コード例 #1
0
ファイル: YGNode.cpp プロジェクト: dreamevil/litho
void YGNode::setPosition(
    const YGDirection direction,
    const float mainSize,
    const float crossSize,
    const float parentWidth) {
  /* Root nodes should be always layouted as LTR, so we don't return negative
   * values. */
  const YGDirection directionRespectingRoot =
      parent_ != nullptr ? direction : YGDirectionLTR;
  const YGFlexDirection mainAxis =
      YGResolveFlexDirection(style_.flexDirection, directionRespectingRoot);
  const YGFlexDirection crossAxis =
      YGFlexDirectionCross(mainAxis, directionRespectingRoot);

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

  setLayoutPosition(
      getLeadingMargin(mainAxis, parentWidth) + relativePositionMain,
      leading[mainAxis]);
  setLayoutPosition(
      getTrailingMargin(mainAxis, parentWidth) + relativePositionMain,
      trailing[mainAxis]);
  setLayoutPosition(
      getLeadingMargin(crossAxis, parentWidth) + relativePositionCross,
      leading[crossAxis]);
  setLayoutPosition(
      getTrailingMargin(crossAxis, parentWidth) + relativePositionCross,
      trailing[crossAxis]);
}
コード例 #2
0
ファイル: YGNode.cpp プロジェクト: dreamevil/litho
float YGNode::getMarginForAxis(
    const YGFlexDirection axis,
    const float widthSize) {
  return getLeadingMargin(axis, widthSize) + getTrailingMargin(axis, widthSize);
}
コード例 #3
0
ファイル: Layout.c プロジェクト: jsautreau/react-native
static float getDimWithMargin(css_node_t *node, css_flex_direction_t axis) {
  return node->layout.dimensions[dim[axis]] +
    getLeadingMargin(node, axis) +
    getTrailingMargin(node, axis);
}
コード例 #4
0
ファイル: Layout.c プロジェクト: jsautreau/react-native
static void layoutNodeImpl(css_node_t *node, float parentMaxWidth, css_direction_t parentDirection) {
  /** START_GENERATED **/
  css_direction_t direction = resolveDirection(node, parentDirection);
  css_flex_direction_t mainAxis = resolveAxis(getFlexDirection(node), direction);
  css_flex_direction_t crossAxis = getCrossFlexDirection(mainAxis, direction);
  css_flex_direction_t resolvedRowAxis = resolveAxis(CSS_FLEX_DIRECTION_ROW, direction);

  // Handle width and height style attributes
  setDimensionFromStyle(node, mainAxis);
  setDimensionFromStyle(node, crossAxis);

  // Set the resolved resolution in the node's layout
  node->layout.direction = direction;

  // The position is set by the parent, but we need to complete it with a
  // delta composed of the margin and left/top/right/bottom
  node->layout.position[leading[mainAxis]] += getLeadingMargin(node, mainAxis) +
    getRelativePosition(node, mainAxis);
  node->layout.position[trailing[mainAxis]] += getTrailingMargin(node, mainAxis) +
    getRelativePosition(node, mainAxis);
  node->layout.position[leading[crossAxis]] += getLeadingMargin(node, crossAxis) +
    getRelativePosition(node, crossAxis);
  node->layout.position[trailing[crossAxis]] += getTrailingMargin(node, crossAxis) +
    getRelativePosition(node, crossAxis);

  // Inline immutable values from the target node to avoid excessive method
  // invocations during the layout calculation.
  int childCount = node->children_count;
  float paddingAndBorderAxisResolvedRow = getPaddingAndBorderAxis(node, resolvedRowAxis);

  if (isMeasureDefined(node)) {
    bool isResolvedRowDimDefined = !isUndefined(node->layout.dimensions[dim[resolvedRowAxis]]);

    float width = CSS_UNDEFINED;
    if (isDimDefined(node, resolvedRowAxis)) {
      width = node->style.dimensions[CSS_WIDTH];
    } else if (isResolvedRowDimDefined) {
      width = node->layout.dimensions[dim[resolvedRowAxis]];
    } else {
      width = parentMaxWidth -
        getMarginAxis(node, resolvedRowAxis);
    }
    width -= paddingAndBorderAxisResolvedRow;

    // We only need to give a dimension for the text if we haven't got any
    // for it computed yet. It can either be from the style attribute or because
    // the element is flexible.
    bool isRowUndefined = !isDimDefined(node, resolvedRowAxis) && !isResolvedRowDimDefined;
    bool isColumnUndefined = !isDimDefined(node, CSS_FLEX_DIRECTION_COLUMN) &&
      isUndefined(node->layout.dimensions[dim[CSS_FLEX_DIRECTION_COLUMN]]);

    // Let's not measure the text if we already know both dimensions
    if (isRowUndefined || isColumnUndefined) {
      css_dim_t measureDim = node->measure(
        node->context,

        width
      );
      if (isRowUndefined) {
        node->layout.dimensions[CSS_WIDTH] = measureDim.dimensions[CSS_WIDTH] +
          paddingAndBorderAxisResolvedRow;
      }
      if (isColumnUndefined) {
        node->layout.dimensions[CSS_HEIGHT] = measureDim.dimensions[CSS_HEIGHT] +
          getPaddingAndBorderAxis(node, CSS_FLEX_DIRECTION_COLUMN);
      }
    }
    if (childCount == 0) {
      return;
    }
  }

  bool isNodeFlexWrap = isFlexWrap(node);

  css_justify_t justifyContent = node->style.justify_content;

  float leadingPaddingAndBorderMain = getLeadingPaddingAndBorder(node, mainAxis);
  float leadingPaddingAndBorderCross = getLeadingPaddingAndBorder(node, crossAxis);
  float paddingAndBorderAxisMain = getPaddingAndBorderAxis(node, mainAxis);
  float paddingAndBorderAxisCross = getPaddingAndBorderAxis(node, crossAxis);

  bool isMainDimDefined = !isUndefined(node->layout.dimensions[dim[mainAxis]]);
  bool isCrossDimDefined = !isUndefined(node->layout.dimensions[dim[crossAxis]]);
  bool isMainRowDirection = isRowDirection(mainAxis);

  int i;
  int ii;
  css_node_t* child;
  css_flex_direction_t axis;

  css_node_t* firstAbsoluteChild = NULL;
  css_node_t* currentAbsoluteChild = NULL;

  float definedMainDim = CSS_UNDEFINED;
  if (isMainDimDefined) {
    definedMainDim = node->layout.dimensions[dim[mainAxis]] - paddingAndBorderAxisMain;
  }

  // We want to execute the next two loops one per line with flex-wrap
  int startLine = 0;
  int endLine = 0;
  // int nextOffset = 0;
  int alreadyComputedNextLayout = 0;
  // We aggregate the total dimensions of the container in those two variables
  float linesCrossDim = 0;
  float linesMainDim = 0;
  int linesCount = 0;
  while (endLine < childCount) {
    // <Loop A> Layout non flexible children and count children by type

    // mainContentDim is accumulation of the dimensions and margin of all the
    // non flexible children. This will be used in order to either set the
    // dimensions of the node if none already exist, or to compute the
    // remaining space left for the flexible children.
    float mainContentDim = 0;

    // There are three kind of children, non flexible, flexible and absolute.
    // We need to know how many there are in order to distribute the space.
    int flexibleChildrenCount = 0;
    float totalFlexible = 0;
    int nonFlexibleChildrenCount = 0;

    // Use the line loop to position children in the main axis for as long
    // as they are using a simple stacking behaviour. Children that are
    // immediately stacked in the initial loop will not be touched again
    // in <Loop C>.
    bool isSimpleStackMain =
        (isMainDimDefined && justifyContent == CSS_JUSTIFY_FLEX_START) ||
        (!isMainDimDefined && justifyContent != CSS_JUSTIFY_CENTER);
    int firstComplexMain = (isSimpleStackMain ? childCount : startLine);

    // Use the initial line loop to position children in the cross axis for
    // as long as they are relatively positioned with alignment STRETCH or
    // FLEX_START. Children that are immediately stacked in the initial loop
    // will not be touched again in <Loop D>.
    bool isSimpleStackCross = true;
    int firstComplexCross = childCount;

    css_node_t* firstFlexChild = NULL;
    css_node_t* currentFlexChild = NULL;

    float mainDim = leadingPaddingAndBorderMain;
    float crossDim = 0;

    float maxWidth;
    for (i = startLine; i < childCount; ++i) {
      child = node->get_child(node->context, i);
      child->line_index = linesCount;

      child->next_absolute_child = NULL;
      child->next_flex_child = NULL;

      css_align_t alignItem = getAlignItem(node, child);

      // Pre-fill cross axis dimensions when the child is using stretch before
      // we call the recursive layout pass
      if (alignItem == CSS_ALIGN_STRETCH &&
          child->style.position_type == CSS_POSITION_RELATIVE &&
          isCrossDimDefined &&
          !isDimDefined(child, crossAxis)) {
        child->layout.dimensions[dim[crossAxis]] = fmaxf(
          boundAxis(child, crossAxis, node->layout.dimensions[dim[crossAxis]] -
            paddingAndBorderAxisCross - getMarginAxis(child, crossAxis)),
          // You never want to go smaller than padding
          getPaddingAndBorderAxis(child, crossAxis)
        );
      } else if (child->style.position_type == CSS_POSITION_ABSOLUTE) {
        // Store a private linked list of absolutely positioned children
        // so that we can efficiently traverse them later.
        if (firstAbsoluteChild == NULL) {
          firstAbsoluteChild = child;
        }
        if (currentAbsoluteChild != NULL) {
          currentAbsoluteChild->next_absolute_child = child;
        }
        currentAbsoluteChild = child;

        // Pre-fill dimensions when using absolute position and both offsets for the axis are defined (either both
        // left and right or top and bottom).
        for (ii = 0; ii < 2; ii++) {
          axis = (ii != 0) ? CSS_FLEX_DIRECTION_ROW : CSS_FLEX_DIRECTION_COLUMN;
          if (!isUndefined(node->layout.dimensions[dim[axis]]) &&
              !isDimDefined(child, axis) &&
              isPosDefined(child, leading[axis]) &&
              isPosDefined(child, trailing[axis])) {
            child->layout.dimensions[dim[axis]] = fmaxf(
              boundAxis(child, axis, node->layout.dimensions[dim[axis]] -
                getPaddingAndBorderAxis(node, axis) -
                getMarginAxis(child, axis) -
                getPosition(child, leading[axis]) -
                getPosition(child, trailing[axis])),
              // You never want to go smaller than padding
              getPaddingAndBorderAxis(child, axis)
            );
          }
        }
      }

      float nextContentDim = 0;

      // It only makes sense to consider a child flexible if we have a computed
      // dimension for the node->
      if (isMainDimDefined && isFlex(child)) {
        flexibleChildrenCount++;
        totalFlexible += child->style.flex;

        // Store a private linked list of flexible children so that we can
        // efficiently traverse them later.
        if (firstFlexChild == NULL) {
          firstFlexChild = child;
        }
        if (currentFlexChild != NULL) {
          currentFlexChild->next_flex_child = child;
        }
        currentFlexChild = child;

        // Even if we don't know its exact size yet, we already know the padding,
        // border and margin. We'll use this partial information, which represents
        // the smallest possible size for the child, to compute the remaining
        // available space.
        nextContentDim = getPaddingAndBorderAxis(child, mainAxis) +
          getMarginAxis(child, mainAxis);

      } else {
        maxWidth = CSS_UNDEFINED;
        if (!isMainRowDirection) {
          if (isDimDefined(node, resolvedRowAxis)) {
            maxWidth = node->layout.dimensions[dim[resolvedRowAxis]] -
              paddingAndBorderAxisResolvedRow;
          } else {
            maxWidth = parentMaxWidth -
              getMarginAxis(node, resolvedRowAxis) -
              paddingAndBorderAxisResolvedRow;
          }
        }

        // This is the main recursive call. We layout non flexible children.
        if (alreadyComputedNextLayout == 0) {
          layoutNode(child, maxWidth, direction);
        }

        // Absolute positioned elements do not take part of the layout, so we
        // don't use them to compute mainContentDim
        if (child->style.position_type == CSS_POSITION_RELATIVE) {
          nonFlexibleChildrenCount++;
          // At this point we know the final size and margin of the element.
          nextContentDim = getDimWithMargin(child, mainAxis);
        }
      }

      // The element we are about to add would make us go to the next line
      if (isNodeFlexWrap &&
          isMainDimDefined &&
          mainContentDim + nextContentDim > definedMainDim &&
          // If there's only one element, then it's bigger than the content
          // and needs its own line
          i != startLine) {
        nonFlexibleChildrenCount--;
        alreadyComputedNextLayout = 1;
        break;
      }

      // Disable simple stacking in the main axis for the current line as
      // we found a non-trivial child-> The remaining children will be laid out
      // in <Loop C>.
      if (isSimpleStackMain &&
          (child->style.position_type != CSS_POSITION_RELATIVE || isFlex(child))) {
        isSimpleStackMain = false;
        firstComplexMain = i;
      }

      // Disable simple stacking in the cross axis for the current line as
      // we found a non-trivial child-> The remaining children will be laid out
      // in <Loop D>.
      if (isSimpleStackCross &&
          (child->style.position_type != CSS_POSITION_RELATIVE ||
              (alignItem != CSS_ALIGN_STRETCH && alignItem != CSS_ALIGN_FLEX_START) ||
              isUndefined(child->layout.dimensions[dim[crossAxis]]))) {
        isSimpleStackCross = false;
        firstComplexCross = i;
      }

      if (isSimpleStackMain) {
        child->layout.position[pos[mainAxis]] += mainDim;
        if (isMainDimDefined) {
          setTrailingPosition(node, child, mainAxis);
        }

        mainDim += getDimWithMargin(child, mainAxis);
        crossDim = fmaxf(crossDim, boundAxis(child, crossAxis, getDimWithMargin(child, crossAxis)));
      }

      if (isSimpleStackCross) {
        child->layout.position[pos[crossAxis]] += linesCrossDim + leadingPaddingAndBorderCross;
        if (isCrossDimDefined) {
          setTrailingPosition(node, child, crossAxis);
        }
      }

      alreadyComputedNextLayout = 0;
      mainContentDim += nextContentDim;
      endLine = i + 1;
    }

    // <Loop B> Layout flexible children and allocate empty space

    // In order to position the elements in the main axis, we have two
    // controls. The space between the beginning and the first element
    // and the space between each two elements.
    float leadingMainDim = 0;
    float betweenMainDim = 0;

    // The remaining available space that needs to be allocated
    float remainingMainDim = 0;
    if (isMainDimDefined) {
      remainingMainDim = definedMainDim - mainContentDim;
    } else {
      remainingMainDim = fmaxf(mainContentDim, 0) - mainContentDim;
    }

    // If there are flexible children in the mix, they are going to fill the
    // remaining space
    if (flexibleChildrenCount != 0) {
      float flexibleMainDim = remainingMainDim / totalFlexible;
      float baseMainDim;
      float boundMainDim;

      // If the flex share of remaining space doesn't meet min/max bounds,
      // remove this child from flex calculations.
      currentFlexChild = firstFlexChild;
      while (currentFlexChild != NULL) {
        baseMainDim = flexibleMainDim * currentFlexChild->style.flex +
            getPaddingAndBorderAxis(currentFlexChild, mainAxis);
        boundMainDim = boundAxis(currentFlexChild, mainAxis, baseMainDim);

        if (baseMainDim != boundMainDim) {
          remainingMainDim -= boundMainDim;
          totalFlexible -= currentFlexChild->style.flex;
        }

        currentFlexChild = currentFlexChild->next_flex_child;
      }
      flexibleMainDim = remainingMainDim / totalFlexible;

      // The non flexible children can overflow the container, in this case
      // we should just assume that there is no space available.
      if (flexibleMainDim < 0) {
        flexibleMainDim = 0;
      }

      currentFlexChild = firstFlexChild;
      while (currentFlexChild != NULL) {
        // At this point we know the final size of the element in the main
        // dimension
        currentFlexChild->layout.dimensions[dim[mainAxis]] = boundAxis(currentFlexChild, mainAxis,
          flexibleMainDim * currentFlexChild->style.flex +
              getPaddingAndBorderAxis(currentFlexChild, mainAxis)
        );

        maxWidth = CSS_UNDEFINED;
        if (isDimDefined(node, resolvedRowAxis)) {
          maxWidth = node->layout.dimensions[dim[resolvedRowAxis]] -
            paddingAndBorderAxisResolvedRow;
        } else if (!isMainRowDirection) {
          maxWidth = parentMaxWidth -
            getMarginAxis(node, resolvedRowAxis) -
            paddingAndBorderAxisResolvedRow;
        }

        // And we recursively call the layout algorithm for this child
        layoutNode(currentFlexChild, maxWidth, direction);

        child = currentFlexChild;
        currentFlexChild = currentFlexChild->next_flex_child;
        child->next_flex_child = NULL;
      }

    // We use justifyContent to figure out how to allocate the remaining
    // space available
    } else if (justifyContent != CSS_JUSTIFY_FLEX_START) {
      if (justifyContent == CSS_JUSTIFY_CENTER) {
        leadingMainDim = remainingMainDim / 2;
      } else if (justifyContent == CSS_JUSTIFY_FLEX_END) {
        leadingMainDim = remainingMainDim;
      } else if (justifyContent == CSS_JUSTIFY_SPACE_BETWEEN) {
        remainingMainDim = fmaxf(remainingMainDim, 0);
        if (flexibleChildrenCount + nonFlexibleChildrenCount - 1 != 0) {
          betweenMainDim = remainingMainDim /
            (flexibleChildrenCount + nonFlexibleChildrenCount - 1);
        } else {
          betweenMainDim = 0;
        }
      } else if (justifyContent == CSS_JUSTIFY_SPACE_AROUND) {
        // Space on the edges is half of the space between elements
        betweenMainDim = remainingMainDim /
          (flexibleChildrenCount + nonFlexibleChildrenCount);
        leadingMainDim = betweenMainDim / 2;
      }
    }

    // <Loop C> Position elements in the main axis and compute dimensions

    // At this point, all the children have their dimensions set. We need to
    // find their position. In order to do that, we accumulate data in
    // variables that are also useful to compute the total dimensions of the
    // container!
    mainDim += leadingMainDim;

    for (i = firstComplexMain; i < endLine; ++i) {
      child = node->get_child(node->context, i);

      if (child->style.position_type == CSS_POSITION_ABSOLUTE &&
          isPosDefined(child, leading[mainAxis])) {
        // In case the child is position absolute and has left/top being
        // defined, we override the position to whatever the user said
        // (and margin/border).
        child->layout.position[pos[mainAxis]] = getPosition(child, leading[mainAxis]) +
          getLeadingBorder(node, mainAxis) +
          getLeadingMargin(child, mainAxis);
      } else {
        // If the child is position absolute (without top/left) or relative,
        // we put it at the current accumulated offset.
        child->layout.position[pos[mainAxis]] += mainDim;

        // Define the trailing position accordingly.
        if (isMainDimDefined) {
          setTrailingPosition(node, child, mainAxis);
        }

        // Now that we placed the element, we need to update the variables
        // We only need to do that for relative elements. Absolute elements
        // do not take part in that phase.
        if (child->style.position_type == CSS_POSITION_RELATIVE) {
          // The main dimension is the sum of all the elements dimension plus
          // the spacing.
          mainDim += betweenMainDim + getDimWithMargin(child, mainAxis);
          // The cross dimension is the max of the elements dimension since there
          // can only be one element in that cross dimension.
          crossDim = fmaxf(crossDim, boundAxis(child, crossAxis, getDimWithMargin(child, crossAxis)));
        }
      }
    }

    float containerCrossAxis = node->layout.dimensions[dim[crossAxis]];
    if (!isCrossDimDefined) {
      containerCrossAxis = fmaxf(
        // For the cross dim, we add both sides at the end because the value
        // is aggregate via a max function. Intermediate negative values
        // can mess this computation otherwise
        boundAxis(node, crossAxis, crossDim + paddingAndBorderAxisCross),
        paddingAndBorderAxisCross
      );
    }

    // <Loop D> Position elements in the cross axis
    for (i = firstComplexCross; i < endLine; ++i) {
      child = node->get_child(node->context, i);

      if (child->style.position_type == CSS_POSITION_ABSOLUTE &&
          isPosDefined(child, leading[crossAxis])) {
        // In case the child is absolutely positionned and has a
        // top/left/bottom/right being set, we override all the previously
        // computed positions to set it correctly.
        child->layout.position[pos[crossAxis]] = getPosition(child, leading[crossAxis]) +
          getLeadingBorder(node, crossAxis) +
          getLeadingMargin(child, crossAxis);

      } else {
        float leadingCrossDim = leadingPaddingAndBorderCross;

        // For a relative children, we're either using alignItems (parent) or
        // alignSelf (child) in order to determine the position in the cross axis
        if (child->style.position_type == CSS_POSITION_RELATIVE) {
          css_align_t alignItem = getAlignItem(node, child);
          if (alignItem == CSS_ALIGN_STRETCH) {
            // You can only stretch if the dimension has not already been set
            // previously.
            if (!isDimDefined(child, crossAxis)) {
              child->layout.dimensions[dim[crossAxis]] = fmaxf(
                boundAxis(child, crossAxis, containerCrossAxis -
                  paddingAndBorderAxisCross - getMarginAxis(child, crossAxis)),
                // You never want to go smaller than padding
                getPaddingAndBorderAxis(child, crossAxis)
              );
            }
          } else if (alignItem != CSS_ALIGN_FLEX_START) {
            // The remaining space between the parent dimensions+padding and child
            // dimensions+margin.
            float remainingCrossDim = containerCrossAxis -
              paddingAndBorderAxisCross - getDimWithMargin(child, crossAxis);

            if (alignItem == CSS_ALIGN_CENTER) {
              leadingCrossDim += remainingCrossDim / 2;
            } else { // CSS_ALIGN_FLEX_END
              leadingCrossDim += remainingCrossDim;
            }
          }
        }

        // And we apply the position
        child->layout.position[pos[crossAxis]] += linesCrossDim + leadingCrossDim;

        // Define the trailing position accordingly.
        if (isCrossDimDefined) {
          setTrailingPosition(node, child, crossAxis);
        }
      }
    }

    linesCrossDim += crossDim;
    linesMainDim = fmaxf(linesMainDim, mainDim);
    linesCount += 1;
    startLine = endLine;
  }

  // <Loop E>
  //
  // Note(prenaux): More than one line, we need to layout the crossAxis
  // according to alignContent.
  //
  // Note that we could probably remove <Loop D> and handle the one line case
  // here too, but for the moment this is safer since it won't interfere with
  // previously working code.
  //
  // See specs:
  // http://www.w3.org/TR/2012/CR-css3-flexbox-20120918/#layout-algorithm
  // section 9.4
  //
  if (linesCount > 1 && isCrossDimDefined) {
    float nodeCrossAxisInnerSize = node->layout.dimensions[dim[crossAxis]] -
        paddingAndBorderAxisCross;
    float remainingAlignContentDim = nodeCrossAxisInnerSize - linesCrossDim;

    float crossDimLead = 0;
    float currentLead = leadingPaddingAndBorderCross;

    css_align_t alignContent = node->style.align_content;
    if (alignContent == CSS_ALIGN_FLEX_END) {
      currentLead += remainingAlignContentDim;
    } else if (alignContent == CSS_ALIGN_CENTER) {
      currentLead += remainingAlignContentDim / 2;
    } else if (alignContent == CSS_ALIGN_STRETCH) {
      if (nodeCrossAxisInnerSize > linesCrossDim) {
        crossDimLead = (remainingAlignContentDim / linesCount);
      }
    }

    int endIndex = 0;
    for (i = 0; i < linesCount; ++i) {
      int startIndex = endIndex;

      // compute the line's height and find the endIndex
      float lineHeight = 0;
      for (ii = startIndex; ii < childCount; ++ii) {
        child = node->get_child(node->context, ii);
        if (child->style.position_type != CSS_POSITION_RELATIVE) {
          continue;
        }
        if (child->line_index != i) {
          break;
        }
        if (!isUndefined(child->layout.dimensions[dim[crossAxis]])) {
          lineHeight = fmaxf(
            lineHeight,
            child->layout.dimensions[dim[crossAxis]] + getMarginAxis(child, crossAxis)
          );
        }
      }
      endIndex = ii;
      lineHeight += crossDimLead;

      for (ii = startIndex; ii < endIndex; ++ii) {
        child = node->get_child(node->context, ii);
        if (child->style.position_type != CSS_POSITION_RELATIVE) {
          continue;
        }

        css_align_t alignContentAlignItem = getAlignItem(node, child);
        if (alignContentAlignItem == CSS_ALIGN_FLEX_START) {
          child->layout.position[pos[crossAxis]] = currentLead + getLeadingMargin(child, crossAxis);
        } else if (alignContentAlignItem == CSS_ALIGN_FLEX_END) {
          child->layout.position[pos[crossAxis]] = currentLead + lineHeight - getTrailingMargin(child, crossAxis) - child->layout.dimensions[dim[crossAxis]];
        } else if (alignContentAlignItem == CSS_ALIGN_CENTER) {
          float childHeight = child->layout.dimensions[dim[crossAxis]];
          child->layout.position[pos[crossAxis]] = currentLead + (lineHeight - childHeight) / 2;
        } else if (alignContentAlignItem == CSS_ALIGN_STRETCH) {
          child->layout.position[pos[crossAxis]] = currentLead + getLeadingMargin(child, crossAxis);
          // TODO(prenaux): Correctly set the height of items with undefined
          //                (auto) crossAxis dimension.
        }
      }

      currentLead += lineHeight;
    }
  }

  bool needsMainTrailingPos = false;
  bool needsCrossTrailingPos = false;

  // If the user didn't specify a width or height, and it has not been set
  // by the container, then we set it via the children.
  if (!isMainDimDefined) {
    node->layout.dimensions[dim[mainAxis]] = fmaxf(
      // We're missing the last padding at this point to get the final
      // dimension
      boundAxis(node, mainAxis, linesMainDim + getTrailingPaddingAndBorder(node, mainAxis)),
      // We can never assign a width smaller than the padding and borders
      paddingAndBorderAxisMain
    );

    if (mainAxis == CSS_FLEX_DIRECTION_ROW_REVERSE ||
        mainAxis == CSS_FLEX_DIRECTION_COLUMN_REVERSE) {
      needsMainTrailingPos = true;
    }
  }

  if (!isCrossDimDefined) {
    node->layout.dimensions[dim[crossAxis]] = fmaxf(
      // For the cross dim, we add both sides at the end because the value
      // is aggregate via a max function. Intermediate negative values
      // can mess this computation otherwise
      boundAxis(node, crossAxis, linesCrossDim + paddingAndBorderAxisCross),
      paddingAndBorderAxisCross
    );

    if (crossAxis == CSS_FLEX_DIRECTION_ROW_REVERSE ||
        crossAxis == CSS_FLEX_DIRECTION_COLUMN_REVERSE) {
      needsCrossTrailingPos = true;
    }
  }

  // <Loop F> Set trailing position if necessary
  if (needsMainTrailingPos || needsCrossTrailingPos) {
    for (i = 0; i < childCount; ++i) {
      child = node->get_child(node->context, i);

      if (needsMainTrailingPos) {
        setTrailingPosition(node, child, mainAxis);
      }

      if (needsCrossTrailingPos) {
        setTrailingPosition(node, child, crossAxis);
      }
    }
  }

  // <Loop G> Calculate dimensions for absolutely positioned elements
  currentAbsoluteChild = firstAbsoluteChild;
  while (currentAbsoluteChild != NULL) {
    // Pre-fill dimensions when using absolute position and both offsets for
    // the axis are defined (either both left and right or top and bottom).
    for (ii = 0; ii < 2; ii++) {
      axis = (ii != 0) ? CSS_FLEX_DIRECTION_ROW : CSS_FLEX_DIRECTION_COLUMN;

      if (!isUndefined(node->layout.dimensions[dim[axis]]) &&
          !isDimDefined(currentAbsoluteChild, axis) &&
          isPosDefined(currentAbsoluteChild, leading[axis]) &&
          isPosDefined(currentAbsoluteChild, trailing[axis])) {
        currentAbsoluteChild->layout.dimensions[dim[axis]] = fmaxf(
          boundAxis(currentAbsoluteChild, axis, node->layout.dimensions[dim[axis]] -
            getBorderAxis(node, axis) -
            getMarginAxis(currentAbsoluteChild, axis) -
            getPosition(currentAbsoluteChild, leading[axis]) -
            getPosition(currentAbsoluteChild, trailing[axis])
          ),
          // You never want to go smaller than padding
          getPaddingAndBorderAxis(currentAbsoluteChild, axis)
        );
      }

      if (isPosDefined(currentAbsoluteChild, trailing[axis]) &&
          !isPosDefined(currentAbsoluteChild, leading[axis])) {
        currentAbsoluteChild->layout.position[leading[axis]] =
          node->layout.dimensions[dim[axis]] -
          currentAbsoluteChild->layout.dimensions[dim[axis]] -
          getPosition(currentAbsoluteChild, trailing[axis]);
      }
    }

    child = currentAbsoluteChild;
    currentAbsoluteChild = currentAbsoluteChild->next_absolute_child;
    child->next_absolute_child = NULL;
  }
  /** END_GENERATED **/
}
コード例 #5
0
ファイル: Layout.c プロジェクト: jsautreau/react-native
static float getMarginAxis(css_node_t *node, css_flex_direction_t axis) {
  return getLeadingMargin(node, axis) + getTrailingMargin(node, axis);
}