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 "nsCOMPtr.h"
  11 #include "nsXPCOM.h"
  12 #include "nsISupportsPrimitives.h"
  13
  14 // HTML convertor stuff
  15 #include "nsPrimitiveHelpers.h"
  16 #include "nsIDocumentEncoder.h"
  17 #include "nsContentUtils.h"
  18
  19 nsHTMLFormatConverter::nsHTMLFormatConverter() {}
  20
  21 nsHTMLFormatConverter::~nsHTMLFormatConverter() {}
  22
  23 NS_IMPL_ISUPPORTS(nsHTMLFormatConverter, nsIFormatConverter)
  24
  25 //
  26 // GetInputDataFlavors
  27 //
  28 // Creates a new list and returns the list of all the flavors this converter
  29 // knows how to import. In this case, it's just HTML.
  30 //
  31 NS_IMETHODIMP
  32 nsHTMLFormatConverter::GetInputDataFlavors(nsTArray<nsCString>& aFlavors) {
  33   aFlavors.AppendElement(NS_LITERAL_CSTRING(kHTMLMime));
  34   return NS_OK;
  35 }
  36
  37 //
  38 // GetOutputDataFlavors
  39 //
  40 // Creates a new list and returns the list of all the flavors this converter
  41 // knows how to export (convert). In this case, it's all sorts of things that
  42 // HTML can be converted to.
  43 //
  44 NS_IMETHODIMP
  45 nsHTMLFormatConverter::GetOutputDataFlavors(nsTArray<nsCString>& aFlavors) {
  46   aFlavors.AppendElement(NS_LITERAL_CSTRING(kHTMLMime));
  47   aFlavors.AppendElement(NS_LITERAL_CSTRING(kUnicodeMime));
  48   return NS_OK;
  49 }
  50
  51 //
  52 // CanConvert
  53 //
  54 // Determines if we support the given conversion. Currently, this method only
  55 // converts from HTML to others.
  56 //
  57 NS_IMETHODIMP
  58 nsHTMLFormatConverter::CanConvert(const char* aFromDataFlavor,
  59                                   const char* aToDataFlavor, bool* _retval) {
  60   if (!_retval) return NS_ERROR_INVALID_ARG;
  61
  62   *_retval = false;
  63   if (!nsCRT::strcmp(aFromDataFlavor, kHTMLMime)) {
  64     if (!nsCRT::strcmp(aToDataFlavor, kHTMLMime))
  65       *_retval = true;
  66     else if (!nsCRT::strcmp(aToDataFlavor, kUnicodeMime))
  67       *_retval = true;
  68 #if NOT_NOW
  69     // pinkerton
  70     // no one uses this flavor right now, so it's just slowing things down. If
  71     // anyone cares I can put it back in.
  72     else if (toFlavor.Equals(kAOLMailMime))
  73       *_retval = true;
  74 #endif
  75   }
  76   return NS_OK;
  77
  78 }  // CanConvert
  79
  80 //
  81 // Convert
  82 //
  83 // Convert data from one flavor to another. The data is wrapped in primitive
  84 // objects so that it is accessible from JS. Currently, this only accepts HTML
  85 // input, so anything else is invalid.
  86 //
  87 // XXX This method copies the data WAAAAY too many time for my liking. Grrrrrr.
  88 // Mostly it's because
  89 // XXX we _must_ put things into nsStrings so that the parser will accept it.
  90 // Lame lame lame lame. We
  91 // XXX also can't just get raw unicode out of the nsString, so we have to
  92 // allocate heap to get
  93 // XXX unicode out of the string. Lame lame lame.
  94 //
  95 NS_IMETHODIMP
  96 nsHTMLFormatConverter::Convert(const char* aFromDataFlavor,
  97                                nsISupports* aFromData,
  98                                const char* aToDataFlavor,
  99                                nsISupports** aToData) {
 100   if (!aToData) return NS_ERROR_INVALID_ARG;
 101
 102   nsresult rv = NS_OK;
 103   *aToData = nullptr;
 104
 105   if (!nsCRT::strcmp(aFromDataFlavor, kHTMLMime)) {
 106     nsAutoCString toFlavor(aToDataFlavor);
 107
 108     // HTML on clipboard is going to always be double byte so it will be in a
 109     // primitive class of nsISupportsString. Also, since the data is in two byte
 110     // chunks the length represents the length in 1-byte chars, so we need to
 111     // divide by two.
 112     nsCOMPtr<nsISupportsString> dataWrapper0(do_QueryInterface(aFromData));
 113     if (!dataWrapper0) {
 114       return NS_ERROR_INVALID_ARG;
 115     }
 116
 117     nsAutoString dataStr;
 118     dataWrapper0->GetData(dataStr);  // COPY #1
 119     // note: conversion to text/plain is done inside the clipboard. we do not
 120     // need to worry about it here.
 121     if (toFlavor.Equals(kHTMLMime) || toFlavor.Equals(kUnicodeMime)) {
 122       nsresult res;
 123       if (toFlavor.Equals(kHTMLMime)) {
 124         int32_t dataLen = dataStr.Length() * 2;
 125         nsPrimitiveHelpers::CreatePrimitiveForData(toFlavor, dataStr.get(),
 126                                                    dataLen, aToData);
 127       } else {
 128         nsAutoString outStr;
 129         res = ConvertFromHTMLToUnicode(dataStr, outStr);
 130         if (NS_SUCCEEDED(res)) {
 131           int32_t dataLen = outStr.Length() * 2;
 132           nsPrimitiveHelpers::CreatePrimitiveForData(toFlavor, outStr.get(),
 133                                                      dataLen, aToData);
 134         }
 135       }
 136     }  // else if HTML or Unicode
 137     else if (toFlavor.Equals(kAOLMailMime)) {
 138       nsAutoString outStr;
 139       if (NS_SUCCEEDED(ConvertFromHTMLToAOLMail(dataStr, outStr))) {
 140         int32_t dataLen = outStr.Length() * 2;
 141         nsPrimitiveHelpers::CreatePrimitiveForData(toFlavor, outStr.get(),
 142                                                    dataLen, aToData);
 143       }
 144     }  // else if AOL mail
 145     else {
 146       rv = NS_ERROR_FAILURE;
 147     }
 148   }  // if we got html mime
 149   else
 150     rv = NS_ERROR_FAILURE;
 151
 152   return rv;
 153
 154 }  // Convert
 155
 156 //
 157 // ConvertFromHTMLToUnicode
 158 //
 159 // Takes HTML and converts it to plain text but in unicode.
 160 //
 161 NS_IMETHODIMP
 162 nsHTMLFormatConverter::ConvertFromHTMLToUnicode(const nsAutoString& aFromStr,
 163                                                 nsAutoString& aToStr) {
 164   return nsContentUtils::ConvertToPlainText(
 165       aFromStr, aToStr,
 166       nsIDocumentEncoder::OutputSelectionOnly |
 167           nsIDocumentEncoder::OutputAbsoluteLinks |
 168           nsIDocumentEncoder::OutputNoScriptContent |
 169           nsIDocumentEncoder::OutputNoFramesContent,
 170       0);
 171 }  // ConvertFromHTMLToUnicode
 172
 173 NS_IMETHODIMP
 174 nsHTMLFormatConverter::ConvertFromHTMLToAOLMail(const nsAutoString& aFromStr,
 175                                                 nsAutoString& aToStr) {
 176   aToStr.AssignLiteral("<HTML>");
 177   aToStr.Append(aFromStr);
 178   aToStr.AppendLiteral("</HTML>");
 179
 180   return NS_OK;
 181 }