Introduce DeviceInfo as a new native module

Summary:
The `UIManager` already has a lot of responsibilities and is deeply
tied with React Native's view architecture. This diff separates out a
`DeviceInfo` native module to provide information about screen dimensions and
font scale, etc.

Reviewed By: fkgozali

Differential Revision: D4713834

fbshipit-source-id: f2ee93acf876a4221c29a8c731f5abeffbb97974

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

@@ -87,7 +87,6 @@ public class UIManagerModule extends ReactContextBaseJavaModule implements
   private final Map<String, Object> mModuleConstants;
   private final UIImplementation mUIImplementation;
   private final MemoryTrimCallback mMemoryTrimCallback = new MemoryTrimCallback();
-  private float mFontScale;
 
   private int mNextRootViewTag = 1;
   private int mBatchId = 0;
@@ -100,8 +99,7 @@ public class UIManagerModule extends ReactContextBaseJavaModule implements
     super(reactContext);
     DisplayMetricsHolder.initDisplayMetricsIfNotInitialized(reactContext);
     mEventDispatcher = new EventDispatcher(reactContext);
-    mFontScale = getReactApplicationContext().getResources().getConfiguration().fontScale;
-    mModuleConstants = createConstants(viewManagerList, lazyViewManagersEnabled, mFontScale);
+    mModuleConstants = createConstants(viewManagerList, lazyViewManagersEnabled);
     mUIImplementation = uiImplementationProvider
       .createUIImplementation(reactContext, viewManagerList, mEventDispatcher);
 
@@ -134,12 +132,6 @@ public class UIManagerModule extends ReactContextBaseJavaModule implements
   @Override
   public void onHostResume() {
     mUIImplementation.onHostResume();
-
-    float fontScale = getReactApplicationContext().getResources().getConfiguration().fontScale;
-    if (mFontScale != fontScale) {
-      mFontScale = fontScale;
-      emitUpdateDimensionsEvent();
-    }
   }
 
   @Override
@@ -163,15 +155,13 @@ public class UIManagerModule extends ReactContextBaseJavaModule implements
 
   private static Map<String, Object> createConstants(
     List<ViewManager> viewManagerList,
-    boolean lazyViewManagersEnabled,
-    float fontScale) {
+    boolean lazyViewManagersEnabled) {
     ReactMarker.logMarker(CREATE_UI_MANAGER_MODULE_CONSTANTS_START);
     Systrace.beginSection(Systrace.TRACE_TAG_REACT_JAVA_BRIDGE, "CreateUIManagerConstants");
     try {
       return UIManagerModuleConstantsHelper.createConstants(
         viewManagerList,
-        lazyViewManagersEnabled,
-        fontScale);
+        lazyViewManagersEnabled);
     } finally {
       Systrace.endSection(Systrace.TRACE_TAG_REACT_JAVA_BRIDGE);
       ReactMarker.logMarker(CREATE_UI_MANAGER_MODULE_CONSTANTS_END);
@@ -550,16 +540,6 @@ public class UIManagerModule extends ReactContextBaseJavaModule implements
     mUIImplementation.sendAccessibilityEvent(tag, eventType);
   }
 
-  public void emitUpdateDimensionsEvent() {
-    sendEvent("didUpdateDimensions", UIManagerModuleConstants.getDimensionsConstants(mFontScale));
-  }
-
-  private void sendEvent(String eventName, @Nullable WritableMap params) {
-    getReactApplicationContext()
-        .getJSModule(DeviceEventManagerModule.RCTDeviceEventEmitter.class)
-        .emit(eventName, params);
-  }
-
   /**
    * Schedule a block to be executed on the UI thread. Useful if you need to execute
    * view logic after all currently queued view updates have completed.

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

@@ -83,7 +83,7 @@ import com.facebook.react.uimanager.events.TouchEventType;
         .build();
   }
 
-  public static Map<String, Object> getConstants(float fontScale) {
+  public static Map<String, Object> getConstants() {
     HashMap<String, Object> constants = new HashMap<String, Object>();
     constants.put(
         "UIView",
@@ -97,10 +97,6 @@ import com.facebook.react.uimanager.events.TouchEventType;
                 "ScaleAspectCenter",
                 ImageView.ScaleType.CENTER_INSIDE.ordinal())));
 
-    constants.put(
-        "Dimensions",
-        getDimensionsConstants(fontScale));
-
     constants.put(
         "StyleConstants",
         MapBuilder.of(
@@ -133,29 +129,4 @@ import com.facebook.react.uimanager.events.TouchEventType;
 
     return constants;
   }
-
-  public static WritableMap getDimensionsConstants(float fontScale) {
-    DisplayMetrics windowDisplayMetrics = DisplayMetricsHolder.getWindowDisplayMetrics();
-    DisplayMetrics screenDisplayMetrics = DisplayMetricsHolder.getScreenDisplayMetrics();
-
-    WritableMap windowDisplayMetricsMap = Arguments.createMap();
-    windowDisplayMetricsMap.putInt("width", windowDisplayMetrics.widthPixels);
-    windowDisplayMetricsMap.putInt("height", windowDisplayMetrics.heightPixels);
-    windowDisplayMetricsMap.putDouble("scale", windowDisplayMetrics.density);
-    windowDisplayMetricsMap.putDouble("fontScale", fontScale);
-    windowDisplayMetricsMap.putDouble("densityDpi", windowDisplayMetrics.densityDpi);
-
-    WritableMap screenDisplayMetricsMap = Arguments.createMap();
-    screenDisplayMetricsMap.putInt("width", screenDisplayMetrics.widthPixels);
-    screenDisplayMetricsMap.putInt("height", screenDisplayMetrics.heightPixels);
-    screenDisplayMetricsMap.putDouble("scale", screenDisplayMetrics.density);
-    screenDisplayMetricsMap.putDouble("fontScale", fontScale);
-    screenDisplayMetricsMap.putDouble("densityDpi", screenDisplayMetrics.densityDpi);
-
-    WritableMap dimensionsMap = Arguments.createMap();
-    dimensionsMap.putMap("windowPhysicalPixels", windowDisplayMetricsMap);
-    dimensionsMap.putMap("screenPhysicalPixels", screenDisplayMetricsMap);
-    
-    return dimensionsMap;
-  }
 }

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

@@ -43,9 +43,8 @@ import static com.facebook.systrace.Systrace.TRACE_TAG_REACT_JAVA_BRIDGE;
    */
   /* package */ static Map<String, Object> createConstants(
     List<ViewManager> viewManagers,
-    boolean lazyViewManagersEnabled,
-    float fontScale) {
-    Map<String, Object> constants = UIManagerModuleConstants.getConstants(fontScale);
+    boolean lazyViewManagersEnabled) {
+    Map<String, Object> constants = UIManagerModuleConstants.getConstants();
     Map bubblingEventTypesConstants = UIManagerModuleConstants.getBubblingEventTypeConstants();
     Map directEventTypesConstants = UIManagerModuleConstants.getDirectEventTypeConstants();