/28 15:53:31]

can class be package visible only?

[mthiesse, 2016/11/28 19:16:42]

Done.

     private static final String TAG = "DisplayAndroid";
 
-    private static final DisplayAndroidObserver[] EMPTY_OBSERVER_ARRAY =
-            new DisplayAndroidObserver[0];
-
     private final int mSdkDisplayId;
-    private final WeakHashMap<DisplayAndroidObserver, Object /* null */> mObservers;
     // Do NOT add strong references to objects with potentially complex lifetime, like Context.
 
     // Updated by updateFromDisplay.
@@ -93,109 +62,47 @@ public class DisplayAndroid {
         return sForcedDIPScale.floatValue() > 0;
     }
 
-    private static DisplayAndroidManager getManager() {
-        return DisplayAndroidManager.getInstance();
-    }
-
-    /**
-     * Get the non-multi-display DisplayAndroid for the given context. It's safe to call this with
-     * any type of context, including the Application.
-     *
-     * To support multi-display, obtain DisplayAndroid from WindowAndroid instead.
-     *
-     * This function is intended to be analogous to GetPrimaryDisplay() for other platforms.
-     * However, Android has historically had no real concept of a Primary Display, and instead uses
-     * the notion of a default display for an Activity. Under normal circumstances, this function,
-     * called with the correct context, will return the expected display for an Activity. However,
-     * virtual, or "fake", displays that are not associated with any context may be used in special
-     * cases, like Virtual Reality, and will lead to this function returning the incorrect display.
-     *
-     * @return What the Android WindowManager considers to be the default display for this context.
-     */
-    public static DisplayAndroid getNonMultiDisplay(Context context) {
-        Display display = DisplayAndroidManager.getDefaultDisplayForContext(context);
-        return getManager().getDisplayAndroid(display);
-    }
-
-    /**
-     * @return Display id as defined in Android's Display.
-     */
-    public int getSdkDisplayId() {
+    @Override
+    public int getDisplayId() {
         return mSdkDisplayId;
     }
 
-    /**
-     * @return Display height in physical pixels.
-     */
+    @Override
     public int getDisplayHeight() {
         return mSize.y;
     }
 
-    /**
-     * @return Display width in physical pixels.
-     */
+    @Override
     public int getDisplayWidth() {
         return mSize.x;
     }
 
-    /**
-     * @return Real physical display height in physical pixels. Or 0 if not supported.
-     */
+    @Override
     public int getPhysicalDisplayHeight() {
         return mPhysicalSize.y;
     }
 
-    /**
-     * @return Real physical display width in physical pixels. Or 0 if not supported.
-     */
+    @Override
     public int getPhysicalDisplayWidth() {
         return mPhysicalSize.x;
     }
 
-    /**
-     * @return current orientation. One of Surface.ORIENTATION_* values.
-     */
+    @Override
     public int getRotation() {
         return mRotation;
     }
 
-    /**
-     * @return current orientation in degrees. One of the values 0, 90, 180, 270.
-     */
-    /* package */ int getRotationDegrees() {
-        switch (mRotation) {
-            case Surface.ROTATION_0:
-                return 0;
-            case Surface.ROTATION_90:
-                return 90;
-            case Surface.ROTATION_180:
-                return 180;
-            case Surface.ROTATION_270:
-                return 270;
-        }
-
-        // This should not happen.
-        assert false;
-        return 0;
-    }
-
-    /**
-     * @return A scaling factor for the Density Independent Pixel unit.
-     */
+    @Override
     public float getDipScale() {
         return mDisplayMetrics.density;
     }
 
-    /**
-     * @return Number of bits per pixel.
-     */
+    @Override
     /* package */ int getBitsPerPixel() {
         return mPixelFormatInfo.bitsPerPixel;
     }
 
-    /**
-     * @return Number of bits per each color component.
-     */
+    @Override
     @SuppressWarnings("deprecation")
     /* package */ int getBitsPerComponent() {
         switch (mPixelFormatId) {
@@ -228,40 +135,8 @@ public class DisplayAndroid {
         }
     }
 
-    /**
-     * Add observer. Note repeat observers will be called only one.
-     * Observers are held only weakly by Display.
-     */
-    public void addObserver(DisplayAndroidObserver observer) {
-        mObservers.put(observer, null);
-    }
-
-    /**
-     * Remove observer.
-     */
-    public void removeObserver(DisplayAndroidObserver observer) {
-        mObservers.remove(observer);
-    }
-
-    /**
-     * Toggle the accurate mode if it wasn't already doing so. The backend will
-     * keep track of the number of times this has been called.
-     */
-    public static void startAccurateListening() {
-        getManager().startAccurateListening();
-    }
-
-    /**
-     * Request to stop the accurate mode. It will effectively be stopped only if
-     * this method is called as many times as startAccurateListening().
-     */
-    public static void stopAccurateListening() {
-        getManager().startAccurateListening();
-    }
-
-    /* package */ DisplayAndroid(Display display) {
+    /* package */ DisplayAndroidImpl(Display display) {
         mSdkDisplayId = display.getDisplayId();
-        mObservers = new WeakHashMap<>();
         mSize = new Point();
         mPhysicalSize = new Point();
         mDisplayMetrics = new DisplayMetrics();
@@ -320,9 +195,4 @@ public class DisplayAndroid {
             }
         }
     }
-
-    private DisplayAndroidObserver[] getObservers() {
-        // Makes a copy to allow concurrent edit.
-        return mObservers.keySet().toArray(EMPTY_OBSERVER_ARRAY);
-    }
 }