src/cobalt/render_tree/font_provider.h

/*
 * Copyright 2016 Google Inc. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef COBALT_RENDER_TREE_FONT_PROVIDER_H_
#define COBALT_RENDER_TREE_FONT_PROVIDER_H_

#include "cobalt/render_tree/font.h"
#include "cobalt/render_tree/glyph.h"

namespace cobalt {
namespace render_tree {

// The FontProvider class is an abstract base class representing a collection of
// fonts with a matching size and style, which provides fonts for any given
// character based upon what it considers to be the best match.
class FontProvider {
 public:
  // Returns a font-glyph combination based upon a passed in character. The
  // returned font is guaranteed to be non-NULL. However, the glyph index may
  // be set to |kInvalidGlyphIndex| if no font is found that supports the
  // requested character.
  virtual const scoped_refptr<Font>& GetCharacterFont(
      int32 utf32_character, GlyphIndex* glyph_index) = 0;

 protected:
  virtual ~FontProvider() {}
};

}  // namespace render_tree
}  // namespace cobalt

#endif  // COBALT_RENDER_TREE_FONT_PROVIDER_H_