add event for window dimension change on active

When the app becomes active, check to see if the window size has changed. If so, send a device event with update dimensions.

React/Modules/RCTDeviceInfo.m

@@ -16,6 +16,7 @@
 @implementation RCTDeviceInfo {
 #if !TARGET_OS_TV
  UIInterfaceOrientation _currentInterfaceOrientation;
+ NSDictionary *_currentInterfaceDimensions;
 #endif
 }
 
@@ -48,6 +49,13 @@ - (void)setBridge:(RCTBridge *)bridge
  selector:@selector(interfaceOrientationDidChange)
  name:UIApplicationDidChangeStatusBarOrientationNotification
  object:nil];
+
+ _currentInterfaceDimensions = RCTExportedDimensions(_bridge);
+
+ [[NSNotificationCenter defaultCenter] addObserver:self
+ selector:@selector(interfaceFrameDidChange)
+ name:UIApplicationDidBecomeActiveNotification
+ object:nil];
 #endif
 }
 
@@ -165,6 +173,31 @@ - (void)_interfaceOrientationDidChange
  _currentInterfaceOrientation = nextOrientation;
 }
 
+
+- (void)interfaceFrameDidChange
+{
+ __weak typeof(self) weakSelf = self;
+ RCTExecuteOnMainQueue(^{
+ [weakSelf _interfaceFrameDidChange];
+ });
+}
+
+
+- (void)_interfaceFrameDidChange
+{
+ NSDictionary *nextInterfaceDimensions = RCTExportedDimensions(_bridge);
+
+ if (!([nextInterfaceDimensions isEqual:_currentInterfaceDimensions])) {
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wdeprecated-declarations"
+ [_bridge.eventDispatcher sendDeviceEventWithName:@"didUpdateDimensions"
+ body:RCTExportedDimensions(_bridge)];
+#pragma clang diagnostic pop
+ }
+
+ _currentInterfaceDimensions = nextInterfaceDimensions;
+}
+
 #endif // TARGET_OS_TV