ui/gfx/linux_font_delegate.h

// Copyright 2013 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 UI_GFX_LINUX_FONT_DELEGATE_H_
#define UI_GFX_LINUX_FONT_DELEGATE_H_

#include <string>

#include "base/memory/scoped_ptr.h"
#include "ui/gfx/font_render_params.h"
#include "ui/gfx/gfx_export.h"

namespace gfx {

class ScopedPangoFontDescription;

// Allows a Linux platform-specific overriding of font preferences.
class GFX_EXPORT LinuxFontDelegate {
 public:
  virtual ~LinuxFontDelegate() {}

  // Sets the dynamically loaded singleton that provides font preferences.
  // This pointer is not owned, and if this method is called a second time,
  // the first instance is not deleted.
  static void SetInstance(LinuxFontDelegate* instance);

  // Returns a LinuxFontDelegate instance for the toolkit used in
  // the user's desktop environment.
  //
  // Can return NULL, in case no toolkit has been set. (For example, if we're
  // running with the "--ash" flag.)
  static const LinuxFontDelegate* instance();

  // Returns the default font rendering settings.
  virtual FontRenderParams GetDefaultFontRenderParams() const = 0;

  // Returns the Pango description for the default UI font.
  virtual scoped_ptr<ScopedPangoFontDescription>
      GetDefaultPangoFontDescription() const = 0;

  // Returns the resolution (as pixels-per-inch) that should be used to convert
  // font sizes between points and pixels. -1 is returned if the DPI is unset.
  virtual double GetFontDPI() const = 0;
};

}  // namespace gfx

#endif  // UI_GFX_LINUX_FONT_DELEGATE_H_