Nobody outside RCTTouchHandler should treat it as UIGestureRecognizer subclass

Reviewed By: mmmulani

Differential Revision: D4387821

fbshipit-source-id: 8060772a5de669eeaca159ceac13b995d7518a1b

Author: shergin

React/Base/RCTRootView.m

@@ -380,7 +380,7 @@ - (instancetype)initWithFrame:(CGRect)frame
     _bridge = bridge;
     self.reactTag = reactTag;
     _touchHandler = [[RCTTouchHandler alloc] initWithBridge:_bridge];
-    [self addGestureRecognizer:_touchHandler];
+    [_touchHandler attachToView:self];
     [_bridge.uiManager registerRootView:self withSizeFlexibility:sizeFlexibility];
     self.layer.backgroundColor = NULL;
   }

React/Base/RCTTouchHandler.h

@@ -16,6 +16,10 @@
 @interface RCTTouchHandler : UIGestureRecognizer
 
 - (instancetype)initWithBridge:(RCTBridge *)bridge NS_DESIGNATED_INITIALIZER;
+
+- (void)attachToView:(UIView *)view;
+- (void)detachFromView:(UIView *)view;
+
 - (void)cancel;
 
 @end

React/Base/RCTTouchHandler.m

@@ -64,6 +64,21 @@ - (instancetype)initWithBridge:(RCTBridge *)bridge
 
 RCT_NOT_IMPLEMENTED(- (instancetype)initWithTarget:(id)target action:(SEL)action)
 
+- (void)attachToView:(UIView *)view
+{
+  RCTAssert(self.view == nil, @"RCTTouchHandler already has attached view.");
+
+  [view addGestureRecognizer:self];
+}
+
+- (void)detachFromView:(UIView *)view
+{
+  RCTAssertParam(view);
+  RCTAssert(self.view == view, @"RCTTouchHandler attached to another view.");
+
+  [view removeGestureRecognizer:self];
+}
+
 typedef NS_ENUM(NSInteger, RCTTouchEventType) {
   RCTTouchEventTypeStart,
   RCTTouchEventTypeMove,

React/Views/RCTModalHostView.m

@@ -9,15 +9,15 @@
 
 #import "RCTModalHostView.h"
 
+#import <UIKit/UIKit.h>
+
 #import "RCTAssert.h"
 #import "RCTBridge.h"
 #import "RCTModalHostViewController.h"
 #import "RCTTouchHandler.h"
 #import "RCTUIManager.h"
 #import "UIView+React.h"
 
-#import <UIKit/UIKit.h>
-
 @implementation RCTModalHostView
 {
   __weak RCTBridge *_bridge;
@@ -87,7 +87,7 @@ - (void)insertReactSubview:(UIView *)subview atIndex:(NSInteger)atIndex
 {
   RCTAssert(_reactSubview == nil, @"Modal view can only have one subview");
   [super insertReactSubview:subview atIndex:atIndex];
-  [subview addGestureRecognizer:_touchHandler];
+  [_touchHandler attachToView:subview];
   subview.autoresizingMask = UIViewAutoresizingFlexibleHeight |
                              UIViewAutoresizingFlexibleWidth;
 
@@ -99,7 +99,7 @@ - (void)removeReactSubview:(UIView *)subview
 {
   RCTAssert(subview == _reactSubview, @"Cannot remove view other than modal view");
   [super removeReactSubview:subview];
-  [subview removeGestureRecognizer:_touchHandler];
+  [_touchHandler detachFromView:subview];
   _reactSubview = nil;
 }
 

React/Views/RCTModalHostViewManager.m

@@ -12,7 +12,6 @@
 #import "RCTBridge.h"
 #import "RCTModalHostView.h"
 #import "RCTModalHostViewController.h"
-#import "RCTTouchHandler.h"
 #import "RCTShadowView.h"
 #import "RCTUtils.h"