michael@0: /*
michael@0:  * Copyright 2013 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: #ifndef SkFontConfigInterface_DEFINED
michael@0: #define SkFontConfigInterface_DEFINED
michael@0: 
michael@0: #include "SkDataTable.h"
michael@0: #include "SkFontStyle.h"
michael@0: #include "SkRefCnt.h"
michael@0: #include "SkTArray.h"
michael@0: #include "SkTypeface.h"
michael@0: 
michael@0: /**
michael@0:  *  \class SkFontConfigInterface
michael@0:  *
michael@0:  *  Provides SkFontHost clients with access to fontconfig services. They will
michael@0:  *  access the global instance found in RefGlobal().
michael@0:  */
michael@0: class SK_API SkFontConfigInterface : public SkRefCnt {
michael@0: public:
michael@0:     SK_DECLARE_INST_COUNT(SkFontConfigInterface)
michael@0: 
michael@0:     /**
michael@0:      *  Returns the global SkFontConfigInterface instance, and if it is not
michael@0:      *  NULL, calls ref() on it. The caller must balance this with a call to
michael@0:      *  unref().
michael@0:      */
michael@0:     static SkFontConfigInterface* RefGlobal();
michael@0: 
michael@0:     /**
michael@0:      *  Replace the current global instance with the specified one, safely
michael@0:      *  ref'ing the new instance, and unref'ing the previous. Returns its
michael@0:      *  parameter (the new global instance).
michael@0:      */
michael@0:     static SkFontConfigInterface* SetGlobal(SkFontConfigInterface*);
michael@0: 
michael@0:     /**
michael@0:      *  This should be treated as private to the impl of SkFontConfigInterface.
michael@0:      *  Callers should not change or expect any particular values. It is meant
michael@0:      *  to be a union of possible storage types to aid the impl.
michael@0:      */
michael@0:     struct FontIdentity {
michael@0:         FontIdentity() : fID(0), fTTCIndex(0) {}
michael@0: 
michael@0:         bool operator==(const FontIdentity& other) const {
michael@0:             return fID == other.fID &&
michael@0:                    fTTCIndex == other.fTTCIndex &&
michael@0:                    fString == other.fString;
michael@0:         }
michael@0:         bool operator!=(const FontIdentity& other) const {
michael@0:             return !(*this == other);
michael@0:         }
michael@0: 
michael@0:         uint32_t    fID;
michael@0:         int32_t     fTTCIndex;
michael@0:         SkString    fString;
michael@0:         SkFontStyle fStyle;
michael@0: 
michael@0:         // If buffer is NULL, just return the number of bytes that would have
michael@0:         // been written. Will pad contents to a multiple of 4.
michael@0:         size_t writeToMemory(void* buffer = NULL) const;
michael@0: 
michael@0:         // Recreate from a flattened buffer, returning the number of bytes read.
michael@0:         size_t readFromMemory(const void* buffer, size_t length);
michael@0:     };
michael@0: 
michael@0:     /**
michael@0:      *  Given a familyName and style, find the best match.
michael@0:      *
michael@0:      *  If a match is found, return true and set its outFontIdentifier.
michael@0:      *      If outFamilyName is not null, assign the found familyName to it
michael@0:      *          (which may differ from the requested familyName).
michael@0:      *      If outStyle is not null, assign the found style to it
michael@0:      *          (which may differ from the requested style).
michael@0:      *
michael@0:      *  If a match is not found, return false, and ignore all out parameters.
michael@0:      */
michael@0:     virtual bool matchFamilyName(const char familyName[],
michael@0:                                  SkTypeface::Style requested,
michael@0:                                  FontIdentity* outFontIdentifier,
michael@0:                                  SkString* outFamilyName,
michael@0:                                  SkTypeface::Style* outStyle) = 0;
michael@0: 
michael@0:     /**
michael@0:      *  Given a FontRef, open a stream to access its data, or return null
michael@0:      *  if the FontRef's data is not available. The caller is responsible for
michael@0:      *  calling stream->unref() when it is done accessing the data.
michael@0:      */
michael@0:     virtual SkStream* openStream(const FontIdentity&) = 0;
michael@0: 
michael@0:     /**
michael@0:      *  Return a singleton instance of a direct subclass that calls into
michael@0:      *  libfontconfig. This does not affect the refcnt of the returned instance.
michael@0:      */
michael@0:     static SkFontConfigInterface* GetSingletonDirectInterface();
michael@0: 
michael@0:     // New APIS, which have default impls for now (which do nothing)
michael@0: 
michael@0:     virtual SkDataTable* getFamilyNames() { return SkDataTable::NewEmpty(); }
michael@0:     virtual bool matchFamilySet(const char inFamilyName[],
michael@0:                                 SkString* outFamilyName,
michael@0:                                 SkTArray<FontIdentity>*) {
michael@0:         return false;
michael@0:     }
michael@0:     typedef SkRefCnt INHERITED;
michael@0: };
michael@0: 
michael@0: #endif