Fabric: Introducing `RootShadowNode`

Summary: `RootShadowNode` is a dedicated class for managing the root node.

Reviewed By: mdvacca

Differential Revision: D7857050

fbshipit-source-id: f15f4b177f03cea4c0fd5a60d761ee2745319d77

ReactCommon/fabric/core/shadownode/ConcreteShadowNode.h

@@ -81,7 +81,6 @@ public:
 
   const SharedConcreteProps getProps() const {
     assert(std::dynamic_pointer_cast<const PropsT>(props_));
-
     return std::static_pointer_cast<const PropsT>(props_);
   }
 

ReactCommon/fabric/uimanager/Scheduler.h

@@ -9,16 +9,11 @@
 #include <fabric/uimanager/SchedulerDelegate.h>
 #include <fabric/uimanager/UIManagerDelegate.h>
 #include <fabric/view/ViewShadowNode.h>
+#include <fabric/view/RootShadowNode.h>
 
 namespace facebook {
 namespace react {
 
-/*
- * We expect having a dedicated subclass for root shadow node.
- */
-using SharedRootShadowNode = SharedViewShadowNode;
-using RootShadowNode = ViewShadowNode;
-
 class FabricUIManager;
 
 /*

ReactCommon/fabric/view/BUCK

@@ -22,6 +22,7 @@ rn_xplat_cxx_library(
         [
             ("", "*.h"),
             ("accessibility", "*.h"),
+            ("root", "*.h"),
             ("yoga", "*.h"),
         ],
         prefix = "fabric/view",

ReactCommon/fabric/view/root/RootProps.cpp

@@ -0,0 +1,45 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#include "RootProps.h"
+
+#include "yogaValuesConversions.h"
+
+namespace facebook {
+namespace react {
+
+void RootProps::applyLayoutConstraints(const LayoutConstraints &layoutConstraints) {
+  ensureUnsealed();
+
+  layoutConstraints_ = layoutConstraints;
+
+  yogaStyle_.minDimensions[YGDimensionWidth] =
+    yogaStyleValueFromFloat(layoutConstraints.minimumSize.width);
+  yogaStyle_.minDimensions[YGDimensionHeight] =
+    yogaStyleValueFromFloat(layoutConstraints.minimumSize.height);
+
+  yogaStyle_.maxDimensions[YGDimensionWidth] =
+    yogaStyleValueFromFloat(layoutConstraints.maximumSize.width);
+  yogaStyle_.maxDimensions[YGDimensionHeight] =
+    yogaStyleValueFromFloat(layoutConstraints.maximumSize.height);
+}
+
+void RootProps::applyLayoutContext(const LayoutContext &layoutContext) {
+  ensureUnsealed();
+  layoutContext_ = layoutContext;
+}
+
+LayoutConstraints RootProps::getLayoutConstraints() const {
+  return layoutConstraints_;
+}
+
+LayoutContext RootProps::getLayoutContext() const {
+  return layoutContext_;
+}
+
+} // namespace react
+} // namespace facebook

ReactCommon/fabric/view/root/RootProps.h

@@ -0,0 +1,44 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#pragma once
+
+#include <memory>
+
+#include <fabric/core/LayoutConstraints.h>
+#include <fabric/core/LayoutContext.h>
+#include <fabric/view/ViewProps.h>
+
+namespace facebook {
+namespace react {
+
+class RootProps;
+
+using SharedRootProps = std::shared_ptr<const RootProps>;
+
+class RootProps final:
+  public ViewProps {
+
+public:
+
+  /*
+   * Same semantic as `apply()` but LayoutConstraints & LayoutContext specific.
+   */
+  void applyLayoutConstraints(const LayoutConstraints &layoutConstraints);
+  void applyLayoutContext(const LayoutContext &layoutContext);
+
+  LayoutConstraints getLayoutConstraints() const;
+  LayoutContext getLayoutContext() const;
+
+private:
+
+  LayoutConstraints layoutConstraints_;
+  LayoutContext layoutContext_;
+};
+
+} // namespace react
+} // namespace facebook

ReactCommon/fabric/view/root/RootShadowNode.cpp

@@ -0,0 +1,23 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#include "RootShadowNode.h"
+
+namespace facebook {
+namespace react {
+
+ComponentName RootShadowNode::getComponentName() const {
+  return ComponentName("RootView");
+}
+
+void RootShadowNode::layout() {
+  ensureUnsealed();
+  layout(getProps()->getLayoutContext());
+}
+
+} // namespace react
+} // namespace facebook

ReactCommon/fabric/view/root/RootShadowNode.h

@@ -0,0 +1,50 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#pragma once
+
+#include <memory>
+
+#include <fabric/core/LayoutContext.h>
+#include <fabric/view/RootProps.h>
+#include <fabric/view/ConcreteViewShadowNode.h>
+
+namespace facebook {
+namespace react {
+
+class RootShadowNode;
+
+using SharedRootShadowNode = std::shared_ptr<const RootShadowNode>;
+using UnsharedRootShadowNode = std::shared_ptr<RootShadowNode>;
+
+/*
+ * `ShadowNode` for the root component.
+ * Besides all functionality of the `View` component, `RootShadowNode` contains
+ * props which represent external layout constraints and context of the
+ * shadow tree.
+ */
+class RootShadowNode final:
+  public ConcreteViewShadowNode<RootProps> {
+
+public:
+
+  using ConcreteViewShadowNode::ConcreteViewShadowNode;
+
+  ComponentName getComponentName() const override;
+
+  /*
+   * Layouts the shadow tree.
+   */
+  void layout();
+
+private:
+
+  using YogaLayoutableShadowNode::layout;
+};
+
+} // namespace react
+} // namespace facebook