Add support for measure mode

dist/css-layout.h

@@ -80,6 +80,12 @@ typedef enum {
   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_t;
+
 typedef enum {
   CSS_WIDTH = 0,
   CSS_HEIGHT
@@ -144,7 +150,7 @@ struct css_node {
   css_node_t *next_absolute_child;
   css_node_t *next_flex_child;
 
-  css_dim_t (*measure)(void *context, float width, float height);
+  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);
@@ -734,26 +740,40 @@ static void layoutNodeImpl(css_node_t *node, float parentMaxWidth, float parentM
     bool isResolvedRowDimDefined = isLayoutDimDefined(node, resolvedRowAxis);
 
     float width = CSS_UNDEFINED;
+    css_measure_mode_t widthMode = CSS_MEASURE_MODE_UNDEFINED;
     if (isStyleDimDefined(node, resolvedRowAxis)) {
       width = node->style.dimensions[CSS_WIDTH];
+      widthMode = CSS_MEASURE_MODE_EXACTLY;
     } else if (isResolvedRowDimDefined) {
       width = node->layout.dimensions[dim[resolvedRowAxis]];
+      widthMode = CSS_MEASURE_MODE_EXACTLY;
     } else {
       width = parentMaxWidth -
         getMarginAxis(node, resolvedRowAxis);
+      widthMode = CSS_MEASURE_MODE_AT_MOST;
     }
     width -= paddingAndBorderAxisResolvedRow;
+    if (isUndefined(width)) {
+      widthMode = CSS_MEASURE_MODE_UNDEFINED;
+    }
 
     float height = CSS_UNDEFINED;
+    css_measure_mode_t heightMode = CSS_MEASURE_MODE_UNDEFINED;
     if (isStyleDimDefined(node, CSS_FLEX_DIRECTION_COLUMN)) {
       height = node->style.dimensions[CSS_HEIGHT];
+      heightMode = CSS_MEASURE_MODE_EXACTLY;
     } else if (isLayoutDimDefined(node, CSS_FLEX_DIRECTION_COLUMN)) {
       height = node->layout.dimensions[dim[CSS_FLEX_DIRECTION_COLUMN]];
+      heightMode = CSS_MEASURE_MODE_EXACTLY;
     } else {
       height = parentMaxHeight -
         getMarginAxis(node, resolvedRowAxis);
+      heightMode = CSS_MEASURE_MODE_AT_MOST;
     }
     height -= getPaddingAndBorderAxis(node, CSS_FLEX_DIRECTION_COLUMN);
+    if (isUndefined(height)) {
+      heightMode = CSS_MEASURE_MODE_UNDEFINED;
+    }
 
     // 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
@@ -768,7 +788,9 @@ static void layoutNodeImpl(css_node_t *node, float parentMaxWidth, float parentM
         node->context,
         
         width,
-        height
+        widthMode,
+        height,
+        heightMode
       );
       if (isRowUndefined) {
         node->layout.dimensions[CSS_WIDTH] = measureDim.dimensions[CSS_WIDTH] +
@@ -1447,8 +1469,8 @@ void layoutNode(css_node_t *node, float parentMaxWidth, float parentMaxHeight, c
     !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_parent_max_width, parentMaxWidth) &&
+    eq(layout->last_parent_max_height, parentMaxHeight) &&
     eq(layout->last_direction, direction);
 
   if (skipLayout) {

dist/css-layout.js

@@ -53,6 +53,10 @@ var computeLayout = (function() {
   var CSS_POSITION_RELATIVE = 'relative';
   var CSS_POSITION_ABSOLUTE = 'absolute';
 
+  var CSS_MEASURE_MODE_UNDEFINED = 'undefined';
+  var CSS_MEASURE_MODE_EXACTLY = 'exactly';
+  var CSS_MEASURE_MODE_AT_MOST = 'at-most';
+
   var leading = {
     'row': 'left',
     'row-reverse': 'right',
@@ -110,7 +114,7 @@ var computeLayout = (function() {
   }
 
   function isUndefined(value) {
-    return value === undefined;
+    return value === undefined || isNaN(value);
   }
 
   function isRowDirection(flexDirection) {
@@ -501,26 +505,40 @@ var computeLayout = (function() {
       var/*bool*/ isResolvedRowDimDefined = isLayoutDimDefined(node, resolvedRowAxis);
 
       var/*float*/ width = CSS_UNDEFINED;
+      var/*css_measure_mode_t*/ widthMode = CSS_MEASURE_MODE_UNDEFINED;
       if (isStyleDimDefined(node, resolvedRowAxis)) {
         width = node.style.width;
+        widthMode = CSS_MEASURE_MODE_EXACTLY;
       } else if (isResolvedRowDimDefined) {
         width = node.layout[dim[resolvedRowAxis]];
+        widthMode = CSS_MEASURE_MODE_EXACTLY;
       } else {
         width = parentMaxWidth -
           getMarginAxis(node, resolvedRowAxis);
+        widthMode = CSS_MEASURE_MODE_AT_MOST;
       }
       width -= paddingAndBorderAxisResolvedRow;
+      if (isUndefined(width)) {
+        widthMode = CSS_MEASURE_MODE_UNDEFINED;
+      }
 
       var/*float*/ height = CSS_UNDEFINED;
+      var/*css_measure_mode_t*/ heightMode = CSS_MEASURE_MODE_UNDEFINED;
       if (isStyleDimDefined(node, CSS_FLEX_DIRECTION_COLUMN)) {
         height = node.style.height;
+        heightMode = CSS_MEASURE_MODE_EXACTLY;
       } else if (isLayoutDimDefined(node, CSS_FLEX_DIRECTION_COLUMN)) {
         height = node.layout[dim[CSS_FLEX_DIRECTION_COLUMN]];
+        heightMode = CSS_MEASURE_MODE_EXACTLY;
       } else {
         height = parentMaxHeight -
           getMarginAxis(node, resolvedRowAxis);
+        heightMode = CSS_MEASURE_MODE_AT_MOST;
       }
       height -= getPaddingAndBorderAxis(node, CSS_FLEX_DIRECTION_COLUMN);
+      if (isUndefined(height)) {
+        heightMode = CSS_MEASURE_MODE_UNDEFINED;
+      }
 
       // 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
@@ -535,7 +553,9 @@ var computeLayout = (function() {
           /*(c)!node->context,*/
           /*(java)!layoutContext.measureOutput,*/
           width,
-          height
+          widthMode,
+          height,
+          heightMode
         );
         if (isRowUndefined) {
           node.layout.width = measureDim.width +