WebCore/platform/win/FontCacheWin.cpp

/*
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 *     its contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission. 
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 * 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 "FontData.h"
#include "Font.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;
}

const FontData* FontCache::getFontDataForCharacters(const Font& font, const UChar* characters, int length)
{
    // IMLangFontLink::MapFont Method does what we want.
    IMLangFontLink2* langFontLink = getFontLinkInterface();
    if (!langFontLink)
        return 0;

    FontData* fontData = 0;
    HDC hdc = GetDC(0);
    HFONT primaryFont = font.primaryFont()->m_font.hfont();
    HGDIOBJ oldFont = SelectObject(hdc, primaryFont);
    HFONT hfont = 0;

    DWORD acpCodePages;
    langFontLink->CodePageToCodePages(CP_ACP, &acpCodePages);

    DWORD actualCodePages;
    long cchActual;
    langFontLink->GetStrCodePages(characters, length, acpCodePages, &actualCodePages, &cchActual);
    if (cchActual) {
        HFONT result;
        if (langFontLink->MapFont(hdc, actualCodePages, characters[0], &result) == S_OK) {
            // Fill in a log font with the returned font from MLang, and then use that to create a new font.
            LOGFONT lf;
            GetObject(result, sizeof(LOGFONT), &lf);
            langFontLink->ReleaseFont(result);

            hfont = CreateFontIndirect(&lf);
            SelectObject(hdc, hfont);

            WCHAR name[LF_FACESIZE];
            GetTextFace(hdc, LF_FACESIZE, name);
            
            String familyName(name);
            if (!familyName.isEmpty()) {
                FontPlatformData* result = getCachedFontPlatformData(font.fontDescription(), familyName);
                if (result)
                    fontData = getCachedFontData(result);
            }
        }
    }

    SelectObject(hdc, oldFont);
    if (hfont)
        DeleteObject(hfont);
    ReleaseDC(0, hdc);
    return fontData;
}

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

FontPlatformData* FontCache::getLastResortFallbackFont(const Font& font)
{
    // 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(font.fontDescription(), timesStr);
}

FontPlatformData* FontCache::createFontPlatformData(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((HWND)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());
    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;
}

}