/** * * !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! * !! This file is a check-in from github! !! * !! !! * !! You should not modify this file directly. Instead: !! * !! 1) Go to https://github.com/facebook/css-layout !! * !! 2) Make a pull request and get it merged !! * !! 3) Copy the file from github to here !! * !! (don't forget to keep this header) !! * !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! * @generated * * Copyright (c) 2014, Facebook, Inc. * All rights reserved. * * This source code is licensed under the BSD-style license found in the * LICENSE file in the root directory of this source tree. An additional grant * of patent rights can be found in the PATENTS file in the same directory. */ #include #include #include #include // in concatenated header, don't include Layout.h it's already at the top #ifndef CSS_LAYOUT_IMPLEMENTATION #include "Layout.h" #endif #ifdef _MSC_VER #include #define isnan _isnan /* define fmaxf if < VC12 */ #if _MSC_VER < 1800 __forceinline const float fmaxf(const float a, const float b) { return (a > b) ? a : b; } #endif #endif bool isUndefined(float value) { return isnan(value); } static bool eq(float a, float b) { if (isUndefined(a)) { return isUndefined(b); } return fabs(a - b) < 0.0001; } void init_css_node(css_node_t *node) { node->style.align_items = CSS_ALIGN_STRETCH; node->style.align_content = CSS_ALIGN_FLEX_START; node->style.direction = CSS_DIRECTION_INHERIT; node->style.flex_direction = CSS_FLEX_DIRECTION_COLUMN; // Some of the fields default to undefined and not 0 node->style.dimensions[CSS_WIDTH] = CSS_UNDEFINED; node->style.dimensions[CSS_HEIGHT] = CSS_UNDEFINED; node->style.minDimensions[CSS_WIDTH] = CSS_UNDEFINED; node->style.minDimensions[CSS_HEIGHT] = CSS_UNDEFINED; node->style.maxDimensions[CSS_WIDTH] = CSS_UNDEFINED; node->style.maxDimensions[CSS_HEIGHT] = CSS_UNDEFINED; node->style.position[CSS_LEFT] = CSS_UNDEFINED; node->style.position[CSS_TOP] = CSS_UNDEFINED; node->style.position[CSS_RIGHT] = CSS_UNDEFINED; node->style.position[CSS_BOTTOM] = CSS_UNDEFINED; node->style.margin[CSS_START] = CSS_UNDEFINED; node->style.margin[CSS_END] = CSS_UNDEFINED; node->style.padding[CSS_START] = CSS_UNDEFINED; node->style.padding[CSS_END] = CSS_UNDEFINED; node->style.border[CSS_START] = CSS_UNDEFINED; node->style.border[CSS_END] = CSS_UNDEFINED; node->layout.dimensions[CSS_WIDTH] = CSS_UNDEFINED; node->layout.dimensions[CSS_HEIGHT] = CSS_UNDEFINED; // Such that the comparison is always going to be false node->layout.last_requested_dimensions[CSS_WIDTH] = -1; node->layout.last_requested_dimensions[CSS_HEIGHT] = -1; node->layout.last_parent_max_width = -1; node->layout.last_parent_max_height = -1; node->layout.last_direction = (css_direction_t)-1; node->layout.should_update = true; } css_node_t *new_css_node() { css_node_t *node = (css_node_t *)calloc(1, sizeof(*node)); init_css_node(node); return node; } void free_css_node(css_node_t *node) { free(node); } static void indent(int n) { for (int i = 0; i < n; ++i) { printf(" "); } } static void print_number_0(const char *str, float number) { if (!eq(number, 0)) { printf("%s: %g, ", str, number); } } static void print_number_nan(const char *str, float number) { if (!isnan(number)) { printf("%s: %g, ", str, number); } } static bool four_equal(float four[4]) { return eq(four[0], four[1]) && eq(four[0], four[2]) && eq(four[0], four[3]); } static void print_css_node_rec( css_node_t *node, css_print_options_t options, int level ) { indent(level); printf("{"); if (node->print) { node->print(node->context); } if (options & CSS_PRINT_LAYOUT) { printf("layout: {"); printf("width: %g, ", node->layout.dimensions[CSS_WIDTH]); printf("height: %g, ", node->layout.dimensions[CSS_HEIGHT]); printf("top: %g, ", node->layout.position[CSS_TOP]); printf("left: %g", node->layout.position[CSS_LEFT]); printf("}, "); } if (options & CSS_PRINT_STYLE) { if (node->style.flex_direction == CSS_FLEX_DIRECTION_COLUMN) { printf("flexDirection: 'column', "); } else if (node->style.flex_direction == CSS_FLEX_DIRECTION_COLUMN_REVERSE) { printf("flexDirection: 'columnReverse', "); } else if (node->style.flex_direction == CSS_FLEX_DIRECTION_ROW) { printf("flexDirection: 'row', "); } else if (node->style.flex_direction == CSS_FLEX_DIRECTION_ROW_REVERSE) { printf("flexDirection: 'rowReverse', "); } if (node->style.justify_content == CSS_JUSTIFY_CENTER) { printf("justifyContent: 'center', "); } else if (node->style.justify_content == CSS_JUSTIFY_FLEX_END) { printf("justifyContent: 'flex-end', "); } else if (node->style.justify_content == CSS_JUSTIFY_SPACE_AROUND) { printf("justifyContent: 'space-around', "); } else if (node->style.justify_content == CSS_JUSTIFY_SPACE_BETWEEN) { printf("justifyContent: 'space-between', "); } if (node->style.align_items == CSS_ALIGN_CENTER) { printf("alignItems: 'center', "); } else if (node->style.align_items == CSS_ALIGN_FLEX_END) { printf("alignItems: 'flex-end', "); } else if (node->style.align_items == CSS_ALIGN_STRETCH) { printf("alignItems: 'stretch', "); } if (node->style.align_content == CSS_ALIGN_CENTER) { printf("alignContent: 'center', "); } else if (node->style.align_content == CSS_ALIGN_FLEX_END) { printf("alignContent: 'flex-end', "); } else if (node->style.align_content == CSS_ALIGN_STRETCH) { printf("alignContent: 'stretch', "); } if (node->style.align_self == CSS_ALIGN_FLEX_START) { printf("alignSelf: 'flex-start', "); } else if (node->style.align_self == CSS_ALIGN_CENTER) { printf("alignSelf: 'center', "); } else if (node->style.align_self == CSS_ALIGN_FLEX_END) { printf("alignSelf: 'flex-end', "); } else if (node->style.align_self == CSS_ALIGN_STRETCH) { printf("alignSelf: 'stretch', "); } print_number_nan("flex", node->style.flex); if (four_equal(node->style.margin)) { print_number_0("margin", node->style.margin[CSS_LEFT]); } else { print_number_0("marginLeft", node->style.margin[CSS_LEFT]); print_number_0("marginRight", node->style.margin[CSS_RIGHT]); print_number_0("marginTop", node->style.margin[CSS_TOP]); print_number_0("marginBottom", node->style.margin[CSS_BOTTOM]); print_number_0("marginStart", node->style.margin[CSS_START]); print_number_0("marginEnd", node->style.margin[CSS_END]); } if (four_equal(node->style.padding)) { print_number_0("padding", node->style.margin[CSS_LEFT]); } else { print_number_0("paddingLeft", node->style.padding[CSS_LEFT]); print_number_0("paddingRight", node->style.padding[CSS_RIGHT]); print_number_0("paddingTop", node->style.padding[CSS_TOP]); print_number_0("paddingBottom", node->style.padding[CSS_BOTTOM]); print_number_0("paddingStart", node->style.padding[CSS_START]); print_number_0("paddingEnd", node->style.padding[CSS_END]); } if (four_equal(node->style.border)) { print_number_0("borderWidth", node->style.border[CSS_LEFT]); } else { print_number_0("borderLeftWidth", node->style.border[CSS_LEFT]); print_number_0("borderRightWidth", node->style.border[CSS_RIGHT]); print_number_0("borderTopWidth", node->style.border[CSS_TOP]); print_number_0("borderBottomWidth", node->style.border[CSS_BOTTOM]); print_number_0("borderStartWidth", node->style.border[CSS_START]); print_number_0("borderEndWidth", node->style.border[CSS_END]); } print_number_nan("width", node->style.dimensions[CSS_WIDTH]); print_number_nan("height", node->style.dimensions[CSS_HEIGHT]); if (node->style.position_type == CSS_POSITION_ABSOLUTE) { printf("position: 'absolute', "); } print_number_nan("left", node->style.position[CSS_LEFT]); print_number_nan("right", node->style.position[CSS_RIGHT]); print_number_nan("top", node->style.position[CSS_TOP]); print_number_nan("bottom", node->style.position[CSS_BOTTOM]); } if (options & CSS_PRINT_CHILDREN && node->children_count > 0) { printf("children: [\n"); for (int i = 0; i < node->children_count; ++i) { print_css_node_rec(node->get_child(node->context, i), options, level + 1); } indent(level); printf("]},\n"); } else { printf("},\n"); } } void print_css_node(css_node_t *node, css_print_options_t options) { print_css_node_rec(node, options, 0); } static css_position_t leading[4] = { /* CSS_FLEX_DIRECTION_COLUMN = */ CSS_TOP, /* CSS_FLEX_DIRECTION_COLUMN_REVERSE = */ CSS_BOTTOM, /* CSS_FLEX_DIRECTION_ROW = */ CSS_LEFT, /* CSS_FLEX_DIRECTION_ROW_REVERSE = */ CSS_RIGHT }; static css_position_t trailing[4] = { /* CSS_FLEX_DIRECTION_COLUMN = */ CSS_BOTTOM, /* CSS_FLEX_DIRECTION_COLUMN_REVERSE = */ CSS_TOP, /* CSS_FLEX_DIRECTION_ROW = */ CSS_RIGHT, /* CSS_FLEX_DIRECTION_ROW_REVERSE = */ CSS_LEFT }; static css_position_t pos[4] = { /* CSS_FLEX_DIRECTION_COLUMN = */ CSS_TOP, /* CSS_FLEX_DIRECTION_COLUMN_REVERSE = */ CSS_BOTTOM, /* CSS_FLEX_DIRECTION_ROW = */ CSS_LEFT, /* CSS_FLEX_DIRECTION_ROW_REVERSE = */ CSS_RIGHT }; static css_dimension_t dim[4] = { /* CSS_FLEX_DIRECTION_COLUMN = */ CSS_HEIGHT, /* CSS_FLEX_DIRECTION_COLUMN_REVERSE = */ CSS_HEIGHT, /* CSS_FLEX_DIRECTION_ROW = */ CSS_WIDTH, /* CSS_FLEX_DIRECTION_ROW_REVERSE = */ CSS_WIDTH }; static bool isRowDirection(css_flex_direction_t flex_direction) { return flex_direction == CSS_FLEX_DIRECTION_ROW || flex_direction == CSS_FLEX_DIRECTION_ROW_REVERSE; } static bool isColumnDirection(css_flex_direction_t flex_direction) { return flex_direction == CSS_FLEX_DIRECTION_COLUMN || flex_direction == CSS_FLEX_DIRECTION_COLUMN_REVERSE; } static float getLeadingMargin(css_node_t *node, css_flex_direction_t axis) { if (isRowDirection(axis) && !isUndefined(node->style.margin[CSS_START])) { return node->style.margin[CSS_START]; } return node->style.margin[leading[axis]]; } static float getTrailingMargin(css_node_t *node, css_flex_direction_t axis) { if (isRowDirection(axis) && !isUndefined(node->style.margin[CSS_END])) { return node->style.margin[CSS_END]; } return node->style.margin[trailing[axis]]; } static float getLeadingPadding(css_node_t *node, css_flex_direction_t axis) { if (isRowDirection(axis) && !isUndefined(node->style.padding[CSS_START]) && node->style.padding[CSS_START] >= 0) { return node->style.padding[CSS_START]; } if (node->style.padding[leading[axis]] >= 0) { return node->style.padding[leading[axis]]; } return 0; } static float getTrailingPadding(css_node_t *node, css_flex_direction_t axis) { if (isRowDirection(axis) && !isUndefined(node->style.padding[CSS_END]) && node->style.padding[CSS_END] >= 0) { return node->style.padding[CSS_END]; } if (node->style.padding[trailing[axis]] >= 0) { return node->style.padding[trailing[axis]]; } return 0; } static float getLeadingBorder(css_node_t *node, css_flex_direction_t axis) { if (isRowDirection(axis) && !isUndefined(node->style.border[CSS_START]) && node->style.border[CSS_START] >= 0) { return node->style.border[CSS_START]; } if (node->style.border[leading[axis]] >= 0) { return node->style.border[leading[axis]]; } return 0; } static float getTrailingBorder(css_node_t *node, css_flex_direction_t axis) { if (isRowDirection(axis) && !isUndefined(node->style.border[CSS_END]) && node->style.border[CSS_END] >= 0) { return node->style.border[CSS_END]; } if (node->style.border[trailing[axis]] >= 0) { return node->style.border[trailing[axis]]; } return 0; } static float getLeadingPaddingAndBorder(css_node_t *node, css_flex_direction_t axis) { return getLeadingPadding(node, axis) + getLeadingBorder(node, axis); } static float getTrailingPaddingAndBorder(css_node_t *node, css_flex_direction_t axis) { return getTrailingPadding(node, axis) + getTrailingBorder(node, axis); } static float getBorderAxis(css_node_t *node, css_flex_direction_t axis) { return getLeadingBorder(node, axis) + getTrailingBorder(node, axis); } static float getMarginAxis(css_node_t *node, css_flex_direction_t axis) { return getLeadingMargin(node, axis) + getTrailingMargin(node, axis); } static float getPaddingAndBorderAxis(css_node_t *node, css_flex_direction_t axis) { return getLeadingPaddingAndBorder(node, axis) + getTrailingPaddingAndBorder(node, axis); } static css_align_t getAlignItem(css_node_t *node, css_node_t *child) { if (child->style.align_self != CSS_ALIGN_AUTO) { return child->style.align_self; } return node->style.align_items; } static css_direction_t resolveDirection(css_node_t *node, css_direction_t parentDirection) { css_direction_t direction = node->style.direction; if (direction == CSS_DIRECTION_INHERIT) { direction = parentDirection > CSS_DIRECTION_INHERIT ? parentDirection : CSS_DIRECTION_LTR; } return direction; } static css_flex_direction_t getFlexDirection(css_node_t *node) { return node->style.flex_direction; } static css_flex_direction_t resolveAxis(css_flex_direction_t flex_direction, css_direction_t direction) { if (direction == CSS_DIRECTION_RTL) { if (flex_direction == CSS_FLEX_DIRECTION_ROW) { return CSS_FLEX_DIRECTION_ROW_REVERSE; } else if (flex_direction == CSS_FLEX_DIRECTION_ROW_REVERSE) { return CSS_FLEX_DIRECTION_ROW; } } return flex_direction; } static css_flex_direction_t getCrossFlexDirection(css_flex_direction_t flex_direction, css_direction_t direction) { if (isColumnDirection(flex_direction)) { return resolveAxis(CSS_FLEX_DIRECTION_ROW, direction); } else { return CSS_FLEX_DIRECTION_COLUMN; } } static float getFlex(css_node_t *node) { return node->style.flex; } static bool isFlex(css_node_t *node) { return ( node->style.position_type == CSS_POSITION_RELATIVE && getFlex(node) > 0 ); } static bool isFlexWrap(css_node_t *node) { return node->style.flex_wrap == CSS_WRAP; } static float getDimWithMargin(css_node_t *node, css_flex_direction_t axis) { return node->layout.dimensions[dim[axis]] + getLeadingMargin(node, axis) + getTrailingMargin(node, axis); } static bool isDimDefined(css_node_t *node, css_flex_direction_t axis) { float value = node->style.dimensions[dim[axis]]; return !isUndefined(value) && value >= 0.0; } static bool isPosDefined(css_node_t *node, css_position_t position) { return !isUndefined(node->style.position[position]); } static bool isMeasureDefined(css_node_t *node) { return node->measure; } static float getPosition(css_node_t *node, css_position_t position) { float result = node->style.position[position]; if (!isUndefined(result)) { return result; } return 0; } static float boundAxis(css_node_t *node, css_flex_direction_t axis, float value) { float min = CSS_UNDEFINED; float max = CSS_UNDEFINED; if (isColumnDirection(axis)) { min = node->style.minDimensions[CSS_HEIGHT]; max = node->style.maxDimensions[CSS_HEIGHT]; } else if (isRowDirection(axis)) { min = node->style.minDimensions[CSS_WIDTH]; max = node->style.maxDimensions[CSS_WIDTH]; } float boundValue = value; if (!isUndefined(max) && max >= 0.0 && boundValue > max) { boundValue = max; } if (!isUndefined(min) && min >= 0.0 && boundValue < min) { boundValue = min; } return boundValue; } // When the user specifically sets a value for width or height static void setDimensionFromStyle(css_node_t *node, css_flex_direction_t axis) { // The parent already computed us a width or height. We just skip it if (!isUndefined(node->layout.dimensions[dim[axis]])) { return; } // We only run if there's a width or height defined if (!isDimDefined(node, axis)) { return; } // The dimensions can never be smaller than the padding and border node->layout.dimensions[dim[axis]] = fmaxf( boundAxis(node, axis, node->style.dimensions[dim[axis]]), getPaddingAndBorderAxis(node, axis) ); } static void setTrailingPosition(css_node_t *node, css_node_t *child, css_flex_direction_t axis) { child->layout.position[trailing[axis]] = node->layout.dimensions[dim[axis]] - child->layout.dimensions[dim[axis]] - child->layout.position[pos[axis]]; } // If both left and right are defined, then use left. Otherwise return // +left or -right depending on which is defined. static float getRelativePosition(css_node_t *node, css_flex_direction_t axis) { float lead = node->style.position[leading[axis]]; if (!isUndefined(lead)) { return lead; } return -getPosition(node, trailing[axis]); } static void layoutNodeImpl(css_node_t *node, float parentMaxWidth, float parentMaxHeight, 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); float paddingAndBorderAxisColumn = getPaddingAndBorderAxis(node, CSS_FLEX_DIRECTION_COLUMN); 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; float height = CSS_UNDEFINED; if (isDimDefined(node, CSS_FLEX_DIRECTION_COLUMN)) { height = node->style.dimensions[CSS_HEIGHT]; } else if (!isUndefined(node->layout.dimensions[dim[CSS_FLEX_DIRECTION_COLUMN]])) { height = node->layout.dimensions[dim[CSS_FLEX_DIRECTION_COLUMN]]; } else { height = parentMaxHeight - getMarginAxis(node, resolvedRowAxis); } height -= getPaddingAndBorderAxis(node, CSS_FLEX_DIRECTION_COLUMN); // 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, height ); if (isRowUndefined) { node->layout.dimensions[CSS_WIDTH] = measureDim.dimensions[CSS_WIDTH] + paddingAndBorderAxisResolvedRow; } if (isColumnUndefined) { node->layout.dimensions[CSS_HEIGHT] = measureDim.dimensions[CSS_HEIGHT] + paddingAndBorderAxisColumn; } } 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) { // 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 . 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 . bool isSimpleStackCross = true; int firstComplexCross = childCount; css_node_t* firstFlexChild = NULL; css_node_t* currentFlexChild = NULL; float mainDim = leadingPaddingAndBorderMain; float crossDim = 0; float maxWidth; float maxHeight; 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; maxHeight = CSS_UNDEFINED; if (!isMainRowDirection) { if (isDimDefined(node, resolvedRowAxis)) { maxWidth = node->layout.dimensions[dim[resolvedRowAxis]] - paddingAndBorderAxisResolvedRow; } else { maxWidth = parentMaxWidth - getMarginAxis(node, resolvedRowAxis) - paddingAndBorderAxisResolvedRow; } } else { if (isDimDefined(node, CSS_FLEX_DIRECTION_COLUMN)) { maxHeight = node->layout.dimensions[dim[CSS_FLEX_DIRECTION_COLUMN]] - paddingAndBorderAxisColumn; } else { maxHeight = parentMaxHeight - getMarginAxis(node, CSS_FLEX_DIRECTION_COLUMN) - paddingAndBorderAxisColumn; } } // This is the main recursive call. We layout non flexible children. if (alreadyComputedNextLayout == 0) { layoutNode(child, maxWidth, maxHeight, 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 . 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 . 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; } // 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; } maxHeight = CSS_UNDEFINED; if (isDimDefined(node, CSS_FLEX_DIRECTION_COLUMN)) { maxHeight = node->layout.dimensions[dim[CSS_FLEX_DIRECTION_COLUMN]] - paddingAndBorderAxisColumn; } else if (isMainRowDirection) { maxHeight = parentMaxHeight - getMarginAxis(node, CSS_FLEX_DIRECTION_COLUMN) - paddingAndBorderAxisColumn; } // And we recursively call the layout algorithm for this child layoutNode(currentFlexChild, maxWidth, maxHeight, 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; } } // 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 ); } // 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) { /*eslint-disable */ // This variable is intentionally re-defined as the code is transpiled to a block scope language css_align_t alignItem = getAlignItem(node, child); /*eslint-enable */ if (alignItem == CSS_ALIGN_STRETCH) { // You can only stretch if the dimension has not already been set // previously. if (isUndefined(child->layout.dimensions[dim[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; } // // // Note(prenaux): More than one line, we need to layout the crossAxis // according to alignContent. // // Note that we could probably remove 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; } } // 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); } } } // 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 **/ } void layoutNode(css_node_t *node, float parentMaxWidth, float parentMaxHeight, css_direction_t parentDirection) { css_layout_t *layout = &node->layout; css_direction_t direction = node->style.direction; layout->should_update = true; bool skipLayout = !node->is_dirty(node->context) && eq(layout->last_requested_dimensions[CSS_WIDTH], layout->dimensions[CSS_WIDTH]) && eq(layout->last_requested_dimensions[CSS_HEIGHT], layout->dimensions[CSS_HEIGHT]) && eq(layout->last_parent_max_width, parentMaxWidth); eq(layout->last_parent_max_height, parentMaxHeight); eq(layout->last_direction, direction); if (skipLayout) { layout->dimensions[CSS_WIDTH] = layout->last_dimensions[CSS_WIDTH]; layout->dimensions[CSS_HEIGHT] = layout->last_dimensions[CSS_HEIGHT]; layout->position[CSS_TOP] = layout->last_position[CSS_TOP]; layout->position[CSS_LEFT] = layout->last_position[CSS_LEFT]; } else { layout->last_requested_dimensions[CSS_WIDTH] = layout->dimensions[CSS_WIDTH]; layout->last_requested_dimensions[CSS_HEIGHT] = layout->dimensions[CSS_HEIGHT]; layout->last_parent_max_width = parentMaxWidth; layout->last_parent_max_height = parentMaxHeight; layout->last_direction = direction; layoutNodeImpl(node, parentMaxWidth, parentMaxHeight, parentDirection); layout->last_dimensions[CSS_WIDTH] = layout->dimensions[CSS_WIDTH]; layout->last_dimensions[CSS_HEIGHT] = layout->dimensions[CSS_HEIGHT]; layout->last_position[CSS_TOP] = layout->position[CSS_TOP]; layout->last_position[CSS_LEFT] = layout->position[CSS_LEFT]; } }