Implement Virtual Display class for Android.

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

Index: ui/android/java/src/org/chromium/ui/display/DisplayAndroid.java
diff --git a/ui/android/java/src/org/chromium/ui/display/DisplayAndroid.java b/ui/android/java/src/org/chromium/ui/display/DisplayAndroid.java
index fc17ef77548ab1e562913d10993dd28720278112..e725f95da9e691bd016ad15a29f55fc94e2864b7 100644
--- a/ui/android/java/src/org/chromium/ui/display/DisplayAndroid.java
+++ b/ui/android/java/src/org/chromium/ui/display/DisplayAndroid.java
@@ -4,18 +4,11 @@
 
 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;
 
 /**
@@ -45,55 +38,21 @@ public class DisplayAndroid {
         void onDIPScaleChanged(float dipScale);
     }
 
-    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.
-    private final Point mSize;
-    private final Point mPhysicalSize;
-    private final DisplayMetrics mDisplayMetrics;
-    private final PixelFormat mPixelFormatInfo;
-    private int mPixelFormatId;
+    private final int mDisplayId;
+    private Point mSize;
+    private Point mPhysicalSize;
+    private float mDipScale;
+    private int mBitsPerPixel;
+    private int mBitsPerComponent;
     private int mRotation;
 
-    // When this object exists, a positive value means that the forced DIP scale is set and
-    // the zero means it is not. The non existing object (i.e. null reference) means that
-    // the existence and value of the forced DIP scale has not yet been determined.
-    private static Float sForcedDIPScale;
-
-    private static boolean hasForcedDIPScale() {
-        if (sForcedDIPScale == null) {
-            String forcedScaleAsString = CommandLine.getInstance().getSwitchValue(
-                    DisplaySwitches.FORCE_DEVICE_SCALE_FACTOR);
-            if (forcedScaleAsString == null) {
-                sForcedDIPScale = Float.valueOf(0.0f);
-            } else {
-                boolean isInvalid = false;
-                try {
-                    sForcedDIPScale = Float.valueOf(forcedScaleAsString);
-                    // Negative values are discarded.
-                    if (sForcedDIPScale.floatValue() <= 0.0f) isInvalid = true;
-                } catch (NumberFormatException e) {
-                    // Strings that do not represent numbers are discarded.
-                    isInvalid = true;
-                }
-
-                if (isInvalid) {
-                    Log.w(TAG, "Ignoring invalid forced DIP scale '" + forcedScaleAsString + "'");
-                    sForcedDIPScale = Float.valueOf(0.0f);
-                }
-            }
-        }
-        return sForcedDIPScale.floatValue() > 0;
-    }
-
-    private static DisplayAndroidManager getManager() {
+    protected static DisplayAndroidManager getManager() {
         return DisplayAndroidManager.getInstance();
     }
 
@@ -118,10 +77,10 @@ public class DisplayAndroid {
     }
 
     /**
-     * @return Display id as defined in Android's Display.
+     * @return Display id that does not necessarily match the one defined in Android's Display.
      */
-    public int getSdkDisplayId() {
-        return mSdkDisplayId;
+    public int getDisplayId() {
+        return mDisplayId;
     }
 
     /**
@@ -163,7 +122,7 @@ public class DisplayAndroid {
      * @return current orientation in degrees. One of the values 0, 90, 180, 270.
      */
     /* package */ int getRotationDegrees() {
-        switch (mRotation) {
+        switch (getRotation()) {
             case Surface.ROTATION_0:
                 return 0;
             case Surface.ROTATION_90:
@@ -183,14 +142,14 @@ public class DisplayAndroid {
      * @return A scaling factor for the Density Independent Pixel unit.
      */
     public float getDipScale() {
-        return mDisplayMetrics.density;
+        return mDipScale;
     }
 
     /**
      * @return Number of bits per pixel.
      */
     /* package */ int getBitsPerPixel() {
-        return mPixelFormatInfo.bitsPerPixel;
+        return mBitsPerPixel;
     }
 
     /**
@@ -198,34 +157,7 @@ public class DisplayAndroid {
      */
     @SuppressWarnings("deprecation")
     /* package */ int getBitsPerComponent() {
-        switch (mPixelFormatId) {
-            case PixelFormat.RGBA_4444:
-                return 4;
-
-            case PixelFormat.RGBA_5551:
-                return 5;
-
-            case PixelFormat.RGBA_8888:
-            case PixelFormat.RGBX_8888:
-            case PixelFormat.RGB_888:
-                return 8;
-
-            case PixelFormat.RGB_332:
-                return 2;
-
-            case PixelFormat.RGB_565:
-                return 5;
-
-            // Non-RGB formats.
-            case PixelFormat.A_8:
-            case PixelFormat.LA_88:
-            case PixelFormat.L_8:
-                return 0;
-
-            // Unknown format. Use 8 as a sensible default.
-            default:
-                return 8;
-        }
+        return mBitsPerComponent;
     }
 
     /**
@@ -259,70 +191,56 @@ public class DisplayAndroid {
         getManager().startAccurateListening();
     }
 
-    /* package */ DisplayAndroid(Display display) {
-        mSdkDisplayId = display.getDisplayId();
+    protected DisplayAndroid(int displayId) {
+        mDisplayId = displayId;
         mObservers = new WeakHashMap<>();
         mSize = new Point();
         mPhysicalSize = new Point();
-        mDisplayMetrics = new DisplayMetrics();
-        mPixelFormatInfo = new PixelFormat();
     }
 
-    @SuppressWarnings("deprecation")
-    @TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR1)
-    /* package */ void updateFromDisplay(Display display) {
-        final Point oldSize = new Point(mSize);
-        final Point oldPhysicalSize = new Point(mPhysicalSize);
-        final float oldDensity = mDisplayMetrics.density;
-        final int oldPixelFormatId = mPixelFormatId;
-        final int oldRotation = mRotation;
-
-        display.getSize(mSize);
-        display.getMetrics(mDisplayMetrics);
-
-        if (hasForcedDIPScale()) mDisplayMetrics.density = sForcedDIPScale.floatValue();
-
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
-            display.getRealSize(mPhysicalSize);
-        }
+    private DisplayAndroidObserver[] getObservers() {
+        // Makes a copy to allow concurrent edit.
+        return mObservers.keySet().toArray(EMPTY_OBSERVER_ARRAY);
+    }
 
-        // JellyBean MR1 and later always uses RGBA_8888.
-        mPixelFormatId = (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN_MR1)
-                ? display.getPixelFormat()
-                : PixelFormat.RGBA_8888;
-        if (oldPixelFormatId != mPixelFormatId) {
-            PixelFormat.getPixelFormatInfo(mPixelFormatId, mPixelFormatInfo);
-        }
+    /**
+     * Update the display to the provided parameters. Null values leave the parameter unchanged.
+     */
+    protected void update(Point size, Point physicalSize, Float dipScale, Integer bitsPerPixel,
+            Integer bitsPerComponent, Integer rotation) {
+        boolean sizeChanged = size != null && !mSize.equals(size);
+        boolean physicalSizeChanged = physicalSize != null && !mPhysicalSize.equals(physicalSize);
+        // Intentional comparison of floats: we assume that if scales differ, they differ
+        // significantly.
+        boolean dipScaleChanged = dipScale != null && mDipScale != dipScale;
+        boolean bitsPerPixelChanged = bitsPerPixel != null && mBitsPerPixel != bitsPerPixel;
+        boolean bitsPerComponentChanged = bitsPerComponent != null
+                && mBitsPerComponent != bitsPerComponent;
+        boolean rotationChanged = rotation != null && mRotation != rotation;
 
-        mRotation = display.getRotation();
+        boolean changed = sizeChanged || physicalSizeChanged || dipScaleChanged
+                || bitsPerPixelChanged || bitsPerComponentChanged || rotationChanged;
+        if (!changed) return;
 
-        final boolean noChanges = oldSize.equals(mSize) && oldPhysicalSize.equals(mPhysicalSize)
-                && oldDensity == mDisplayMetrics.density && oldPixelFormatId == mPixelFormatId
-                && oldRotation == mRotation;
-        if (noChanges) return;
+        if (sizeChanged) mSize = size;
+        if (physicalSizeChanged) mPhysicalSize = physicalSize;
+        if (dipScaleChanged) mDipScale = dipScale;
+        if (bitsPerPixelChanged) mBitsPerPixel = bitsPerPixel;
+        if (bitsPerComponentChanged) mBitsPerComponent = bitsPerComponent;
+        if (rotationChanged) mRotation = rotation;
 
         getManager().updateDisplayOnNativeSide(this);
-
-        if (oldRotation != mRotation) {
+        if (rotationChanged) {
             DisplayAndroidObserver[] observers = getObservers();
             for (DisplayAndroidObserver o : observers) {
                 o.onRotationChanged(mRotation);
             }
         }
-
-        // Intentional comparison of floats: we assume that if scales differ,
-        // they differ significantly.
-        boolean dipScaleChanged = oldDensity != mDisplayMetrics.density;
         if (dipScaleChanged) {
             DisplayAndroidObserver[] observers = getObservers();
             for (DisplayAndroidObserver o : observers) {
-                o.onDIPScaleChanged(mDisplayMetrics.density);
+                o.onDIPScaleChanged(mDipScale);
             }
         }
     }
-
-    private DisplayAndroidObserver[] getObservers() {
-        // Makes a copy to allow concurrent edit.
-        return mObservers.keySet().toArray(EMPTY_OBSERVER_ARRAY);
-    }
 }