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// Copyright 2018 Google LLC.
// Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
#ifndef SkPDFUnion_DEFINED
#define SkPDFUnion_DEFINED
#include "SkPDFTypes.h"
template <class T>
class SkStorageFor {
const T& get() const { return *reinterpret_cast<const T*>(&fStore); }
T& get() { return *reinterpret_cast<T*>(&fStore); }
// Up to caller to keep track of status.
template<class... Args> void init(Args&&... args) {
new (&this->get()) T(std::forward<Args>(args)...);
void destroy() { this->get().~T(); }
typename std::aligned_storage<sizeof(T), alignof(T)>::type fStore;
// Exposed for unit testing.
void SkPDFWriteString(SkWStream* wStream, const char* cin, size_t len);
A SkPDFUnion is a non-virtualized implementation of the
non-compound, non-specialized PDF Object types: Name, String,
Number, Boolean.
class SkPDFUnion {
// Move contstructor and assignment operator destroy the argument
// and steal their references (if needed).
SkPDFUnion(SkPDFUnion&& other);
SkPDFUnion& operator=(SkPDFUnion&& other);
/** The following nine functions are the standard way of creating
SkPDFUnion objects. */
static SkPDFUnion Int(int32_t);
static SkPDFUnion Int(size_t v) { return SkPDFUnion::Int(SkToS32(v)); }
static SkPDFUnion Bool(bool);
static SkPDFUnion Scalar(SkScalar);
static SkPDFUnion ColorComponent(uint8_t);
static SkPDFUnion ColorComponentF(float);
/** These two functions do NOT take ownership of char*, and do NOT
copy the string. Suitable for passing in static const
strings. For example:
SkPDFUnion n = SkPDFUnion::Name("Length");
SkPDFUnion u = SkPDFUnion::String("Identity"); */
/** SkPDFUnion::Name(const char*) assumes that the passed string
is already a valid name (that is: it has no control or
whitespace characters). This will not copy the name. */
static SkPDFUnion Name(const char*);
/** SkPDFUnion::String will encode the passed string. This will
not copy the name. */
static SkPDFUnion String(const char*);
/** SkPDFUnion::Name(SkString) does not assume that the
passed string is already a valid name and it will escape the
string. */
static SkPDFUnion Name(SkString);
/** SkPDFUnion::String will encode the passed string. */
static SkPDFUnion String(SkString);
static SkPDFUnion Object(std::unique_ptr<SkPDFObject>);
static SkPDFUnion Ref(SkPDFIndirectReference);
/** These two non-virtual methods mirror SkPDFObject's
corresponding virtuals. */
void emitObject(SkWStream*) const;
bool isName() const;
union {
int32_t fIntValue;
bool fBoolValue;
SkScalar fScalarValue;
const char* fStaticString;
SkStorageFor<SkString> fSkString;
SkPDFObject* fObject;
enum class Type : char {
/** It is an error to call emitObject() or addResources() on an
kDestroyed object. */
kDestroyed = 0,
Type fType;
SkPDFUnion(Type, int32_t);
SkPDFUnion(Type, bool);
SkPDFUnion(Type, SkScalar);
SkPDFUnion(Type, SkString);
// We do not now need copy constructor and copy assignment, so we
// will disable this functionality.
SkPDFUnion& operator=(const SkPDFUnion&) = delete;
SkPDFUnion(const SkPDFUnion&) = delete;
static_assert(sizeof(SkString) == sizeof(void*), "SkString_size");
#endif // SkPDFUnion_DEFINED