Bug 446569 - Implement prefixed CSS3 columns shorthand r=dbaron

dom/interfaces/css/nsIDOMCSS2Properties.idl

@@ -51,7 +51,7 @@
  * http://www.w3.org/TR/DOM-Level-2-Style
  */
 
-[builtinclass, scriptable, uuid(10f43750-b379-11e0-aff2-0800200c9a66)]
+[builtinclass, scriptable, uuid(286466f1-4246-4574-afdb-2f8a03ad7cc8)]
 interface nsIDOMCSS2Properties : nsISupports
 {
            attribute DOMString        background;
@@ -657,6 +657,9 @@ interface nsIDOMCSS2Properties : nsISupports
            attribute DOMString        MozBorderImage;
                                         // raises(DOMException) on setting
 
+           attribute DOMString        MozColumns;
+                                        // raises(DOMException) on setting
+
            attribute DOMString        MozColumnRule;
                                         // raises(DOMException) on setting
 

layout/style/Declaration.cpp

@@ -769,6 +769,15 @@ Declaration::GetValue(nsCSSProperty aProperty, nsAString& aValue) const
         AppendValueToString(eCSSProperty_marker_end, aValue);
       break;
     }
+    case eCSSProperty__moz_columns: {
+      // Two values, column-count and column-width, separated by a space.
+      const nsCSSProperty* subprops =
+        nsCSSProps::SubpropertyEntryFor(aProperty);
+      AppendValueToString(subprops[0], aValue);
+      aValue.Append(PRUnichar(' '));
+      AppendValueToString(subprops[1], aValue);
+      break;
+    }
     default:
       NS_ABORT_IF_FALSE(false, "no other shorthands");
       break;

layout/style/nsCSSParser.cpp

@@ -492,6 +492,7 @@ protected:
 
   // for 'clip' and '-moz-image-region'
   PRBool ParseRect(nsCSSProperty aPropID);
+  PRBool ParseColumns();
   PRBool ParseContent();
   PRBool ParseCounterData(nsCSSProperty aPropID);
   PRBool ParseCursor();
@@ -5492,6 +5493,8 @@ CSSParserImpl::ParsePropertyByFunction(nsCSSProperty aPropID)
 
   case eCSSProperty_clip:
     return ParseRect(eCSSProperty_clip);
+  case eCSSProperty__moz_columns:
+    return ParseColumns();
   case eCSSProperty__moz_column_rule:
     return ParseBorderSide(kColumnRuleIDs, PR_FALSE);
   case eCSSProperty_content:
@@ -5587,6 +5590,10 @@ CSSParserImpl::ParseSingleValueProperty(nsCSSValue& aValue,
     return ParseVariant(aValue, VARIANT_NONE | VARIANT_INHERIT, nsnull);
   }
 
+  if (aPropID == eCSSPropertyExtra_x_auto_value) {
+    return ParseVariant(aValue, VARIANT_AUTO | VARIANT_INHERIT, nsnull);
+  }
+
   if (aPropID < 0 || aPropID >= eCSSProperty_COUNT_no_shorthands) {
     NS_ABORT_IF_FALSE(PR_FALSE, "not a single value property");
     return PR_FALSE;
@@ -6846,6 +6853,48 @@ CSSParserImpl::ParseRect(nsCSSProperty aPropID)
   return PR_TRUE;
 }
 
+PRBool
+CSSParserImpl::ParseColumns()
+{
+  // We use a similar "fake value" hack to ParseListStyle, because
+  // "auto" is acceptable for both column-count and column-width.
+  // If the fake "auto" value is found, and one of the real values isn't,
+  // that means the fake auto value is meant for the real value we didn't
+  // find.
+  static const nsCSSProperty columnIDs[] = {
+    eCSSPropertyExtra_x_auto_value,
+    eCSSProperty__moz_column_count,
+    eCSSProperty__moz_column_width
+  };
+  const PRInt32 numProps = NS_ARRAY_LENGTH(columnIDs);
+
+  nsCSSValue values[numProps];
+  PRInt32 found = ParseChoice(values, columnIDs, numProps);
+  if (found < 1 || !ExpectEndProperty()) {
+    return PR_FALSE;
+  }
+  if ((found & (1|2|4)) == (1|2|4) &&
+      values[0].GetUnit() ==  eCSSUnit_Auto) {
+    // We filled all 3 values, which is invalid
+    return PR_FALSE;
+  }
+
+  if ((found & 2) == 0) {
+    // Provide auto column-count
+    values[1].SetAutoValue();
+  }
+  if ((found & 4) == 0) {
+    // Provide auto column-width
+    values[2].SetAutoValue();
+  }
+
+  // Start at index 1 to skip the fake auto value.
+  for (PRInt32 index = 1; index < numProps; index++) {
+    AppendValue(columnIDs[index], values[index]);
+  }
+  return PR_TRUE;
+}
+
 #define VARIANT_CONTENT (VARIANT_STRING | VARIANT_URL | VARIANT_COUNTER | VARIANT_ATTR | \
                          VARIANT_KEYWORD)
 PRBool

layout/style/nsCSSPropList.h

@@ -1239,6 +1239,11 @@ CSS_PROP_COLOR(
     nsnull,
     offsetof(nsStyleColor, mColor),
     eStyleAnimType_Color)
+CSS_PROP_SHORTHAND(
+    -moz-columns,
+    _moz_columns,
+    CSS_PROP_DOMPROP_PREFIXED(Columns),
+    CSS_PROPERTY_PARSE_FUNCTION)
 CSS_PROP_COLUMN(
     -moz-column-count,
     _moz_column_count,

layout/style/nsCSSProperty.h

@@ -76,7 +76,8 @@ enum nsCSSProperty {
   eCSSPropertyExtra_all_properties,
 
   // Extra dummy values for nsCSSParser internal use.
-  eCSSPropertyExtra_x_none_value
+  eCSSPropertyExtra_x_none_value,
+  eCSSPropertyExtra_x_auto_value
 };
 
 // The "descriptors" that can appear in a @font-face rule.

layout/style/nsCSSProps.cpp

@@ -1968,6 +1968,12 @@ static const nsCSSProperty gOutlineSubpropTable[] = {
   eCSSProperty_UNKNOWN
 };
 
+static const nsCSSProperty gColumnsSubpropTable[] = {
+  eCSSProperty__moz_column_count,
+  eCSSProperty__moz_column_width,
+  eCSSProperty_UNKNOWN
+};
+
 static const nsCSSProperty gColumnRuleSubpropTable[] = {
   // nsCSSDeclaration.cpp outputs the subproperties in this order.
   // It also depends on the color being third.

layout/style/test/property_database.js

@@ -472,6 +472,16 @@ var gCSSProperties = {
 		other_values: [ "border-box", "padding-box" ],
 		invalid_values: [ "margin-box", "content", "padding", "border", "margin" ]
 	},
+	"-moz-columns": {
+		domProp: "MozColumns",
+		inherited: false,
+		type: CSS_TYPE_TRUE_SHORTHAND,
+		subproperties: [ "-moz-column-count", "-moz-column-width" ],
+		initial_values: [ "auto", "auto auto" ],
+		other_values: [ "3", "20px", "2 10px", "10px 2", "2 auto", "auto 2", "auto 50px", "50px auto" ],
+		invalid_values: [ "5%", "-1px", "-1", "3 5", "10px 4px", "10 2px 5in", "30px -1",
+		                  "auto 3 5px", "5 auto 20px", "auto auto auto" ]
+	},
 	"-moz-column-count": {
 		domProp: "MozColumnCount",
 		inherited: false,