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// 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_TYPEFACE_H_
#define COBALT_RENDER_TREE_TYPEFACE_H_
#include "base/memory/ref_counted.h"
#include "cobalt/render_tree/glyph.h"
namespace cobalt {
namespace render_tree {
class Font;
typedef uint32_t TypefaceId;
// The Typeface class is an abstract base class representing an implementation
// specific typeface object. While it has no associated size, it supports the
// creation of concrete Font objects at any requested size. The specific glyph
// that the typeface provides for each UTF-32 character is queryable.
// NOTE: Typeface objects are not immutable and offer no thread safety
// guarantees. While Typeface is intended to assist in the creation of
// GlyphBuffer objects, only GlyphBuffer objects, which are immutable and
// thread-safe, should be accessed on multiple threads.
class Typeface : public base::RefCounted<Typeface> {
public:
// Returns the typeface's id, which is guaranteed to be unique among the
// typefaces registered with the resource provider.
virtual TypefaceId GetId() const = 0;
// Returns a size estimate for this typeface in bytes. While the derived class
// can potentially return an exact value, there is no guarantee that this will
// be the case.
virtual uint32 GetEstimatedSizeInBytes() const = 0;
// Returns a newly created font using this typeface, with the font size set to
// the passed in value.
virtual scoped_refptr<Font> CreateFontWithSize(float font_size) = 0;
// Returns an index to the glyph that the typeface provides for a given UTF-32
// unicode character. If the character is unsupported, then it returns
// kInvalidGlyphIndex.
virtual GlyphIndex GetGlyphForCharacter(int32 utf32_character) = 0;
protected:
virtual ~Typeface() {}
// Allow the reference counting system access to our destructor.
friend class base::RefCounted<Typeface>;
};
} // namespace render_tree
} // namespace cobalt
#endif // COBALT_RENDER_TREE_TYPEFACE_H_