YGNode.cpp

/*
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

#include "YGNode.h"
#include <algorithm>
#include <iostream>
#include "CompactValue.h"
#include "Utils.h"

using namespace facebook;
using facebook::yoga::detail::CompactValue;

YGNode::YGNode(YGNode&& node) {
  context_ = node.context_;
  flags = node.flags;
  measure_ = node.measure_;
  baseline_ = node.baseline_;
  print_ = node.print_;
  dirtied_ = node.dirtied_;
  style_ = node.style_;
  layout_ = node.layout_;
  lineIndex_ = node.lineIndex_;
  owner_ = node.owner_;
  children_ = std::move(node.children_);
  config_ = node.config_;
  resolvedDimensions_ = node.resolvedDimensions_;
  for (auto c : children_) {
    c->setOwner(c);
  }
}

YGNode::YGNode(const YGNode& node, YGConfigRef config) : YGNode{node} {
  config_ = config;
  if (config->useWebDefaults) {
    useWebDefaults();
  }
}

void YGNode::print(void* printContext) {
  if (print_.noContext != nullptr) {
    if (facebook::yoga::detail::getBooleanData(flags, printUsesContext_)) {
      print_.withContext(this, printContext);
    } else {
      print_.noContext(this);
    }
  }
}

YGFloatOptional YGNode::getLeadingPosition(
    const YGFlexDirection axis,
    const float axisSize) const {
  if (YGFlexDirectionIsRow(axis)) {
    auto leadingPosition = YGComputedEdgeValue(
        style_.position(), YGEdgeStart, CompactValue::ofUndefined());
    if (!leadingPosition.isUndefined()) {
      return YGResolveValue(leadingPosition, axisSize);
    }
  }

  auto leadingPosition = YGComputedEdgeValue(
      style_.position(), leading[axis], CompactValue::ofUndefined());

  return leadingPosition.isUndefined()
      ? YGFloatOptional{0}
      : YGResolveValue(leadingPosition, axisSize);
}

YGFloatOptional YGNode::getTrailingPosition(
    const YGFlexDirection axis,
    const float axisSize) const {
  if (YGFlexDirectionIsRow(axis)) {
    auto trailingPosition = YGComputedEdgeValue(
        style_.position(), YGEdgeEnd, CompactValue::ofUndefined());
    if (!trailingPosition.isUndefined()) {
      return YGResolveValue(trailingPosition, axisSize);
    }
  }

  auto trailingPosition = YGComputedEdgeValue(
      style_.position(), trailing[axis], CompactValue::ofUndefined());

  return trailingPosition.isUndefined()
      ? YGFloatOptional{0}
      : YGResolveValue(trailingPosition, axisSize);
}

bool YGNode::isLeadingPositionDefined(const YGFlexDirection axis) const {
  return (YGFlexDirectionIsRow(axis) &&
          !YGComputedEdgeValue(
               style_.position(), YGEdgeStart, CompactValue::ofUndefined())
               .isUndefined()) ||
      !YGComputedEdgeValue(
           style_.position(), leading[axis], CompactValue::ofUndefined())
           .isUndefined();
}

bool YGNode::isTrailingPosDefined(const YGFlexDirection axis) const {
  return (YGFlexDirectionIsRow(axis) &&
          !YGComputedEdgeValue(
               style_.position(), YGEdgeEnd, CompactValue::ofUndefined())
               .isUndefined()) ||
      !YGComputedEdgeValue(
           style_.position(), trailing[axis], CompactValue::ofUndefined())
           .isUndefined();
}

YGFloatOptional YGNode::getLeadingMargin(
    const YGFlexDirection axis,
    const float widthSize) const {
  if (YGFlexDirectionIsRow(axis) &&
      !style_.margin()[YGEdgeStart].isUndefined()) {
    return YGResolveValueMargin(style_.margin()[YGEdgeStart], widthSize);
  }

  return YGResolveValueMargin(
      YGComputedEdgeValue(
          style_.margin(), leading[axis], CompactValue::ofZero()),
      widthSize);
}

YGFloatOptional YGNode::getTrailingMargin(
    const YGFlexDirection axis,
    const float widthSize) const {
  if (YGFlexDirectionIsRow(axis) && !style_.margin()[YGEdgeEnd].isUndefined()) {
    return YGResolveValueMargin(style_.margin()[YGEdgeEnd], widthSize);
  }

  return YGResolveValueMargin(
      YGComputedEdgeValue(
          style_.margin(), trailing[axis], CompactValue::ofZero()),
      widthSize);
}

YGFloatOptional YGNode::getMarginForAxis(
    const YGFlexDirection axis,
    const float widthSize) const {
  return getLeadingMargin(axis, widthSize) + getTrailingMargin(axis, widthSize);
}

YGSize YGNode::measure(
    float width,
    YGMeasureMode widthMode,
    float height,
    YGMeasureMode heightMode,
    void* layoutContext) {

  return facebook::yoga::detail::getBooleanData(flags, measureUsesContext_)
      ? measure_.withContext(
            this, width, widthMode, height, heightMode, layoutContext)
      : measure_.noContext(this, width, widthMode, height, heightMode);
}

float YGNode::baseline(float width, float height, void* layoutContext) {
  return facebook::yoga::detail::getBooleanData(flags, baselineUsesContext_)
      ? baseline_.withContext(this, width, height, layoutContext)
      : baseline_.noContext(this, width, height);
}

// Setters

void YGNode::setMeasureFunc(decltype(YGNode::measure_) measureFunc) {
  if (measureFunc.noContext == nullptr) {
    // TODO: t18095186 Move nodeType to opt-in function and mark appropriate
    // places in Litho
    setNodeType(YGNodeTypeDefault);
  } else {
    YGAssertWithNode(
        this,
        children_.size() == 0,
        "Cannot set measure function: Nodes with measure functions cannot have "
        "children.");
    // TODO: t18095186 Move nodeType to opt-in function and mark appropriate
    // places in Litho
    setNodeType(YGNodeTypeText);
  }

  measure_ = measureFunc;
}

void YGNode::setMeasureFunc(YGMeasureFunc measureFunc) {
  facebook::yoga::detail::setBooleanData(flags, measureUsesContext_, false);
  decltype(YGNode::measure_) m;
  m.noContext = measureFunc;
  setMeasureFunc(m);
}

YOGA_EXPORT void YGNode::setMeasureFunc(MeasureWithContextFn measureFunc) {
  facebook::yoga::detail::setBooleanData(flags, measureUsesContext_, true);
  decltype(YGNode::measure_) m;
  m.withContext = measureFunc;
  setMeasureFunc(m);
}

void YGNode::replaceChild(YGNodeRef child, uint32_t index) {
  children_[index] = child;
}

void YGNode::replaceChild(YGNodeRef oldChild, YGNodeRef newChild) {
  std::replace(children_.begin(), children_.end(), oldChild, newChild);
}

void YGNode::insertChild(YGNodeRef child, uint32_t index) {
  children_.insert(children_.begin() + index, child);
}

void YGNode::setDirty(bool isDirty) {
  if (isDirty == facebook::yoga::detail::getBooleanData(flags, isDirty_)) {
    return;
  }
  facebook::yoga::detail::setBooleanData(flags, isDirty_, isDirty);
  if (isDirty && dirtied_) {
    dirtied_(this);
  }
}

bool YGNode::removeChild(YGNodeRef child) {
  std::vector<YGNodeRef>::iterator p =
      std::find(children_.begin(), children_.end(), child);
  if (p != children_.end()) {
    children_.erase(p);
    return true;
  }
  return false;
}

void YGNode::removeChild(uint32_t index) {
  children_.erase(children_.begin() + index);
}

void YGNode::setLayoutDirection(YGDirection direction) {
  layout_.setDirection(direction);
}

void YGNode::setLayoutMargin(float margin, int index) {
  layout_.margin[index] = margin;
}

void YGNode::setLayoutBorder(float border, int index) {
  layout_.border[index] = border;
}

void YGNode::setLayoutPadding(float padding, int index) {
  layout_.padding[index] = padding;
}

void YGNode::setLayoutLastOwnerDirection(YGDirection direction) {
  layout_.lastOwnerDirection = direction;
}

void YGNode::setLayoutComputedFlexBasis(
    const YGFloatOptional computedFlexBasis) {
  layout_.computedFlexBasis = computedFlexBasis;
}

void YGNode::setLayoutPosition(float position, int index) {
  layout_.position[index] = position;
}

void YGNode::setLayoutComputedFlexBasisGeneration(
    uint32_t computedFlexBasisGeneration) {
  layout_.computedFlexBasisGeneration = computedFlexBasisGeneration;
}

void YGNode::setLayoutMeasuredDimension(float measuredDimension, int index) {
  layout_.measuredDimensions[index] = measuredDimension;
}

void YGNode::setLayoutHadOverflow(bool hadOverflow) {
  layout_.setHadOverflow(hadOverflow);
}

void YGNode::setLayoutDimension(float dimension, int index) {
  layout_.dimensions[index] = dimension;
}

// If both left and right are defined, then use left. Otherwise return +left or
// -right depending on which is defined.
YGFloatOptional YGNode::relativePosition(
    const YGFlexDirection axis,
    const float axisSize) const {
  if (isLeadingPositionDefined(axis)) {
    return getLeadingPosition(axis, axisSize);
  }

  YGFloatOptional trailingPosition = getTrailingPosition(axis, axisSize);
  if (!trailingPosition.isUndefined()) {
    trailingPosition = YGFloatOptional{-1 * trailingPosition.unwrap()};
  }
  return trailingPosition;
}

void YGNode::setPosition(
    const YGDirection direction,
    const float mainSize,
    const float crossSize,
    const float ownerWidth) {
  /* Root nodes should be always layouted as LTR, so we don't return negative
   * values. */
  const YGDirection directionRespectingRoot =
      owner_ != nullptr ? direction : YGDirectionLTR;
  const YGFlexDirection mainAxis =
      YGResolveFlexDirection(style_.flexDirection(), directionRespectingRoot);
  const YGFlexDirection crossAxis =
      YGFlexDirectionCross(mainAxis, directionRespectingRoot);

  const YGFloatOptional relativePositionMain =
      relativePosition(mainAxis, mainSize);
  const YGFloatOptional relativePositionCross =
      relativePosition(crossAxis, crossSize);

  setLayoutPosition(
      (getLeadingMargin(mainAxis, ownerWidth) + relativePositionMain).unwrap(),
      leading[mainAxis]);
  setLayoutPosition(
      (getTrailingMargin(mainAxis, ownerWidth) + relativePositionMain).unwrap(),
      trailing[mainAxis]);
  setLayoutPosition(
      (getLeadingMargin(crossAxis, ownerWidth) + relativePositionCross)
          .unwrap(),
      leading[crossAxis]);
  setLayoutPosition(
      (getTrailingMargin(crossAxis, ownerWidth) + relativePositionCross)
          .unwrap(),
      trailing[crossAxis]);
}

YGValue YGNode::marginLeadingValue(const YGFlexDirection axis) const {
  if (YGFlexDirectionIsRow(axis) &&
      !style_.margin()[YGEdgeStart].isUndefined()) {
    return style_.margin()[YGEdgeStart];
  } else {
    return style_.margin()[leading[axis]];
  }
}

YGValue YGNode::marginTrailingValue(const YGFlexDirection axis) const {
  if (YGFlexDirectionIsRow(axis) && !style_.margin()[YGEdgeEnd].isUndefined()) {
    return style_.margin()[YGEdgeEnd];
  } else {
    return style_.margin()[trailing[axis]];
  }
}

YGValue YGNode::resolveFlexBasisPtr() const {
  YGValue flexBasis = style_.flexBasis();
  if (flexBasis.unit != YGUnitAuto && flexBasis.unit != YGUnitUndefined) {
    return flexBasis;
  }
  if (!style_.flex().isUndefined() && style_.flex().unwrap() > 0.0f) {
    return facebook::yoga::detail::getBooleanData(flags, useWebDefaults_)
        ? YGValueAuto
        : YGValueZero;
  }
  return YGValueAuto;
}

void YGNode::resolveDimension() {
  using namespace yoga;
  const YGStyle& style = getStyle();
  for (auto dim : {YGDimensionWidth, YGDimensionHeight}) {
    if (!style.maxDimensions()[dim].isUndefined() &&
        YGValueEqual(style.maxDimensions()[dim], style.minDimensions()[dim])) {
      resolvedDimensions_[dim] = style.maxDimensions()[dim];
    } else {
      resolvedDimensions_[dim] = style.dimensions()[dim];
    }
  }
}

YGDirection YGNode::resolveDirection(const YGDirection ownerDirection) {
  if (style_.direction() == YGDirectionInherit) {
    return ownerDirection > YGDirectionInherit ? ownerDirection
                                               : YGDirectionLTR;
  } else {
    return style_.direction();
  }
}

YOGA_EXPORT void YGNode::clearChildren() {
  children_.clear();
  children_.shrink_to_fit();
}

// Other Methods

void YGNode::cloneChildrenIfNeeded(void* cloneContext) {
  iterChildrenAfterCloningIfNeeded([](YGNodeRef, void*) {}, cloneContext);
}

void YGNode::markDirtyAndPropogate() {
  if (!facebook::yoga::detail::getBooleanData(flags, isDirty_)) {
    setDirty(true);
    setLayoutComputedFlexBasis(YGFloatOptional());
    if (owner_) {
      owner_->markDirtyAndPropogate();
    }
  }
}

void YGNode::markDirtyAndPropogateDownwards() {
  facebook::yoga::detail::setBooleanData(flags, isDirty_, true);
  for_each(children_.begin(), children_.end(), [](YGNodeRef childNode) {
    childNode->markDirtyAndPropogateDownwards();
  });
}

float YGNode::resolveFlexGrow() const {
  // Root nodes flexGrow should always be 0
  if (owner_ == nullptr) {
    return 0.0;
  }
  if (!style_.flexGrow().isUndefined()) {
    return style_.flexGrow().unwrap();
  }
  if (!style_.flex().isUndefined() && style_.flex().unwrap() > 0.0f) {
    return style_.flex().unwrap();
  }
  return kDefaultFlexGrow;
}

float YGNode::resolveFlexShrink() const {
  if (owner_ == nullptr) {
    return 0.0;
  }
  if (!style_.flexShrink().isUndefined()) {
    return style_.flexShrink().unwrap();
  }
  if (!facebook::yoga::detail::getBooleanData(flags, useWebDefaults_) &&
      !style_.flex().isUndefined() && style_.flex().unwrap() < 0.0f) {
    return -style_.flex().unwrap();
  }
  return facebook::yoga::detail::getBooleanData(flags, useWebDefaults_)
      ? kWebDefaultFlexShrink
      : kDefaultFlexShrink;
}

bool YGNode::isNodeFlexible() {
  return (
      (style_.positionType() == YGPositionTypeRelative) &&
      (resolveFlexGrow() != 0 || resolveFlexShrink() != 0));
}

float YGNode::getLeadingBorder(const YGFlexDirection axis) const {
  YGValue leadingBorder;
  if (YGFlexDirectionIsRow(axis) &&
      !style_.border()[YGEdgeStart].isUndefined()) {
    leadingBorder = style_.border()[YGEdgeStart];
    if (leadingBorder.value >= 0) {
      return leadingBorder.value;
    }
  }

  leadingBorder = YGComputedEdgeValue(
      style_.border(), leading[axis], CompactValue::ofZero());
  return YGFloatMax(leadingBorder.value, 0.0f);
}

float YGNode::getTrailingBorder(const YGFlexDirection flexDirection) const {
  YGValue trailingBorder;
  if (YGFlexDirectionIsRow(flexDirection) &&
      !style_.border()[YGEdgeEnd].isUndefined()) {
    trailingBorder = style_.border()[YGEdgeEnd];
    if (trailingBorder.value >= 0.0f) {
      return trailingBorder.value;
    }
  }

  trailingBorder = YGComputedEdgeValue(
      style_.border(), trailing[flexDirection], CompactValue::ofZero());
  return YGFloatMax(trailingBorder.value, 0.0f);
}

YGFloatOptional YGNode::getLeadingPadding(
    const YGFlexDirection axis,
    const float widthSize) const {
  const YGFloatOptional paddingEdgeStart =
      YGResolveValue(style_.padding()[YGEdgeStart], widthSize);
  if (YGFlexDirectionIsRow(axis) &&
      !style_.padding()[YGEdgeStart].isUndefined() &&
      !paddingEdgeStart.isUndefined() && paddingEdgeStart.unwrap() >= 0.0f) {
    return paddingEdgeStart;
  }

  YGFloatOptional resolvedValue = YGResolveValue(
      YGComputedEdgeValue(
          style_.padding(), leading[axis], CompactValue::ofZero()),
      widthSize);
  return YGFloatOptionalMax(resolvedValue, YGFloatOptional(0.0f));
}

YGFloatOptional YGNode::getTrailingPadding(
    const YGFlexDirection axis,
    const float widthSize) const {
  const YGFloatOptional paddingEdgeEnd =
      YGResolveValue(style_.padding()[YGEdgeEnd], widthSize);
  if (YGFlexDirectionIsRow(axis) && paddingEdgeEnd >= YGFloatOptional{0.0f}) {
    return paddingEdgeEnd;
  }

  YGFloatOptional resolvedValue = YGResolveValue(
      YGComputedEdgeValue(
          style_.padding(), trailing[axis], CompactValue::ofZero()),
      widthSize);

  return YGFloatOptionalMax(resolvedValue, YGFloatOptional(0.0f));
}

YGFloatOptional YGNode::getLeadingPaddingAndBorder(
    const YGFlexDirection axis,
    const float widthSize) const {
  return getLeadingPadding(axis, widthSize) +
      YGFloatOptional(getLeadingBorder(axis));
}

YGFloatOptional YGNode::getTrailingPaddingAndBorder(
    const YGFlexDirection axis,
    const float widthSize) const {
  return getTrailingPadding(axis, widthSize) +
      YGFloatOptional(getTrailingBorder(axis));
}

bool YGNode::didUseLegacyFlag() {
  bool didUseLegacyFlag = layout_.didUseLegacyFlag();
  if (didUseLegacyFlag) {
    return true;
  }
  for (const auto& child : children_) {
    if (child->layout_.didUseLegacyFlag()) {
      didUseLegacyFlag = true;
      break;
    }
  }
  return didUseLegacyFlag;
}

void YGNode::setLayoutDoesLegacyFlagAffectsLayout(
    bool doesLegacyFlagAffectsLayout) {
  layout_.setDoesLegacyStretchFlagAffectsLayout(doesLegacyFlagAffectsLayout);
}

void YGNode::setLayoutDidUseLegacyFlag(bool didUseLegacyFlag) {
  layout_.setDidUseLegacyFlag(didUseLegacyFlag);
}

bool YGNode::isLayoutTreeEqualToNode(const YGNode& node) const {
  if (children_.size() != node.children_.size()) {
    return false;
  }
  if (layout_ != node.layout_) {
    return false;
  }
  if (children_.size() == 0) {
    return true;
  }

  bool isLayoutTreeEqual = true;
  YGNodeRef otherNodeChildren = nullptr;
  for (std::vector<YGNodeRef>::size_type i = 0; i < children_.size(); ++i) {
    otherNodeChildren = node.children_[i];
    isLayoutTreeEqual =
        children_[i]->isLayoutTreeEqualToNode(*otherNodeChildren);
    if (!isLayoutTreeEqual) {
      return false;
    }
  }
  return isLayoutTreeEqual;
}

void YGNode::reset() {
  YGAssertWithNode(
      this,
      children_.size() == 0,
      "Cannot reset a node which still has children attached");
  YGAssertWithNode(
      this, owner_ == nullptr, "Cannot reset a node still attached to a owner");

  clearChildren();

  auto webDefaults =
      facebook::yoga::detail::getBooleanData(flags, useWebDefaults_);
  *this = YGNode{getConfig()};
  if (webDefaults) {
    useWebDefaults();
  }
}