Introduction of RCTRootViewDelegate

Reviewed By: adamjernst

Differential Revision: D2532327

fb-gh-sync-id: 0d018a6c2842f8021718fb7387ee6acb5d894645

React/Base/RCTRootView.h

@@ -11,12 +11,14 @@
 
 #import "RCTBridge.h"
 
+@protocol RCTRootViewDelegate;
+
 /**
  * This enum is used to define size flexibility type of the root view.
  * If a dimension is flexible, the view will recalculate that dimension
  * so the content fits. Recalculations are performed when the root's frame,
  * size flexibility mode or content size changes. After a recalculation,
- * TODO:<DelegateName> will be called with the new size passed as an argument.
+ * rootViewDidChangeIntrinsicSize method of the RCTRootViewDelegate will be called.
  */
 typedef NS_ENUM(NSInteger, RCTRootViewSizeFlexibility) {
   RCTRootViewSizeFlexibilityNone = 0,
@@ -90,6 +92,17 @@ extern NSString *const RCTContentDidAppearNotification;
  */
 @property (nonatomic, assign) RCTRootViewSizeFlexibility sizeFlexibility;
 
+/**
+ * The size of the root view's content. This is set right before the
+ * rootViewDidChangeIntrinsicSize method of RCTRootViewDelegate is called.
+ */
+@property (readonly, nonatomic, assign) CGSize intrinsicSize;
+
+/**
+ * The delegate that handles intrinsic size updates.
+ */
+@property (nonatomic, weak) id<RCTRootViewDelegate> delegate;
+
 /**
  * The backing view controller of the root view.
  */

React/Base/RCTRootView.m

@@ -8,6 +8,8 @@
  */
 
 #import "RCTRootView.h"
+#import "RCTRootViewDelegate.h"
+#import "RCTRootViewInternal.h"
 
 #import <objc/runtime.h>
 
@@ -206,6 +208,14 @@ RCT_NOT_IMPLEMENTED(- (instancetype)initWithCoder:(NSCoder *)aDecoder)
   };
 }
 
+- (void)setIntrinsicSize:(CGSize)intrinsicSize
+{
+  if (!CGSizeEqualToSize(_intrinsicSize, intrinsicSize)) {
+    _intrinsicSize = intrinsicSize;
+    [_delegate rootViewDidChangeIntrinsicSize:self];
+  }
+}
+
 - (NSNumber *)reactTag
 {
   return _contentView.reactTag;

React/Base/RCTRootViewDelegate.h

@@ -0,0 +1,24 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+#import <Foundation/Foundation.h>
+
+@class RCTRootView;
+
+@protocol RCTRootViewDelegate <NSObject>
+/**
+ * Called after the root view's content is updated to a new size.
+ *
+ * The delegate can use this callback to appropriately resize the root view frame to fit the new
+ * content view size. The view will not resize itself. The new content size is available via the
+ * intrinsicSize propery of the root view.
+ */
+- (void)rootViewDidChangeIntrinsicSize:(RCTRootView *)rootView;
+
+@end

React/Base/RCTRootViewInternal.h

@@ -0,0 +1,23 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+#import "RCTRootView.h"
+
+/**
+ * The interface provides a set of functions that allow other internal framework
+ * classes to change the RCTRootViews's internal state.
+ */
+@interface RCTRootView ()
+
+/**
+ * This setter should be used only by RCTUIManager on react root view size update.
+ */
+@property (readwrite, nonatomic, assign) CGSize intrinsicSize;
+
+@end

React/Modules/RCTUIManager.m

@@ -24,6 +24,7 @@
 #import "RCTLog.h"
 #import "RCTProfile.h"
 #import "RCTRootView.h"
+#import "RCTRootViewInternal.h"
 #import "RCTScrollableProtocol.h"
 #import "RCTShadowView.h"
 #import "RCTSparseArray.h"
@@ -357,10 +358,6 @@ extern NSString *RCTBridgeModuleNameForClass(Class cls);
     RCTAssert(rootShadowView != nil, @"Could not locate root view with tag #%@", reactTag);
 
     if (RCTIsReactRootView(reactTag)) {
-      if (CGRectEqualToRect(frame, rootShadowView.frame) && rootShadowView.sizeFlexibility == sizeFlexibility) {
-        // This is to prevent infinite recursion when the frame update is trigerred by TODO(8608567):<DelegateName>
-        return;
-      }
       rootShadowView.frame = frame;
       rootShadowView.sizeFlexibility = sizeFlexibility;
     } else {
@@ -491,6 +488,22 @@ extern NSString *RCTBridgeModuleNameForClass(Class cls);
         },
       });
     }
+
+    if (RCTIsReactRootView(shadowView.reactTag)) {
+      NSNumber *reactTag = shadowView.reactTag;
+      CGSize contentSize = shadowView.frame.size;
+
+      dispatch_async(dispatch_get_main_queue(), ^{
+        UIView *view = _viewRegistry[reactTag];
+        RCTAssert(view != nil, @"view (for ID %@) not found", reactTag);
+
+        RCTRootView *rootView = (RCTRootView *)[view superview];
+        RCTAssert(rootView != nil, @"View with react tag %@ has not a superview", reactTag);
+
+        rootView.intrinsicSize = contentSize;
+      });
+    }
+
     if (block) {
       [updateBlocks addObject:block];
     }