Restructure things to fit upcoming diff

java/Layout.h

@@ -0,0 +1,200 @@
+/**
+ * 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.
+ */
+
+#ifndef __LAYOUT_H
+#define __LAYOUT_H
+
+#include <math.h>
+#ifndef __cplusplus
+#include <stdbool.h>
+#endif
+
+// Not defined in MSVC++
+#ifndef NAN
+static const unsigned long __nan[2] = {0xffffffff, 0x7fffffff};
+#define NAN (*(const float *)__nan)
+#endif
+
+#define CSS_UNDEFINED NAN
+
+typedef enum {
+  CSS_DIRECTION_INHERIT = 0,
+  CSS_DIRECTION_LTR,
+  CSS_DIRECTION_RTL
+} css_direction_t;
+
+typedef enum {
+  CSS_FLEX_DIRECTION_COLUMN = 0,
+  CSS_FLEX_DIRECTION_COLUMN_REVERSE,
+  CSS_FLEX_DIRECTION_ROW,
+  CSS_FLEX_DIRECTION_ROW_REVERSE
+} css_flex_direction_t;
+
+typedef enum {
+  CSS_JUSTIFY_FLEX_START = 0,
+  CSS_JUSTIFY_CENTER,
+  CSS_JUSTIFY_FLEX_END,
+  CSS_JUSTIFY_SPACE_BETWEEN,
+  CSS_JUSTIFY_SPACE_AROUND
+} css_justify_t;
+
+typedef enum {
+  CSS_OVERFLOW_VISIBLE = 0,
+  CSS_OVERFLOW_HIDDEN
+} css_overflow_t;
+
+// Note: auto is only a valid value for alignSelf. It is NOT a valid value for
+// alignItems.
+typedef enum {
+  CSS_ALIGN_AUTO = 0,
+  CSS_ALIGN_FLEX_START,
+  CSS_ALIGN_CENTER,
+  CSS_ALIGN_FLEX_END,
+  CSS_ALIGN_STRETCH
+} css_align_t;
+
+typedef enum {
+  CSS_POSITION_RELATIVE = 0,
+  CSS_POSITION_ABSOLUTE
+} css_position_type_t;
+
+typedef enum {
+  CSS_NOWRAP = 0,
+  CSS_WRAP
+} css_wrap_type_t;
+
+// Note: left and top are shared between position[2] and position[4], so
+// they have to be before right and bottom.
+typedef enum {
+  CSS_LEFT = 0,
+  CSS_TOP,
+  CSS_RIGHT,
+  CSS_BOTTOM,
+  CSS_START,
+  CSS_END,
+  CSS_POSITION_COUNT
+} css_position_t;
+
+typedef enum {
+  CSS_MEASURE_MODE_UNDEFINED = 0,
+  CSS_MEASURE_MODE_EXACTLY,
+  CSS_MEASURE_MODE_AT_MOST,
+  CSS_MEASURE_MODE_COUNT
+} css_measure_mode_t;
+
+typedef enum {
+  CSS_WIDTH = 0,
+  CSS_HEIGHT
+} css_dimension_t;
+
+typedef struct {
+  float available_width;
+  float available_height;
+  css_measure_mode_t width_measure_mode;
+  css_measure_mode_t height_measure_mode;
+
+  float computed_width;
+  float computed_height;
+} css_cached_measurement_t;
+
+enum {
+  // This value was chosen based on empiracle data. Even the most complicated
+  // layouts should not require more than 16 entries to fit within the cache.
+  CSS_MAX_CACHED_RESULT_COUNT = 16
+};
+
+typedef struct {
+  float position[4];
+  float dimensions[2];
+  css_direction_t direction;
+
+  float flex_basis;
+
+  // Instead of recomputing the entire layout every single time, we
+  // cache some information to break early when nothing changed
+  bool should_update;
+  int generation_count;
+  css_direction_t last_parent_direction;
+
+  int next_cached_measurements_index;
+  css_cached_measurement_t cached_measurements[CSS_MAX_CACHED_RESULT_COUNT];
+  float measured_dimensions[2];
+
+  css_cached_measurement_t cached_layout;
+} css_layout_t;
+
+typedef struct {
+  float dimensions[2];
+} css_dim_t;
+
+typedef struct {
+  css_direction_t direction;
+  css_flex_direction_t flex_direction;
+  css_justify_t justify_content;
+  css_align_t align_content;
+  css_align_t align_items;
+  css_align_t align_self;
+  css_position_type_t position_type;
+  css_wrap_type_t flex_wrap;
+  css_overflow_t overflow;
+  float flex;
+  float margin[6];
+  float position[4];
+  /**
+   * You should skip all the rules that contain negative values for the
+   * following attributes. For example:
+   *   {padding: 10, paddingLeft: -5}
+   * should output:
+   *   {left: 10 ...}
+   * the following two are incorrect:
+   *   {left: -5 ...}
+   *   {left: 0 ...}
+   */
+  float padding[6];
+  float border[6];
+  float dimensions[2];
+  float minDimensions[2];
+  float maxDimensions[2];
+} css_style_t;
+
+typedef struct css_node css_node_t;
+struct css_node {
+  css_style_t style;
+  css_layout_t layout;
+  int children_count;
+  int line_index;
+
+  css_node_t* next_child;
+
+  css_dim_t (*measure)(void *context, float width, css_measure_mode_t widthMode, float height, css_measure_mode_t heightMode);
+  void (*print)(void *context);
+  struct css_node* (*get_child)(void *context, int i);
+  bool (*is_dirty)(void *context);
+  bool (*is_text_node)(void *context);
+  void *context;
+};
+
+// Lifecycle of nodes and children
+css_node_t *new_css_node(void);
+void init_css_node(css_node_t *node);
+void free_css_node(css_node_t *node);
+
+// Print utilities
+typedef enum {
+  CSS_PRINT_LAYOUT = 1,
+  CSS_PRINT_STYLE = 2,
+  CSS_PRINT_CHILDREN = 4,
+} css_print_options_t;
+void print_css_node(css_node_t *node, css_print_options_t options);
+
+// Function that computes the layout!
+void layoutNode(css_node_t *node, float availableWidth, float availableHeight, css_direction_t parentDirection);
+bool isUndefined(float value);
+
+#endif