Use Skia for font selection on windows

Source/core/platform/graphics/skia/FontCacheSkiaWin.cpp

Index: Source/core/platform/graphics/skia/FontCacheSkiaWin.cpp
diff --git a/Source/core/platform/graphics/skia/FontCacheSkiaWin.cpp b/Source/core/platform/graphics/skia/FontCacheSkiaWin.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..e3e8f34565249d37bb4c4302fd5f313159ba604f
--- /dev/null
+++ b/Source/core/platform/graphics/skia/FontCacheSkiaWin.cpp
@@ -0,0 +1,192 @@
+/*
+ * Copyright (C) 2006, 2007 Apple Computer, Inc.
+ * Copyright (c) 2006, 2007, 2008, 2009, 2012 Google Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "core/platform/graphics/FontCache.h"
+
+#include "core/platform/NotImplemented.h"
+#include "core/platform/graphics/Font.h"
+#include "core/platform/graphics/SimpleFontData.h"
+#include "core/platform/graphics/chromium/FontPlatformDataChromiumWin.h"
+#include "core/platform/graphics/chromium/FontUtilsChromiumWin.h"
+
+namespace WebCore {
+
+static bool fontContainsCharacter(const FontPlatformData* fontData, const wchar_t* family, UChar32 character)
+{
+    char characters[2] = {character, 0};
+    return fontData->typeface()->charsToGlyphs(characters, SkTypeface::kUTF32_Encoding, 0, 1) == 1;
+}
+
+// Given the desired base font, this will create a SimpleFontData for a specific
+// font that can be used to render the given range of characters.
+PassRefPtr<SimpleFontData> FontCache::getFontDataForCharacter(const Font& font, UChar32 inputC)
+{
+    // FIXME: We should fix getFallbackFamily to take a UChar32
+    // and remove this split-to-UChar16 code.
+    UChar codeUnits[2];
+    int codeUnitsLength;
+    if (inputC <= 0xFFFF) {
+        codeUnits[0] = inputC;
+        codeUnitsLength = 1;
+    } else {
+        codeUnits[0] = U16_LEAD(inputC);
+        codeUnits[1] = U16_TRAIL(inputC);
+        codeUnitsLength = 2;
+    }
+
+    // FIXME: Consider passing fontDescription.dominantScript()
+    // to GetFallbackFamily here.
+    FontDescription fontDescription = font.fontDescription();
+    UChar32 c;
+    UScriptCode script;
+    const wchar_t* family = getFallbackFamily(codeUnits, codeUnitsLength, fontDescription.genericFamily(), &c, &script);
+    FontPlatformData* data = 0;
+    if (family)
+        data = getFontResourcePlatformData(font.fontDescription(),  AtomicString(family, wcslen(family)), false);
+
+    // Last resort font list : PanUnicode. CJK fonts have a pretty
+    // large repertoire. Eventually, we need to scan all the fonts
+    // on the system to have a Firefox-like coverage.
+    // Make sure that all of them are lowercased.
+    const static wchar_t* const cjkFonts[] = {
+        L"arial unicode ms",
+        L"ms pgothic",
+        L"simsun",
+        L"gulim",
+        L"pmingliu",
+        L"wenquanyi zen hei", // Partial CJK Ext. A coverage but more widely known to Chinese users.
+        L"ar pl shanheisun uni",
+        L"ar pl zenkai uni",
+        L"han nom a", // Complete CJK Ext. A coverage.
+        L"code2000" // Complete CJK Ext. A coverage.
+        // CJK Ext. B fonts are not listed here because it's of no use
+        // with our current non-BMP character handling because we use
+        // Uniscribe for it and that code path does not go through here.
+    };
+
+    const static wchar_t* const commonFonts[] = {
+        L"tahoma",
+        L"arial unicode ms",
+        L"lucida sans unicode",
+        L"microsoft sans serif",
+        L"palatino linotype",
+        // Six fonts below (and code2000 at the end) are not from MS, but
+        // once installed, cover a very wide range of characters.
+        L"dejavu serif",
+        L"dejavu sasns",
+        L"freeserif",
+        L"freesans",
+        L"gentium",
+        L"gentiumalt",
+        L"ms pgothic",
+        L"simsun",
+        L"gulim",
+        L"pmingliu",
+        L"code2000"
+    };
+
+    const wchar_t* const* panUniFonts = 0;
+    int numFonts = 0;
+    if (script == USCRIPT_HAN) {
+        panUniFonts = cjkFonts;
+        numFonts = WTF_ARRAY_LENGTH(cjkFonts);
+    } else {
+        panUniFonts = commonFonts;
+        numFonts = WTF_ARRAY_LENGTH(commonFonts);
+    }
+    // Font returned from GetFallbackFamily may not cover |characters|
+    // because it's based on script to font mapping. This problem is
+    // critical enough for non-Latin scripts (especially Han) to
+    // warrant an additional (real coverage) check with fontCotainsCharacter.
+    int i;
+    for (i = 0; (!data || !fontContainsCharacter(data, family, c)) && i < numFonts; ++i) {
+        family = panUniFonts[i];
+        data = getFontResourcePlatformData(font.fontDescription(), AtomicString(family, wcslen(family)));
+    }
+    // When i-th font (0-base) in |panUniFonts| contains a character and
+    // we get out of the loop, |i| will be |i + 1|. That is, if only the
+    // last font in the array covers the character, |i| will be numFonts.
+    // So, we have to use '<=" rather than '<' to see if we found a font
+    // covering the character.
+    if (i <= numFonts)
+        return getFontResourceData(data, DoNotRetain);
+
+    return 0;
+}
+
+static bool typefacesMatchesFamily(const SkTypeface* tf, const AtomicString& family)
+{
+    SkTypeface::LocalizedStrings* actualFamilies = tf->createFamilyNameIterator();
+    bool matchesRequestedFamily = false;
+    SkTypeface::LocalizedString actualFamily;
+
+    while (actualFamilies->next(&actualFamily)) {
+        if (equalIgnoringCase(family, actualFamily.fString.c_str())) {
+            matchesRequestedFamily = true;
+            break;
+        }
+    }
+    actualFamilies->unref();

[bungeman-chromium, 2013/08/15 22:24:44]

Hmmm... I think if I put a deref on this you could use a RefPtr to unref it, I
think. It was designed with SkAutoTUnref in mind, but I'm not sure that's
supposed to be publicly usable or not.

Also, all Skia SkStrings are in UTF-8. I'm not familiar with AtomicString, but
it looks like it should have enough overrides of equalIgnoringCase for this to
work.

[eae, 2013/08/15 22:34:50]

Might make sense long term but for now calling unref manually is fine and
consistent with existing APIs.
As long as both are UTF-8 that should not be a problem, I suppose the requested
family could be 8859-1 though...

+
+    return matchesRequestedFamily;
+}
+
+FontPlatformData* FontCache::createFontPlatformData(const FontDescription& fontDescription, const AtomicString& family)
+{
+    SkTypeface* tf = createTypeface(fontDescription, family);
+    if (!tf)
+        return 0;
+
+    // Windows will always give us a valid pointer here, even if the face name
+    // is non-existent. We have to double-check and see if the family name was
+    // really used.
+    // FIXME: Do we need to use predefined fonts "guaranteed" to exist
+    // when we're running in layout-test mode?
+    if (!typefacesMatchesFamily(tf, family)) {
+        tf->unref();
+        return 0;
+    }
+
+    SkString name;
+    tf->getFamilyName(&name);
+
+    FontPlatformData* result = new FontPlatformData(tf,
+        name.c_str(),
+        fontDescription.computedSize(),
+        fontDescription.weight() >= FontWeightBold && !tf->isBold(),
+        fontDescription.italic() && !tf->isItalic(),
+        fontDescription.orientation());
+    tf->unref();
+    return result;
+}
+
+}