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, 281 insertions, 0 deletions

diff --git a/gfx/canvas_linux.cc b/gfx/canvas_linux.cc
new file mode 100644
index 0000000..0981d56
--- /dev/null
+++ b/gfx/canvas_linux.cc
@@ -0,0 +1,281 @@
+// Copyright (c) 2009 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/canvas.h"
+
+#include <cairo/cairo.h>
+#include <gtk/gtk.h>
+#include <pango/pango.h>
+#include <pango/pangocairo.h>
+
+#include "base/logging.h"
+#include "base/utf_string_conversions.h"
+#include "gfx/font.h"
+#include "gfx/rect.h"
+
+namespace {
+
+const gunichar kAcceleratorChar = '&';
+
+// Font settings that we initialize once and then use when drawing text in
+// DrawStringInt().
+static cairo_font_options_t* cairo_font_options = NULL;
+
+// Returns the resolution used by pango. A negative values means the resolution
+// hasn't been set.
+static double GetPangoResolution() {
+  static double resolution;
+  static bool determined_resolution = false;
+  if (!determined_resolution) {
+    determined_resolution = true;
+    PangoContext* default_context = gdk_pango_context_get();
+    resolution = pango_cairo_context_get_resolution(default_context);
+    g_object_unref(default_context);
+  }
+  return resolution;
+}
+
+// Update |cairo_font_options| based on GtkSettings, allocating it if needed.
+static void UpdateCairoFontOptions() {
+  if (!cairo_font_options)
+    cairo_font_options = cairo_font_options_create();
+
+  GtkSettings* gtk_settings = gtk_settings_get_default();
+  gint antialias = 0;
+  gint hinting = 0;
+  gchar* hint_style = NULL;
+  gchar* rgba_style = NULL;
+  g_object_get(gtk_settings,
+               "gtk-xft-antialias", &antialias,
+               "gtk-xft-hinting", &hinting,
+               "gtk-xft-hintstyle", &hint_style,
+               "gtk-xft-rgba", &rgba_style,
+               NULL);
+
+  // g_object_get() doesn't tell us whether the properties were present or not,
+  // but if they aren't (because gnome-settings-daemon isn't running), we'll get
+  // NULL values for the strings.
+  if (hint_style && rgba_style) {
+    if (!antialias) {
+      cairo_font_options_set_antialias(cairo_font_options,
+                                       CAIRO_ANTIALIAS_NONE);
+    } else if (strcmp(rgba_style, "none") == 0) {
+      cairo_font_options_set_antialias(cairo_font_options,
+                                       CAIRO_ANTIALIAS_GRAY);
+    } else {
+      cairo_font_options_set_antialias(cairo_font_options,
+                                       CAIRO_ANTIALIAS_SUBPIXEL);
+      cairo_subpixel_order_t cairo_subpixel_order =
+          CAIRO_SUBPIXEL_ORDER_DEFAULT;
+      if (strcmp(rgba_style, "rgb") == 0) {
+        cairo_subpixel_order = CAIRO_SUBPIXEL_ORDER_RGB;
+      } else if (strcmp(rgba_style, "bgr") == 0) {
+        cairo_subpixel_order = CAIRO_SUBPIXEL_ORDER_BGR;
+      } else if (strcmp(rgba_style, "vrgb") == 0) {
+        cairo_subpixel_order = CAIRO_SUBPIXEL_ORDER_VRGB;
+      } else if (strcmp(rgba_style, "vbgr") == 0) {
+        cairo_subpixel_order = CAIRO_SUBPIXEL_ORDER_VBGR;
+      }
+      cairo_font_options_set_subpixel_order(cairo_font_options,
+                                            cairo_subpixel_order);
+    }
+
+    cairo_hint_style_t cairo_hint_style = CAIRO_HINT_STYLE_DEFAULT;
+    if (hinting == 0 || strcmp(hint_style, "hintnone") == 0) {
+      cairo_hint_style = CAIRO_HINT_STYLE_NONE;
+    } else if (strcmp(hint_style, "hintslight") == 0) {
+      cairo_hint_style = CAIRO_HINT_STYLE_SLIGHT;
+    } else if (strcmp(hint_style, "hintmedium") == 0) {
+      cairo_hint_style = CAIRO_HINT_STYLE_MEDIUM;
+    } else if (strcmp(hint_style, "hintfull") == 0) {
+      cairo_hint_style = CAIRO_HINT_STYLE_FULL;
+    }
+    cairo_font_options_set_hint_style(cairo_font_options, cairo_hint_style);
+  }
+
+  if (hint_style)
+    g_free(hint_style);
+  if (rgba_style)
+    g_free(rgba_style);
+}
+
+}  // namespace
+
+namespace gfx {
+
+Canvas::Canvas(int width, int height, bool is_opaque)
+    : skia::PlatformCanvas(width, height, is_opaque) {
+}
+
+Canvas::Canvas() : skia::PlatformCanvas() {
+}
+
+Canvas::~Canvas() {
+}
+
+// Pass a width > 0 to force wrapping and elliding.
+static void SetupPangoLayout(PangoLayout* layout,
+                             const std::wstring& text,
+                             const gfx::Font& font,
+                             int width,
+                             int flags) {
+  if (!cairo_font_options)
+    UpdateCairoFontOptions();
+  // This needs to be done early on; it has no effect when called just before
+  // pango_cairo_show_layout().
+  pango_cairo_context_set_font_options(
+      pango_layout_get_context(layout), cairo_font_options);
+
+  // Callers of DrawStringInt handle RTL layout themselves, so tell pango to not
+  // scope out RTL characters.
+  pango_layout_set_auto_dir(layout, FALSE);
+
+  if (width > 0)
+    pango_layout_set_width(layout, width * PANGO_SCALE);
+
+  if (flags & Canvas::NO_ELLIPSIS) {
+    pango_layout_set_ellipsize(layout, PANGO_ELLIPSIZE_NONE);
+  } else {
+    pango_layout_set_ellipsize(layout, PANGO_ELLIPSIZE_END);
+  }
+
+  if (flags & Canvas::TEXT_ALIGN_CENTER) {
+    pango_layout_set_alignment(layout, PANGO_ALIGN_CENTER);
+  } else if (flags & Canvas::TEXT_ALIGN_RIGHT) {
+    pango_layout_set_alignment(layout, PANGO_ALIGN_RIGHT);
+  }
+
+  if (flags & Canvas::MULTI_LINE) {
+    pango_layout_set_wrap(layout,
+        (flags & Canvas::CHARACTER_BREAK) ?
+            PANGO_WRAP_WORD_CHAR : PANGO_WRAP_WORD);
+  }
+
+  // Set the resolution to match that used by Gtk. If we don't set the
+  // resolution and the resolution differs from the default, Gtk and Chrome end
+  // up drawing at different sizes.
+  double resolution = GetPangoResolution();
+  if (resolution > 0) {
+    pango_cairo_context_set_resolution(pango_layout_get_context(layout),
+                                       resolution);
+  }
+
+  PangoFontDescription* desc = gfx::Font::PangoFontFromGfxFont(font);
+  pango_layout_set_font_description(layout, desc);
+  pango_font_description_free(desc);
+
+  // Set text and accelerator character if needed.
+  std::string utf8 = WideToUTF8(text);
+  if (flags & gfx::Canvas::HIDE_PREFIX) {
+    // Escape the text string to be used as markup.
+    gchar* escaped_text = g_markup_escape_text(utf8.c_str(), utf8.size());
+    pango_layout_set_markup_with_accel(layout,
+                                       escaped_text,
+                                       strlen(escaped_text),
+                                       kAcceleratorChar, NULL);
+    g_free(escaped_text);
+  } else {
+    pango_layout_set_text(layout, utf8.data(), utf8.size());
+  }
+}
+
+// static
+void Canvas::SizeStringInt(const std::wstring& text,
+                           const gfx::Font& font,
+                           int* width, int* height, int flags) {
+  int org_width = *width;
+  cairo_surface_t* surface =
+      cairo_image_surface_create(CAIRO_FORMAT_ARGB32, 0, 0);
+  cairo_t* cr = cairo_create(surface);
+  PangoLayout* layout = pango_cairo_create_layout(cr);
+
+  SetupPangoLayout(layout, text, font, *width, flags);
+
+  pango_layout_get_pixel_size(layout, width, height);
+
+  if (org_width > 0 && flags & Canvas::MULTI_LINE &&
+      pango_layout_is_wrapped(layout)) {
+    // The text wrapped. There seems to be a bug in Pango when this happens
+    // such that the width returned from pango_layout_get_pixel_size is too
+    // small. Using the width from pango_layout_get_pixel_size in this case
+    // results in wrapping across more lines, which requires a bigger height.
+    // As a workaround we use the original width, which is not necessarily
+    // exactly correct, but isn't wrong by much.
+    //
+    // It looks like Pango uses the size of whitespace in calculating wrapping
+    // but doesn't include the size of the whitespace when the extents are
+    // asked for. See the loop in pango-layout.c process_item that determines
+    // where to wrap.
+    *width = org_width;
+  }
+
+  g_object_unref(layout);
+  cairo_destroy(cr);
+  cairo_surface_destroy(surface);
+}
+
+void Canvas::DrawStringInt(const std::wstring& text,
+                           const gfx::Font& font,
+                           const SkColor& color,
+                           int x, int y, int w, int h,
+                           int flags) {
+  if (w <= 0 || h <= 0)
+    return;
+
+  cairo_t* cr = beginPlatformPaint();
+  PangoLayout* layout = pango_cairo_create_layout(cr);
+
+  SetupPangoLayout(layout, text, font, w, flags);
+
+  pango_layout_set_height(layout, h * PANGO_SCALE);
+
+  cairo_save(cr);
+  cairo_set_source_rgb(cr,
+                       SkColorGetR(color) / 255.0,
+                       SkColorGetG(color) / 255.0,
+                       SkColorGetB(color) / 255.0);
+
+  int width, height;
+  pango_layout_get_pixel_size(layout, &width, &height);
+
+  cairo_rectangle(cr, x, y, w, h);
+  cairo_clip(cr);
+
+  if (flags & Canvas::TEXT_VALIGN_TOP) {
+    // Cairo should draw from the top left corner already.
+  } else if (flags & Canvas::TEXT_VALIGN_BOTTOM) {
+    y += (h - height);
+  } else {
+    // Vertically centered.
+    y += ((h - height) / 2);
+  }
+
+  cairo_move_to(cr, x, y);
+  pango_cairo_show_layout(cr, layout);
+  if (font.style() & gfx::Font::UNDERLINED) {
+    double underline_y =
+        static_cast<double>(y) + height + font.underline_position();
+    cairo_set_line_width(cr, font.underline_thickness());
+    cairo_move_to(cr, x, underline_y);
+    cairo_line_to(cr, x + width, underline_y);
+    cairo_stroke(cr);
+  }
+  cairo_restore(cr);
+
+  g_object_unref(layout);
+  // NOTE: beginPlatformPaint returned its surface, we shouldn't destroy it.
+}
+
+void Canvas::DrawGdkPixbuf(GdkPixbuf* pixbuf, int x, int y) {
+  if (!pixbuf) {
+    NOTREACHED();
+    return;
+  }
+
+  cairo_t* cr = beginPlatformPaint();
+  gdk_cairo_set_source_pixbuf(cr, pixbuf, x, y);
+  cairo_paint(cr);
+}
+
+}  // namespace gfx