FontCacheWin.cpp   [plain text]

/*
 * Copyright (C) 2006, 2007 Apple Inc.  All rights reserved.
 *
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 * modification, are permitted provided that the following conditions
 * are met:
 *
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 *     notice, this list of conditions and the following disclaimer. 
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 *     notice, this list of conditions and the following disclaimer in the
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 * 3.  Neither the name of Apple Computer, Inc. ("Apple") 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 APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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#include "config.h"
#include <winsock2.h>
#include "FontCache.h"
#include "Font.h"
#include "SimpleFontData.h"
#include "StringHash.h"
#include "UnicodeRange.h"
#include <windows.h>
#include <mlang.h>
#include <ApplicationServices/ApplicationServices.h>
#include <WebKitSystemInterface/WebKitSystemInterface.h>

using std::min;

namespace WebCore
{

void FontCache::platformInit()
{
    wkSetUpFontCache(1536 * 1024 * 4); // This size matches Mac.
}

IMLangFontLink2* FontCache::getFontLinkInterface()
{
    static IMultiLanguage *multiLanguage;
    if (!multiLanguage) {
        if (CoCreateInstance(CLSID_CMultiLanguage, 0, CLSCTX_ALL, IID_IMultiLanguage, (void**)&multiLanguage) != S_OK)
            return 0;
    }

    static IMLangFontLink2* langFontLink;
    if (!langFontLink) {
        if (multiLanguage->QueryInterface(&langFontLink) != S_OK)
            return 0;
    }

    return langFontLink;
}

static int CALLBACK metaFileEnumProc(HDC hdc, HANDLETABLE* table, CONST ENHMETARECORD* record, int tableEntries, LPARAM logFont)
{
    if (record->iType == EMR_EXTCREATEFONTINDIRECTW) {
        const EMREXTCREATEFONTINDIRECTW* createFontRecord = reinterpret_cast<const EMREXTCREATEFONTINDIRECTW*>(record);
        *reinterpret_cast<LOGFONT*>(logFont) = createFontRecord->elfw.elfLogFont;
    }
    return true;
}

static int CALLBACK linkedFontEnumProc(CONST LOGFONT* logFont, CONST TEXTMETRIC* metrics, DWORD fontType, LPARAM hfont)
{
    *reinterpret_cast<HFONT*>(hfont) = CreateFontIndirect(logFont);
    return false;
}

static const Vector<String>* getLinkedFonts(String& family)
{
    static HashMap<String, Vector<String>*> systemLinkMap;
    Vector<String>* result = systemLinkMap.get(family);
    if (result)
        return result;

    result = new Vector<String>;
    systemLinkMap.set(family, result);
    HKEY fontLinkKey;
    if (FAILED(RegOpenKeyEx(HKEY_LOCAL_MACHINE, L"Software\\Microsoft\\Windows NT\\CurrentVersion\\FontLink\\SystemLink", 0, KEY_READ, &fontLinkKey)))
        return result;

    DWORD linkedFontsBufferSize = 0;
    RegQueryValueEx(fontLinkKey, family.charactersWithNullTermination(), 0, NULL, NULL, &linkedFontsBufferSize);
    WCHAR* linkedFonts = reinterpret_cast<WCHAR*>(malloc(linkedFontsBufferSize));
    if (SUCCEEDED(RegQueryValueEx(fontLinkKey, family.charactersWithNullTermination(), 0, NULL, reinterpret_cast<BYTE*>(linkedFonts), &linkedFontsBufferSize))) {
        unsigned i = 0;
        unsigned length = linkedFontsBufferSize / sizeof(*linkedFonts);
        while (i < length) {
            while (i < length && linkedFonts[i] != ',')
                i++;
            i++;
            unsigned j = i;
            while (j < length && linkedFonts[j])
                j++;
            result->append(String(linkedFonts + i, j - i));
            i = j + 1;
        }
    }
    free(linkedFonts);
    RegCloseKey(fontLinkKey);
    return result;
}

static const Vector<DWORD, 4>& getCJKCodePageMasks()
{
    // The default order in which we look for a font for a CJK character. If the user's default code page is
    // one of these, we will use it first.
    static const UINT CJKCodePages[] = { 
        932, /* Japanese */
        936, /* Simplified Chinese */
        950, /* Traditional Chinese */
        949  /* Korean */
    };

    static Vector<DWORD, 4> codePageMasks;
    static bool initialized;
    if (!initialized) {
        initialized = true;
        IMLangFontLink2* langFontLink = FontCache::getFontLinkInterface();
        if (!langFontLink)
            return codePageMasks;

        UINT defaultCodePage;
        DWORD defaultCodePageMask = 0;
        if (GetLocaleInfo(LOCALE_USER_DEFAULT, LOCALE_RETURN_NUMBER | LOCALE_IDEFAULTANSICODEPAGE, reinterpret_cast<LPWSTR>(&defaultCodePage), sizeof(defaultCodePage)))
            langFontLink->CodePageToCodePages(defaultCodePage, &defaultCodePageMask);

        if (defaultCodePage == CJKCodePages[0] || defaultCodePage == CJKCodePages[1] || defaultCodePage == CJKCodePages[2] || defaultCodePage == CJKCodePages[3])
            codePageMasks.append(defaultCodePageMask);
        for (unsigned i = 0; i < 4; ++i) {
            if (defaultCodePage != CJKCodePages[i]) {
                DWORD codePageMask;
                langFontLink->CodePageToCodePages(CJKCodePages[i], &codePageMask);
                codePageMasks.append(codePageMask);
            }
        }
    }
    return codePageMasks;
}

static bool currentFontContainsCharacter(HDC hdc, UChar character)
{
    static Vector<char, 512> glyphsetBuffer;
    glyphsetBuffer.resize(GetFontUnicodeRanges(hdc, 0));
    GLYPHSET* glyphset = reinterpret_cast<GLYPHSET*>(glyphsetBuffer.data());
    GetFontUnicodeRanges(hdc, glyphset);

    // FIXME: Change this to a binary search.
    unsigned i = 0;
    while (i < glyphset->cRanges && glyphset->ranges[i].wcLow <= character)
        i++;

    return i && glyphset->ranges[i - 1].wcLow + glyphset->ranges[i - 1].cGlyphs > character;
}

static HFONT createMLangFont(IMLangFontLink2* langFontLink, HDC hdc, DWORD codePageMask, UChar character = 0)
{
    HFONT MLangFont;
    HFONT hfont = 0;
    if (SUCCEEDED(langFontLink->MapFont(hdc, codePageMask, character, &MLangFont)) && MLangFont) {
        LOGFONT lf;
        GetObject(MLangFont, sizeof(LOGFONT), &lf);
        langFontLink->ReleaseFont(MLangFont);
        hfont = CreateFontIndirect(&lf);
    }
    return hfont;
}

const SimpleFontData* FontCache::getFontDataForCharacters(const Font& font, const UChar* characters, int length)
{
    UChar character = characters[0];
    SimpleFontData* fontData = 0;
    HDC hdc = GetDC(0);
    HFONT primaryFont = font.primaryFont()->fontDataForCharacter(character)->platformData().hfont();
    HGDIOBJ oldFont = SelectObject(hdc, primaryFont);
    HFONT hfont = 0;

    if (IMLangFontLink2* langFontLink = getFontLinkInterface()) {
        // Try MLang font linking first.
        DWORD codePages = 0;
        langFontLink->GetCharCodePages(character, &codePages);

        if (codePages && findCharUnicodeRange(character) == cRangeSetCJK) {
            // The CJK character may belong to multiple code pages. We want to
            // do font linking against a single one of them, preferring the default
            // code page for the user's locale.
            const Vector<DWORD, 4>& CJKCodePageMasks = getCJKCodePageMasks();
            unsigned numCodePages = CJKCodePageMasks.size();
            for (unsigned i = 0; i < numCodePages && !hfont; ++i) {
                hfont = createMLangFont(langFontLink, hdc, CJKCodePageMasks[i]);
                if (hfont && !(codePages & CJKCodePageMasks[i])) {
                    // We asked about a code page that is not one of the code pages
                    // returned by MLang, so the font might not contain the character.
                    SelectObject(hdc, hfont);
                    if (!currentFontContainsCharacter(hdc, character)) {
                        DeleteObject(hfont);
                        hfont = 0;
                    }
                    SelectObject(hdc, primaryFont);
                }
            }
        } else
            hfont = createMLangFont(langFontLink, hdc, codePages, character);
    }

    // A font returned from MLang is trusted to contain the character.
    bool containsCharacter = hfont;

    if (!hfont) {
        // To find out what font Uniscribe would use, we make it draw into a metafile and intercept
        // calls to CreateFontIndirect().
        HDC metaFileDc = CreateEnhMetaFile(hdc, NULL, NULL, NULL);
        SelectObject(metaFileDc, primaryFont);

        bool scriptStringOutSucceeded = false;
        SCRIPT_STRING_ANALYSIS ssa;

        // FIXME: If length is greater than 1, we actually return the font for the last character.
        // This function should be renamed getFontDataForCharacter and take a single 32-bit character.
        if (SUCCEEDED(ScriptStringAnalyse(metaFileDc, characters, length, 0, -1, SSA_METAFILE | SSA_FALLBACK | SSA_GLYPHS | SSA_LINK,
            0, NULL, NULL, NULL, NULL, NULL, &ssa))) {
            scriptStringOutSucceeded = SUCCEEDED(ScriptStringOut(ssa, 0, 0, 0, NULL, 0, 0, FALSE));
            ScriptStringFree(&ssa);
        }
        HENHMETAFILE metaFile = CloseEnhMetaFile(metaFileDc);
        if (scriptStringOutSucceeded) {
            LOGFONT logFont;
            logFont.lfFaceName[0] = 0;
            EnumEnhMetaFile(0, metaFile, metaFileEnumProc, &logFont, NULL);
            if (logFont.lfFaceName[0])
                hfont = CreateFontIndirect(&logFont);
        }
        DeleteEnhMetaFile(metaFile);
    }

    String familyName;
    const Vector<String>* linkedFonts = 0;
    unsigned linkedFontIndex = 0;
    while (hfont) {
        SelectObject(hdc, hfont);
        WCHAR name[LF_FACESIZE];
        GetTextFace(hdc, LF_FACESIZE, name);
        familyName = name;

        if (containsCharacter || currentFontContainsCharacter(hdc, character))
            break;

        if (!linkedFonts)
            linkedFonts = getLinkedFonts(familyName);
        SelectObject(hdc, oldFont);
        DeleteObject(hfont);
        hfont = 0;

        if (linkedFonts->size() <= linkedFontIndex)
            break;

        LOGFONT logFont;
        logFont.lfCharSet = DEFAULT_CHARSET;
        memcpy(logFont.lfFaceName, linkedFonts->at(linkedFontIndex).characters(), linkedFonts->at(linkedFontIndex).length() * sizeof(WCHAR));
        logFont.lfFaceName[linkedFonts->at(linkedFontIndex).length()] = 0;
        EnumFontFamiliesEx(hdc, &logFont, linkedFontEnumProc, reinterpret_cast<LPARAM>(&hfont), 0);
        linkedFontIndex++;
    }

    if (hfont) {
        if (!familyName.isEmpty()) {
            FontPlatformData* result = getCachedFontPlatformData(font.fontDescription(), familyName);
            if (result)
                fontData = getCachedFontData(result);
        }

        SelectObject(hdc, oldFont);
        DeleteObject(hfont);
    }

    ReleaseDC(0, hdc);
    return fontData;
}

FontPlatformData* FontCache::getSimilarFontPlatformData(const Font& font)
{
    return 0;
}

FontPlatformData* FontCache::getLastResortFallbackFont(const FontDescription& fontDescription)
{
    // FIXME: Would be even better to somehow get the user's default font here.  For now we'll pick
    // the default that the user would get without changing any prefs.
    static AtomicString timesStr("Times New Roman");
    return getCachedFontPlatformData(fontDescription, timesStr);
}

bool FontCache::fontExists(const FontDescription& fontDescription, const AtomicString& family)
{
    LOGFONT winfont;

    // The size here looks unusual.  The negative number is intentional.  The logical size constant is 32.
    winfont.lfHeight = -fontDescription.computedPixelSize() * 32;
    winfont.lfWidth = 0;
    winfont.lfEscapement = 0;
    winfont.lfOrientation = 0;
    winfont.lfUnderline = false;
    winfont.lfStrikeOut = false;
    winfont.lfCharSet = DEFAULT_CHARSET;
#if PLATFORM(CG)
    winfont.lfOutPrecision = OUT_TT_ONLY_PRECIS;
#else
    winfont.lfOutPrecision = OUT_TT_PRECIS;
#endif
    winfont.lfQuality = 5; // Force cleartype.
    winfont.lfPitchAndFamily = DEFAULT_PITCH | FF_DONTCARE;
    winfont.lfItalic = fontDescription.italic();

    // FIXME: Support weights for real.  Do our own enumeration of the available weights.
    // We can't rely on Windows here, since we need to follow the CSS2 algorithm for how to fill in
    // gaps in the weight list.
    // FIXME: Hardcoding Lucida Grande for now.  It uses different weights than typical Win32 fonts
    // (500/600 instead of 400/700).
    static AtomicString lucidaStr("Lucida Grande");
    if (equalIgnoringCase(family, lucidaStr))
        winfont.lfWeight = fontDescription.bold() ? 600 : 500;
    else
        winfont.lfWeight = fontDescription.bold() ? 700 : 400;
    int len = min(family.length(), (unsigned int)LF_FACESIZE - 1);
    memcpy(winfont.lfFaceName, family.characters(), len * sizeof(WORD));
    winfont.lfFaceName[len] = '\0';

    HFONT hfont = CreateFontIndirect(&winfont);
    // 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.
    HDC dc = GetDC(0);
    SaveDC(dc);
    SelectObject(dc, hfont);
    WCHAR name[LF_FACESIZE];
    GetTextFace(dc, LF_FACESIZE, name);
    RestoreDC(dc, -1);
    ReleaseDC(0, dc);

    DeleteObject(hfont);

    return !wcsicmp(winfont.lfFaceName, name);
}

FontPlatformData* FontCache::createFontPlatformData(const FontDescription& fontDescription, const AtomicString& family)
{
    bool isLucidaGrande = false;
    static AtomicString lucidaStr("Lucida Grande");
    if (equalIgnoringCase(family, lucidaStr))
        isLucidaGrande = true;

    bool useGDI = fontDescription.renderingMode() == AlternateRenderingMode && !isLucidaGrande;

    LOGFONT winfont;

    // The size here looks unusual.  The negative number is intentional.  The logical size constant is 32. We do this
    // for subpixel precision when rendering using Uniscribe.  This masks rounding errors related to the HFONT metrics being
    // different from the CGFont metrics.
    // FIXME: We will eventually want subpixel precision for GDI mode, but the scaled rendering doesn't look as nice.  That may be solvable though.
    winfont.lfHeight = -fontDescription.computedPixelSize() * (useGDI ? 1 : 32);
    winfont.lfWidth = 0;
    winfont.lfEscapement = 0;
    winfont.lfOrientation = 0;
    winfont.lfUnderline = false;
    winfont.lfStrikeOut = false;
    winfont.lfCharSet = DEFAULT_CHARSET;
    winfont.lfOutPrecision = OUT_TT_ONLY_PRECIS;
    winfont.lfQuality = DEFAULT_QUALITY;
    winfont.lfPitchAndFamily = DEFAULT_PITCH | FF_DONTCARE;
    winfont.lfItalic = fontDescription.italic();

    // FIXME: Support weights for real.  Do our own enumeration of the available weights.
    // We can't rely on Windows here, since we need to follow the CSS2 algorithm for how to fill in
    // gaps in the weight list.
    // FIXME: Hardcoding Lucida Grande for now.  It uses different weights than typical Win32 fonts
    // (500/600 instead of 400/700).
    if (isLucidaGrande) {
        winfont.lfWeight = fontDescription.bold() ? 600 : 500;
        useGDI = false; // Never use GDI for Lucida Grande.
    } else
        winfont.lfWeight = fontDescription.bold() ? 700 : 400;
    int len = min(family.length(), (unsigned int)LF_FACESIZE - 1);
    memcpy(winfont.lfFaceName, family.characters(), len * sizeof(WORD));
    winfont.lfFaceName[len] = '\0';

    HFONT hfont = CreateFontIndirect(&winfont);
    // 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.
    HDC dc = GetDC(0);
    SaveDC(dc);
    SelectObject(dc, hfont);
    WCHAR name[LF_FACESIZE];
    GetTextFace(dc, LF_FACESIZE, name);
    RestoreDC(dc, -1);
    ReleaseDC(0, dc);

    if (_wcsicmp(winfont.lfFaceName, name)) {
        DeleteObject(hfont);
        return 0;
    }
    
    FontPlatformData* result = new FontPlatformData(hfont, fontDescription.computedPixelSize(),
                                                    fontDescription.bold(), fontDescription.italic(), useGDI);
    if (!result->cgFont()) {
        // The creation of the CGFontRef failed for some reason.  We already asserted in debug builds, but to make
        // absolutely sure that we don't use this font, go ahead and return 0 so that we can fall back to the next
        // font.
        delete result;
        DeleteObject(hfont);
        return 0;
    }        

    return result;
}

}