Add Voice Over related change to AccessibilityManager.

Reviewed By: @hedgerwang

Differential Revision: D2491520

React/Modules/RCTAccessibilityManager.h

@@ -21,6 +21,8 @@ extern NSString *const RCTAccessibilityManagerDidUpdateMultiplierNotification; /
 /// map from UIKit categories to multipliers
 @property (nonatomic, copy) NSDictionary *multipliers;
 
+@property (nonatomic, assign) BOOL isVoiceOverEnabled;
+
 @end
 
 @interface RCTBridge (RCTAccessibilityManager)

React/Modules/RCTAccessibilityManager.m

@@ -9,6 +9,8 @@
 
 #import "RCTAccessibilityManager.h"
 
+#import "RCTBridge.h"
+#import "RCTEventDispatcher.h"
 #import "RCTLog.h"
 
 NSString *const RCTAccessibilityManagerDidUpdateMultiplierNotification = @"RCTAccessibilityManagerDidUpdateMultiplierNotification";
@@ -24,6 +26,7 @@ NSString *const RCTAccessibilityManagerDidUpdateMultiplierNotification = @"RCTAc
 
 @synthesize bridge = _bridge;
 @synthesize multipliers = _multipliers;
+@synthesize isVoiceOverEnabled = _isVoiceOverEnabled;
 
 RCT_EXPORT_MODULE()
 
@@ -61,7 +64,14 @@ RCT_EXPORT_MODULE()
                                              selector:@selector(didReceiveNewContentSizeCategory:)
                                                  name:UIContentSizeCategoryDidChangeNotification
                                                object:[UIApplication sharedApplication]];
+
+    [[NSNotificationCenter defaultCenter] addObserver:self
+                                             selector:@selector(didReceiveNewVoiceOverStatus:)
+                                                 name:UIAccessibilityVoiceOverStatusChanged
+                                               object:nil];
+
     self.contentSizeCategory = [UIApplication sharedApplication].preferredContentSizeCategory;
+    _isVoiceOverEnabled = UIAccessibilityIsVoiceOverRunning();
   }
   return self;
 }
@@ -76,6 +86,16 @@ RCT_EXPORT_MODULE()
   self.contentSizeCategory = note.userInfo[UIContentSizeCategoryNewValueKey];
 }
 
+- (void)didReceiveNewVoiceOverStatus:(NSNotification *)notification
+{
+  BOOL newIsVoiceOverEnabled = UIAccessibilityIsVoiceOverRunning();
+  if (_isVoiceOverEnabled != newIsVoiceOverEnabled) {
+    _isVoiceOverEnabled = newIsVoiceOverEnabled;
+    [_bridge.eventDispatcher sendDeviceEventWithName:@"voiceOverDidChange"
+                                                body:@(_isVoiceOverEnabled)];
+  }
+}
+
 - (void)setContentSizeCategory:(NSString *)contentSizeCategory
 {
   if (_contentSizeCategory != contentSizeCategory) {
@@ -145,6 +165,12 @@ RCT_EXPORT_METHOD(getMultiplier:(RCTResponseSenderBlock)callback)
   }
 }
 
+RCT_EXPORT_METHOD(getCurrentVoiceOverState:(RCTResponseSenderBlock)callback
+                  error:(__unused RCTResponseSenderBlock)error)
+{
+  callback(@[@(_isVoiceOverEnabled)]);
+}
+
 @end
 
 @implementation RCTBridge (RCTAccessibilityManager)