Move app/gfx/canvas and app/gfx/font to gfx/.

TBR=darin
BUG=none
TEST=none

Review URL: http://codereview.chromium.org/1132006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@42312 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 255 insertions, 0 deletions

diff --git a/gfx/font_skia.cc b/gfx/font_skia.cc
new file mode 100644
index 0000000..fffc53e
--- /dev/null
+++ b/gfx/font_skia.cc
@@ -0,0 +1,255 @@
+// Copyright (c) 2006-2008 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 "gfx/font.h"
+
+#include <gdk/gdk.h>
+#include <map>
+#include <pango/pango.h>
+
+#include "base/logging.h"
+#include "base/string_piece.h"
+#include "base/sys_string_conversions.h"
+#include "gfx/canvas.h"
+#include "third_party/skia/include/core/SkTypeface.h"
+#include "third_party/skia/include/core/SkPaint.h"
+
+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.
+const char* kFallbackFontFamilyName = "sans";
+
+// Retrieves the pango metrics for a pango font description. Caches the metrics
+// and never frees them. The metrics objects are relatively small and
+// very expensive to look up.
+static PangoFontMetrics* GetPangoFontMetrics(PangoFontDescription* desc) {
+  static std::map<int, PangoFontMetrics*>* desc_to_metrics = NULL;
+  static PangoContext* context = NULL;
+
+  if (!context) {
+    context = gdk_pango_context_get_for_screen(gdk_screen_get_default());
+    pango_context_set_language(context, pango_language_get_default());
+  }
+
+  if (!desc_to_metrics) {
+    desc_to_metrics = new std::map<int, PangoFontMetrics*>();
+  }
+
+  int desc_hash = pango_font_description_hash(desc);
+  std::map<int, PangoFontMetrics*>::iterator i =
+      desc_to_metrics->find(desc_hash);
+
+  if (i == desc_to_metrics->end()) {
+    PangoFontMetrics* metrics = pango_context_get_metrics(context, desc, NULL);
+    (*desc_to_metrics)[desc_hash] = metrics;
+    return metrics;
+  } else {
+    return i->second;
+  }
+}
+
+}  // namespace
+
+namespace gfx {
+
+Font::Font(const Font& other) {
+  CopyFont(other);
+}
+
+Font& Font::operator=(const Font& other) {
+  CopyFont(other);
+  return *this;
+}
+
+Font::Font(SkTypeface* tf, const std::wstring& font_family, int font_size,
+           int style)
+    : typeface_helper_(new SkAutoUnref(tf)),
+      typeface_(tf),
+      font_family_(font_family),
+      font_size_(font_size),
+      style_(style),
+      pango_metrics_inited_(false),
+      avg_width_(0.0),
+      underline_position_(0.0),
+      underline_thickness_(0.0) {
+  tf->ref();
+  calculateMetrics();
+}
+
+void Font::calculateMetrics() {
+  SkPaint paint;
+  SkPaint::FontMetrics metrics;
+  PaintSetup(&paint);
+  paint.getFontMetrics(&metrics);
+
+  ascent_ = SkScalarCeil(-metrics.fAscent);
+  height_ = ascent_ + SkScalarCeil(metrics.fDescent);
+
+}
+
+void Font::CopyFont(const Font& other) {
+  typeface_helper_.reset(new SkAutoUnref(other.typeface_));
+  typeface_ = other.typeface_;
+  typeface_->ref();
+  font_family_ = other.font_family_;
+  font_size_ = other.font_size_;
+  style_ = other.style_;
+  height_ = other.height_;
+  ascent_ = other.ascent_;
+  pango_metrics_inited_ = other.pango_metrics_inited_;
+  avg_width_ = other.avg_width_;
+  underline_position_ = other.underline_position_;
+  underline_thickness_ = other.underline_thickness_;
+}
+
+int Font::height() const {
+  return height_;
+}
+
+int Font::baseline() const {
+  return ascent_;
+}
+
+int Font::ave_char_width() const {
+  return SkScalarRound(avg_width());
+}
+
+Font Font::CreateFont(const std::wstring& font_family, int font_size) {
+  DCHECK_GT(font_size, 0);
+  std::wstring fallback;
+
+  SkTypeface* tf = SkTypeface::CreateFromName(
+      base::SysWideToUTF8(font_family).c_str(), SkTypeface::kNormal);
+  if (!tf) {
+    // A non-scalable font such as .pcf is specified. Falls back to a default
+    // scalable font.
+    tf = SkTypeface::CreateFromName(
+        kFallbackFontFamilyName, SkTypeface::kNormal);
+    CHECK(tf) << "Could not find any font: "
+              << base::SysWideToUTF8(font_family)
+              << ", " << kFallbackFontFamilyName;
+    fallback = base::SysUTF8ToWide(kFallbackFontFamilyName);
+  }
+  SkAutoUnref tf_helper(tf);
+
+  return Font(
+      tf, fallback.empty() ? font_family : fallback, font_size, NORMAL);
+}
+
+Font Font::DeriveFont(int size_delta, int style) const {
+  // If the delta is negative, if must not push the size below 1
+  if (size_delta < 0) {
+    DCHECK_LT(-size_delta, font_size_);
+  }
+
+  if (style == style_) {
+    // Fast path, we just use the same typeface at a different size
+    return Font(typeface_, font_family_, font_size_ + size_delta, style_);
+  }
+
+  // If the style has changed we may need to load a new face
+  int skstyle = SkTypeface::kNormal;
+  if (BOLD & style)
+    skstyle |= SkTypeface::kBold;
+  if (ITALIC & style)
+    skstyle |= SkTypeface::kItalic;
+
+  SkTypeface* tf = SkTypeface::CreateFromName(
+      base::SysWideToUTF8(font_family_).c_str(),
+      static_cast<SkTypeface::Style>(skstyle));
+  SkAutoUnref tf_helper(tf);
+
+  return Font(tf, font_family_, font_size_ + size_delta, style);
+}
+
+void Font::PaintSetup(SkPaint* paint) const {
+  paint->setAntiAlias(false);
+  paint->setSubpixelText(false);
+  paint->setTextSize(SkFloatToScalar(font_size_ * Font::GetPangoScaleFactor()));
+  paint->setTypeface(typeface_);
+  paint->setFakeBoldText((BOLD & style_) && !typeface_->isBold());
+  paint->setTextSkewX((ITALIC & style_) && !typeface_->isItalic() ?
+                      -SK_Scalar1/4 : 0);
+}
+
+int Font::GetStringWidth(const std::wstring& text) const {
+  int width = 0, height = 0;
+
+  Canvas::SizeStringInt(text, *this, &width, &height, 0);
+  return width;
+}
+
+void Font::InitPangoMetrics() {
+  if (!pango_metrics_inited_) {
+    pango_metrics_inited_ = true;
+    PangoFontDescription* pango_desc = PangoFontFromGfxFont(*this);
+    PangoFontMetrics* pango_metrics = GetPangoFontMetrics(pango_desc);
+
+    underline_position_ =
+        pango_font_metrics_get_underline_position(pango_metrics);
+    underline_position_ /= PANGO_SCALE;
+
+    // todo(davemoore) Come up with a better solution.
+    // This is a hack, but without doing this the underlines
+    // we get end up fuzzy. So we align to the midpoint of a pixel.
+    underline_position_ /= 2;
+
+    underline_thickness_ =
+        pango_font_metrics_get_underline_thickness(pango_metrics);
+    underline_thickness_ /= PANGO_SCALE;
+
+    // First get the pango based width
+    double pango_width =
+        pango_font_metrics_get_approximate_char_width(pango_metrics);
+    pango_width /= PANGO_SCALE;
+
+    // Yes, this is how Microsoft recommends calculating the dialog unit
+    // conversions.
+    int text_width = GetStringWidth(
+        L"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz");
+    double dialog_units = (text_width / 26 + 1) / 2;
+    avg_width_ = std::min(pango_width, dialog_units);
+    pango_font_description_free(pango_desc);
+  }
+}
+
+double Font::avg_width() const {
+  const_cast<Font*>(this)->InitPangoMetrics();
+  return avg_width_;
+}
+
+double Font::underline_position() const {
+  const_cast<Font*>(this)->InitPangoMetrics();
+  return underline_position_;
+}
+
+double Font::underline_thickness() const {
+  const_cast<Font*>(this)->InitPangoMetrics();
+  return underline_thickness_;
+}
+
+int Font::GetExpectedTextWidth(int length) const {
+  double char_width = const_cast<Font*>(this)->avg_width();
+  return round(static_cast<float>(length) * char_width);
+}
+
+int Font::style() const {
+  return style_;
+}
+
+const std::wstring& Font::FontName() const {
+  return font_family_;
+}
+
+int Font::FontSize() {
+  return font_size_;
+}
+
+NativeFont Font::nativeFont() const {
+  return typeface_;
+}
+
+}  // namespace gfx