Fabric: `constraintLayout` is now return boolean

Summary:
Setting the right expectations: setting layout constraints might fail. Nothing really changed.
Implementing a reliable `constraintLayout` which locks instead of returning immediately requires some additional work and new/additional API.

Reviewed By: mdvacca

Differential Revision: D10159457

fbshipit-source-id: bb23c7de105629ef086ae0b04667ff32c6ffb81d

React/Fabric/RCTScheduler.h

@@ -49,7 +49,7 @@ NS_ASSUME_NONNULL_BEGIN
                                 layoutContext:(facebook::react::LayoutContext)layoutContext
                                     surfaceId:(facebook::react::SurfaceId)surfaceId;
 
-- (void)constraintSurfaceLayoutWithLayoutConstraints:(facebook::react::LayoutConstraints)layoutConstraints
+- (BOOL)constraintSurfaceLayoutWithLayoutConstraints:(facebook::react::LayoutConstraints)layoutConstraints
                                        layoutContext:(facebook::react::LayoutContext)layoutContext
                                            surfaceId:(facebook::react::SurfaceId)surfaceId;
 

React/Fabric/RCTScheduler.mm

@@ -80,11 +80,11 @@ private:
   return RCTCGSizeFromSize(_scheduler->measureSurface(surfaceId, layoutConstraints, layoutContext));
 }
 
-- (void)constraintSurfaceLayoutWithLayoutConstraints:(LayoutConstraints)layoutConstraints
+- (BOOL)constraintSurfaceLayoutWithLayoutConstraints:(LayoutConstraints)layoutConstraints
                                        layoutContext:(LayoutContext)layoutContext
                                            surfaceId:(SurfaceId)surfaceId
 {
-  _scheduler->constraintSurfaceLayout(surfaceId, layoutConstraints, layoutContext);
+  return _scheduler->constraintSurfaceLayout(surfaceId, layoutConstraints, layoutContext);
 }
 
 @end

React/Fabric/RCTSurfacePresenter.h

@@ -57,8 +57,9 @@ NS_ASSUME_NONNULL_BEGIN
 
 /**
  * Sets `minimumSize` and `maximumSize` layout constraints for the Surface.
+ * Returns `YES` if the operation finished successfully.
  */
-- (void)setMinimumSize:(CGSize)minimumSize
+- (BOOL)setMinimumSize:(CGSize)minimumSize
            maximumSize:(CGSize)maximumSize
                surface:(RCTFabricSurface *)surface;
 

React/Fabric/RCTSurfacePresenter.mm

@@ -119,7 +119,7 @@ using namespace facebook::react;
                                                     surfaceId:surface.rootTag];
 }
 
-- (void)setMinimumSize:(CGSize)minimumSize
+- (BOOL)setMinimumSize:(CGSize)minimumSize
            maximumSize:(CGSize)maximumSize
                surface:(RCTFabricSurface *)surface
 {
@@ -129,9 +129,9 @@ using namespace facebook::react;
   layoutConstraints.minimumSize = RCTSizeFromCGSize(minimumSize);
   layoutConstraints.maximumSize = RCTSizeFromCGSize(maximumSize);
 
-  [self._scheduler constraintSurfaceLayoutWithLayoutConstraints:layoutConstraints
-                                                  layoutContext:layoutContext
-                                                      surfaceId:surface.rootTag];
+  return [self._scheduler constraintSurfaceLayoutWithLayoutConstraints:layoutConstraints
+                                                         layoutContext:layoutContext
+                                                             surfaceId:surface.rootTag];
 }
 
 #pragma mark - Private

React/Fabric/Surface/RCTFabricSurface.mm

@@ -216,9 +216,9 @@
     _minimumSize = minimumSize;
   }
 
-  return [_surfacePresenter setMinimumSize:minimumSize
-                               maximumSize:maximumSize
-                                   surface:self];
+  [_surfacePresenter setMinimumSize:minimumSize
+                        maximumSize:maximumSize
+                            surface:self];
 }
 
 - (CGSize)minimumSize

ReactCommon/fabric/uimanager/Scheduler.cpp

@@ -94,7 +94,7 @@ Size Scheduler::measureSurface(
   return shadowTree->measure(layoutConstraints, layoutContext);
 }
 
-void Scheduler::constraintSurfaceLayout(
+bool Scheduler::constraintSurfaceLayout(
   SurfaceId surfaceId,
   const LayoutConstraints &layoutConstraints,
   const LayoutContext &layoutContext
@@ -135,7 +135,7 @@ void Scheduler::uiManagerDidFinishTransaction(Tag rootTag, const SharedShadowNod
     return;
   }
 
-  return iterator->second->complete(rootChildNodes);
+  iterator->second->complete(rootChildNodes);
 }
 
 void Scheduler::uiManagerDidCreateShadowNode(const SharedShadowNode &shadowNode) {

ReactCommon/fabric/uimanager/Scheduler.h

@@ -48,7 +48,15 @@ public:
     const LayoutContext &layoutContext
   ) const;
 
-  void constraintSurfaceLayout(
+  /*
+   * Applies given `layoutConstraints` and `layoutContext` to a Surface.
+   * The user interface will be relaid out as a result. The operation will be
+   * performed synchronously (including mounting) if the method is called
+   * on the main thread.
+   * Returns `true` if the operation finished successfully.
+   * Can be called from any thread.
+   */
+  bool constraintSurfaceLayout(
     SurfaceId surfaceId,
     const LayoutConstraints &layoutConstraints,
     const LayoutContext &layoutContext

ReactCommon/fabric/uimanager/ShadowTree.cpp

@@ -51,9 +51,9 @@ Size ShadowTree::measure(const LayoutConstraints &layoutConstraints, const Layou
   return newRootShadowNode->getLayoutMetrics().frame.size;
 }
 
-void ShadowTree::constraintLayout(const LayoutConstraints &layoutConstraints, const LayoutContext &layoutContext) const {
+bool ShadowTree::constraintLayout(const LayoutConstraints &layoutConstraints, const LayoutContext &layoutContext) const {
   auto newRootShadowNode = cloneRootShadowNode(layoutConstraints, layoutContext);
-  complete(newRootShadowNode);
+  return complete(newRootShadowNode);
 }
 
 #pragma mark - Commiting
@@ -66,7 +66,7 @@ UnsharedRootShadowNode ShadowTree::cloneRootShadowNode(const LayoutConstraints &
   return newRootShadowNode;
 }
 
-void ShadowTree::complete(const SharedShadowNodeUnsharedList &rootChildNodes) const {
+bool  ShadowTree::complete(const SharedShadowNodeUnsharedList &rootChildNodes) const {
   auto oldRootShadowNode = getRootShadowNode();
   auto newRootShadowNode =
     std::make_shared<RootShadowNode>(
@@ -76,10 +76,10 @@ void ShadowTree::complete(const SharedShadowNodeUnsharedList &rootChildNodes) co
       }
     );
 
-  complete(newRootShadowNode);
+  return complete(newRootShadowNode);
 }
 
-void ShadowTree::complete(UnsharedRootShadowNode newRootShadowNode) const {
+bool ShadowTree::complete(UnsharedRootShadowNode newRootShadowNode) const {
   SharedRootShadowNode oldRootShadowNode = getRootShadowNode();
 
   newRootShadowNode->layout();
@@ -91,13 +91,17 @@ void ShadowTree::complete(UnsharedRootShadowNode newRootShadowNode) const {
     *newRootShadowNode
   );
 
-  if (commit(oldRootShadowNode, newRootShadowNode, mutations)) {
-    emitLayoutEvents(mutations);
-
-    if (delegate_) {
-      delegate_->shadowTreeDidCommit(*this, mutations);
-    }
+  if (!commit(oldRootShadowNode, newRootShadowNode, mutations)) {
+    return false;
   }
+
+  emitLayoutEvents(mutations);
+
+  if (delegate_) {
+    delegate_->shadowTreeDidCommit(*this, mutations);
+  }
+
+  return true;
 }
 
 bool ShadowTree::commit(

ReactCommon/fabric/uimanager/ShadowTree.h

@@ -49,19 +49,19 @@ public:
   /*
    * Applies given `layoutConstraints` and `layoutContext` and commit
    * the new shadow tree.
-   * Returns `true` if the operation is finished successfully.
+   * Returns `true` if the operation finished successfully.
    * Can be called from any thread.
    */
-  void constraintLayout(const LayoutConstraints &layoutConstraints, const LayoutContext &layoutContext) const;
+  bool constraintLayout(const LayoutConstraints &layoutConstraints, const LayoutContext &layoutContext) const;
 
 #pragma mark - Application
 
   /*
    * Create a new shadow tree with given `rootChildNodes` and commit.
    * Can be called from any thread.
-   * Returns `true` if the operation is finished successfully.
+   * Returns `true` if the operation finished successfully.
    */
-  void complete(const SharedShadowNodeUnsharedList &rootChildNodes) const;
+  bool complete(const SharedShadowNodeUnsharedList &rootChildNodes) const;
 
 #pragma mark - Delegate
 
@@ -76,7 +76,7 @@ public:
 private:
 
   UnsharedRootShadowNode cloneRootShadowNode(const LayoutConstraints &layoutConstraints, const LayoutContext &layoutContext) const;
-  void complete(UnsharedRootShadowNode newRootShadowNode) const;
+  bool complete(UnsharedRootShadowNode newRootShadowNode) const;
   bool commit(
     const SharedRootShadowNode &oldRootShadowNode,
     const SharedRootShadowNode &newRootShadowNode,