| /* |
| * Copyright (C) 2006 The Android Open Source Project |
| * |
| * 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 SkFontHost_DEFINED |
| #define SkFontHost_DEFINED |
| |
| #include "SkScalerContext.h" |
| #include "SkTypeface.h" |
| |
| class SkDescriptor; |
| class SkStream; |
| class SkWStream; |
| |
| /** \class SkFontHost |
| |
| This class is ported to each environment. It is responsible for bridging the gap |
| between SkTypeface and the resulting platform-specific instance of SkScalerContext. |
| */ |
| class SkFontHost { |
| public: |
| /** Return the closest matching typeface given either an existing family |
| (specified by a typeface in that family) or by a familyName, and a |
| requested style. |
| 1) If familyFace is null, use famillyName. |
| 2) If famillyName is null, use familyFace. |
| 3) If both are null, return the default font that best matches style |
| |
| NOTE: this does not return a new typeface, nor does it affect the |
| owner count of an existing one, so the caller is free to ignore the |
| return result, or just compare it against null. |
| */ |
| static SkTypeface* FindTypeface(const SkTypeface* familyFace, |
| const char famillyName[], |
| SkTypeface::Style style); |
| |
| /** Return the typeface associated with the uniqueID, or null if that ID |
| does not match any faces. |
| |
| NOTE: this does not return a new typeface, nor does it affect the |
| owner count of an existing one, so the caller is free to ignore the |
| return result, or just compare it against null. |
| */ |
| static SkTypeface* ResolveTypeface(uint32_t uniqueID); |
| |
| /** Return a new stream to read the font data, or null if the uniqueID does |
| not match an existing typeface. The caller must call CloseStream() when |
| it is finished reading the stream. |
| */ |
| static SkStream* OpenStream(uint32_t uniqueID); |
| |
| /** Call this when finished reading from the stream returned by OpenStream. |
| The caller should NOT try to delete the stream. |
| */ |
| static void CloseStream(uint32_t uniqueID, SkStream*); |
| |
| /** Return a new typeface given the data buffer (owned by the caller). |
| If the data does not represent a valid font, return null. The caller is |
| responsible for unref-ing the returned typeface (if it is not null). |
| */ |
| static SkTypeface* CreateTypeface(SkStream*); |
| |
| /** Return a new typeface from the specified file path. If the file does not |
| represent a valid font, this returns null. If a typeface is returned, |
| the caller is responsible for calling unref() when it is no longer used. |
| */ |
| static SkTypeface* CreateTypefaceFromFile(const char path[]); |
| |
| /////////////////////////////////////////////////////////////////////////// |
| |
| /** Write a unique identifier to the stream, so that the same typeface can |
| be retrieved with Deserialize(). |
| */ |
| static void Serialize(const SkTypeface*, SkWStream*); |
| |
| /** Given a stream created by Serialize(), return the corresponding typeface |
| or null if no match is found. |
| |
| NOTE: this does not return a new typeface, nor does it affect the |
| owner count of an existing one, so the caller is free to ignore the |
| return result, or just compare it against null. |
| */ |
| static SkTypeface* Deserialize(SkStream*); |
| |
| /////////////////////////////////////////////////////////////////////////// |
| |
| /** Return a subclass of SkScalarContext |
| */ |
| static SkScalerContext* CreateScalerContext(const SkDescriptor* desc); |
| |
| /** Return a scalercontext using the "fallback" font. If there is no designated |
| fallback, return null. |
| */ |
| static SkScalerContext* CreateFallbackScalerContext(const SkScalerContext::Rec&); |
| |
| /** Return the number of bytes (approx) that should be purged from the font |
| cache. The input parameter is the cache's estimate of how much as been |
| allocated by the cache so far. |
| To purge (basically) everything, return the input parameter. |
| To purge nothing, return 0 |
| */ |
| static size_t ShouldPurgeFontCache(size_t sizeAllocatedSoFar); |
| |
| /** Return SkScalerContext gamma flag, or 0, based on the paint that will be |
| used to draw something with antialiasing. |
| */ |
| static int ComputeGammaFlag(const SkPaint& paint); |
| |
| /** Return NULL or a pointer to 256 bytes for the black (table[0]) and |
| white (table[1]) gamma tables. |
| */ |
| static void GetGammaTables(const uint8_t* tables[2]); |
| }; |
| |
| #endif |
| |