widget/src/xpwidgets/nsPrimitiveHelpers.cpp

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  39
  40
  41 //
  42 // Part of the reason these routines are all in once place is so that as new
  43 // data flavors are added that are known to be one-byte or two-byte strings, or even
  44 // raw binary data, then we just have to go to one place to change how the data
  45 // moves into/out of the primitives and native line endings.
  46 //
  47 // If you add new flavors that have special consideration (binary data or one-byte
  48 // char* strings), please update all the helper classes in this file.
  49 //
  50 // For now, this is the assumption that we are making:
  51 //  - text/plain is always a char*
  52 //  - anything else is a PRUnichar*
  53 //
  54
  55
  56 #include "nsPrimitiveHelpers.h"
  57 #include "nsCOMPtr.h"
  58 #include "nsXPCOM.h"
  59 #include "nsISupportsPrimitives.h"
  60 #include "nsITransferable.h"
  61 #include "nsIComponentManager.h"
  62 #include "nsLinebreakConverter.h"
  63 #include "nsReadableUtils.h"
  64
  65 #include "nsIServiceManager.h"
  66 #include "nsICharsetConverterManager.h"
  67 // unicode conversion
  68 #  include "nsIPlatformCharset.h"
  69 #include "nsISaveAsCharset.h"
  70 #include "nsAutoPtr.h"
  71
  72
  73 //
  74 // CreatePrimitiveForData
  75 //
  76 // Given some data and the flavor it corresponds to, creates the appropriate
  77 // nsISupports* wrapper for passing across IDL boundaries. Right now, everything
  78 // creates a two-byte |nsISupportsString|, except for "text/plain" and native
  79 // platform HTML (CF_HTML on win32)
  80 //
  81 void
  82 nsPrimitiveHelpers :: CreatePrimitiveForData ( const char* aFlavor, void* aDataBuff,
  83                                                  PRUint32 aDataLen, nsISupports** aPrimitive )
  84 {
  85   if ( !aPrimitive )
  86     return;
  87
  88   if ( strcmp(aFlavor,kTextMime) == 0 || strcmp(aFlavor,kNativeHTMLMime) == 0 ) {
  89     nsCOMPtr<nsISupportsCString> primitive =
  90         do_CreateInstance(NS_SUPPORTS_CSTRING_CONTRACTID);
  91     if ( primitive ) {
  92       const char * start = reinterpret_cast<const char*>(aDataBuff);
  93       primitive->SetData(Substring(start, start + aDataLen));
  94       NS_ADDREF(*aPrimitive = primitive);
  95     }
  96   }
  97   else {
  98     nsCOMPtr<nsISupportsString> primitive =
  99         do_CreateInstance(NS_SUPPORTS_STRING_CONTRACTID);
 100     if (primitive ) {
 101       if (aDataLen % 2) {
 102         nsAutoArrayPtr<char> buffer(new char[aDataLen + 1]);
 103         if (!NS_LIKELY(buffer))
 104           return;
 105
 106         memcpy(buffer, aDataBuff, aDataLen);
 107         buffer[aDataLen] = 0;
 108         const PRUnichar* start = reinterpret_cast<const PRUnichar*>(buffer.get());
 109         // recall that length takes length as characters, not bytes
 110         primitive->SetData(Substring(start, start + (aDataLen + 1) / 2));
 111       } else {
 112         const PRUnichar* start = reinterpret_cast<const PRUnichar*>(aDataBuff);
 113         // recall that length takes length as characters, not bytes
 114         primitive->SetData(Substring(start, start + (aDataLen / 2)));
 115       }
 116       NS_ADDREF(*aPrimitive = primitive);
 117     }
 118   }
 119
 120 } // CreatePrimitiveForData
 121
 122
 123 //
 124 // CreateDataFromPrimitive
 125 //
 126 // Given a nsISupports* primitive and the flavor it represents, creates a new data
 127 // buffer with the data in it. This data will be null terminated, but the length
 128 // parameter does not reflect that.
 129 //
 130 void
 131 nsPrimitiveHelpers :: CreateDataFromPrimitive ( const char* aFlavor, nsISupports* aPrimitive,
 132                                                    void** aDataBuff, PRUint32 aDataLen )
 133 {
 134   if ( !aDataBuff )
 135     return;
 136
 137   *aDataBuff = nsnull;
 138
 139   if ( strcmp(aFlavor,kTextMime) == 0 ) {
 140     nsCOMPtr<nsISupportsCString> plainText ( do_QueryInterface(aPrimitive) );
 141     if ( plainText ) {
 142       nsCAutoString data;
 143       plainText->GetData ( data );
 144       *aDataBuff = ToNewCString(data);
 145     }
 146   }
 147   else {
 148     nsCOMPtr<nsISupportsString> doubleByteText ( do_QueryInterface(aPrimitive) );
 149     if ( doubleByteText ) {
 150       nsAutoString data;
 151       doubleByteText->GetData ( data );
 152       *aDataBuff = ToNewUnicode(data);
 153     }
 154   }
 155
 156 }
 157
 158
 159 //
 160 // ConvertUnicodeToPlatformPlainText
 161 //
 162 // Given a unicode buffer (flavor text/unicode), this converts it to plain text using
 163 // the appropriate platform charset encoding. |inUnicodeLen| is the length of the input
 164 // string, not the # of bytes in the buffer. The |outPlainTextData| is null terminated,
 165 // but its length parameter, |outPlainTextLen|, does not reflect that.
 166 //
 167 nsresult
 168 nsPrimitiveHelpers :: ConvertUnicodeToPlatformPlainText ( PRUnichar* inUnicode, PRInt32 inUnicodeLen,
 169                                                             char** outPlainTextData, PRInt32* outPlainTextLen )
 170 {
 171   if ( !outPlainTextData || !outPlainTextLen )
 172     return NS_ERROR_INVALID_ARG;
 173
 174   // get the charset
 175   nsresult rv;
 176   nsCOMPtr <nsIPlatformCharset> platformCharsetService = do_GetService(NS_PLATFORMCHARSET_CONTRACTID, &rv);
 177
 178   nsCAutoString platformCharset;
 179   if (NS_SUCCEEDED(rv))
 180     rv = platformCharsetService->GetCharset(kPlatformCharsetSel_PlainTextInClipboard, platformCharset);
 181   if (NS_FAILED(rv))
 182     platformCharset.AssignLiteral("ISO-8859-1");
 183
 184   // use transliterate to convert things like smart quotes to normal quotes for plain text
 185
 186   nsCOMPtr<nsISaveAsCharset> converter = do_CreateInstance("@mozilla.org/intl/saveascharset;1", &rv);
 187   NS_ENSURE_SUCCESS(rv, rv);
 188
 189   rv = converter->Init(platformCharset.get(),
 190                   nsISaveAsCharset::attr_EntityAfterCharsetConv +
 191                   nsISaveAsCharset::attr_FallbackQuestionMark,
 192                   nsIEntityConverter::transliterate);
 193   NS_ENSURE_SUCCESS(rv, rv);
 194
 195   rv = converter->Convert(inUnicode, outPlainTextData);
 196   *outPlainTextLen = *outPlainTextData ? strlen(*outPlainTextData) : 0;
 197
 198   NS_ASSERTION ( NS_SUCCEEDED(rv), "Error converting unicode to plain text" );
 199
 200   return rv;
 201 } // ConvertUnicodeToPlatformPlainText
 202
 203
 204 //
 205 // ConvertPlatformPlainTextToUnicode
 206 //
 207 // Given a char buffer (flavor text/plaikn), this converts it to unicode using
 208 // the appropriate platform charset encoding. |outUnicode| is null terminated,
 209 // but its length parameter, |outUnicodeLen|, does not reflect that. |outUnicodeLen| is
 210 // the length of the string in characters, not bytes.
 211 //
 212 nsresult
 213 nsPrimitiveHelpers :: ConvertPlatformPlainTextToUnicode ( const char* inText, PRInt32 inTextLen,
 214                                                             PRUnichar** outUnicode, PRInt32* outUnicodeLen )
 215 {
 216   if ( !outUnicode || !outUnicodeLen )
 217     return NS_ERROR_INVALID_ARG;
 218
 219   // Get the appropriate unicode decoder. We're guaranteed that this won't change
 220   // through the life of the app so we can cache it.
 221   nsresult rv = NS_OK;
 222   static nsCOMPtr<nsIUnicodeDecoder> decoder;
 223   static PRBool hasConverter = PR_FALSE;
 224   if ( !hasConverter ) {
 225     // get the charset
 226     nsCAutoString platformCharset;
 227     nsCOMPtr <nsIPlatformCharset> platformCharsetService = do_GetService(NS_PLATFORMCHARSET_CONTRACTID, &rv);
 228     if (NS_SUCCEEDED(rv))
 229       rv = platformCharsetService->GetCharset(kPlatformCharsetSel_PlainTextInClipboard, platformCharset);
 230     if (NS_FAILED(rv))
 231       platformCharset.AssignLiteral("ISO-8859-1");
 232
 233     // get the decoder
 234     nsCOMPtr<nsICharsetConverterManager> ccm =
 235              do_GetService(NS_CHARSETCONVERTERMANAGER_CONTRACTID, &rv);
 236     rv = ccm->GetUnicodeDecoderRaw(platformCharset.get(),
 237                                    getter_AddRefs(decoder));
 238
 239     NS_ASSERTION(NS_SUCCEEDED(rv), "GetUnicodeEncoderRaw failed.");
 240     if (NS_FAILED(rv))
 241       return NS_ERROR_FAILURE;
 242
 243     hasConverter = PR_TRUE;
 244   }
 245
 246   // Estimate out length and allocate the buffer based on a worst-case estimate, then do
 247   // the conversion.
 248   decoder->GetMaxLength(inText, inTextLen, outUnicodeLen);   // |outUnicodeLen| is number of chars
 249   if ( *outUnicodeLen ) {
 250     *outUnicode = reinterpret_cast<PRUnichar*>(nsMemory::Alloc((*outUnicodeLen + 1) * sizeof(PRUnichar)));
 251     if ( *outUnicode ) {
 252       rv = decoder->Convert(inText, &inTextLen, *outUnicode, outUnicodeLen);
 253       (*outUnicode)[*outUnicodeLen] = '\0';                   // null terminate. Convert() doesn't do it for us
 254     }
 255   } // if valid length
 256
 257   NS_ASSERTION ( NS_SUCCEEDED(rv), "Error converting plain text to unicode" );
 258
 259   return rv;
 260 } // ConvertPlatformPlainTextToUnicode
 261
 262
 263 #ifdef XP_MAC
 264 #pragma mark -
 265 #endif
 266
 267
 268 //
 269 // ConvertPlatformToDOMLinebreaks
 270 //
 271 // Given some data, convert from the platform linebreaks into the LF expected by the
 272 // DOM. This will attempt to convert the data in place, but the buffer may still need to
 273 // be reallocated regardless (disposing the old buffer is taken care of internally, see
 274 // the note below).
 275 //
 276 // NOTE: this assumes that it can use nsMemory to dispose of the old buffer.
 277 //
 278 nsresult
 279 nsLinebreakHelpers :: ConvertPlatformToDOMLinebreaks ( const char* inFlavor, void** ioData,
 280                                                           PRInt32* ioLengthInBytes )
 281 {
 282   NS_ASSERTION ( ioData && *ioData && ioLengthInBytes, "Bad Params");
 283   if ( !(ioData && *ioData && ioLengthInBytes) )
 284     return NS_ERROR_INVALID_ARG;
 285
 286   nsresult retVal = NS_OK;
 287
 288   if ( strcmp(inFlavor, "text/plain") == 0 ) {
 289     char* buffAsChars = reinterpret_cast<char*>(*ioData);
 290     char* oldBuffer = buffAsChars;
 291     retVal = nsLinebreakConverter::ConvertLineBreaksInSitu ( &buffAsChars, nsLinebreakConverter::eLinebreakAny,
 292                                                               nsLinebreakConverter::eLinebreakContent,
 293                                                               *ioLengthInBytes, ioLengthInBytes );
 294     if ( NS_SUCCEEDED(retVal) ) {
 295       if ( buffAsChars != oldBuffer )             // check if buffer was reallocated
 296         nsMemory::Free ( oldBuffer );
 297       *ioData = buffAsChars;
 298     }
 299   }
 300   else if ( strcmp(inFlavor, "image/jpeg") == 0 ) {
 301     // I'd assume we don't want to do anything for binary data....
 302   }
 303   else {
 304     PRUnichar* buffAsUnichar = reinterpret_cast<PRUnichar*>(*ioData);
 305     PRUnichar* oldBuffer = buffAsUnichar;
 306     PRInt32 newLengthInChars;
 307     retVal = nsLinebreakConverter::ConvertUnicharLineBreaksInSitu ( &buffAsUnichar, nsLinebreakConverter::eLinebreakAny,
 308                                                                      nsLinebreakConverter::eLinebreakContent,
 309                                                                      *ioLengthInBytes / sizeof(PRUnichar), &newLengthInChars );
 310     if ( NS_SUCCEEDED(retVal) ) {
 311       if ( buffAsUnichar != oldBuffer )           // check if buffer was reallocated
 312         nsMemory::Free ( oldBuffer );
 313       *ioData = buffAsUnichar;
 314       *ioLengthInBytes = newLengthInChars * sizeof(PRUnichar);
 315     }
 316   }
 317
 318   return retVal;
 319
 320 } // ConvertPlatformToDOMLinebreaks