bug 721750 - support text-shadow property on ::-moz-selection. r=dbaron

layout/base/nsPresContext.h

@@ -116,6 +116,7 @@ public:
 #define NS_AUTHOR_SPECIFIED_BACKGROUND      (1 << 0)
 #define NS_AUTHOR_SPECIFIED_BORDER          (1 << 1)
 #define NS_AUTHOR_SPECIFIED_PADDING         (1 << 2)
+#define NS_AUTHOR_SPECIFIED_TEXT_SHADOW     (1 << 3)
 
 class nsRootPresContext;
 

layout/generic/nsTextFrameThebes.cpp

@@ -304,6 +304,10 @@ public:
                                       float* aRelativeSize,
                                       PRUint8* aStyle);
 
+  // if this returns false, no text-shadow was specified for the selection
+  // and the *aShadow parameter was not modified.
+  bool GetSelectionShadow(nsCSSShadowArray** aShadow);
+
   nsPresContext* PresContext() const { return mPresContext; }
 
   enum {
@@ -337,13 +341,15 @@ protected:
   nsTextFrame*   mFrame;
   nsPresContext* mPresContext;
   bool           mInitCommonColors;
-  bool           mInitSelectionColors;
+  bool           mInitSelectionColorsAndShadow;
 
   // Selection data
 
   PRInt16      mSelectionStatus; // see nsIDocument.h SetDisplaySelection()
   nscolor      mSelectionTextColor;
   nscolor      mSelectionBGColor;
+  nsRefPtr<nsCSSShadowArray> mSelectionShadow;
+  bool                       mHasSelectionShadow;
 
   // Common data
 
@@ -365,7 +371,7 @@ protected:
 
   // Color initializations
   void InitCommonColors();
-  bool InitSelectionColors();
+  bool InitSelectionColorsAndShadow();
 
   nsSelectionStyle* GetSelectionStyle(PRInt32 aIndex);
   void InitSelectionStyle(PRInt32 aIndex);
@@ -3390,7 +3396,8 @@ nsTextPaintStyle::nsTextPaintStyle(nsTextFrame* aFrame)
   : mFrame(aFrame),
     mPresContext(aFrame->PresContext()),
     mInitCommonColors(false),
-    mInitSelectionColors(false)
+    mInitSelectionColorsAndShadow(false),
+    mHasSelectionShadow(false)
 {
   for (PRUint32 i = 0; i < ArrayLength(mSelectionStyle); i++)
     mSelectionStyle[i].mInit = false;
@@ -3434,7 +3441,7 @@ nsTextPaintStyle::GetSelectionColors(nscolor* aForeColor,
   NS_ASSERTION(aForeColor, "aForeColor is null");
   NS_ASSERTION(aBackColor, "aBackColor is null");
 
-  if (!InitSelectionColors())
+  if (!InitSelectionColorsAndShadow())
     return false;
 
   *aForeColor = mSelectionTextColor;
@@ -3566,9 +3573,9 @@ FindElementAncestorForMozSelection(nsIContent* aContent)
 }
 
 bool
-nsTextPaintStyle::InitSelectionColors()
+nsTextPaintStyle::InitSelectionColorsAndShadow()
 {
-  if (mInitSelectionColors)
+  if (mInitSelectionColorsAndShadow)
     return true;
 
   PRInt16 selectionFlags;
@@ -3581,7 +3588,7 @@ nsTextPaintStyle::InitSelectionColors()
     return false;
   }
 
-  mInitSelectionColors = true;
+  mInitSelectionColorsAndShadow = true;
 
   nsIFrame* nonGeneratedAncestor = nsLayoutUtils::GetNonGeneratedAncestor(mFrame);
   Element* selectionElement =
@@ -3599,6 +3606,13 @@ nsTextPaintStyle::InitSelectionColors()
       mSelectionBGColor =
         sc->GetVisitedDependentColor(eCSSProperty_background_color);
       mSelectionTextColor = sc->GetVisitedDependentColor(eCSSProperty_color);
+      mHasSelectionShadow =
+        nsRuleNode::HasAuthorSpecifiedRules(sc,
+                                            NS_AUTHOR_SPECIFIED_TEXT_SHADOW,
+                                            true);
+      if (mHasSelectionShadow) {
+        mSelectionShadow = sc->GetStyleText()->mTextShadow;
+      }
       return true;
     }
   }
@@ -3759,6 +3773,21 @@ nsTextPaintStyle::GetSelectionUnderline(nsPresContext* aPresContext,
          size > 0.0f;
 }
 
+bool
+nsTextPaintStyle::GetSelectionShadow(nsCSSShadowArray** aShadow)
+{
+  if (!InitSelectionColorsAndShadow()) {
+    return false;
+  }
+
+  if (mHasSelectionShadow) {
+    *aShadow = mSelectionShadow;
+    return true;
+  }
+
+  return false;
+}
+
 inline nscolor Get40PercentColor(nscolor aForeColor, nscolor aBackColor)
 {
   nscolor foreColor = NS_RGBA(NS_GET_R(aForeColor),
@@ -4934,6 +4963,24 @@ static bool GetSelectionTextColors(SelectionType aType,
   }
 }
 
+/**
+ * This sets *aShadow to the appropriate shadow, if any, for the given
+ * type of selection. Returns true if *aShadow was set.
+ * If text-shadow was not specified, *aShadow is left untouched
+ * (NOT reset to null), and the function returns false.
+ */
+static bool GetSelectionTextShadow(SelectionType aType,
+                                   nsTextPaintStyle& aTextPaintStyle,
+                                   nsCSSShadowArray** aShadow)
+{
+  switch (aType) {
+    case nsISelectionController::SELECTION_NORMAL:
+      return aTextPaintStyle.GetSelectionShadow(aShadow);
+    default:
+      return false;
+  }
+}
+
 /**
  * This class lets us iterate over chunks of text in a uniform selection state,
  * observing cluster boundaries, in content order, maintaining the current
@@ -5217,8 +5264,13 @@ nsTextFrame::PaintTextWithSelectionColors(gfxContext* aCtx,
                            &foreground, &background);
     gfxPoint textBaselinePt(aFramePt.x + xOffset, aTextBaselinePt.y);
 
+    // Determine what shadow, if any, to draw - either from textStyle
+    // or from the ::-moz-selection pseudo-class if specified there
+    nsCSSShadowArray *shadow = textStyle->mTextShadow;
+    GetSelectionTextShadow(type, aTextPaintStyle, &shadow);
+
     // Draw shadows, if any
-    if (textStyle->mTextShadow) {
+    if (shadow) {
       gfxTextRun::Metrics shadowMetrics =
         mTextRun->MeasureText(offset, length, gfxFont::LOOSE_INK_EXTENTS,
                               nullptr, &aProvider);
@@ -5226,9 +5278,9 @@ nsTextFrame::PaintTextWithSelectionColors(gfxContext* aCtx,
         AddHyphenToMetrics(this, mTextRun, &shadowMetrics,
                            gfxFont::LOOSE_INK_EXTENTS, aCtx);
       }
-      for (PRUint32 i = textStyle->mTextShadow->Length(); i > 0; --i) {
+      for (PRUint32 i = shadow->Length(); i > 0; --i) {
         PaintOneShadow(offset, length,
-                       textStyle->mTextShadow->ShadowAt(i - 1), &aProvider,
+                       shadow->ShadowAt(i - 1), &aProvider,
                        dirtyRect, aFramePt, textBaselinePt, aCtx,
                        foreground, aClipEdges, 
                        xOffset - (mTextRun->IsRightToLeft() ?

layout/style/nsRuleNode.cpp

@@ -7671,8 +7671,12 @@ nsRuleNode::HasAuthorSpecifiedRules(nsStyleContext* aStyleContext,
   if (ruleTypeMask & NS_AUTHOR_SPECIFIED_PADDING)
     inheritBits |= NS_STYLE_INHERIT_BIT(Padding);
 
+  if (ruleTypeMask & NS_AUTHOR_SPECIFIED_TEXT_SHADOW)
+    inheritBits |= NS_STYLE_INHERIT_BIT(Text);
+
   // properties in the SIDS, whether or not we care about them
-  size_t nprops = 0, backgroundOffset, borderOffset, paddingOffset;
+  size_t nprops = 0,
+         backgroundOffset, borderOffset, paddingOffset, textShadowOffset;
 
   if (ruleTypeMask & NS_AUTHOR_SPECIFIED_BACKGROUND) {
     backgroundOffset = nprops;
@@ -7689,6 +7693,11 @@ nsRuleNode::HasAuthorSpecifiedRules(nsStyleContext* aStyleContext,
     nprops += nsCSSProps::PropertyCountInStruct(eStyleStruct_Padding);
   }
 
+  if (ruleTypeMask & NS_AUTHOR_SPECIFIED_TEXT_SHADOW) {
+    textShadowOffset = nprops;
+    nprops += nsCSSProps::PropertyCountInStruct(eStyleStruct_Text);
+  }
+
   void* dataStorage = alloca(nprops * sizeof(nsCSSValue));
   AutoCSSValueArray dataArray(dataStorage, nprops);
 
@@ -7708,6 +7717,10 @@ nsRuleNode::HasAuthorSpecifiedRules(nsStyleContext* aStyleContext,
     ruleData.mValueOffsets[eStyleStruct_Padding] = paddingOffset;
   }
 
+  if (ruleTypeMask & NS_AUTHOR_SPECIFIED_TEXT_SHADOW) {
+    ruleData.mValueOffsets[eStyleStruct_Text] = textShadowOffset;
+  }
+
   static const nsCSSProperty backgroundValues[] = {
     eCSSProperty_background_color,
     eCSSProperty_background_image,
@@ -7747,16 +7760,22 @@ nsRuleNode::HasAuthorSpecifiedRules(nsStyleContext* aStyleContext,
     eCSSProperty_padding_end_value,
   };
 
+  static const nsCSSProperty textShadowValues[] = {
+    eCSSProperty_text_shadow
+  };
+
   // Number of properties we care about
   size_t nValues = 0;
 
   nsCSSValue* values[NS_ARRAY_LENGTH(backgroundValues) +
                      NS_ARRAY_LENGTH(borderValues) +
-                     NS_ARRAY_LENGTH(paddingValues)];
+                     NS_ARRAY_LENGTH(paddingValues) +
+                     NS_ARRAY_LENGTH(textShadowValues)];
 
   nsCSSProperty properties[NS_ARRAY_LENGTH(backgroundValues) +
                            NS_ARRAY_LENGTH(borderValues) +
-                           NS_ARRAY_LENGTH(paddingValues)];
+                           NS_ARRAY_LENGTH(paddingValues) +
+                           NS_ARRAY_LENGTH(textShadowValues)];
 
   if (ruleTypeMask & NS_AUTHOR_SPECIFIED_BACKGROUND) {
     for (PRUint32 i = 0, i_end = ArrayLength(backgroundValues);
@@ -7782,6 +7801,14 @@ nsRuleNode::HasAuthorSpecifiedRules(nsStyleContext* aStyleContext,
     }
   }
 
+  if (ruleTypeMask & NS_AUTHOR_SPECIFIED_TEXT_SHADOW) {
+    for (PRUint32 i = 0, i_end = ArrayLength(textShadowValues);
+         i < i_end; ++i) {
+      properties[nValues] = textShadowValues[i];
+      values[nValues++] = ruleData.ValueFor(textShadowValues[i]);
+    }
+  }
+
   nsStyleContext* styleContext = aStyleContext;
 
   // We need to be careful not to count styles covered up by user-important or