Abstract internal Content Container from Scroll Container

README.md

@@ -52,27 +52,30 @@ import ShadowListContainer from 'shadowlist';
 ## API
 | Prop                       | Type                      | Required | Description                                     |
 |----------------------------|---------------------------|----------|-------------------------------------------------|
-| `data`                     | Array                     | Required | An array of data to be rendered in the list.    |
-| `contentContainerStyle`    | ViewStyle                 | Optional | These styles will be applied to the scroll view content container which wraps all of the child views.  |
-| `ListHeaderComponent`      | React component or null   | Optional | A custom component to render at the top of the list. |
+| `data`                     | Array                     | Required | An array of data to be rendered in the list. |
+| `keyExtractor`             | Function                  | Required | Used to extract a unique key for a given item at the specified index. |
+| `contentContainerStyle`    | ViewStyle                 | Optional | These styles will be applied to the scroll view content container which wraps all of the child views. |
+| `ListHeaderComponent`      | React component           | Optional | A custom component to render at the top of the list. |
 | `ListHeaderComponentStyle` | ViewStyle                 | Optional | Styling for internal View for `ListHeaderComponent` |
-| `ListFooterComponent`      | React component or null   | Optional | A custom component to render at the bottom of the list. |
+| `ListFooterComponent`      | React component           | Optional | A custom component to render at the bottom of the list. |
 | `ListFooterComponentStyle` | ViewStyle                 | Optional | Styling for internal View for `ListFooterComponent` |
-| `ListEmptyComponent`       | React component or null   | Optional | A custom component to render when the list is empty. |
+| `ListEmptyComponent`       | React component           | Optional | A custom component to render when the list is empty. |
 | `ListEmptyComponentStyle`  | ViewStyle                 | Optional | Styling for internal View for `ListEmptyComponent` |
 | `renderItem`               | Function                  | Required | A function to render each item in the list. It receives an object with `item` and `index` properties. |
 | `initialScrollIndex`       | Number                    | Optional | The initial index of the item to scroll to when the list mounts. |
 | `inverted`                 | Boolean                   | Optional | If true, the list will be rendered in an inverted order. |
 | `horizontal`               | Boolean                   | Optional | If true, renders items next to each other horizontally instead of stacked vertically. |
-| `onBatchLayout`            | `({ size: Int32 }) => void` | Optional | Called when a batch of layout calculations is complete. |
-| `onEndReached`             | `({ distanceFromEnd: Int32 }) => void` | Optional | Called when the end of the content is within `onEndReachedThreshold`. |
+| `onEndReached`             | Function                  | Optional | Called when the end of the content is within `onEndReachedThreshold`. |
 | `onEndReachedThreshold`    | Double                    | Optional | The threshold (in content length units) at which `onEndReached` is triggered. |
+| `onStartReached`           | Function                  | Optional | Called when the start of the content is within `onStartReachedThreshold`. |
+| `onStartReachedThreshold`  | Double                    | Optional | The threshold (in content length units) at which `onStartReached` is triggered. |
+
 
 ## Methods
 | Method          | Type                                | Description                                               |
 |-----------------|-------------------------------------|-----------------------------------------------------------|
-| `scrollToIndex` | `({ index: number; animated: boolean }) => void` | Scrolls the list to the specified index.                  |
-| `scrollToOffset`| `({ offset: number; animated: boolean }) => void` | Scrolls the list to the specified offset.                 |
+| `scrollToIndex` | Function                            | Scrolls the list to the specified index.                  |
+| `scrollToOffset`| Function                            | Scrolls the list to the specified offset.                 |
 
 ## Contributing
 
@@ -81,4 +84,3 @@ See the [contributing guide](CONTRIBUTING.md) to learn how to contribute to the
 ## License
 
 MIT
-

cpp/react/renderer/components/RNShadowListContainerSpec/ShadowListContainerEventEmitter.cpp

@@ -11,20 +11,19 @@ void ShadowListContainerEventEmitter::onVisibleChange(VisibleMetrics $event) con
   });
 }
 
-void ShadowListContainerEventEmitter::onBatchLayout(BatchLayout $event) const {
-  dispatchEvent("batchLayout", [$event = std::move($event)](jsi::Runtime &runtime) {
+void ShadowListContainerEventEmitter::onEndReached(EndReached $event) const {
+  dispatchEvent("endReached", [$event = std::move($event)](jsi::Runtime &runtime) {
     auto $payload = jsi::Object(runtime);
-    $payload.setProperty(runtime, "size", $event.size);
+    $payload.setProperty(runtime, "distanceFromEnd", $event.distanceFromEnd);
     return $payload;
   });
 }
 
-void ShadowListContainerEventEmitter::onEndReached(EndReached $event) const {
-  dispatchEvent("endReached", [$event = std::move($event)](jsi::Runtime &runtime) {
+void ShadowListContainerEventEmitter::onStartReached(StartReached $event) const {
+  dispatchEvent("startReached", [$event = std::move($event)](jsi::Runtime &runtime) {
     auto $payload = jsi::Object(runtime);
-    $payload.setProperty(runtime, "distanceFromEnd", $event.distanceFromEnd);
+    $payload.setProperty(runtime, "distanceFromStart", $event.distanceFromStart);
     return $payload;
   });
 }
-
 }

cpp/react/renderer/components/RNShadowListContainerSpec/ShadowListContainerEventEmitter.h

@@ -13,17 +13,17 @@ class ShadowListContainerEventEmitter : public ViewEventEmitter {
     int end;
   };
 
-  struct BatchLayout {
-    int size;
-  };
-
   struct EndReached {
     int distanceFromEnd;
   };
 
+  struct StartReached {
+    int distanceFromStart;
+  };
+
   void onVisibleChange(VisibleMetrics value) const;
-  void onBatchLayout(BatchLayout value) const;
   void onEndReached(EndReached value) const;
+  void onStartReached(StartReached value) const;
 };
 
 }

cpp/react/renderer/components/RNShadowListContainerSpec/ShadowListContainerProps.cpp

@@ -11,10 +11,9 @@ ShadowListContainerProps::ShadowListContainerProps(
 
   inverted(convertRawProp(context, rawProps, "inverted", sourceProps.inverted, {false})),
   horizontal(convertRawProp(context, rawProps, "horizontal", sourceProps.horizontal, {false})),
-  hasListHeaderComponent(convertRawProp(context, rawProps, "hasListHeaderComponent", sourceProps.hasListHeaderComponent, {false})),
-  hasListFooterComponent(convertRawProp(context, rawProps, "hasListFooterComponent", sourceProps.hasListFooterComponent, {false})),
   initialScrollIndex(convertRawProp(context, rawProps, "initialScrollIndex", sourceProps.initialScrollIndex, {0})),
-  onEndReachedThreshold(convertRawProp(context, rawProps, "onEndReachedThreshold", sourceProps.onEndReachedThreshold, {0}))
+  onEndReachedThreshold(convertRawProp(context, rawProps, "onEndReachedThreshold", sourceProps.onEndReachedThreshold, {0})),
+  onStartReachedThreshold(convertRawProp(context, rawProps, "onStartReachedThreshold", sourceProps.onStartReachedThreshold, {0}))
   {}
 
 }

cpp/react/renderer/components/RNShadowListContainerSpec/ShadowListContainerProps.h

@@ -12,10 +12,9 @@ class ShadowListContainerProps final : public ViewProps {
 
   bool inverted{false};
   bool horizontal{false};
-  bool hasListHeaderComponent{false};
-  bool hasListFooterComponent{false};
   int initialScrollIndex{0};
   double onEndReachedThreshold{0};
+  double onStartReachedThreshold{0};
 };
 
 }

cpp/react/renderer/components/RNShadowListContainerSpec/ShadowListContainerShadowNode.cpp

@@ -4,70 +4,4 @@ namespace facebook::react {
 
 extern const char ShadowListContainerComponentName[] = "ShadowListContainer";
 
-/*
- * Native layout function
- */
-void ShadowListContainerShadowNode::layout(LayoutContext layoutContext) {
-  ensureUnsealed();
-  ConcreteShadowNode::layout(layoutContext);
-
-  auto &props = getConcreteProps();
-  auto state = getStateData();
-
-  calculateContainerMeasurements(
-    layoutContext,
-    props.horizontal,
-    props.inverted
-  );
-
-  if (scrollContainer_.size != state.scrollContainer) {
-    state.scrollContainer = scrollContainer_.size;
-  }
-
-  if (scrollContent_.size != state.scrollContent) {
-    state.scrollContent = scrollContent_.size;
-    state.scrollContentTree = scrollContentTree_;
-  }
-
-  if (props.initialScrollIndex && props.horizontal) {
-    state.scrollPosition = Point{state.calculateItemOffset(props.initialScrollIndex), 0};
-  } else if (props.initialScrollIndex) {
-    state.scrollPosition = Point{0, state.calculateItemOffset(props.initialScrollIndex)};
-  } else if (props.inverted && props.horizontal) {
-    state.scrollPosition = Point{scrollContent_.size.width - scrollContainer_.size.width, 0};
-  } else if (props.inverted) {
-    state.scrollPosition = Point{0, scrollContent_.size.height - scrollContainer_.size.height};
-  } else {
-    state.scrollPosition = Point{0, 0};
-  }
-
-  setStateData(std::move(state));
-
-  getConcreteEventEmitter().onBatchLayout({
-    .size = static_cast<int>(scrollContentTree_.size())
-  });
-}
-
-/*
- * Measure visible container, and all childs aka list
- */
-void ShadowListContainerShadowNode::calculateContainerMeasurements(LayoutContext layoutContext, bool horizontal, bool inverted) {
-  auto scrollContent = Rect{};
-  auto scrollContentTree = ShadowListFenwickTree(yogaNode_.getChildCount());
-
-  for (std::size_t index = 0; index < yogaNode_.getChildCount(); ++index) {
-    auto childYogaNode = yogaNode_.getChild(index);
-    auto childNodeMetrics = shadowNodeFromContext(childYogaNode).getLayoutMetrics();
-    scrollContent.unionInPlace(childNodeMetrics.frame);
-    scrollContentTree[index] = Scrollable::getScrollContentItemSize(childNodeMetrics.frame.size, horizontal);
-  }
-
-  scrollContent_ = scrollContent;
-  scrollContainer_ = getLayoutMetrics().frame;
-  scrollContentTree_ = scrollContentTree;
-}
-
-YogaLayoutableShadowNode& ShadowListContainerShadowNode::shadowNodeFromContext(YGNodeConstRef yogaNode) {
-  return dynamic_cast<YogaLayoutableShadowNode&>(*static_cast<ShadowNode*>(YGNodeGetContext(yogaNode)));
-}
 }

cpp/react/renderer/components/RNShadowListContainerSpec/ShadowListContainerShadowNode.h

@@ -3,7 +3,6 @@
 #include "ShadowListContainerEventEmitter.h"
 #include "ShadowListContainerProps.h"
 #include "ShadowListContainerState.h"
-#include "ShadowListFenwickTree.hpp"
 #include <react/renderer/graphics/Point.h>
 #include <react/renderer/components/view/conversions.h>
 #include <react/renderer/components/view/ConcreteViewShadowNode.h>
@@ -26,24 +25,6 @@ class ShadowListContainerShadowNode final : public ConcreteViewShadowNode<
 
   public:
   using ConcreteViewShadowNode::ConcreteViewShadowNode;
-
-  void layout(LayoutContext layoutContext) override;
-
-  void calculateContainerMeasurements(LayoutContext layoutContext, bool horizontal, bool inverted);
-
-  private:
-
-  /*
-   * Measurements
-   */
-  Rect scrollContainer_;
-  Rect scrollContent_;
-  ShadowListFenwickTree scrollContentTree_;
-
-  /*
-   * Caster
-   */
-  static YogaLayoutableShadowNode& shadowNodeFromContext(YGNodeConstRef yogaNode);
 };
 
 }

cpp/react/renderer/components/RNShadowListContainerSpec/ShadowListContainerState.cpp

@@ -5,81 +5,9 @@ namespace facebook::react {
 ShadowListContainerState::ShadowListContainerState(
   Point scrollPosition,
   Size scrollContainer,
-  Size scrollContent,
-  ShadowListFenwickTree scrollContentTree) :
+  Size scrollContent) :
 
     scrollPosition(scrollPosition),
     scrollContainer(scrollContainer),
-    scrollContent(scrollContent),
-    scrollContentTree(scrollContentTree) {}
-
-/*
- * Measure layout and children metrics
- */
-ShadowListContainerExtendedMetrics ShadowListContainerState::calculateExtendedMetrics(
-  Point scrollPosition,
-  bool horizontal,
-  bool inverted) const {
-
-  auto virtualizedOffset = Scrollable::getVirtualizedOffset();
-  auto scrollPositionOffset = Scrollable::getScrollPositionOffset(scrollPosition, horizontal);
-  auto scrollContentSize = Scrollable::getScrollContentSize(scrollContent, horizontal);
-  auto scrollContainerSize = Scrollable::getScrollContainerSize(scrollContainer, horizontal);
-
-  auto visibleStartPixels = std::max<float>(0.f, static_cast<double>(scrollPositionOffset));
-  auto visibleEndPixels = std::min<float>(scrollContentSize, scrollPositionOffset + scrollContainerSize);
-
-  int visibleStartIndex = scrollContentTree.lower_bound(visibleStartPixels);
-  visibleStartIndex = std::max(0, visibleStartIndex - virtualizedOffset);
-
-  int visibleEndIndex = scrollContentTree.lower_bound(visibleEndPixels);
-  visibleEndIndex = std::min(scrollContentTree.size(), size_t(visibleEndIndex + virtualizedOffset));
-
-  int blankTopStartIndex = 0;
-  int blankTopEndIndex = std::max(0, visibleStartIndex - 1);
-
-  auto blankTopStartPixels = 0.0;
-  auto blankTopEndPixels = scrollContentTree.sum(blankTopStartIndex, blankTopEndIndex);
-
-  int blankBottomStartIndex = std::min(size_t(visibleEndIndex + 1), scrollContentTree.size());
-  int blankBottomEndIndex = scrollContentTree.size();
-
-  auto blankBottomStartPixels = scrollContentTree.sum(blankBottomStartIndex, scrollContentTree.size());
-  auto blankBottomEndPixels = scrollContentTree.sum(0, scrollContentTree.size());
-
-  return ShadowListContainerExtendedMetrics{
-    visibleStartIndex,
-    visibleEndIndex,
-    visibleStartPixels,
-    visibleEndPixels,
-    blankTopStartIndex,
-    blankTopEndIndex,
-    blankTopStartPixels,
-    blankTopEndPixels,
-    blankBottomStartIndex,
-    blankBottomEndIndex,
-    blankBottomStartPixels,
-    blankBottomEndPixels,
-  };
-}
-
-/*
- * Measure layout
- */
-ShadowListContainerLayoutMetrics ShadowListContainerState::calculateLayoutMetrics() const {
-  auto height = scrollContentTree.sum(0, scrollContentTree.size());
-
-  return ShadowListContainerLayoutMetrics{
-    height
-  };
-}
-
-float ShadowListContainerState::calculateItemOffset(int index) const {
-  return scrollContentTree.sum(0, index);
-}
-
-int ShadowListContainerState::countTree() const {
-  return scrollContentTree.size();
-}
-
+    scrollContent(scrollContent) {}
 }