Bug 1038663 (part 6) - Allow percentage values for 'word-spacing'. r=heycam.

--HG--
extra : rebase_source : b7220e3c156dfef451e79b2911fbba7dec93850d

layout/generic/nsTextFrame.cpp

@@ -1,4 +1,5 @@
-/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
@@ -1628,8 +1629,10 @@ LetterSpacing(nsIFrame* aFrame, const nsStyleText* aStyleText = nullptr)
   return 0;
 }
 
+// This function converts non-coord values (e.g. percentages) to nscoord.
 static nscoord
-WordSpacing(nsIFrame* aFrame, const nsStyleText* aStyleText = nullptr)
+WordSpacing(nsIFrame* aFrame, gfxTextRun* aTextRun,
+            const nsStyleText* aStyleText = nullptr)
 {
   if (aFrame->IsSVGText()) {
     return 0;
@@ -1642,6 +1645,11 @@ WordSpacing(nsIFrame* aFrame, const nsStyleText* aStyleText = nullptr)
   if (eStyleUnit_Coord == coord.GetUnit()) {
     return coord.GetCoordValue();
   }
+  if (eStyleUnit_Percent == coord.GetUnit() ||
+      eStyleUnit_Calc == coord.GetUnit()) {
+    return nsRuleNode::ComputeCoordPercentCalc(coord,
+                                               GetSpaceWidthAppUnits(aTextRun));
+  }
   return 0;
 }
 
@@ -1658,9 +1666,15 @@ GetSpacingFlags(nsIFrame* aFrame, const nsStyleText* aStyleText = nullptr)
   const nsStyleCoord& ls = styleText->mLetterSpacing;
   const nsStyleCoord& ws = styleText->mWordSpacing;
 
+  // It's possible to have a calc() value that computes to zero but for which
+  // IsDefinitelyZero() is false, in which case we'll return
+  // TEXT_ENABLE_SPACING unnecessarily. That's ok because such cases are likely
+  // to be rare, and avoiding TEXT_ENABLE_SPACING is just an optimization.
   bool nonStandardSpacing =
     (eStyleUnit_Coord == ls.GetUnit() && ls.GetCoordValue() != 0) ||
-    (eStyleUnit_Coord == ws.GetUnit() && ws.GetCoordValue() != 0);
+    (eStyleUnit_Coord == ws.GetUnit() && ws.GetCoordValue() != 0) ||
+    (eStyleUnit_Percent == ws.GetUnit() && ws.GetPercentValue() != 0) ||
+    (eStyleUnit_Calc == ws.GetUnit() && !ws.GetCalcValue()->IsDefinitelyZero());
 
   return nonStandardSpacing ? gfxTextRunFactory::TEXT_ENABLE_SPACING : 0;
 }
@@ -2902,7 +2916,7 @@ public:
       mFrame(aFrame), mStart(aStart), mTempIterator(aStart),
       mTabWidths(nullptr), mTabWidthsAnalyzedLimit(0),
       mLength(aLength),
-      mWordSpacing(WordSpacing(aFrame, aTextStyle)),
+      mWordSpacing(WordSpacing(aFrame, mTextRun, aTextStyle)),
       mLetterSpacing(LetterSpacing(aFrame, aTextStyle)),
       mHyphenWidth(-1),
       mOffsetFromBlockOriginForTabs(aOffsetFromBlockOriginForTabs),
@@ -2927,7 +2941,7 @@ public:
       mFrame(aFrame), mStart(aStart), mTempIterator(aStart),
       mTabWidths(nullptr), mTabWidthsAnalyzedLimit(0),
       mLength(aFrame->GetContentLength()),
-      mWordSpacing(WordSpacing(aFrame)),
+      mWordSpacing(WordSpacing(aFrame, mTextRun)),
       mLetterSpacing(LetterSpacing(aFrame)),
       mHyphenWidth(-1),
       mOffsetFromBlockOriginForTabs(0),

layout/style/nsCSSPropList.h

@@ -3623,9 +3623,10 @@ CSS_PROP_TEXT(
     CSS_PROPERTY_PARSE_VALUE |
         CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE |
         CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
-        CSS_PROPERTY_UNITLESS_LENGTH_QUIRK,
+        CSS_PROPERTY_UNITLESS_LENGTH_QUIRK |
+        CSS_PROPERTY_STORES_CALC,
     "",
-    VARIANT_HL | VARIANT_NORMAL | VARIANT_CALC,
+    VARIANT_HLP | VARIANT_NORMAL | VARIANT_CALC,
     nullptr,
     offsetof(nsStyleText, mWordSpacing),
     eStyleAnimType_Coord)

layout/style/nsRuleNode.cpp

@@ -4408,7 +4408,7 @@ nsRuleNode::ComputeTextData(void* aStartStruct,
               parentText->mWordBreak,
               NS_STYLE_WORDBREAK_NORMAL, 0, 0, 0, 0);
 
-  // word-spacing: normal, length, inherit
+  // word-spacing: normal, length, percent, inherit
   const nsCSSValue* wordSpacingValue = aRuleData->ValueForWordSpacing();
   if (wordSpacingValue->GetUnit() == eCSSUnit_Normal) {
     // Do this so that "normal" computes to 0px, as the CSS 2.1 spec requires.
@@ -4416,8 +4416,8 @@ nsRuleNode::ComputeTextData(void* aStartStruct,
   } else {
     SetCoord(*aRuleData->ValueForWordSpacing(),
              text->mWordSpacing, parentText->mWordSpacing,
-             SETCOORD_LH | SETCOORD_INITIAL_ZERO |
-               SETCOORD_CALC_LENGTH_ONLY | SETCOORD_UNSET_INHERIT,
+             SETCOORD_LPH | SETCOORD_INITIAL_ZERO |
+               SETCOORD_STORE_CALC | SETCOORD_UNSET_INHERIT,
              aContext, mPresContext, conditions);
   }
 

layout/style/nsStyleCoord.h

@@ -90,6 +90,10 @@ public:
     bool operator!=(const CalcValue& aOther) const {
       return !(*this == aOther);
     }
+
+    // If this returns true the value is definitely zero. It it returns false
+    // it might be zero. So it's best used for conservative optimization.
+    bool IsDefinitelyZero() const { return mLength == 0 && mPercent == 0; }
   };
 
   // Reference counted calc() value.  This is the type that is used to store

layout/style/nsStyleStruct.h

@@ -1736,7 +1736,7 @@ struct nsStyleText {
   uint8_t mControlCharacterVisibility;  // [inherited] see nsStyleConsts.h
   int32_t mTabSize;                     // [inherited] see nsStyleConsts.h
 
-  nsStyleCoord mWordSpacing;            // [inherited] coord
+  nsStyleCoord mWordSpacing;            // [inherited] coord, percent, calc
   nsStyleCoord mLetterSpacing;          // [inherited] coord, normal
   nsStyleCoord mLineHeight;             // [inherited] coord, factor, normal
   nsStyleCoord mTextIndent;             // [inherited] coord, percent, calc

layout/style/test/property_database.js

@@ -3737,10 +3737,11 @@ var gCSSProperties = {
     initial_values: [ "normal", "0", "0px", "-0em",
       "calc(-0px)", "calc(0em)"
     ],
-    other_values: [ "1em", "2px", "-3px",
+    other_values: [ "1em", "2px", "-3px", "0%", "50%", "-120%",
       "calc(1em)", "calc(1em + 3px)",
       "calc(15px / 2)", "calc(15px/2)",
-      "calc(-2em)"
+      "calc(-2em)", "calc(0% + 0px)",
+      "calc(-10%/2 - 1em)"
     ],
     invalid_values: [],
     quirks_values: { "5": "5px" },