Linux: match average char width with Windows

webkit/port/platform/graphics/chromium/SimpleFontDataLinux.cpp

 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "SimpleFontData.h"
 
 #include "Font.h"
 #include "FontCache.h"
 #include "FloatRect.h"
@@ skipping 34 matching lines @@
 
     // In WebKit/WebCore/platform/graphics/SimpleFontData.cpp, m_spaceWidth is
     // calculated for us, but we need to calculate m_maxCharWidth and
     // m_avgCharWidth in order for text entry widgets to be sized correctly.
     // Skia doesn't expose either of these so we calculate them ourselves
 
     GlyphPage* glyphPageZero = GlyphPageTreeNode::getRootChild(this, 0)->page();
     if (!glyphPageZero)
       return;
 
-    static const UChar32 e_char = 'e';
     static const UChar32 M_char = 'M';
-    m_avgCharWidth = widthForGlyph(glyphPageZero->glyphDataForCharacter(e_char).glyph);
     m_maxCharWidth = widthForGlyph(glyphPageZero->glyphDataForCharacter(M_char).glyph);
+
+    if (metrics.fAvgCharWidth) {
+        m_avgCharWidth = SkScalarRound(metrics.fAvgCharWidth);
+    } else {
+        static const UChar32 x_char = 'x';

[ojan, 2008/11/26 00:17:45]

Why "x" as the fallback? This is what Firefox uses, but WebKit currently uses
"0".

[agl, 2008/11/26 00:22:19]

Microsoft documents suggest using the 'x' width and we're trying to match
Windows. Other than that I don't have any good reason...

+        m_avgCharWidth = widthForGlyph(glyphPageZero->glyphDataForCharacter(x_char).glyph);
+    }
 }
 
 void SimpleFontData::platformDestroy()
 {
     delete m_smallCapsFontData;
 }
 
 SimpleFontData* SimpleFontData::smallCapsFontData(const FontDescription& fontDescription) const
 {
     if (!m_smallCapsFontData) {
@@ skipping 42 matching lines @@
 
     m_font.setupPaint(&paint);
 
     paint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
     SkScalar width = paint.measureText(&glyph, 2);
     
     return SkScalarToFloat(width);
 }
 
 }  // namespace WebCore