Fabric: Polishing RCTSurfacePresenter

Summary:
Now RCTSurfacePresenter is uniquely responsible for:
* Starting and stopping JS apps;
* Restarting JS apps during hot-reload;
* Recreating Scheduler during hot-reload.

Reviewed By: mdvacca

Differential Revision: D9931318

fbshipit-source-id: a6a3fb58814222f71cc6cb2caad620ed6319089d

React/Fabric/RCTSurfacePresenter.h

@@ -37,6 +37,9 @@ NS_ASSUME_NONNULL_BEGIN
  */
 - (void)registerSurface:(RCTFabricSurface *)surface;
 - (void)unregisterSurface:(RCTFabricSurface *)surface;
+- (void)setProps:(NSDictionary *)props
+         surface:(RCTFabricSurface *)surface;
+
 - (nullable RCTFabricSurface *)surfaceForRootTag:(ReactTag)rootTag;
 
 /**
@@ -57,6 +60,9 @@ NS_ASSUME_NONNULL_BEGIN
 
 @interface RCTSurfacePresenter (Deprecated)
 
+@property (nonatomic) std::function<facebook::react::UIManagerInstaller> uiManagerInstaller;
+@property (nonatomic) std::function<facebook::react::UIManagerUninstaller> uiManagerUninstaller;
+
 /**
  * We need to expose `uiManager` for registration
  * purposes. Eventually, we will move this down to C++ side.

React/Fabric/RCTSurfacePresenter.mm

@@ -38,11 +38,12 @@ using namespace facebook::react;
 @end
 
 @implementation RCTSurfacePresenter {
-  RCTScheduler *_scheduler;
+  RCTScheduler *_Nullable _scheduler;
   RCTMountingManager *_mountingManager;
   RCTBridge *_bridge;
   RCTBridge *_batchedBridge;
   RCTSurfaceRegistry *_surfaceRegistry;
+  SharedContextContainer _contextContainer;
 }
 
 - (instancetype)initWithBridge:(RCTBridge *)bridge
@@ -69,10 +70,10 @@ using namespace facebook::react;
     void *imageLoader = (__bridge void *)[[RCTBridge currentBridge] imageLoader];
     contextContainer->registerInstance(std::make_shared<ImageManager>(imageLoader));
 
-    _scheduler = [[RCTScheduler alloc] initWithContextContainer:contextContainer];
-    _scheduler.delegate = self;
+    _contextContainer = contextContainer;
 
     _surfaceRegistry = [[RCTSurfaceRegistry alloc] init];
+
     _mountingManager = [[RCTMountingManager alloc] init];
     _mountingManager.delegate = self;
 
@@ -94,18 +95,19 @@ using namespace facebook::react;
   [[NSNotificationCenter defaultCenter] removeObserver:self];
 }
 
-#pragma mark - RCTSchedulerDelegate
-
-- (void)schedulerDidFinishTransaction:(facebook::react::ShadowViewMutationList)mutations
-                                        rootTag:(ReactTag)rootTag
+- (void)createSchedulerIfNeeded
 {
-  [_mountingManager performTransactionWithMutations:mutations
-                                            rootTag:rootTag];
+  if (_scheduler) {
+    return;
+  }
+
+  _scheduler = [[RCTScheduler alloc] initWithContextContainer:_contextContainer];
+  _scheduler.delegate = self;
 }
 
-- (void)schedulerDidRequestPreliminaryViewAllocationWithComponentName:(NSString *)componentName
+- (void)ensureSchedulerDoesExist
 {
-  [_mountingManager preliminaryCreateComponentViewWithName:componentName];
+  RCTAssert(_scheduler, @"RCTSurfacePresenter: RCTScheduler instance must be already instantiated at this point.");
 }
 
 #pragma mark - Internal Surface-dedicated Interface
@@ -113,20 +115,25 @@ using namespace facebook::react;
 - (void)registerSurface:(RCTFabricSurface *)surface
 {
   [_surfaceRegistry registerSurface:surface];
-  [_scheduler registerRootTag:surface.rootTag];
-  [self runSurface:surface];
 
-  // FIXME: mutation MUST produce instruction for root node.
-  [_mountingManager.componentViewRegistry dequeueComponentViewWithName:@"Root" tag:surface.rootTag];
+  [self startSurface:surface];
 }
 
 - (void)unregisterSurface:(RCTFabricSurface *)surface
 {
   [self stopSurface:surface];
-  [_scheduler unregisterRootTag:surface.rootTag];
+
   [_surfaceRegistry unregisterSurface:surface];
 }
 
+- (void)setProps:(NSDictionary *)props
+         surface:(RCTFabricSurface *)surface
+{
+  // This implementation is suboptimal indeed but still better than nothing for now.
+  [self stopSurface:surface];
+  [self startSurface:surface];
+}
+
 - (RCTFabricSurface *)surfaceForRootTag:(ReactTag)rootTag
 {
   return [_surfaceRegistry surfaceForRootTag:rootTag];
@@ -136,6 +143,8 @@ using namespace facebook::react;
                       maximumSize:(CGSize)maximumSize
                           surface:(RCTFabricSurface *)surface
 {
+  [self ensureSchedulerDoesExist];
+
   LayoutContext layoutContext;
   layoutContext.pointScaleFactor = RCTScreenScale();
   LayoutConstraints layoutConstraints = {};
@@ -151,6 +160,8 @@ using namespace facebook::react;
            maximumSize:(CGSize)maximumSize
                surface:(RCTFabricSurface *)surface
 {
+  [self ensureSchedulerDoesExist];
+
   LayoutContext layoutContext;
   layoutContext.pointScaleFactor = RCTScreenScale();
   LayoutConstraints layoutConstraints = {};
@@ -162,53 +173,101 @@ using namespace facebook::react;
                                             rootTag:surface.rootTag];
 }
 
-- (void)runSurface:(RCTFabricSurface *)surface
+- (void)startSurface:(RCTFabricSurface *)surface
 {
+  [_mountingManager.componentViewRegistry dequeueComponentViewWithName:@"Root" tag:surface.rootTag];
+
+  [self createSchedulerIfNeeded];
+  [_scheduler registerRootTag:surface.rootTag];
+
+  [self setMinimumSize:surface.minimumSize
+           maximumSize:surface.maximumSize
+               surface:surface];
+
+  // TODO: Move this down to Scheduler.
   NSDictionary *applicationParameters = @{
     @"rootTag": @(surface.rootTag),
     @"initialProps": surface.properties,
   };
-
-  [_batchedBridge enqueueJSCall:@"AppRegistry" method:@"runApplication" args:@[surface.moduleName, applicationParameters] completion:NULL];
+  [self->_batchedBridge enqueueJSCall:@"AppRegistry" method:@"runApplication" args:@[surface.moduleName, applicationParameters] completion:NULL];
 }
 
 - (void)stopSurface:(RCTFabricSurface *)surface
 {
+  // TODO: Move this down to Scheduler.
   [_batchedBridge enqueueJSCall:@"ReactFabric" method:@"unmountComponentAtNode" args:@[@(surface.rootTag)] completion:NULL];
+
+  [self ensureSchedulerDoesExist];
+  [_scheduler unregisterRootTag:surface.rootTag];
+
+  UIView<RCTComponentViewProtocol> *rootView = [_mountingManager.componentViewRegistry componentViewByTag:surface.rootTag];
+  [_mountingManager.componentViewRegistry enqueueComponentViewWithName:@"Root" tag:surface.rootTag componentView:rootView];
+
+  [surface _unsetStage:(RCTSurfaceStagePrepared | RCTSurfaceStageMounted)];
+}
+
+- (void)startAllSurfaces
+{
+  for (RCTFabricSurface *surface in _surfaceRegistry.enumerator) {
+    [self startSurface:surface];
+  }
+}
+
+- (void)stopAllSurfaces
+{
+  for (RCTFabricSurface *surface in _surfaceRegistry.enumerator) {
+    [self stopSurface:surface];
+  }
+}
+
+#pragma mark - RCTSchedulerDelegate
+
+- (void)schedulerDidFinishTransaction:(facebook::react::ShadowViewMutationList)mutations
+                                        rootTag:(ReactTag)rootTag
+{
+  RCTFabricSurface *surface = [_surfaceRegistry surfaceForRootTag:rootTag];
+
+  [surface _setStage:RCTSurfaceStagePrepared];
+
+  [_mountingManager performTransactionWithMutations:mutations
+                                            rootTag:rootTag];
+}
+
+- (void)schedulerDidRequestPreliminaryViewAllocationWithComponentName:(NSString *)componentName
+{
+  [_mountingManager preliminaryCreateComponentViewWithName:componentName];
 }
 
 #pragma mark - RCTMountingManagerDelegate
 
 - (void)mountingManager:(RCTMountingManager *)mountingManager willMountComponentsWithRootTag:(ReactTag)rootTag
 {
-  RCTIsMainQueue();
-  // TODO: Propagate state change to Surface.
+  RCTAssertMainQueue();
+
+  // Does nothing.
 }
 
 - (void)mountingManager:(RCTMountingManager *)mountingManager didMountComponentsWithRootTag:(ReactTag)rootTag
 {
-  RCTIsMainQueue();
+  RCTAssertMainQueue();
+
   RCTFabricSurface *surface = [_surfaceRegistry surfaceForRootTag:rootTag];
-
-  // FIXME: Implement proper state propagation mechanism.
-  [surface _setStage:RCTSurfaceStageSurfaceDidInitialRendering];
-  [surface _setStage:RCTSurfaceStageSurfaceDidInitialLayout];
-  [surface _setStage:RCTSurfaceStageSurfaceDidInitialMounting];
-
-  UIView *rootComponentView = [_mountingManager.componentViewRegistry componentViewByTag:rootTag];
-
-  surface.view.rootView = (RCTSurfaceRootView *)rootComponentView;
+  RCTSurfaceStage stage = surface.stage;
+  if (stage & RCTSurfaceStagePrepared) {
+    // We have to progress the stage only if the preparing phase is done.
+    if ([surface _setStage:RCTSurfaceStageMounted]) {
+      UIView *rootComponentView = [_mountingManager.componentViewRegistry componentViewByTag:rootTag];
+      surface.view.rootView = (RCTSurfaceRootView *)rootComponentView;
+    }
+  }
 }
 
 #pragma mark - Bridge events
 
 - (void)handleBridgeWillReloadNotification:(NSNotification *)notification
 {
-  // TODO: Define a lifecycle contract for the pieces involved here including the scheduler, mounting manager, and
-  // the surface registry. For now simply recreate the scheduler on reload.
-  // The goal is to deallocate the Scheduler and its underlying references before the JS runtime is destroyed.
-  _scheduler = [[RCTScheduler alloc] init];
-  _scheduler.delegate = self;
+  [self stopAllSurfaces];
+  _scheduler = nil;
 }
 
 - (void)handleJavaScriptDidLoadNotification:(NSNotification *)notification
@@ -216,6 +275,8 @@ using namespace facebook::react;
   RCTBridge *bridge = notification.userInfo[@"bridge"];
   if (bridge != _batchedBridge) {
     _batchedBridge = bridge;
+
+    [self startAllSurfaces];
   }
 }
 
@@ -233,6 +294,26 @@ using namespace facebook::react;
   return _bridge;
 }
 
+- (void)setUiManagerInstaller:(std::function<facebook::react::UIManagerInstaller>)uiManagerInstaller
+{
+  _contextContainer->registerInstance(uiManagerInstaller, "uimanager-installer");
+}
+
+- (std::function<facebook::react::UIManagerInstaller>)uiManagerInstaller
+{
+  return _contextContainer->getInstance<std::function<facebook::react::UIManagerInstaller>>("uimanager-installer");
+}
+
+- (void)setUiManagerUninstaller:(std::function<facebook::react::UIManagerUninstaller>)uiManagerUninstaller
+{
+  _contextContainer->registerInstance(uiManagerUninstaller, "uimanager-uninstaller");
+}
+
+- (std::function<facebook::react::UIManagerUninstaller>)uiManagerUninstaller
+{
+  return _contextContainer->getInstance<std::function<facebook::react::UIManagerUninstaller>>("uimanager-uninstaller");
+}
+
 @end
 
 @implementation RCTBridge (RCTSurfacePresenter)

React/Fabric/Surface/RCTFabricSurface.mm

@@ -162,8 +162,7 @@
     _properties = [properties copy];
   }
 
-  // TODO: Implement this in RCTSurfacePresenter.
-  // [_surfacePresenter setProps:properties surface:self];
+  [_surfacePresenter setProps:properties surface:self];
 }
 
 #pragma mark - Layout