widget/nsHTMLFormatConverter.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "nsHTMLFormatConverter.h"
   7
   8 #include "nsArray.h"
   9 #include "nsCRT.h"
  10 #include "nsIComponentManager.h"
  11 #include "nsCOMPtr.h"
  12 #include "nsXPCOM.h"
  13 #include "nsISupportsPrimitives.h"
  14
  15 #include "nsITransferable.h" // for mime defs, this is BAD
  16
  17 // HTML convertor stuff
  18 #include "nsPrimitiveHelpers.h"
  19 #include "nsIDocumentEncoder.h"
  20 #include "nsContentUtils.h"
  21
  22 nsHTMLFormatConverter::nsHTMLFormatConverter()
  23 {
  24 }
  25
  26 nsHTMLFormatConverter::~nsHTMLFormatConverter()
  27 {
  28 }
  29
  30 NS_IMPL_ISUPPORTS(nsHTMLFormatConverter, nsIFormatConverter)
  31
  32 //
  33 // GetInputDataFlavors
  34 //
  35 // Creates a new list and returns the list of all the flavors this converter
  36 // knows how to import. In this case, it's just HTML.
  37 //
  38 // Flavors (strings) are wrapped in a primitive object so that JavaScript can
  39 // access them easily via XPConnect.
  40 //
  41 NS_IMETHODIMP
  42 nsHTMLFormatConverter::GetInputDataFlavors(nsIArray **_retval)
  43 {
  44   if ( !_retval )
  45     return NS_ERROR_INVALID_ARG;
  46
  47   nsCOMPtr<nsIMutableArray> array = nsArray::Create();
  48   nsresult rv = AddFlavorToList ( array, kHTMLMime );
  49
  50   array.forget(_retval);
  51   return rv;
  52
  53 } // GetInputDataFlavors
  54
  55
  56 //
  57 // GetOutputDataFlavors
  58 //
  59 // Creates a new list and returns the list of all the flavors this converter
  60 // knows how to export (convert). In this case, it's all sorts of things that HTML can be
  61 // converted to.
  62 //
  63 // Flavors (strings) are wrapped in a primitive object so that JavaScript can
  64 // access them easily via XPConnect.
  65 //
  66 NS_IMETHODIMP
  67 nsHTMLFormatConverter::GetOutputDataFlavors(nsIArray **_retval)
  68 {
  69   if ( !_retval )
  70     return NS_ERROR_INVALID_ARG;
  71
  72   nsCOMPtr<nsIMutableArray> array = nsArray::Create();
  73   nsresult rv = AddFlavorToList ( array, kHTMLMime );
  74   if ( NS_FAILED(rv) )
  75     return rv;
  76   rv = AddFlavorToList ( array, kUnicodeMime );
  77   if ( NS_FAILED(rv) )
  78     return rv;
  79
  80   array.forget(_retval);
  81   return rv;
  82
  83 } // GetOutputDataFlavors
  84
  85
  86 //
  87 // AddFlavorToList
  88 //
  89 // Convenience routine for adding a flavor wrapped in an nsISupportsCString object
  90 // to a list
  91 //
  92 nsresult
  93 nsHTMLFormatConverter :: AddFlavorToList ( nsCOMPtr<nsIMutableArray>& inList, const char* inFlavor )
  94 {
  95   nsresult rv;
  96
  97   nsCOMPtr<nsISupportsCString> dataFlavor =
  98       do_CreateInstance(NS_SUPPORTS_CSTRING_CONTRACTID, &rv);
  99   if ( dataFlavor ) {
 100     dataFlavor->SetData ( nsDependentCString(inFlavor) );
 101     // add to list as an nsISupports so the correct interface gets the addref
 102     // in AppendElement()
 103     nsCOMPtr<nsISupports> genericFlavor ( do_QueryInterface(dataFlavor) );
 104     inList->AppendElement ( genericFlavor, /*weak =*/ false);
 105   }
 106   return rv;
 107
 108 } // AddFlavorToList
 109
 110
 111 //
 112 // CanConvert
 113 //
 114 // Determines if we support the given conversion. Currently, this method only
 115 // converts from HTML to others.
 116 //
 117 NS_IMETHODIMP
 118 nsHTMLFormatConverter::CanConvert(const char *aFromDataFlavor, const char *aToDataFlavor, bool *_retval)
 119 {
 120   if ( !_retval )
 121     return NS_ERROR_INVALID_ARG;
 122
 123   *_retval = false;
 124   if ( !nsCRT::strcmp(aFromDataFlavor, kHTMLMime) ) {
 125     if ( !nsCRT::strcmp(aToDataFlavor, kHTMLMime) )
 126       *_retval = true;
 127     else if ( !nsCRT::strcmp(aToDataFlavor, kUnicodeMime) )
 128       *_retval = true;
 129 #if NOT_NOW
 130 // pinkerton
 131 // no one uses this flavor right now, so it's just slowing things down. If anyone cares I
 132 // can put it back in.
 133     else if ( toFlavor.Equals(kAOLMailMime) )
 134       *_retval = true;
 135 #endif
 136   }
 137   return NS_OK;
 138
 139 } // CanConvert
 140
 141
 142
 143 //
 144 // Convert
 145 //
 146 // Convert data from one flavor to another. The data is wrapped in primitive objects so that it is
 147 // accessible from JS. Currently, this only accepts HTML input, so anything else is invalid.
 148 //
 149 //XXX This method copies the data WAAAAY too many time for my liking. Grrrrrr. Mostly it's because
 150 //XXX we _must_ put things into nsStrings so that the parser will accept it. Lame lame lame lame. We
 151 //XXX also can't just get raw unicode out of the nsString, so we have to allocate heap to get
 152 //XXX unicode out of the string. Lame lame lame.
 153 //
 154 NS_IMETHODIMP
 155 nsHTMLFormatConverter::Convert(const char *aFromDataFlavor, nsISupports *aFromData, uint32_t aDataLen,
 156                                const char *aToDataFlavor, nsISupports **aToData, uint32_t *aDataToLen)
 157 {
 158   if ( !aToData || !aDataToLen )
 159     return NS_ERROR_INVALID_ARG;
 160
 161   nsresult rv = NS_OK;
 162   *aToData = nullptr;
 163   *aDataToLen = 0;
 164
 165   if ( !nsCRT::strcmp(aFromDataFlavor, kHTMLMime) ) {
 166     nsAutoCString toFlavor ( aToDataFlavor );
 167
 168     // HTML on clipboard is going to always be double byte so it will be in a primitive
 169     // class of nsISupportsString. Also, since the data is in two byte chunks the
 170     // length represents the length in 1-byte chars, so we need to divide by two.
 171     nsCOMPtr<nsISupportsString> dataWrapper0 ( do_QueryInterface(aFromData) );
 172     if (!dataWrapper0) {
 173       return NS_ERROR_INVALID_ARG;
 174     }
 175
 176     nsAutoString dataStr;
 177     dataWrapper0->GetData ( dataStr );  // COPY #1
 178     // note: conversion to text/plain is done inside the clipboard. we do not need to worry
 179     // about it here.
 180     if ( toFlavor.Equals(kHTMLMime) || toFlavor.Equals(kUnicodeMime) ) {
 181       nsresult res;
 182       if (toFlavor.Equals(kHTMLMime)) {
 183         int32_t dataLen = dataStr.Length() * 2;
 184         nsPrimitiveHelpers::CreatePrimitiveForData ( toFlavor.get(), dataStr.get(), dataLen, aToData );
 185         if ( *aToData )
 186           *aDataToLen = dataLen;
 187       } else {
 188         nsAutoString outStr;
 189         res = ConvertFromHTMLToUnicode(dataStr, outStr);
 190         if (NS_SUCCEEDED(res)) {
 191           int32_t dataLen = outStr.Length() * 2;
 192           nsPrimitiveHelpers::CreatePrimitiveForData ( toFlavor.get(), outStr.get(), dataLen, aToData );
 193           if ( *aToData )
 194             *aDataToLen = dataLen;
 195         }
 196       }
 197     } // else if HTML or Unicode
 198     else if ( toFlavor.Equals(kAOLMailMime) ) {
 199       nsAutoString outStr;
 200       if ( NS_SUCCEEDED(ConvertFromHTMLToAOLMail(dataStr, outStr)) ) {
 201         int32_t dataLen = outStr.Length() * 2;
 202         nsPrimitiveHelpers::CreatePrimitiveForData ( toFlavor.get(), outStr.get(), dataLen, aToData );
 203         if ( *aToData )
 204           *aDataToLen = dataLen;
 205       }
 206     } // else if AOL mail
 207     else {
 208       rv = NS_ERROR_FAILURE;
 209     }
 210   } // if we got html mime
 211   else
 212     rv = NS_ERROR_FAILURE;
 213
 214   return rv;
 215
 216 } // Convert
 217
 218
 219 //
 220 // ConvertFromHTMLToUnicode
 221 //
 222 // Takes HTML and converts it to plain text but in unicode.
 223 //
 224 NS_IMETHODIMP
 225 nsHTMLFormatConverter::ConvertFromHTMLToUnicode(const nsAutoString & aFromStr, nsAutoString & aToStr)
 226 {
 227   return nsContentUtils::ConvertToPlainText(aFromStr,
 228     aToStr,
 229     nsIDocumentEncoder::OutputSelectionOnly |
 230     nsIDocumentEncoder::OutputAbsoluteLinks |
 231     nsIDocumentEncoder::OutputNoScriptContent |
 232     nsIDocumentEncoder::OutputNoFramesContent,
 233     0);
 234 } // ConvertFromHTMLToUnicode
 235
 236
 237 NS_IMETHODIMP
 238 nsHTMLFormatConverter::ConvertFromHTMLToAOLMail(const nsAutoString & aFromStr,
 239                                                 nsAutoString & aToStr)
 240 {
 241   aToStr.AssignLiteral("<HTML>");
 242   aToStr.Append(aFromStr);
 243   aToStr.AppendLiteral("</HTML>");
 244
 245   return NS_OK;
 246 }
 247