| // 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_ |