simplefontdatamac.mm

linux下开源浏览器WebKit的源码,市面上的很多商用浏览器都是移植自WebKit

/*
 * Copyright (C) 2005, 2006 Apple Computer, Inc.  All rights reserved.
 * Copyright (C) 2006 Alexey Proskuryakov
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1.  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer. 
 * 2.  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. 
 * 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
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS 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.
 */

#import "config.h"
#import "SimpleFontData.h"

#import "BlockExceptions.h"
#import "Color.h"
#import "FloatRect.h"
#import "Font.h"
#import "FontCache.h"
#import "FontDescription.h"
#import "SharedBuffer.h"
#import "WebCoreSystemInterface.h"
#import <ApplicationServices/ApplicationServices.h>
#import <float.h>
#import <unicode/uchar.h>
#import <wtf/Assertions.h>
#import <wtf/StdLibExtras.h>
#import <wtf/RetainPtr.h>

@interface NSFont (WebAppKitSecretAPI)
- (BOOL)_isFakeFixedPitch;
@end

namespace WebCore {
  
const float smallCapsFontSizeMultiplier = 0.7f;
const float contextDPI = 72.0f;
static inline float scaleEmToUnits(float x, unsigned unitsPerEm) { return x * (contextDPI / (contextDPI * unitsPerEm)); }

static bool initFontData(SimpleFontData* fontData)
{
    if (!fontData->m_font.cgFont())
        return false;

#ifdef BUILDING_ON_TIGER
    ATSUStyle fontStyle;
    if (ATSUCreateStyle(&fontStyle) != noErr)
        return false;

    ATSUFontID fontId = fontData->m_font.m_atsuFontID;
    if (!fontId) {
        ATSUDisposeStyle(fontStyle);
        return false;
    }

    ATSUAttributeTag tag = kATSUFontTag;
    ByteCount size = sizeof(ATSUFontID);
    ATSUFontID *valueArray[1] = {&fontId};
    OSStatus status = ATSUSetAttributes(fontStyle, 1, &tag, &size, (void* const*)valueArray);
    if (status != noErr) {
        ATSUDisposeStyle(fontStyle);
        return false;
    }

    if (wkGetATSStyleGroup(fontStyle, &fontData->m_styleGroup) != noErr) {
        ATSUDisposeStyle(fontStyle);
        return false;
    }

    ATSUDisposeStyle(fontStyle);
#endif

    return true;
}

static NSString *webFallbackFontFamily(void)
{
    DEFINE_STATIC_LOCAL(RetainPtr<NSString>, webFallbackFontFamily, ([[NSFont systemFontOfSize:16.0f] familyName]));
    return webFallbackFontFamily.get();
}

#if !ERROR_DISABLED
#ifdef __LP64__
static NSString* pathFromFont(NSFont*)
{
    // FMGetATSFontRefFromFont is not available in 64-bit. As pathFromFont is only used for debugging
    // purposes, returning nil is acceptable.
    return nil;
}
#else
static NSString* pathFromFont(NSFont *font)
{
#ifndef BUILDING_ON_TIGER
    ATSFontRef atsFont = FMGetATSFontRefFromFont(CTFontGetPlatformFont(toCTFontRef(font), 0));
#else
    ATSFontRef atsFont = FMGetATSFontRefFromFont(wkGetNSFontATSUFontId(font));
#endif
    FSRef fileRef;

#ifndef BUILDING_ON_TIGER
    OSStatus status = ATSFontGetFileReference(atsFont, &fileRef);
    if (status != noErr)
        return nil;
#else
    FSSpec oFile;
    OSStatus status = ATSFontGetFileSpecification(atsFont, &oFile);
    if (status != noErr)
        return nil;

    status = FSpMakeFSRef(&oFile, &fileRef);
    if (status != noErr)
        return nil;
#endif

    UInt8 filePathBuffer[PATH_MAX];
    status = FSRefMakePath(&fileRef, filePathBuffer, PATH_MAX);
    if (status == noErr)
        return [NSString stringWithUTF8String:(const char*)filePathBuffer];

    return nil;
}
#endif // __LP64__
#endif // !ERROR_DISABLED

void SimpleFontData::platformInit()
{
#ifdef BUILDING_ON_TIGER
    m_styleGroup = 0;
#endif
#if USE(ATSUI)
    m_ATSUStyleInitialized = false;
    m_ATSUMirrors = false;
    m_checkedShapesArabic = false;
    m_shapesArabic = false;
#endif

    m_syntheticBoldOffset = m_font.m_syntheticBold ? 1.0f : 0.f;

    bool failedSetup = false;
    if (!initFontData(this)) {
        // Ack! Something very bad happened, like a corrupt font.
        // Try looking for an alternate 'base' font for this renderer.

        // Special case hack to use "Times New Roman" in place of "Times".
        // "Times RO" is a common font whose family name is "Times".
        // It overrides the normal "Times" family font.
        // It also appears to have a corrupt regular variant.
        NSString *fallbackFontFamily;
        if ([[m_font.font() familyName] isEqual:@"Times"])
            fallbackFontFamily = @"Times New Roman";
        else
            fallbackFontFamily = webFallbackFontFamily();
        
        // Try setting up the alternate font.
        // This is a last ditch effort to use a substitute font when something has gone wrong.
#if !ERROR_DISABLED
        RetainPtr<NSFont> initialFont = m_font.font();
#endif
        if (m_font.font())
            m_font.setFont([[NSFontManager sharedFontManager] convertFont:m_font.font() toFamily:fallbackFontFamily]);
        else
            m_font.setFont([NSFont fontWithName:fallbackFontFamily size:m_font.size()]);
#if !ERROR_DISABLED
        NSString *filePath = pathFromFont(initialFont.get());
        if (!filePath)
            filePath = @"not known";
#endif
        if (!initFontData(this)) {
            if ([fallbackFontFamily isEqual:@"Times New Roman"]) {
                // OK, couldn't setup Times New Roman as an alternate to Times, fallback
                // on the system font.  If this fails we have no alternative left.
                m_font.setFont([[NSFontManager sharedFontManager] convertFont:m_font.font() toFamily:webFallbackFontFamily()]);
                if (!initFontData(this)) {
                    // We tried, Times, Times New Roman, and the system font. No joy. We have to give up.
                    LOG_ERROR("unable to initialize with font %@ at %@", initialFont.get(), filePath);
                    failedSetup = true;
                }
            } else {
                // We tried the requested font and the system font. No joy. We have to give up.
                LOG_ERROR("unable to initialize with font %@ at %@", initialFont.get(), filePath);
                failedSetup = true;
            }
        }

        // Report the problem.
        LOG_ERROR("Corrupt font detected, using %@ in place of %@ located at \"%@\".",
            [m_font.font() familyName], [initialFont.get() familyName], filePath);
    }

    // If all else fails, try to set up using the system font.
    // This is probably because Times and Times New Roman are both unavailable.
    if (failedSetup) {
        m_font.setFont([NSFont systemFontOfSize:[m_font.font() pointSize]]);
        LOG_ERROR("failed to set up font, using system font %s", m_font.font());
        initFontData(this);
    }
    
    int iAscent;
    int iDescent;
    int iLineGap;