809 lines
30 KiB
C
809 lines
30 KiB
C
/**
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*
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* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
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* !! This file is a check-in from github! !!
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* !! !!
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* !! You should not modify this file directly. Instead: !!
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* !! 1) Go to https://github.com/facebook/css-layout !!
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* !! 2) Make a pull request and get it merged !!
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* !! 3) Execute ./import.sh to pull in the latest version !!
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* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
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*
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* Copyright (c) 2014, Facebook, Inc.
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* All rights reserved.
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*
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* This source code is licensed under the BSD-style license found in the
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* LICENSE file in the root directory of this source tree. An additional grant
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* of patent rights can be found in the PATENTS file in the same directory.
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*/
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#include <math.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <stdbool.h>
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#include "Layout.h"
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bool isUndefined(float value) {
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return isnan(value);
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}
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static bool eq(float a, float b) {
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if (isUndefined(a)) {
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return isUndefined(b);
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}
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return fabs(a - b) < 0.0001;
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}
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void init_css_node(css_node_t *node) {
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node->style.align_items = CSS_ALIGN_STRETCH;
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// Some of the fields default to undefined and not 0
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node->style.dimensions[CSS_WIDTH] = CSS_UNDEFINED;
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node->style.dimensions[CSS_HEIGHT] = CSS_UNDEFINED;
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node->style.position[CSS_LEFT] = CSS_UNDEFINED;
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node->style.position[CSS_TOP] = CSS_UNDEFINED;
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node->style.position[CSS_RIGHT] = CSS_UNDEFINED;
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node->style.position[CSS_BOTTOM] = CSS_UNDEFINED;
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node->layout.dimensions[CSS_WIDTH] = CSS_UNDEFINED;
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node->layout.dimensions[CSS_HEIGHT] = CSS_UNDEFINED;
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// Such that the comparison is always going to be false
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node->layout.last_requested_dimensions[CSS_WIDTH] = -1;
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node->layout.last_requested_dimensions[CSS_HEIGHT] = -1;
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node->layout.last_parent_max_width = -1;
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node->layout.should_update = true;
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}
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css_node_t *new_css_node() {
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css_node_t *node = calloc(1, sizeof(*node));
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init_css_node(node);
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return node;
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}
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void free_css_node(css_node_t *node) {
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free(node);
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}
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static void indent(int n) {
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for (int i = 0; i < n; ++i) {
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printf(" ");
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}
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}
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static void print_number_0(const char *str, float number) {
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if (!eq(number, 0)) {
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printf("%s: %g, ", str, number);
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}
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}
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static void print_number_nan(const char *str, float number) {
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if (!isnan(number)) {
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printf("%s: %g, ", str, number);
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}
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}
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static bool four_equal(float four[4]) {
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return
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eq(four[0], four[1]) &&
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eq(four[0], four[2]) &&
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eq(four[0], four[3]);
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}
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static void print_css_node_rec(
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css_node_t *node,
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css_print_options_t options,
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int level
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) {
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indent(level);
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printf("{");
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if (node->print) {
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node->print(node->context);
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}
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if (options & CSS_PRINT_LAYOUT) {
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printf("layout: {");
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printf("width: %g, ", node->layout.dimensions[CSS_WIDTH]);
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printf("height: %g, ", node->layout.dimensions[CSS_HEIGHT]);
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printf("top: %g, ", node->layout.position[CSS_TOP]);
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printf("left: %g", node->layout.position[CSS_LEFT]);
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printf("}, ");
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}
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if (options & CSS_PRINT_STYLE) {
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if (node->style.flex_direction == CSS_FLEX_DIRECTION_ROW) {
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printf("flexDirection: 'row', ");
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}
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if (node->style.justify_content == CSS_JUSTIFY_CENTER) {
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printf("justifyContent: 'center', ");
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} else if (node->style.justify_content == CSS_JUSTIFY_FLEX_END) {
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printf("justifyContent: 'flex-end', ");
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} else if (node->style.justify_content == CSS_JUSTIFY_SPACE_AROUND) {
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printf("justifyContent: 'space-around', ");
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} else if (node->style.justify_content == CSS_JUSTIFY_SPACE_BETWEEN) {
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printf("justifyContent: 'space-between', ");
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}
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if (node->style.align_items == CSS_ALIGN_CENTER) {
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printf("alignItems: 'center', ");
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} else if (node->style.align_items == CSS_ALIGN_FLEX_END) {
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printf("alignItems: 'flex-end', ");
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} else if (node->style.align_items == CSS_ALIGN_STRETCH) {
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printf("alignItems: 'stretch', ");
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}
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if (node->style.align_self == CSS_ALIGN_FLEX_START) {
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printf("alignSelf: 'flex-start', ");
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} else if (node->style.align_self == CSS_ALIGN_CENTER) {
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printf("alignSelf: 'center', ");
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} else if (node->style.align_self == CSS_ALIGN_FLEX_END) {
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printf("alignSelf: 'flex-end', ");
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} else if (node->style.align_self == CSS_ALIGN_STRETCH) {
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printf("alignSelf: 'stretch', ");
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}
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print_number_nan("flex", node->style.flex);
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if (four_equal(node->style.margin)) {
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print_number_0("margin", node->style.margin[CSS_LEFT]);
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} else {
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print_number_0("marginLeft", node->style.margin[CSS_LEFT]);
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print_number_0("marginRight", node->style.margin[CSS_RIGHT]);
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print_number_0("marginTop", node->style.margin[CSS_TOP]);
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print_number_0("marginBottom", node->style.margin[CSS_BOTTOM]);
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}
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if (four_equal(node->style.padding)) {
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print_number_0("padding", node->style.margin[CSS_LEFT]);
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} else {
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print_number_0("paddingLeft", node->style.padding[CSS_LEFT]);
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print_number_0("paddingRight", node->style.padding[CSS_RIGHT]);
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print_number_0("paddingTop", node->style.padding[CSS_TOP]);
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print_number_0("paddingBottom", node->style.padding[CSS_BOTTOM]);
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}
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if (four_equal(node->style.border)) {
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print_number_0("borderWidth", node->style.border[CSS_LEFT]);
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} else {
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print_number_0("borderLeftWidth", node->style.border[CSS_LEFT]);
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print_number_0("borderRightWidth", node->style.border[CSS_RIGHT]);
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print_number_0("borderTopWidth", node->style.border[CSS_TOP]);
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print_number_0("borderBottomWidth", node->style.border[CSS_BOTTOM]);
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}
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print_number_nan("width", node->style.dimensions[CSS_WIDTH]);
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print_number_nan("height", node->style.dimensions[CSS_HEIGHT]);
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if (node->style.position_type == CSS_POSITION_ABSOLUTE) {
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printf("position: 'absolute', ");
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}
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print_number_nan("left", node->style.position[CSS_LEFT]);
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print_number_nan("right", node->style.position[CSS_RIGHT]);
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print_number_nan("top", node->style.position[CSS_TOP]);
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print_number_nan("bottom", node->style.position[CSS_BOTTOM]);
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}
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if (options & CSS_PRINT_CHILDREN && node->children_count > 0) {
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printf("children: [\n");
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for (int i = 0; i < node->children_count; ++i) {
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print_css_node_rec(node->get_child(node->context, i), options, level + 1);
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}
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indent(level);
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printf("]},\n");
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} else {
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printf("},\n");
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}
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}
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void print_css_node(css_node_t *node, css_print_options_t options) {
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print_css_node_rec(node, options, 0);
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}
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static css_position_t leading[2] = {
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/* CSS_FLEX_DIRECTION_COLUMN = */ CSS_TOP,
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/* CSS_FLEX_DIRECTION_ROW = */ CSS_LEFT
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};
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static css_position_t trailing[2] = {
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/* CSS_FLEX_DIRECTION_COLUMN = */ CSS_BOTTOM,
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/* CSS_FLEX_DIRECTION_ROW = */ CSS_RIGHT
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};
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static css_position_t pos[2] = {
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/* CSS_FLEX_DIRECTION_COLUMN = */ CSS_TOP,
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/* CSS_FLEX_DIRECTION_ROW = */ CSS_LEFT
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};
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static css_dimension_t dim[2] = {
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/* CSS_FLEX_DIRECTION_COLUMN = */ CSS_HEIGHT,
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/* CSS_FLEX_DIRECTION_ROW = */ CSS_WIDTH
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};
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static float getMargin(css_node_t *node, int location) {
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return node->style.margin[location];
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}
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static float getPadding(css_node_t *node, int location) {
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if (node->style.padding[location] >= 0) {
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return node->style.padding[location];
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}
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return 0;
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}
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static float getBorder(css_node_t *node, int location) {
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if (node->style.border[location] >= 0) {
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return node->style.border[location];
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}
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return 0;
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}
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static float getPaddingAndBorder(css_node_t *node, int location) {
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return getPadding(node, location) + getBorder(node, location);
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}
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static float getMarginAxis(css_node_t *node, css_flex_direction_t axis) {
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return getMargin(node, leading[axis]) + getMargin(node, trailing[axis]);
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}
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static float getPaddingAndBorderAxis(css_node_t *node, css_flex_direction_t axis) {
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return getPaddingAndBorder(node, leading[axis]) + getPaddingAndBorder(node, trailing[axis]);
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}
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static css_position_type_t getPositionType(css_node_t *node) {
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return node->style.position_type;
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}
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static css_justify_t getJustifyContent(css_node_t *node) {
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return node->style.justify_content;
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}
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static css_align_t getAlignItem(css_node_t *node, css_node_t *child) {
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if (child->style.align_self != CSS_ALIGN_AUTO) {
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return child->style.align_self;
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}
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return node->style.align_items;
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}
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static css_flex_direction_t getFlexDirection(css_node_t *node) {
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return node->style.flex_direction;
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}
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static float getFlex(css_node_t *node) {
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return node->style.flex;
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}
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static bool isFlex(css_node_t *node) {
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return (
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getPositionType(node) == CSS_POSITION_RELATIVE &&
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getFlex(node) > 0
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);
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}
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static bool isFlexWrap(css_node_t *node) {
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return node->style.flex_wrap == CSS_WRAP;
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}
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static float getDimWithMargin(css_node_t *node, css_flex_direction_t axis) {
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return node->layout.dimensions[dim[axis]] +
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getMargin(node, leading[axis]) +
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getMargin(node, trailing[axis]);
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}
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static bool isDimDefined(css_node_t *node, css_flex_direction_t axis) {
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return !isUndefined(node->style.dimensions[dim[axis]]);
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}
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static bool isPosDefined(css_node_t *node, css_position_t position) {
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return !isUndefined(node->style.position[position]);
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}
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static bool isMeasureDefined(css_node_t *node) {
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return node->measure;
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}
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static float getPosition(css_node_t *node, css_position_t position) {
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float result = node->style.position[position];
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if (!isUndefined(result)) {
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return result;
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}
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return 0;
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}
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// When the user specifically sets a value for width or height
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static void setDimensionFromStyle(css_node_t *node, css_flex_direction_t axis) {
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// The parent already computed us a width or height. We just skip it
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if (!isUndefined(node->layout.dimensions[dim[axis]])) {
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return;
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}
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// We only run if there's a width or height defined
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if (!isDimDefined(node, axis)) {
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return;
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}
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// The dimensions can never be smaller than the padding and border
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node->layout.dimensions[dim[axis]] = fmaxf(
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node->style.dimensions[dim[axis]],
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getPaddingAndBorderAxis(node, axis)
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);
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}
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// If both left and right are defined, then use left. Otherwise return
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// +left or -right depending on which is defined.
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static float getRelativePosition(css_node_t *node, css_flex_direction_t axis) {
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float lead = node->style.position[leading[axis]];
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if (!isUndefined(lead)) {
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return lead;
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}
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return -getPosition(node, trailing[axis]);
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}
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static void layoutNodeImpl(css_node_t *node, float parentMaxWidth) {
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/** START_GENERATED **/
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css_flex_direction_t mainAxis = getFlexDirection(node);
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css_flex_direction_t crossAxis = mainAxis == CSS_FLEX_DIRECTION_ROW ?
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CSS_FLEX_DIRECTION_COLUMN :
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CSS_FLEX_DIRECTION_ROW;
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// Handle width and height style attributes
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setDimensionFromStyle(node, mainAxis);
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setDimensionFromStyle(node, crossAxis);
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// The position is set by the parent, but we need to complete it with a
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// delta composed of the margin and left/top/right/bottom
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node->layout.position[leading[mainAxis]] += getMargin(node, leading[mainAxis]) +
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getRelativePosition(node, mainAxis);
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node->layout.position[leading[crossAxis]] += getMargin(node, leading[crossAxis]) +
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getRelativePosition(node, crossAxis);
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if (isMeasureDefined(node)) {
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float width = CSS_UNDEFINED;
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if (isDimDefined(node, CSS_FLEX_DIRECTION_ROW)) {
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width = node->style.dimensions[CSS_WIDTH];
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} else if (!isUndefined(node->layout.dimensions[dim[CSS_FLEX_DIRECTION_ROW]])) {
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width = node->layout.dimensions[dim[CSS_FLEX_DIRECTION_ROW]];
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} else {
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width = parentMaxWidth -
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getMarginAxis(node, CSS_FLEX_DIRECTION_ROW);
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}
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width -= getPaddingAndBorderAxis(node, CSS_FLEX_DIRECTION_ROW);
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// We only need to give a dimension for the text if we haven't got any
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// for it computed yet. It can either be from the style attribute or because
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// the element is flexible.
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bool isRowUndefined = !isDimDefined(node, CSS_FLEX_DIRECTION_ROW) &&
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isUndefined(node->layout.dimensions[dim[CSS_FLEX_DIRECTION_ROW]]);
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bool isColumnUndefined = !isDimDefined(node, CSS_FLEX_DIRECTION_COLUMN) &&
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isUndefined(node->layout.dimensions[dim[CSS_FLEX_DIRECTION_COLUMN]]);
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// Let's not measure the text if we already know both dimensions
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if (isRowUndefined || isColumnUndefined) {
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css_dim_t measure_dim = node->measure(
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node->context,
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width
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);
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if (isRowUndefined) {
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node->layout.dimensions[CSS_WIDTH] = measure_dim.dimensions[CSS_WIDTH] +
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getPaddingAndBorderAxis(node, CSS_FLEX_DIRECTION_ROW);
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}
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if (isColumnUndefined) {
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node->layout.dimensions[CSS_HEIGHT] = measure_dim.dimensions[CSS_HEIGHT] +
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getPaddingAndBorderAxis(node, CSS_FLEX_DIRECTION_COLUMN);
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}
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}
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return;
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}
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// Pre-fill some dimensions straight from the parent
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for (int i = 0; i < node->children_count; ++i) {
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css_node_t* child = node->get_child(node->context, i);
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// Pre-fill cross axis dimensions when the child is using stretch before
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// we call the recursive layout pass
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if (getAlignItem(node, child) == CSS_ALIGN_STRETCH &&
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getPositionType(child) == CSS_POSITION_RELATIVE &&
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!isUndefined(node->layout.dimensions[dim[crossAxis]]) &&
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!isDimDefined(child, crossAxis)) {
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child->layout.dimensions[dim[crossAxis]] = fmaxf(
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node->layout.dimensions[dim[crossAxis]] -
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getPaddingAndBorderAxis(node, crossAxis) -
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getMarginAxis(child, crossAxis),
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// You never want to go smaller than padding
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getPaddingAndBorderAxis(child, crossAxis)
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);
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} else if (getPositionType(child) == CSS_POSITION_ABSOLUTE) {
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// Pre-fill dimensions when using absolute position and both offsets for the axis are defined (either both
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// left and right or top and bottom).
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for (int ii = 0; ii < 2; ii++) {
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css_flex_direction_t axis = (ii != 0) ? CSS_FLEX_DIRECTION_ROW : CSS_FLEX_DIRECTION_COLUMN;
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if (!isUndefined(node->layout.dimensions[dim[axis]]) &&
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!isDimDefined(child, axis) &&
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isPosDefined(child, leading[axis]) &&
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isPosDefined(child, trailing[axis])) {
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child->layout.dimensions[dim[axis]] = fmaxf(
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node->layout.dimensions[dim[axis]] -
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getPaddingAndBorderAxis(node, axis) -
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getMarginAxis(child, axis) -
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getPosition(child, leading[axis]) -
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getPosition(child, trailing[axis]),
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// You never want to go smaller than padding
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getPaddingAndBorderAxis(child, axis)
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);
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}
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}
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}
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}
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float definedMainDim = CSS_UNDEFINED;
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if (!isUndefined(node->layout.dimensions[dim[mainAxis]])) {
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definedMainDim = node->layout.dimensions[dim[mainAxis]] -
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getPaddingAndBorderAxis(node, mainAxis);
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}
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// We want to execute the next two loops one per line with flex-wrap
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int startLine = 0;
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int endLine = 0;
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// int nextOffset = 0;
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int alreadyComputedNextLayout = 0;
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// We aggregate the total dimensions of the container in those two variables
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float linesCrossDim = 0;
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float linesMainDim = 0;
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while (endLine < node->children_count) {
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// <Loop A> Layout non flexible children and count children by type
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// mainContentDim is accumulation of the dimensions and margin of all the
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// non flexible children. This will be used in order to either set the
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// dimensions of the node if none already exist, or to compute the
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// remaining space left for the flexible children.
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float mainContentDim = 0;
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// There are three kind of children, non flexible, flexible and absolute.
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// We need to know how many there are in order to distribute the space.
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int flexibleChildrenCount = 0;
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float totalFlexible = 0;
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int nonFlexibleChildrenCount = 0;
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for (int i = startLine; i < node->children_count; ++i) {
|
|
css_node_t* child = node->get_child(node->context, i);
|
|
float nextContentDim = 0;
|
|
|
|
// It only makes sense to consider a child flexible if we have a computed
|
|
// dimension for the node->
|
|
if (!isUndefined(node->layout.dimensions[dim[mainAxis]]) && isFlex(child)) {
|
|
flexibleChildrenCount++;
|
|
totalFlexible += getFlex(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 to compute the
|
|
// remaining space.
|
|
nextContentDim = getPaddingAndBorderAxis(child, mainAxis) +
|
|
getMarginAxis(child, mainAxis);
|
|
|
|
} else {
|
|
float maxWidth = CSS_UNDEFINED;
|
|
if (mainAxis == CSS_FLEX_DIRECTION_ROW) {
|
|
// do nothing
|
|
} else if (isDimDefined(node, CSS_FLEX_DIRECTION_ROW)) {
|
|
maxWidth = node->layout.dimensions[dim[CSS_FLEX_DIRECTION_ROW]] -
|
|
getPaddingAndBorderAxis(node, CSS_FLEX_DIRECTION_ROW);
|
|
} else {
|
|
maxWidth = parentMaxWidth -
|
|
getMarginAxis(node, CSS_FLEX_DIRECTION_ROW) -
|
|
getPaddingAndBorderAxis(node, CSS_FLEX_DIRECTION_ROW);
|
|
}
|
|
|
|
// This is the main recursive call. We layout non flexible children.
|
|
if (alreadyComputedNextLayout == 0) {
|
|
layoutNode(child, maxWidth);
|
|
}
|
|
|
|
// Absolute positioned elements do not take part of the layout, so we
|
|
// don't use them to compute mainContentDim
|
|
if (getPositionType(child) == 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 (isFlexWrap(node) &&
|
|
!isUndefined(node->layout.dimensions[dim[mainAxis]]) &&
|
|
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;
|
|
}
|
|
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 (!isUndefined(node->layout.dimensions[dim[mainAxis]])) {
|
|
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;
|
|
|
|
// 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;
|
|
}
|
|
// We iterate over the full array and only apply the action on flexible
|
|
// children. This is faster than actually allocating a new array that
|
|
// contains only flexible children.
|
|
for (int i = startLine; i < endLine; ++i) {
|
|
css_node_t* child = node->get_child(node->context, i);
|
|
if (isFlex(child)) {
|
|
// At this point we know the final size of the element in the main
|
|
// dimension
|
|
child->layout.dimensions[dim[mainAxis]] = flexibleMainDim * getFlex(child) +
|
|
getPaddingAndBorderAxis(child, mainAxis);
|
|
|
|
float maxWidth = CSS_UNDEFINED;
|
|
if (mainAxis == CSS_FLEX_DIRECTION_ROW) {
|
|
// do nothing
|
|
} else if (isDimDefined(node, CSS_FLEX_DIRECTION_ROW)) {
|
|
maxWidth = node->layout.dimensions[dim[CSS_FLEX_DIRECTION_ROW]] -
|
|
getPaddingAndBorderAxis(node, CSS_FLEX_DIRECTION_ROW);
|
|
} else {
|
|
maxWidth = parentMaxWidth -
|
|
getMarginAxis(node, CSS_FLEX_DIRECTION_ROW) -
|
|
getPaddingAndBorderAxis(node, CSS_FLEX_DIRECTION_ROW);
|
|
}
|
|
|
|
// And we recursively call the layout algorithm for this child
|
|
layoutNode(child, maxWidth);
|
|
}
|
|
}
|
|
|
|
// We use justifyContent to figure out how to allocate the remaining
|
|
// space available
|
|
} else {
|
|
css_justify_t justifyContent = getJustifyContent(node);
|
|
if (justifyContent == CSS_JUSTIFY_FLEX_START) {
|
|
// Do nothing
|
|
} else 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!
|
|
float crossDim = 0;
|
|
float mainDim = leadingMainDim +
|
|
getPaddingAndBorder(node, leading[mainAxis]);
|
|
|
|
for (int i = startLine; i < endLine; ++i) {
|
|
css_node_t* child = node->get_child(node->context, i);
|
|
|
|
if (getPositionType(child) == 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]) +
|
|
getBorder(node, leading[mainAxis]) +
|
|
getMargin(child, leading[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;
|
|
}
|
|
|
|
// 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 (getPositionType(child) == 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, getDimWithMargin(child, crossAxis));
|
|
}
|
|
}
|
|
|
|
float containerCrossAxis = node->layout.dimensions[dim[crossAxis]];
|
|
if (isUndefined(node->layout.dimensions[dim[crossAxis]])) {
|
|
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
|
|
crossDim + getPaddingAndBorderAxis(node, crossAxis),
|
|
getPaddingAndBorderAxis(node, crossAxis)
|
|
);
|
|
}
|
|
|
|
// <Loop D> Position elements in the cross axis
|
|
|
|
for (int i = startLine; i < endLine; ++i) {
|
|
css_node_t* child = node->get_child(node->context, i);
|
|
|
|
if (getPositionType(child) == 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]) +
|
|
getBorder(node, leading[crossAxis]) +
|
|
getMargin(child, leading[crossAxis]);
|
|
|
|
} else {
|
|
float leadingCrossDim = getPaddingAndBorder(node, leading[crossAxis]);
|
|
|
|
// For a relative children, we're either using alignItems (parent) or
|
|
// alignSelf (child) in order to determine the position in the cross axis
|
|
if (getPositionType(child) == CSS_POSITION_RELATIVE) {
|
|
css_align_t alignItem = getAlignItem(node, child);
|
|
if (alignItem == CSS_ALIGN_FLEX_START) {
|
|
// Do nothing
|
|
} else 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(
|
|
containerCrossAxis -
|
|
getPaddingAndBorderAxis(node, crossAxis) -
|
|
getMarginAxis(child, crossAxis),
|
|
// You never want to go smaller than padding
|
|
getPaddingAndBorderAxis(child, crossAxis)
|
|
);
|
|
}
|
|
} else {
|
|
// The remaining space between the parent dimensions+padding and child
|
|
// dimensions+margin.
|
|
float remainingCrossDim = containerCrossAxis -
|
|
getPaddingAndBorderAxis(node, crossAxis) -
|
|
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;
|
|
}
|
|
}
|
|
|
|
linesCrossDim += crossDim;
|
|
linesMainDim = fmaxf(linesMainDim, mainDim);
|
|
startLine = endLine;
|
|
}
|
|
|
|
// 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 (isUndefined(node->layout.dimensions[dim[mainAxis]])) {
|
|
node->layout.dimensions[dim[mainAxis]] = fmaxf(
|
|
// We're missing the last padding at this point to get the final
|
|
// dimension
|
|
linesMainDim + getPaddingAndBorder(node, trailing[mainAxis]),
|
|
// We can never assign a width smaller than the padding and borders
|
|
getPaddingAndBorderAxis(node, mainAxis)
|
|
);
|
|
}
|
|
|
|
if (isUndefined(node->layout.dimensions[dim[crossAxis]])) {
|
|
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
|
|
linesCrossDim + getPaddingAndBorderAxis(node, crossAxis),
|
|
getPaddingAndBorderAxis(node, crossAxis)
|
|
);
|
|
}
|
|
|
|
// <Loop E> Calculate dimensions for absolutely positioned elements
|
|
|
|
for (int i = 0; i < node->children_count; ++i) {
|
|
css_node_t* child = node->get_child(node->context, i);
|
|
if (getPositionType(child) == CSS_POSITION_ABSOLUTE) {
|
|
// 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 (int ii = 0; ii < 2; ii++) {
|
|
css_flex_direction_t 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(
|
|
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)
|
|
);
|
|
}
|
|
}
|
|
for (int ii = 0; ii < 2; ii++) {
|
|
css_flex_direction_t axis = (ii != 0) ? CSS_FLEX_DIRECTION_ROW : CSS_FLEX_DIRECTION_COLUMN;
|
|
if (isPosDefined(child, trailing[axis]) &&
|
|
!isPosDefined(child, leading[axis])) {
|
|
child->layout.position[leading[axis]] =
|
|
node->layout.dimensions[dim[axis]] -
|
|
child->layout.dimensions[dim[axis]] -
|
|
getPosition(child, trailing[axis]);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
/** END_GENERATED **/
|
|
}
|
|
|
|
void layoutNode(css_node_t *node, float parentMaxWidth) {
|
|
css_layout_t *layout = &node->layout;
|
|
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);
|
|
|
|
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;
|
|
|
|
layoutNodeImpl(node, parentMaxWidth);
|
|
|
|
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];
|
|
}
|
|
}
|