gecko-dev/xpcom/ds/nsVariant.h

178 lines
8.0 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/* The long avoided variant support for xpcom. */
#ifndef nsVariant_h
#define nsVariant_h
#include "nsIVariant.h"
#include "nsStringFwd.h"
#include "mozilla/Attributes.h"
class nsCycleCollectionTraversalCallback;
/**
* Map the nsAUTF8String, nsUTF8String classes to the nsACString and
* nsCString classes respectively for now. These defines need to be removed
* once Jag lands his nsUTF8String implementation.
*/
#define nsAUTF8String nsACString
#define nsUTF8String nsCString
#define PromiseFlatUTF8String PromiseFlatCString
/**
* nsDiscriminatedUnion is a type that nsIVariant implementors *may* use
* to hold underlying data. It has no methods. So, its use requires no linkage
* to the xpcom module.
*/
struct nsDiscriminatedUnion
{
union {
int8_t mInt8Value;
int16_t mInt16Value;
int32_t mInt32Value;
int64_t mInt64Value;
uint8_t mUint8Value;
uint16_t mUint16Value;
uint32_t mUint32Value;
uint64_t mUint64Value;
float mFloatValue;
double mDoubleValue;
bool mBoolValue;
char mCharValue;
PRUnichar mWCharValue;
nsIID mIDValue;
nsAString* mAStringValue;
nsAUTF8String* mUTF8StringValue;
nsACString* mCStringValue;
struct {
nsISupports* mInterfaceValue;
nsIID mInterfaceID;
} iface;
struct {
nsIID mArrayInterfaceID;
void* mArrayValue;
uint32_t mArrayCount;
uint16_t mArrayType;
} array;
struct {
char* mStringValue;
uint32_t mStringLength;
} str;
struct {
PRUnichar* mWStringValue;
uint32_t mWStringLength;
} wstr;
} u;
uint16_t mType;
};
/**
* nsVariant implements the generic variant support. The xpcom module registers
* a factory (see NS_VARIANT_CONTRACTID in nsIVariant.idl) that will create
* these objects. They are created 'empty' and 'writable'.
*
* nsIVariant users won't usually need to see this class.
*
* This class also has static helper methods that nsIVariant *implementors* can
* use to help them do all the 'standard' nsIVariant data conversions.
*/
class nsVariant MOZ_FINAL : public nsIWritableVariant
{
public:
NS_DECL_ISUPPORTS
NS_DECL_NSIVARIANT
NS_DECL_NSIWRITABLEVARIANT
nsVariant();
static nsresult Initialize(nsDiscriminatedUnion* data);
static nsresult Cleanup(nsDiscriminatedUnion* data);
static nsresult ConvertToInt8(const nsDiscriminatedUnion& data, uint8_t *_retval);
static nsresult ConvertToInt16(const nsDiscriminatedUnion& data, int16_t *_retval);
static nsresult ConvertToInt32(const nsDiscriminatedUnion& data, int32_t *_retval);
static nsresult ConvertToInt64(const nsDiscriminatedUnion& data, int64_t *_retval);
static nsresult ConvertToUint8(const nsDiscriminatedUnion& data, uint8_t *_retval);
static nsresult ConvertToUint16(const nsDiscriminatedUnion& data, uint16_t *_retval);
static nsresult ConvertToUint32(const nsDiscriminatedUnion& data, uint32_t *_retval);
static nsresult ConvertToUint64(const nsDiscriminatedUnion& data, uint64_t *_retval);
static nsresult ConvertToFloat(const nsDiscriminatedUnion& data, float *_retval);
static nsresult ConvertToDouble(const nsDiscriminatedUnion& data, double *_retval);
static nsresult ConvertToBool(const nsDiscriminatedUnion& data, bool *_retval);
static nsresult ConvertToChar(const nsDiscriminatedUnion& data, char *_retval);
static nsresult ConvertToWChar(const nsDiscriminatedUnion& data, PRUnichar *_retval);
static nsresult ConvertToID(const nsDiscriminatedUnion& data, nsID * _retval);
static nsresult ConvertToAString(const nsDiscriminatedUnion& data, nsAString & _retval);
static nsresult ConvertToAUTF8String(const nsDiscriminatedUnion& data, nsAUTF8String & _retval);
static nsresult ConvertToACString(const nsDiscriminatedUnion& data, nsACString & _retval);
static nsresult ConvertToString(const nsDiscriminatedUnion& data, char **_retval);
static nsresult ConvertToWString(const nsDiscriminatedUnion& data, PRUnichar **_retval);
static nsresult ConvertToISupports(const nsDiscriminatedUnion& data, nsISupports **_retval);
static nsresult ConvertToInterface(const nsDiscriminatedUnion& data, nsIID * *iid, void * *iface);
static nsresult ConvertToArray(const nsDiscriminatedUnion& data, uint16_t *type, nsIID* iid, uint32_t *count, void * *ptr);
static nsresult ConvertToStringWithSize(const nsDiscriminatedUnion& data, uint32_t *size, char **str);
static nsresult ConvertToWStringWithSize(const nsDiscriminatedUnion& data, uint32_t *size, PRUnichar **str);
static nsresult SetFromVariant(nsDiscriminatedUnion* data, nsIVariant* aValue);
static nsresult SetFromInt8(nsDiscriminatedUnion* data, uint8_t aValue);
static nsresult SetFromInt16(nsDiscriminatedUnion* data, int16_t aValue);
static nsresult SetFromInt32(nsDiscriminatedUnion* data, int32_t aValue);
static nsresult SetFromInt64(nsDiscriminatedUnion* data, int64_t aValue);
static nsresult SetFromUint8(nsDiscriminatedUnion* data, uint8_t aValue);
static nsresult SetFromUint16(nsDiscriminatedUnion* data, uint16_t aValue);
static nsresult SetFromUint32(nsDiscriminatedUnion* data, uint32_t aValue);
static nsresult SetFromUint64(nsDiscriminatedUnion* data, uint64_t aValue);
static nsresult SetFromFloat(nsDiscriminatedUnion* data, float aValue);
static nsresult SetFromDouble(nsDiscriminatedUnion* data, double aValue);
static nsresult SetFromBool(nsDiscriminatedUnion* data, bool aValue);
static nsresult SetFromChar(nsDiscriminatedUnion* data, char aValue);
static nsresult SetFromWChar(nsDiscriminatedUnion* data, PRUnichar aValue);
static nsresult SetFromID(nsDiscriminatedUnion* data, const nsID & aValue);
static nsresult SetFromAString(nsDiscriminatedUnion* data, const nsAString & aValue);
static nsresult SetFromAUTF8String(nsDiscriminatedUnion* data, const nsAUTF8String & aValue);
static nsresult SetFromACString(nsDiscriminatedUnion* data, const nsACString & aValue);
static nsresult SetFromString(nsDiscriminatedUnion* data, const char *aValue);
static nsresult SetFromWString(nsDiscriminatedUnion* data, const PRUnichar *aValue);
static nsresult SetFromISupports(nsDiscriminatedUnion* data, nsISupports *aValue);
static nsresult SetFromInterface(nsDiscriminatedUnion* data, const nsIID& iid, nsISupports *aValue);
static nsresult SetFromArray(nsDiscriminatedUnion* data, uint16_t type, const nsIID* iid, uint32_t count, void * aValue);
static nsresult SetFromStringWithSize(nsDiscriminatedUnion* data, uint32_t size, const char *aValue);
static nsresult SetFromWStringWithSize(nsDiscriminatedUnion* data, uint32_t size, const PRUnichar *aValue);
static nsresult SetToVoid(nsDiscriminatedUnion* data);
static nsresult SetToEmpty(nsDiscriminatedUnion* data);
static nsresult SetToEmptyArray(nsDiscriminatedUnion* data);
static void Traverse(const nsDiscriminatedUnion& data,
nsCycleCollectionTraversalCallback &cb);
private:
~nsVariant();
protected:
nsDiscriminatedUnion mData;
bool mWritable;
};
/**
* Users of nsIVariant should be using the contractID and not this CID.
* - see NS_VARIANT_CONTRACTID in nsIVariant.idl.
*/
#define NS_VARIANT_CID \
{ /* 0D6EA1D0-879C-11d5-90EF-0010A4E73D9A */ \
0xd6ea1d0, \
0x879c, \
0x11d5, \
{0x90, 0xef, 0x0, 0x10, 0xa4, 0xe7, 0x3d, 0x9a}}
#endif // nsVariant_h