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// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "ui/gfx/platform_font_linux.h"
#include <algorithm>
#include <string>
#include "base/lazy_instance.h"
#include "base/logging.h"
#include "base/strings/string_piece.h"
#include "base/strings/string_split.h"
#include "base/strings/utf_string_conversions.h"
#include "third_party/skia/include/core/SkPaint.h"
#include "third_party/skia/include/core/SkString.h"
#include "third_party/skia/include/core/SkTypeface.h"
#include "ui/gfx/canvas.h"
#include "ui/gfx/font.h"
#include "ui/gfx/font_list.h"
#include "ui/gfx/linux_font_delegate.h"
#include "ui/gfx/text_utils.h"
namespace gfx {
namespace {
// The font family name which is used when a user's application font for
// GNOME/KDE is a non-scalable one. The name should be listed in the
// IsFallbackFontAllowed function in skia/ext/SkFontHost_fontconfig_direct.cpp.
#if defined(OS_ANDROID)
const char* kFallbackFontFamilyName = "serif";
#else
const char* kFallbackFontFamilyName = "sans";
#endif
// The default font, used for the default constructor.
base::LazyInstance<scoped_refptr<PlatformFontLinux>>::Leaky g_default_font =
LAZY_INSTANCE_INITIALIZER;
// Creates a SkTypeface for the passed-in Font::FontStyle and family. If a
// fallback typeface is used instead of the requested family, |family| will be
// updated to contain the fallback's family name.
skia::RefPtr<SkTypeface> CreateSkTypeface(int style, std::string* family) {
DCHECK(family);
int skia_style = SkTypeface::kNormal;
if (Font::BOLD & style)
skia_style |= SkTypeface::kBold;
if (Font::ITALIC & style)
skia_style |= SkTypeface::kItalic;
skia::RefPtr<SkTypeface> typeface = skia::AdoptRef(SkTypeface::CreateFromName(
family->c_str(), static_cast<SkTypeface::Style>(skia_style)));
if (!typeface) {
// A non-scalable font such as .pcf is specified. Fall back to a default
// scalable font.
typeface = skia::AdoptRef(SkTypeface::CreateFromName(
kFallbackFontFamilyName, static_cast<SkTypeface::Style>(skia_style)));
CHECK(typeface) << "Could not find any font: " << family << ", "
<< kFallbackFontFamilyName;
*family = kFallbackFontFamilyName;
}
return typeface;
}
} // namespace
#if defined(OS_CHROMEOS)
std::string* PlatformFontLinux::default_font_description_ = NULL;
#endif
////////////////////////////////////////////////////////////////////////////////
// PlatformFontLinux, public:
PlatformFontLinux::PlatformFontLinux() {
if (!g_default_font.Get()) {
std::string family = kFallbackFontFamilyName;
int size_pixels = 12;
int style = Font::NORMAL;
FontRenderParams params;
#if defined(OS_CHROMEOS)
// On Chrome OS, a FontList font description string is stored as a
// translatable resource and passed in via SetDefaultFontDescription().
if (default_font_description_) {
FontRenderParamsQuery query;
CHECK(FontList::ParseDescription(*default_font_description_,
&query.families, &query.style,
&query.pixel_size))
<< "Failed to parse font description " << *default_font_description_;
params = gfx::GetFontRenderParams(query, &family);
size_pixels = query.pixel_size;
style = query.style;
}
#else
// On Linux, LinuxFontDelegate is used to query the native toolkit (e.g.
// GTK+) for the default UI font.
const LinuxFontDelegate* delegate = LinuxFontDelegate::instance();
if (delegate) {
delegate->GetDefaultFontDescription(
&family, &size_pixels, &style, &params);
}
#endif
g_default_font.Get() = new PlatformFontLinux(
CreateSkTypeface(style, &family), family, size_pixels, style, params);
}
InitFromPlatformFont(g_default_font.Get().get());
}
PlatformFontLinux::PlatformFontLinux(const std::string& font_name,
int font_size_pixels) {
FontRenderParamsQuery query;
query.families.push_back(font_name);
query.pixel_size = font_size_pixels;
query.style = Font::NORMAL;
InitFromDetails(skia::RefPtr<SkTypeface>(), font_name, font_size_pixels,
query.style, gfx::GetFontRenderParams(query, NULL));
}
////////////////////////////////////////////////////////////////////////////////
// PlatformFontLinux, PlatformFont implementation:
// static
void PlatformFontLinux::ReloadDefaultFont() {
// Reset the scoped_refptr.
g_default_font.Get() = nullptr;
}
#if defined(OS_CHROMEOS)
// static
void PlatformFontLinux::SetDefaultFontDescription(
const std::string& font_description) {
delete default_font_description_;
default_font_description_ = new std::string(font_description);
}
#endif
Font PlatformFontLinux::DeriveFont(int size_delta, int style) const {
const int new_size = font_size_pixels_ + size_delta;
DCHECK_GT(new_size, 0);
// If the style changed, we may need to load a new face.
std::string new_family = font_family_;
skia::RefPtr<SkTypeface> typeface =
(style == style_) ? typeface_ : CreateSkTypeface(style, &new_family);
FontRenderParamsQuery query;
query.families.push_back(new_family);
query.pixel_size = new_size;
query.style = style;
return Font(new PlatformFontLinux(typeface, new_family, new_size, style,
gfx::GetFontRenderParams(query, NULL)));
}
int PlatformFontLinux::GetHeight() const {
return height_pixels_;
}
int PlatformFontLinux::GetBaseline() const {
return ascent_pixels_;
}
int PlatformFontLinux::GetCapHeight() const {
return cap_height_pixels_;
}
int PlatformFontLinux::GetExpectedTextWidth(int length) const {
return round(static_cast<float>(length) * average_width_pixels_);
}
int PlatformFontLinux::GetStyle() const {
return style_;
}
const std::string& PlatformFontLinux::GetFontName() const {
return font_family_;
}
std::string PlatformFontLinux::GetActualFontNameForTesting() const {
SkString family_name;
typeface_->getFamilyName(&family_name);
return family_name.c_str();
}
int PlatformFontLinux::GetFontSize() const {
return font_size_pixels_;
}
const FontRenderParams& PlatformFontLinux::GetFontRenderParams() {
#if defined(OS_CHROMEOS)
float current_scale_factor = GetFontRenderParamsDeviceScaleFactor();
if (current_scale_factor != device_scale_factor_) {
FontRenderParamsQuery query;
query.families.push_back(font_family_);
query.pixel_size = font_size_pixels_;
query.style = style_;
query.device_scale_factor = current_scale_factor;
font_render_params_ = gfx::GetFontRenderParams(query, nullptr);
device_scale_factor_ = current_scale_factor;
}
#endif
return font_render_params_;
}
////////////////////////////////////////////////////////////////////////////////
// PlatformFontLinux, private:
PlatformFontLinux::PlatformFontLinux(const skia::RefPtr<SkTypeface>& typeface,
const std::string& family,
int size_pixels,
int style,
const FontRenderParams& render_params) {
InitFromDetails(typeface, family, size_pixels, style, render_params);
}
PlatformFontLinux::~PlatformFontLinux() {}
void PlatformFontLinux::InitFromDetails(
const skia::RefPtr<SkTypeface>& typeface,
const std::string& font_family,
int font_size_pixels,
int style,
const FontRenderParams& render_params) {
DCHECK_GT(font_size_pixels, 0);
font_family_ = font_family;
typeface_ = typeface ? typeface : CreateSkTypeface(style, &font_family_);
font_size_pixels_ = font_size_pixels;
style_ = style;
#if defined(OS_CHROMEOS)
device_scale_factor_ = GetFontRenderParamsDeviceScaleFactor();
#endif
font_render_params_ = render_params;
SkPaint paint;
paint.setAntiAlias(false);
paint.setSubpixelText(false);
paint.setTextSize(font_size_pixels_);
paint.setTypeface(typeface_.get());
paint.setFakeBoldText((Font::BOLD & style_) && !typeface_->isBold());
paint.setTextSkewX((Font::ITALIC & style_) && !typeface_->isItalic() ?
-SK_Scalar1/4 : 0);
SkPaint::FontMetrics metrics;
paint.getFontMetrics(&metrics);
ascent_pixels_ = SkScalarCeilToInt(-metrics.fAscent);
height_pixels_ = ascent_pixels_ + SkScalarCeilToInt(metrics.fDescent);
cap_height_pixels_ = SkScalarCeilToInt(metrics.fCapHeight);
average_width_pixels_ = SkScalarToDouble(metrics.fAvgCharWidth);
}
void PlatformFontLinux::InitFromPlatformFont(const PlatformFontLinux* other) {
typeface_ = other->typeface_;
font_family_ = other->font_family_;
font_size_pixels_ = other->font_size_pixels_;
style_ = other->style_;
#if defined(OS_CHROMEOS)
device_scale_factor_ = other->device_scale_factor_;
#endif
font_render_params_ = other->font_render_params_;
ascent_pixels_ = other->ascent_pixels_;
height_pixels_ = other->height_pixels_;
cap_height_pixels_ = other->cap_height_pixels_;
average_width_pixels_ = other->average_width_pixels_;
}
////////////////////////////////////////////////////////////////////////////////
// PlatformFont, public:
// static
PlatformFont* PlatformFont::CreateDefault() {
return new PlatformFontLinux;
}
// static
PlatformFont* PlatformFont::CreateFromNameAndSize(const std::string& font_name,
int font_size) {
return new PlatformFontLinux(font_name, font_size);
}
} // namespace gfx