xpcom/ds/nsVariant.h

   1 /* -*- Mode: IDL; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
   2  *
   3  * ***** BEGIN LICENSE BLOCK *****
   4  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   5  *
   6  * The contents of this file are subject to the Mozilla Public License Version
   7  * 1.1 (the "License"); you may not use this file except in compliance with
   8  * the License. You may obtain a copy of the License at
   9  * http://www.mozilla.org/MPL/
  10  *
  11  * Software distributed under the License is distributed on an "AS IS" basis,
  12  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  13  * for the specific language governing rights and limitations under the
  14  * License.
  15  *
  16  * The Original Code is mozilla.org code.
  17  *
  18  * The Initial Developer of the Original Code is
  19  * Netscape Communications Corporation.
  20  * Portions created by the Initial Developer are Copyright (C) 1998
  21  * the Initial Developer. All Rights Reserved.
  22  *
  23  * Contributor(s):
  24  *   John Bandhauer <jband@netscape.com>
  25  *
  26  * Alternatively, the contents of this file may be used under the terms of
  27  * either of the GNU General Public License Version 2 or later (the "GPL"),
  28  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  29  * in which case the provisions of the GPL or the LGPL are applicable instead
  30  * of those above. If you wish to allow use of your version of this file only
  31  * under the terms of either the GPL or the LGPL, and not to allow others to
  32  * use your version of this file under the terms of the MPL, indicate your
  33  * decision by deleting the provisions above and replace them with the notice
  34  * and other provisions required by the GPL or the LGPL. If you do not delete
  35  * the provisions above, a recipient may use your version of this file under
  36  * the terms of any one of the MPL, the GPL or the LGPL.
  37  *
  38  * ***** END LICENSE BLOCK ***** */
  39
  40 /* The long avoided variant support for xpcom. */
  41
  42 #include "nsIVariant.h"
  43 #include "nsStringFwd.h"
  44 #include "xpt_struct.h"
  45
  46 class nsCycleCollectionTraversalCallback;
  47
  48 /**
  49  * Map the nsAUTF8String, nsUTF8String classes to the nsACString and
  50  * nsCString classes respectively for now.  These defines need to be removed
  51  * once Jag lands his nsUTF8String implementation.
  52  */
  53 #define nsAUTF8String nsACString
  54 #define nsUTF8String nsCString
  55 #define PromiseFlatUTF8String PromiseFlatCString
  56
  57 /**
  58  * nsDiscriminatedUnion is a type that nsIVariant implementors *may* use
  59  * to hold underlying data. It has no methods. So, its use requires no linkage
  60  * to the xpcom module.
  61  */
  62
  63 struct nsDiscriminatedUnion
  64 {
  65     union {
  66         PRInt8         mInt8Value;
  67         PRInt16        mInt16Value;
  68         PRInt32        mInt32Value;
  69         PRInt64        mInt64Value;
  70         PRUint8        mUint8Value;
  71         PRUint16       mUint16Value;
  72         PRUint32       mUint32Value;
  73         PRUint64       mUint64Value;
  74         float          mFloatValue;
  75         double         mDoubleValue;
  76         PRBool         mBoolValue;
  77         char           mCharValue;
  78         PRUnichar      mWCharValue;
  79         nsIID          mIDValue;
  80         nsAString*     mAStringValue;
  81         nsAUTF8String* mUTF8StringValue;
  82         nsACString*    mCStringValue;
  83         struct {
  84             nsISupports* mInterfaceValue;
  85             nsIID        mInterfaceID;
  86         } iface;
  87         struct {
  88             nsIID        mArrayInterfaceID;
  89             void*        mArrayValue;
  90             PRUint32     mArrayCount;
  91             PRUint16     mArrayType;
  92         } array;
  93         struct {
  94             char*        mStringValue;
  95             PRUint32     mStringLength;
  96         } str;
  97         struct {
  98             PRUnichar*   mWStringValue;
  99             PRUint32     mWStringLength;
 100         } wstr;
 101     } u;
 102     PRUint16       mType;
 103 };
 104
 105 /**
 106  * nsVariant implements the generic variant support. The xpcom module registers
 107  * a factory (see NS_VARIANT_CONTRACTID in nsIVariant.idl) that will create
 108  * these objects. They are created 'empty' and 'writable'.
 109  *
 110  * nsIVariant users won't usually need to see this class.
 111  *
 112  * This class also has static helper methods that nsIVariant *implementors* can
 113  * use to help them do all the 'standard' nsIVariant data conversions.
 114  */
 115
 116 class NS_COM nsVariant : public nsIWritableVariant
 117 {
 118 public:
 119     NS_DECL_ISUPPORTS
 120     NS_DECL_NSIVARIANT
 121     NS_DECL_NSIWRITABLEVARIANT
 122
 123     nsVariant();
 124
 125     static nsresult Initialize(nsDiscriminatedUnion* data);
 126     static nsresult Cleanup(nsDiscriminatedUnion* data);
 127
 128     static nsresult ConvertToInt8(const nsDiscriminatedUnion& data, PRUint8 *_retval);
 129     static nsresult ConvertToInt16(const nsDiscriminatedUnion& data, PRInt16 *_retval);
 130     static nsresult ConvertToInt32(const nsDiscriminatedUnion& data, PRInt32 *_retval);
 131     static nsresult ConvertToInt64(const nsDiscriminatedUnion& data, PRInt64 *_retval);
 132     static nsresult ConvertToUint8(const nsDiscriminatedUnion& data, PRUint8 *_retval);
 133     static nsresult ConvertToUint16(const nsDiscriminatedUnion& data, PRUint16 *_retval);
 134     static nsresult ConvertToUint32(const nsDiscriminatedUnion& data, PRUint32 *_retval);
 135     static nsresult ConvertToUint64(const nsDiscriminatedUnion& data, PRUint64 *_retval);
 136     static nsresult ConvertToFloat(const nsDiscriminatedUnion& data, float *_retval);
 137     static nsresult ConvertToDouble(const nsDiscriminatedUnion& data, double *_retval);
 138     static nsresult ConvertToBool(const nsDiscriminatedUnion& data, PRBool *_retval);
 139     static nsresult ConvertToChar(const nsDiscriminatedUnion& data, char *_retval);
 140     static nsresult ConvertToWChar(const nsDiscriminatedUnion& data, PRUnichar *_retval);
 141     static nsresult ConvertToID(const nsDiscriminatedUnion& data, nsID * _retval);
 142     static nsresult ConvertToAString(const nsDiscriminatedUnion& data, nsAString & _retval);
 143     static nsresult ConvertToAUTF8String(const nsDiscriminatedUnion& data, nsAUTF8String & _retval);
 144     static nsresult ConvertToACString(const nsDiscriminatedUnion& data, nsACString & _retval);
 145     static nsresult ConvertToString(const nsDiscriminatedUnion& data, char **_retval);
 146     static nsresult ConvertToWString(const nsDiscriminatedUnion& data, PRUnichar **_retval);
 147     static nsresult ConvertToISupports(const nsDiscriminatedUnion& data, nsISupports **_retval);
 148     static nsresult ConvertToInterface(const nsDiscriminatedUnion& data, nsIID * *iid, void * *iface);
 149     static nsresult ConvertToArray(const nsDiscriminatedUnion& data, PRUint16 *type, nsIID* iid, PRUint32 *count, void * *ptr);
 150     static nsresult ConvertToStringWithSize(const nsDiscriminatedUnion& data, PRUint32 *size, char **str);
 151     static nsresult ConvertToWStringWithSize(const nsDiscriminatedUnion& data, PRUint32 *size, PRUnichar **str);
 152
 153     static nsresult SetFromVariant(nsDiscriminatedUnion* data, nsIVariant* aValue);
 154
 155     static nsresult SetFromInt8(nsDiscriminatedUnion* data, PRUint8 aValue);
 156     static nsresult SetFromInt16(nsDiscriminatedUnion* data, PRInt16 aValue);
 157     static nsresult SetFromInt32(nsDiscriminatedUnion* data, PRInt32 aValue);
 158     static nsresult SetFromInt64(nsDiscriminatedUnion* data, PRInt64 aValue);
 159     static nsresult SetFromUint8(nsDiscriminatedUnion* data, PRUint8 aValue);
 160     static nsresult SetFromUint16(nsDiscriminatedUnion* data, PRUint16 aValue);
 161     static nsresult SetFromUint32(nsDiscriminatedUnion* data, PRUint32 aValue);
 162     static nsresult SetFromUint64(nsDiscriminatedUnion* data, PRUint64 aValue);
 163     static nsresult SetFromFloat(nsDiscriminatedUnion* data, float aValue);
 164     static nsresult SetFromDouble(nsDiscriminatedUnion* data, double aValue);
 165     static nsresult SetFromBool(nsDiscriminatedUnion* data, PRBool aValue);
 166     static nsresult SetFromChar(nsDiscriminatedUnion* data, char aValue);
 167     static nsresult SetFromWChar(nsDiscriminatedUnion* data, PRUnichar aValue);
 168     static nsresult SetFromID(nsDiscriminatedUnion* data, const nsID & aValue);
 169     static nsresult SetFromAString(nsDiscriminatedUnion* data, const nsAString & aValue);
 170     static nsresult SetFromAUTF8String(nsDiscriminatedUnion* data, const nsAUTF8String & aValue);
 171     static nsresult SetFromACString(nsDiscriminatedUnion* data, const nsACString & aValue);
 172     static nsresult SetFromString(nsDiscriminatedUnion* data, const char *aValue);
 173     static nsresult SetFromWString(nsDiscriminatedUnion* data, const PRUnichar *aValue);
 174     static nsresult SetFromISupports(nsDiscriminatedUnion* data, nsISupports *aValue);
 175     static nsresult SetFromInterface(nsDiscriminatedUnion* data, const nsIID& iid, nsISupports *aValue);
 176     static nsresult SetFromArray(nsDiscriminatedUnion* data, PRUint16 type, const nsIID* iid, PRUint32 count, void * aValue);
 177     static nsresult SetFromStringWithSize(nsDiscriminatedUnion* data, PRUint32 size, const char *aValue);
 178     static nsresult SetFromWStringWithSize(nsDiscriminatedUnion* data, PRUint32 size, const PRUnichar *aValue);
 179
 180     static nsresult SetToVoid(nsDiscriminatedUnion* data);
 181     static nsresult SetToEmpty(nsDiscriminatedUnion* data);
 182     static nsresult SetToEmptyArray(nsDiscriminatedUnion* data);
 183
 184     static void Traverse(const nsDiscriminatedUnion& data,
 185                          nsCycleCollectionTraversalCallback &cb);
 186
 187 private:
 188     ~nsVariant();
 189
 190 protected:
 191     nsDiscriminatedUnion mData;
 192     PRBool               mWritable;
 193 };
 194
 195 /**
 196  * Users of nsIVariant should be using the contractID and not this CID.
 197  *  - see NS_VARIANT_CONTRACTID in nsIVariant.idl.
 198  */
 199
 200 #define NS_VARIANT_CID \
 201 { /* 0D6EA1D0-879C-11d5-90EF-0010A4E73D9A */ \
 202     0xd6ea1d0,                               \
 203     0x879c,                                  \
 204     0x11d5,                                  \
 205     {0x90, 0xef, 0x0, 0x10, 0xa4, 0xe7, 0x3d, 0x9a}}
 206
 207 #define NS_VARIANT_CLASSNAME "Variant"
 208