skia2/include/ports/SkFontConfigInterface.h
Ben Wagner a93a14a998 Convert NULL and 0 to nullptr.
This was created by looking at warnings produced by clang's
-Wzero-as-null-pointer-constant. This updates most issues in
Skia code. However, there are places where GL and Vulkan want
pointer values which are explicitly 0, external headers which
use NULL directly, and possibly more uses in un-compiled
sources (for other platforms).

Change-Id: Id22fbac04d5c53497a53d734f0896b4f06fe8345
Reviewed-on: https://skia-review.googlesource.com/39521
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
2017-08-28 17:48:57 +00:00

115 lines
4.0 KiB
C++

/*
* Copyright 2013 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkFontConfigInterface_DEFINED
#define SkFontConfigInterface_DEFINED
#include "SkFontStyle.h"
#include "SkRefCnt.h"
#include "SkTypeface.h"
class SkFontMgr;
/**
* \class SkFontConfigInterface
*
* A simple interface for remotable font management.
* The global instance can be found with RefGlobal().
*/
class SK_API SkFontConfigInterface : public SkRefCnt {
public:
/**
* Returns the global SkFontConfigInterface instance. If it is not
* nullptr, calls ref() on it. The caller must balance this with a call to
* unref(). The default SkFontConfigInterface is the result of calling
* GetSingletonDirectInterface.
*/
static SkFontConfigInterface* RefGlobal();
/**
* Replace the current global instance with the specified one, safely
* ref'ing the new instance, and unref'ing the previous. Returns its
* parameter (the new global instance).
*/
static SkFontConfigInterface* SetGlobal(SkFontConfigInterface*);
/**
* This should be treated as private to the impl of SkFontConfigInterface.
* Callers should not change or expect any particular values. It is meant
* to be a union of possible storage types to aid the impl.
*/
struct FontIdentity {
FontIdentity() : fID(0), fTTCIndex(0) {}
bool operator==(const FontIdentity& other) const {
return fID == other.fID &&
fTTCIndex == other.fTTCIndex &&
fString == other.fString;
}
bool operator!=(const FontIdentity& other) const {
return !(*this == other);
}
uint32_t fID;
int32_t fTTCIndex;
SkString fString;
SkFontStyle fStyle;
// If buffer is NULL, just return the number of bytes that would have
// been written. Will pad contents to a multiple of 4.
size_t writeToMemory(void* buffer = nullptr) const;
// Recreate from a flattened buffer, returning the number of bytes read.
size_t readFromMemory(const void* buffer, size_t length);
};
/**
* Given a familyName and style, find the best match.
*
* If a match is found, return true and set its outFontIdentifier.
* If outFamilyName is not null, assign the found familyName to it
* (which may differ from the requested familyName).
* If outStyle is not null, assign the found style to it
* (which may differ from the requested style).
*
* If a match is not found, return false, and ignore all out parameters.
*/
virtual bool matchFamilyName(const char familyName[],
SkFontStyle requested,
FontIdentity* outFontIdentifier,
SkString* outFamilyName,
SkFontStyle* outStyle) = 0;
/**
* Given a FontRef, open a stream to access its data, or return null
* if the FontRef's data is not available. The caller is responsible for
* deleting the stream when it is done accessing the data.
*/
virtual SkStreamAsset* openStream(const FontIdentity&) = 0;
/**
* Return an SkTypeface for the given FontIdentity.
*
* The default implementation simply returns a new typeface built using data obtained from
* openStream(), but derived classes may implement more complex caching schemes.
*/
virtual sk_sp<SkTypeface> makeTypeface(const FontIdentity& identity) {
return SkTypeface::MakeFromStream(this->openStream(identity), identity.fTTCIndex);
}
/**
* Return a singleton instance of a direct subclass that calls into
* libfontconfig. This does not affect the refcnt of the returned instance.
*/
static SkFontConfigInterface* GetSingletonDirectInterface();
typedef SkRefCnt INHERITED;
};
#endif