Using fullstop Unicode if horizontal ellipsis not present

Source/core/rendering/RenderBlockLineLayout.cpp

Index: Source/core/rendering/RenderBlockLineLayout.cpp
diff --git a/Source/core/rendering/RenderBlockLineLayout.cpp b/Source/core/rendering/RenderBlockLineLayout.cpp
index b31f46799b50a31d90fbfbaf82731fc63da9c7c3..9d9f36f72eeb93f32225add2ea01fabd49490297 100644
--- a/Source/core/rendering/RenderBlockLineLayout.cpp
+++ b/Source/core/rendering/RenderBlockLineLayout.cpp
@@ -1937,14 +1937,35 @@ void RenderBlockFlow::deleteEllipsisLineBoxes()
 void RenderBlockFlow::checkLinesForTextOverflow()
 {
     // Determine the width of the ellipsis using the current font.
-    // FIXME: CSS3 says this is configurable, also need to use 0x002E (FULL STOP) if horizontal ellipsis is "not renderable"
     const Font& font = style()->font();
+
+    const UChar fullStopString[] = {fullstopCharacter, fullstopCharacter, fullstopCharacter};
+    DEFINE_STATIC_LOCAL(AtomicString, fullstopCharacterStr, (fullStopString, 3));
     DEFINE_STATIC_LOCAL(AtomicString, ellipsisStr, (&horizontalEllipsis, 1));
+
     const Font& firstLineFont = firstLineStyle()->font();
     // FIXME: We should probably not hard-code the direction here. https://crbug.com/333004
     TextDirection ellipsisDirection = LTR;
-    float firstLineEllipsisWidth = firstLineFont.width(constructTextRun(this, firstLineFont, &horizontalEllipsis, 1, firstLineStyle(), ellipsisDirection));
-    float ellipsisWidth = (font == firstLineFont) ? firstLineEllipsisWidth : font.width(constructTextRun(this, font, &horizontalEllipsis, 1, style(), ellipsisDirection));
+    float firstLineEllipsisWidth = 0;
+    float ellipsisWidth = 0;
+    bool useHorizontalEllipsis = true;
+
+    // As per CSS3 http://www.w3.org/TR/2003/CR-css3-text-20030514/ sequence of three
+    // Full Stops (002E) can be used.
+    if (firstLineFont.primaryFontHasGlyphForCharacter(horizontalEllipsis)) {
+        firstLineEllipsisWidth = firstLineFont.width(constructTextRun(this, firstLineFont, &horizontalEllipsis, 1, firstLineStyle(), ellipsisDirection));
+    } else {
+        useHorizontalEllipsis = false;
+        firstLineEllipsisWidth = firstLineFont.width(constructTextRun(this, firstLineFont, fullStopString, 1, firstLineStyle(), ellipsisDirection));
+    }
+    ellipsisWidth = (font == firstLineFont) ? firstLineEllipsisWidth : 0;
+
+    if (!ellipsisWidth) {
+        if (font.primaryFontHasGlyphForCharacter(horizontalEllipsis))
+            ellipsisWidth = font.width(constructTextRun(this, font, &horizontalEllipsis, 1, style(), ellipsisDirection));
+        else

[Dominik Röttsches, 2015/01/08 13:02:25]

I think you might be missing useHorizontalEllipsis = false; here - or you might
even need two variables of the kind, if the firstLineFont != font and one has an
ellipsis glyph and the other one doesn't (see below). 

But instead of introducing more booleans, it may be better to not use the
boolean but instead use one additional AtomicString& reference to denote the
string that gets used - more similar to your first approach but without
overriding a static local.

+            ellipsisWidth = font.width(constructTextRun(this, font, fullStopString, 1, style(), ellipsisDirection));
+    }
 
     // For LTR text truncation, we want to get the right edge of our padding box, and then we want to see
     // if the right edge of a line box exceeds that.  For RTL, we use the left edge of the padding box and
@@ -1967,7 +1988,11 @@ void RenderBlockFlow::checkLinesForTextOverflow()
             LayoutUnit width = firstLine ? firstLineEllipsisWidth : ellipsisWidth;
             LayoutUnit blockEdge = ltr ? blockRightEdge : blockLeftEdge;
             if (curr->lineCanAccommodateEllipsis(ltr, blockEdge, lineBoxEdge, width)) {
-                float totalLogicalWidth = curr->placeEllipsis(ellipsisStr, ltr, blockLeftEdge.toFloat(), blockRightEdge.toFloat(), width.toFloat());
+                float totalLogicalWidth = 0;
+                if (useHorizontalEllipsis)
+                    totalLogicalWidth = curr->placeEllipsis(ellipsisStr, ltr, blockLeftEdge.toFloat(), blockRightEdge.toFloat(), width.toFloat());

[Dominik Röttsches, 2015/01/08 13:02:25]

Does this code need to differentiate between firstLineFont and font?

+                else
+                    totalLogicalWidth = curr->placeEllipsis(fullstopCharacterStr, ltr, blockLeftEdge.toFloat(), blockRightEdge.toFloat(), width.toFloat());
 
                 float logicalLeft = 0; // We are only intersted in the delta from the base position.
                 float availableLogicalWidth = (blockRightEdge - blockLeftEdge).toFloat();