Calculate Correct Window Dimensions for iOS

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
 }
 
@@ -77,16 +85,23 @@ static BOOL RCTIsIPhoneX() {
   RCTAssertMainQueue();
 
   RCTDimensions dimensions = RCTGetDimensions(bridge.accessibilityManager.multiplier);
-  typeof (dimensions.window) window = dimensions.window; // Window and Screen are considered equal for iOS.
-  NSDictionary<NSString *, NSNumber *> *dims = @{
+  typeof (dimensions.window) window = dimensions.window;
+  NSDictionary<NSString *, NSNumber *> *dimsWindow = @{
       @"width": @(window.width),
       @"height": @(window.height),
       @"scale": @(window.scale),
       @"fontScale": @(window.fontScale)
   };
+  typeof (dimensions.screen) screen = dimensions.screen;
+  NSDictionary<NSString *, NSNumber *> *dimsScreen = @{
+      @"width": @(screen.width),
+      @"height": @(screen.height),
+      @"scale": @(screen.scale),
+      @"fontScale": @(screen.fontScale)
+  };
   return @{
-      @"window": dims,
-      @"screen": dims
+      @"window": dimsWindow,
+      @"screen": dimsScreen
   };
 }
 
@@ -158,6 +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:nextInterfaceDimensions];
+#pragma clang diagnostic pop
+  }
+
+  _currentInterfaceDimensions = nextInterfaceDimensions;
+}
+
 #endif // TARGET_OS_TV
 
 

React/UIUtils/RCTUIUtils.m

@@ -7,19 +7,32 @@
 
 #import "RCTUIUtils.h"
 
+#import "RCTUtils.h"
+
 RCTDimensions RCTGetDimensions(CGFloat fontScale)
 {
   UIScreen *mainScreen = UIScreen.mainScreen;
   CGSize screenSize = mainScreen.bounds.size;
+
+  UIView *mainWindow;
+  mainWindow = RCTKeyWindow();
+  CGSize windowSize = mainWindow.bounds.size;
+
   RCTDimensions result;
-  typeof (result.window) dims = {
+  typeof (result.screen) dimsScreen = {
     .width = screenSize.width,
     .height = screenSize.height,
     .scale = mainScreen.scale,
     .fontScale = fontScale
   };
-  result.window = dims;
-  result.screen = dims;
+  typeof (result.window) dimsWindow = {
+    .width = windowSize.width,
+    .height = windowSize.height,
+    .scale = mainScreen.scale,
+    .fontScale = fontScale
+  };
+  result.screen = dimsScreen;
+  result.window = dimsWindow;
 
   return result;
 }