Aura/GTK integration: Create a small stub library that can talk to GTK.

chrome/browser/ui/libgtk2ui/gtk2_ui.h

+// 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.
+
+#ifndef CHROME_BROWSER_UI_LIBGTK2UI_GTK2_UI_H_
+#define CHROME_BROWSER_UI_LIBGTK2UI_GTK2_UI_H_
+#pragma once
+
+#include <map>
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "chrome/browser/ui/libgtk2ui/libgtk2ui_export.h"
+#include "chrome/browser/ui/libgtk2ui/owned_widget_gtk2.h"
+#include "ui/base/linux_ui.h"
+#include "ui/gfx/color_utils.h"
+
+typedef struct _GdkColor GdkColor;
+typedef struct _GtkStyle GtkStyle;
+typedef struct _GtkWidget GtkWidget;
+
+class SkBitmap;
+
+namespace gfx {
+class Image;
+}
+
+namespace libgtk2ui {
+
+// Interface to GTK2 desktop features.
+//
+class Gtk2UI : public ui::LinuxUI {
+ public:
+  Gtk2UI();
+  virtual ~Gtk2UI();
+
+  // LinuxShell:
+  virtual bool UseNativeTheme() const OVERRIDE;
+  virtual gfx::Image* GetThemeImageNamed(int id) const OVERRIDE;
+  virtual SkColor GetColor(int id) const OVERRIDE;
+
+ private:
+  typedef std::map<int, SkColor> ColorMap;
+  typedef std::map<int, color_utils::HSL> TintMap;
+  typedef std::map<int, gfx::Image*> ImageCache;
+
+  // This method returns the colors webkit will use for the scrollbars. When no
+  // colors are specified by the GTK+ theme, this function averages of the
+  // thumb part and of the track colors.
+  void GetScrollbarColors(GdkColor* thumb_active_color,
+                          GdkColor* thumb_inactive_color,
+                          GdkColor* track_color);
+
+  // Extracts colors and tints from the GTK theme, both for the
+  // ThemeService interface and the colors we send to webkit.
+  void LoadGtkValues();
+
+  // Reads in explicit theme frame colors from the ChromeGtkFrame style class
+  // or generates them per our fallback algorithm.
+  GdkColor BuildFrameColors(GtkStyle* frame_style);
+
+  // Sets the underlying theme colors/tints from a GTK color.
+  void SetThemeColorFromGtk(int id, const GdkColor* color);
+  void SetThemeTintFromGtk(int id, const GdkColor* color);
+
+  // Creates and returns a frame color, either using |gtk_base| verbatim if
+  // non-NULL, or tinting |base| with |tint|. Also sets |color_id| and
+  // |tint_id| to the returned color.
+  GdkColor BuildAndSetFrameColor(const GdkColor* base,
+                                 const GdkColor* gtk_base,
+                                 const color_utils::HSL& tint,
+                                 int color_id,
+                                 int tint_id);
+
+  // Lazily generates each bitmap used in the gtk theme.
+  SkBitmap GenerateGtkThemeBitmap(int id) const;
+
+  // Creates a GTK+ version of IDR_THEME_FRAME. Instead of tinting, this
+  // creates a theme configurable gradient ending with |color_id| at the
+  // bottom, and |gradient_name| at the top if that color is specified in the
+  // theme.
+  SkBitmap GenerateFrameImage(int color_id,
+                              const char* gradient_name) const;
+
+  // Takes the base frame image |base_id| and tints it with |tint_id|.
+  SkBitmap GenerateTabImage(int base_id) const;
+
+  // Tints an icon based on tint.
+  SkBitmap GenerateTintedIcon(int base_id,
+                              const color_utils::HSL& tint) const;
+
+  // Returns the tint for buttons that contrasts with the normal window
+  // background color.
+  void GetNormalButtonTintHSL(color_utils::HSL* tint) const;
+
+  // Returns a tint that's the color of the current normal text in an entry.
+  void GetNormalEntryForegroundHSL(color_utils::HSL* tint) const;
+
+  // Returns a tint that's the color of the current highlighted text in an
+  // entry.
+  void GetSelectedEntryForegroundHSL(color_utils::HSL* tint) const;
+
+  // Frees all calculated images and color data.
+  void ClearAllThemeData();
+
+  GtkWidget* fake_window_;
+  GtkWidget* fake_frame_;
+  OwnedWidgetGtk fake_label_;
+  OwnedWidgetGtk fake_entry_;
+  OwnedWidgetGtk fake_menu_item_;
+
+  // Tints and colors calculated by LoadGtkValues() that are given to the
+  // caller while |use_gtk_| is true.
+  ColorMap colors_;
+  TintMap tints_;
+
+  // Colors used to tint certain icons.
+  color_utils::HSL button_tint_;
+  color_utils::HSL entry_tint_;
+  color_utils::HSL selected_entry_tint_;
+
+  // Colors that we pass to WebKit. These are generated each time the theme
+  // changes.
+  SkColor focus_ring_color_;
+  SkColor thumb_active_color_;
+  SkColor thumb_inactive_color_;
+  SkColor track_color_;
+  SkColor active_selection_bg_color_;
+  SkColor active_selection_fg_color_;
+  SkColor inactive_selection_bg_color_;
+  SkColor inactive_selection_fg_color_;
+
+  // Image cache of lazily created images.
+  mutable ImageCache gtk_images_;
+
+  DISALLOW_COPY_AND_ASSIGN(Gtk2UI);
+};
+
+}  // namespace libgtk2ui
+
+// Access point to the GTK2 desktop system. This should be the only symbol that
+// is exported in the library; everything else should be used through the
+// interface, because eventually this .so will be loaded through dlopen at
+// runtime so our main binary can conditionally load GTK2 or GTK3 or EFL or
+// QT or whatever.
+LIBGTK2UI_EXPORT ui::LinuxUI* BuildGtk2UI();
+
+#endif  // CHROME_BROWSER_UI_LIBGTK2UI_GTK2_UI_H_