Expose screen metrics and window metrics

Summary:
public
https://github.com/facebook/react-native/pull/4935 changed the window dimensions for android by replacing them with the actual screen dimensions. This changes the window dimensions back to their original values and adds `Dimensions.get('screen')` for the actual screen dimensions of the device.

Reviewed By: astreet

Differential Revision: D2921584

fb-gh-sync-id: 5d2677029c71d50691691dc651a11e9c8b115e8f
shipit-source-id: 5d2677029c71d50691691dc651a11e9c8b115e8f

ReactAndroid/src/main/java/com/facebook/react/ReactInstanceManagerImpl.java

@@ -308,8 +308,11 @@ import static com.facebook.react.bridge.ReactMarkerConstants.*;
   }
 
   private static void setDisplayMetrics(Context context) {
-    DisplayMetrics displayMetrics = new DisplayMetrics();
-    displayMetrics.setTo(context.getResources().getDisplayMetrics());
+    DisplayMetrics displayMetrics = context.getResources().getDisplayMetrics();
+    DisplayMetricsHolder.setWindowDisplayMetrics(displayMetrics);
+
+    DisplayMetrics screenDisplayMetrics = new DisplayMetrics();
+    screenDisplayMetrics.setTo(displayMetrics);
     WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
     Display display = wm.getDefaultDisplay();
 
@@ -317,9 +320,8 @@ import static com.facebook.react.bridge.ReactMarkerConstants.*;
     // The real metrics include system decor elements (e.g. soft menu bar).
     //
     // See: http://developer.android.com/reference/android/view/Display.html#getRealMetrics(android.util.DisplayMetrics)
-    if (Build.VERSION.SDK_INT >= 17){
-      display.getRealMetrics(displayMetrics);
-
+    if (Build.VERSION.SDK_INT >= 17) {
+      display.getRealMetrics(screenDisplayMetrics);
     } else {
       // For 14 <= API level <= 16, we need to invoke getRawHeight and getRawWidth to get the real dimensions.
       // Since react-native only supports API level 16+ we don't have to worry about other cases.
@@ -330,13 +332,13 @@ import static com.facebook.react.bridge.ReactMarkerConstants.*;
       try {
         Method mGetRawH = Display.class.getMethod("getRawHeight");
         Method mGetRawW = Display.class.getMethod("getRawWidth");
-        displayMetrics.widthPixels = (Integer) mGetRawW.invoke(display);
-        displayMetrics.heightPixels = (Integer) mGetRawH.invoke(display);
+        screenDisplayMetrics.widthPixels = (Integer) mGetRawW.invoke(display);
+        screenDisplayMetrics.heightPixels = (Integer) mGetRawH.invoke(display);
       } catch (InvocationTargetException | IllegalAccessException | NoSuchMethodException e) {
         throw new RuntimeException("Error getting real dimensions for API level < 17", e);
       }
     }
-    DisplayMetricsHolder.setDisplayMetrics(displayMetrics);
+    DisplayMetricsHolder.setScreenDisplayMetrics(screenDisplayMetrics);
   }
 
   /**

ReactAndroid/src/main/java/com/facebook/react/ReactRootView.java

@@ -390,7 +390,7 @@ public class ReactRootView extends SizeMonitoringFrameLayout implements RootView
   private class KeyboardListener implements ViewTreeObserver.OnGlobalLayoutListener {
     private final Rect mVisibleViewArea;
     private final int mMinKeyboardHeightDetected;
-    
+
     private int mKeyboardHeight = 0;
 
     /* package */ KeyboardListener() {
@@ -410,7 +410,7 @@ public class ReactRootView extends SizeMonitoringFrameLayout implements RootView
 
       getRootView().getWindowVisibleDisplayFrame(mVisibleViewArea);
       final int heightDiff =
-          DisplayMetricsHolder.getDisplayMetrics().heightPixels - mVisibleViewArea.bottom;
+          DisplayMetricsHolder.getWindowDisplayMetrics().heightPixels - mVisibleViewArea.bottom;
       if (mKeyboardHeight != heightDiff && heightDiff > mMinKeyboardHeightDetected) {
         // keyboard is now showing, or the keyboard height has changed
         mKeyboardHeight = heightDiff;

ReactAndroid/src/main/java/com/facebook/react/uimanager/DisplayMetricsHolder.java

@@ -14,16 +14,39 @@ import android.util.DisplayMetrics;
 /**
  * Holds an instance of the current DisplayMetrics so we don't have to thread it through all the
  * classes that need it.
+ * Note: windowDisplayMetrics are deprecated in favor of ScreenDisplayMetrics: window metrics
+ * are supposed to return the drawable area but there's no guarantee that they correspond to the
+ * actual size of the {@link ReactRootView}. Moreover, they are not consistent with what iOS
+ * returns. Screen metrics returns the metrics of the entire screen, is consistent with iOS and
+ * should be used instead.
  */
 public class DisplayMetricsHolder {
 
-  private static DisplayMetrics sCurrentDisplayMetrics;
+  private static DisplayMetrics sWindowDisplayMetrics;
+  private static DisplayMetrics sScreenDisplayMetrics;
 
-  public static void setDisplayMetrics(DisplayMetrics displayMetrics) {
-    sCurrentDisplayMetrics = displayMetrics;
+  /**
+   * @deprecated Use {@link #setScreenDisplayMetrics(DisplayMetrics)} instead. See comment above as
+   *    to why this is not correct to use.
+   */
+  public static void setWindowDisplayMetrics(DisplayMetrics displayMetrics) {
+    sWindowDisplayMetrics = displayMetrics;
   }
 
-  public static DisplayMetrics getDisplayMetrics() {
-    return sCurrentDisplayMetrics;
+  /**
+   * @deprecated Use {@link #getScreenDisplayMetrics()} instead. See comment above as to why this
+   *    is not correct to use.
+   */
+  @Deprecated
+  public static DisplayMetrics getWindowDisplayMetrics() {
+    return sWindowDisplayMetrics;
+  }
+
+  public static void setScreenDisplayMetrics(DisplayMetrics screenDisplayMetrics) {
+    sScreenDisplayMetrics = screenDisplayMetrics;
+  }
+
+  public static DisplayMetrics getScreenDisplayMetrics() {
+    return sScreenDisplayMetrics;
   }
 }

ReactAndroid/src/main/java/com/facebook/react/uimanager/PixelUtil.java

@@ -23,7 +23,7 @@ public class PixelUtil {
     return TypedValue.applyDimension(
         TypedValue.COMPLEX_UNIT_DIP,
         value,
-        DisplayMetricsHolder.getDisplayMetrics());
+        DisplayMetricsHolder.getWindowDisplayMetrics());
   }
 
   /**
@@ -40,7 +40,7 @@ public class PixelUtil {
     return TypedValue.applyDimension(
         TypedValue.COMPLEX_UNIT_SP,
         value,
-        DisplayMetricsHolder.getDisplayMetrics());
+        DisplayMetricsHolder.getWindowDisplayMetrics());
   }
 
   /**
@@ -54,7 +54,7 @@ public class PixelUtil {
    * Convert from PX to DP
    */
   public static float toDIPFromPixel(float value) {
-    return value / DisplayMetricsHolder.getDisplayMetrics().density;
+    return value / DisplayMetricsHolder.getWindowDisplayMetrics().density;
   }
 
 }

ReactAndroid/src/main/java/com/facebook/react/uimanager/UIManagerModuleConstants.java

@@ -91,7 +91,8 @@ import com.facebook.react.uimanager.events.TouchEventType;
                 "ScaleAspectFill",
                 ImageView.ScaleType.CENTER_CROP.ordinal())));
 
-    DisplayMetrics displayMetrics = DisplayMetricsHolder.getDisplayMetrics();
+    DisplayMetrics displayMetrics = DisplayMetricsHolder.getWindowDisplayMetrics();
+    DisplayMetrics screenDisplayMetrics = DisplayMetricsHolder.getScreenDisplayMetrics();
     constants.put(
         "Dimensions",
         MapBuilder.of(
@@ -106,7 +107,19 @@ import com.facebook.react.uimanager.events.TouchEventType;
                 "fontScale",
                 displayMetrics.scaledDensity,
                 "densityDpi",
-                displayMetrics.densityDpi)));
+                displayMetrics.densityDpi),
+        "screenPhysicalPixels",
+        MapBuilder.of(
+            "width",
+            screenDisplayMetrics.widthPixels,
+            "height",
+            screenDisplayMetrics.heightPixels,
+            "scale",
+            screenDisplayMetrics.density,
+            "fontScale",
+            screenDisplayMetrics.scaledDensity,
+            "densityDpi",
+            screenDisplayMetrics.densityDpi)));
 
     constants.put(
         "StyleConstants",

ReactAndroid/src/main/java/com/facebook/react/views/art/ARTVirtualNode.java

@@ -17,7 +17,6 @@ import android.graphics.Paint;
 
 import com.facebook.react.bridge.JSApplicationIllegalArgumentException;
 import com.facebook.react.bridge.ReadableArray;
-import com.facebook.react.uimanager.ReactStylesDiffMap;
 import com.facebook.react.uimanager.DisplayMetricsHolder;
 import com.facebook.react.uimanager.annotations.ReactProp;
 import com.facebook.react.uimanager.ReactShadowNode;
@@ -39,7 +38,7 @@ public abstract class ARTVirtualNode extends ReactShadowNode {
   protected final float mScale;
 
   public ARTVirtualNode() {
-    mScale = DisplayMetricsHolder.getDisplayMetrics().density;
+    mScale = DisplayMetricsHolder.getWindowDisplayMetrics().density;
   }
 
   @Override