// Copyright 2011 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "content/common/font_list.h"
#include <CoreFoundation/CoreFoundation.h>
#include <CoreText/CoreText.h>
#include <utility>
#include "base/apple/bridging.h"
#include "base/apple/foundation_util.h"
#include "base/apple/scoped_cftyperef.h"
#include "base/logging.h"
#include "base/strings/sys_string_conversions.h"
#include "base/values.h"
// The code here is unusually skeptical about the macOS APIs returning non-null
// values. An earlier version was reverted due to crashing tests on bots running
// older macOS versions. The DCHECKs are there to expedite debugging similar
// problems.
namespace content {
namespace {
// Core Text-based localized family name lookup.
//
// This class is not thread-safe.
//
// This class caches some state for an efficient implementation of
// [NSFontManager localizedNameForFamily:face:] using the Core Text API.
class FontFamilyResolver {
public:
FontFamilyResolver() {
DCHECK(mandatory_attributes_);
DCHECK(font_descriptor_attributes_);
}
~FontFamilyResolver() = default;
FontFamilyResolver(const FontFamilyResolver&) = delete;
FontFamilyResolver& operator=(const FontFamilyResolver&) = delete;
// Returns a localized font family name for the given family name.
base::apple::ScopedCFTypeRef<CFStringRef> CopyLocalizedFamilyName(
CFStringRef family_name) {
DCHECK(family_name);
CFDictionarySetValue(font_descriptor_attributes_.get(),
kCTFontFamilyNameAttribute, family_name);
base::apple::ScopedCFTypeRef<CTFontDescriptorRef> raw_descriptor(
CTFontDescriptorCreateWithAttributes(
font_descriptor_attributes_.get()));
DCHECK(raw_descriptor)
<< "CTFontDescriptorCreateWithAttributes returned null";
base::apple::ScopedCFTypeRef<CFArrayRef> normalized_descriptors(
CTFontDescriptorCreateMatchingFontDescriptors(
raw_descriptor.get(), mandatory_attributes_.get()));
return CopyLocalizedFamilyNameFrom(family_name,
normalized_descriptors.get());
}
private:
// Returns the first font descriptor matching the given family name.
//
// `descriptors` must be an array of CTFontDescriptors whose font family name
// attribute is populated.
//
// `descriptors` may be null, representing an empty array. This case is
// handled because CTFontDescriptorCreateMatchingFontDescriptors() may
// return null, even on macOS 11. Discovery documented in crbug.com/1235042.
//
// Returns null if none of the descriptors match.
static base::apple::ScopedCFTypeRef<CTFontDescriptorRef>
FindFirstWithFamilyName(CFStringRef family_name, CFArrayRef descriptors) {
DCHECK(family_name != nullptr);
CFIndex descriptor_count = descriptors ? CFArrayGetCount(descriptors) : 0;
for (CFIndex i = 0; i < descriptor_count; ++i) {
CTFontDescriptorRef descriptor =
base::apple::CFCastStrict<CTFontDescriptorRef>(
CFArrayGetValueAtIndex(descriptors, i));
DCHECK(descriptor != nullptr)
<< "The descriptors array has a null element.";
base::apple::ScopedCFTypeRef<CFStringRef> descriptor_family_name(
base::apple::CFCastStrict<CFStringRef>(CTFontDescriptorCopyAttribute(
descriptor, kCTFontFamilyNameAttribute)));
if (CFStringCompare(family_name, descriptor_family_name.get(),
/*compareOptions=*/0) == kCFCompareEqualTo) {
return base::apple::ScopedCFTypeRef<CTFontDescriptorRef>(
descriptor, base::scoped_policy::RETAIN);
}
}
return base::apple::ScopedCFTypeRef<CTFontDescriptorRef>(nullptr);
}
// Returns a localized font family name for the given family name.
//
// `descriptors` must be an array of normalized CTFontDescriptors representing
// all the font descriptors on the system matching the given family name.
//
// `descriptors` may be null, representing an empty array. This case is
// handled because CTFontDescriptorCreateMatchingFontDescriptors() may
// return null, even on macOS 11. Discovery documented in crbug.com/1235042.
//
// The given family name is returned as a fallback, if none of the descriptors
// match the desired font family name.
static base::apple::ScopedCFTypeRef<CFStringRef> CopyLocalizedFamilyNameFrom(
CFStringRef family_name,
CFArrayRef descriptors) {
DCHECK(family_name != nullptr);
base::apple::ScopedCFTypeRef<CTFontDescriptorRef> descriptor =
FindFirstWithFamilyName(family_name, descriptors);
if (!descriptor) {
DLOG(WARNING) << "Will use non-localized family name for font family: "
<< family_name;
return base::apple::ScopedCFTypeRef<CFStringRef>(
family_name, base::scoped_policy::RETAIN);
}
base::apple::ScopedCFTypeRef<CFStringRef> localized_family_name(
base::apple::CFCastStrict<CFStringRef>(
CTFontDescriptorCopyLocalizedAttribute(descriptor.get(),
kCTFontFamilyNameAttribute,
/*language=*/nullptr)));
// CTFontDescriptorCopyLocalizedAttribute() is only supposed to return null
// if the desired attribute (family name) is not present.
//
// We found that the function may return null, even when given a normalized
// font descriptor whose attribute (family name) exists --
// FindFirstWithFamilyName() only returns descriptors whose non-localized
// family name attribute is equal to a given string. Discovery documented in
// crbug.com/1235090.
if (!localized_family_name) {
DLOG(WARNING) << "Will use non-localized family name for font family: "
<< family_name;
return base::apple::ScopedCFTypeRef<CFStringRef>(
family_name, base::scoped_policy::RETAIN);
}
return localized_family_name;
}
// Creates the set stored in |mandatory_attributes_|.
static base::apple::ScopedCFTypeRef<CFSetRef> CreateMandatoryAttributes() {
CFStringRef set_values[] = {kCTFontFamilyNameAttribute};
return base::apple::ScopedCFTypeRef<CFSetRef>(CFSetCreate(
kCFAllocatorDefault, reinterpret_cast<const void**>(set_values),
std::size(set_values), &kCFTypeSetCallBacks));
}
// Creates the mutable dictionary stored in |font_descriptor_attributes_|.
static base::apple::ScopedCFTypeRef<CFMutableDictionaryRef>
CreateFontDescriptorAttributes() {
return base::apple::ScopedCFTypeRef<CFMutableDictionaryRef>(
CFDictionaryCreateMutable(kCFAllocatorDefault, /*capacity=*/1,
&kCFTypeDictionaryKeyCallBacks,
&kCFTypeDictionaryValueCallBacks));
}
// Used for all CTFontDescriptorCreateMatchingFontDescriptors() calls.
//
// Caching this dictionary saves one dictionary creation per lookup.
const base::apple::ScopedCFTypeRef<CFSetRef> mandatory_attributes_ =
CreateMandatoryAttributes();
// Used for all CTFontDescriptorCreateMatchingFontDescriptors() calls.
//
// This dictionary has exactly one key, kCTFontFamilyNameAttribute. The value
// associated with the key is overwritten as needed.
//
// Caching this dictionary saves one dictionary creation per lookup.
const base::apple::ScopedCFTypeRef<CFMutableDictionaryRef>
font_descriptor_attributes_ = CreateFontDescriptorAttributes();
};
} // namespace
base::Value::List GetFontList_SlowBlocking() {
@autoreleasepool {
FontFamilyResolver resolver;
NSArray* family_names = base::apple::CFToNSOwnershipCast(
CTFontManagerCopyAvailableFontFamilyNames());
DCHECK(family_names != nil)
<< "CTFontManagerCopyAvailableFontFamilyNames returned null";
// Maps localized font family names to non-localized names.
NSMutableDictionary* family_name_map =
[NSMutableDictionary dictionaryWithCapacity:family_names.count];
for (NSString* family_name in family_names) {
DCHECK(family_name != nil)
<< "CTFontManagerCopyAvailableFontFamilyNames returned an array with "
<< "a null element";
base::apple::ScopedCFTypeRef<CFStringRef> cf_normalized_family_name =
resolver.CopyLocalizedFamilyName(
base::apple::NSToCFPtrCast(family_name));
DCHECK(cf_normalized_family_name)
<< "FontFamilyResolver::CopyLocalizedFamilyName returned null";
family_name_map[base::apple::CFToNSPtrCast(
cf_normalized_family_name.get())] = family_name;
}
// The Apple documentation for CTFontManagerCopyAvailableFontFamilyNames
// states that it returns family names sorted for user interface display.
// https://developer.apple.com/documentation/coretext/1499494-ctfontmanagercopyavailablefontfa
//
// This doesn't seem to be the case, at least on macOS 10.15.3.
NSArray* sorted_localized_family_names = [family_name_map
keysSortedByValueUsingSelector:@selector(localizedStandardCompare:)];
base::Value::List font_list;
for (NSString* localized_family_name in sorted_localized_family_names) {
NSString* family_name = family_name_map[localized_family_name];
base::Value::List font_list_item;
font_list_item.reserve(2);
font_list_item.Append(base::SysNSStringToUTF8(family_name));
font_list_item.Append(base::SysNSStringToUTF8(localized_family_name));
font_list.Append(std::move(font_list_item));
}
return font_list;
}
}
} // namespace content
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