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 "nsITransferable.h"
  12 #include "nsLiteralString.h"
  13 #include "nsXPCOM.h"
  14 #include "nsISupportsPrimitives.h"
  15
  16 // HTML convertor stuff
  17 #include "nsPrimitiveHelpers.h"
  18 #include "nsIDocumentEncoder.h"
  19 #include "nsContentUtils.h"
  20
  21 nsHTMLFormatConverter::nsHTMLFormatConverter() = default;
  22
  23 nsHTMLFormatConverter::~nsHTMLFormatConverter() = default;
  24
  25 NS_IMPL_ISUPPORTS(nsHTMLFormatConverter, nsIFormatConverter)
  26
  27 //
  28 // GetInputDataFlavors
  29 //
  30 // Creates a new list and returns the list of all the flavors this converter
  31 // knows how to import. In this case, it's just HTML.
  32 //
  33 NS_IMETHODIMP
  34 nsHTMLFormatConverter::GetInputDataFlavors(nsTArray<nsCString>& aFlavors) {
  35   aFlavors.AppendElement(nsLiteralCString(kHTMLMime));
  36   return NS_OK;
  37 }
  38
  39 //
  40 // GetOutputDataFlavors
  41 //
  42 // Creates a new list and returns the list of all the flavors this converter
  43 // knows how to export (convert). In this case, it's all sorts of things that
  44 // HTML can be converted to.
  45 //
  46 NS_IMETHODIMP
  47 nsHTMLFormatConverter::GetOutputDataFlavors(nsTArray<nsCString>& aFlavors) {
  48   aFlavors.AppendElement(nsLiteralCString(kHTMLMime));
  49   aFlavors.AppendElement(nsLiteralCString(kUnicodeMime));
  50   return NS_OK;
  51 }
  52
  53 //
  54 // CanConvert
  55 //
  56 // Determines if we support the given conversion. Currently, this method only
  57 // converts from HTML to others.
  58 //
  59 NS_IMETHODIMP
  60 nsHTMLFormatConverter::CanConvert(const char* aFromDataFlavor,
  61                                   const char* aToDataFlavor, bool* _retval) {
  62   if (!_retval) return NS_ERROR_INVALID_ARG;
  63
  64   *_retval = false;
  65   if (!nsCRT::strcmp(aFromDataFlavor, kHTMLMime)) {
  66     if (!nsCRT::strcmp(aToDataFlavor, kHTMLMime))
  67       *_retval = true;
  68     else if (!nsCRT::strcmp(aToDataFlavor, kUnicodeMime))
  69       *_retval = true;
  70 #if NOT_NOW
  71     // pinkerton
  72     // no one uses this flavor right now, so it's just slowing things down. If
  73     // anyone cares I can put it back in.
  74     else if (toFlavor.Equals(kAOLMailMime))
  75       *_retval = true;
  76 #endif
  77   }
  78   return NS_OK;
  79
  80 }  // CanConvert
  81
  82 //
  83 // Convert
  84 //
  85 // Convert data from one flavor to another. The data is wrapped in primitive
  86 // objects so that it is accessible from JS. Currently, this only accepts HTML
  87 // input, so anything else is invalid.
  88 //
  89 // XXX This method copies the data WAAAAY too many time for my liking. Grrrrrr.
  90 // Mostly it's because
  91 // XXX we _must_ put things into nsStrings so that the parser will accept it.
  92 // Lame lame lame lame. We
  93 // XXX also can't just get raw unicode out of the nsString, so we have to
  94 // allocate heap to get
  95 // XXX unicode out of the string. Lame lame lame.
  96 //
  97 NS_IMETHODIMP
  98 nsHTMLFormatConverter::Convert(const char* aFromDataFlavor,
  99                                nsISupports* aFromData,
 100                                const char* aToDataFlavor,
 101                                nsISupports** aToData) {
 102   if (!aToData) return NS_ERROR_INVALID_ARG;
 103
 104   nsresult rv = NS_OK;
 105   *aToData = nullptr;
 106
 107   if (!nsCRT::strcmp(aFromDataFlavor, kHTMLMime)) {
 108     nsAutoCString toFlavor(aToDataFlavor);
 109
 110     // HTML on clipboard is going to always be double byte so it will be in a
 111     // primitive class of nsISupportsString. Also, since the data is in two byte
 112     // chunks the length represents the length in 1-byte chars, so we need to
 113     // divide by two.
 114     nsCOMPtr<nsISupportsString> dataWrapper0(do_QueryInterface(aFromData));
 115     if (!dataWrapper0) {
 116       return NS_ERROR_INVALID_ARG;
 117     }
 118
 119     nsAutoString dataStr;
 120     dataWrapper0->GetData(dataStr);  // COPY #1
 121     // note: conversion to text/plain is done inside the clipboard. we do not
 122     // need to worry about it here.
 123     if (toFlavor.Equals(kHTMLMime) || toFlavor.Equals(kUnicodeMime)) {
 124       nsresult res;
 125       if (toFlavor.Equals(kHTMLMime)) {
 126         int32_t dataLen = dataStr.Length() * 2;
 127         nsPrimitiveHelpers::CreatePrimitiveForData(toFlavor, dataStr.get(),
 128                                                    dataLen, aToData);
 129       } else {
 130         nsAutoString outStr;
 131         res = ConvertFromHTMLToUnicode(dataStr, outStr);
 132         if (NS_SUCCEEDED(res)) {
 133           int32_t dataLen = outStr.Length() * 2;
 134           nsPrimitiveHelpers::CreatePrimitiveForData(toFlavor, outStr.get(),
 135                                                      dataLen, aToData);
 136         }
 137       }
 138     }  // else if HTML or Unicode
 139     else if (toFlavor.Equals(kAOLMailMime)) {
 140       nsAutoString outStr;
 141       if (NS_SUCCEEDED(ConvertFromHTMLToAOLMail(dataStr, outStr))) {
 142         int32_t dataLen = outStr.Length() * 2;
 143         nsPrimitiveHelpers::CreatePrimitiveForData(toFlavor, outStr.get(),
 144                                                    dataLen, aToData);
 145       }
 146     }  // else if AOL mail
 147     else {
 148       rv = NS_ERROR_FAILURE;
 149     }
 150   }  // if we got html mime
 151   else
 152     rv = NS_ERROR_FAILURE;
 153
 154   return rv;
 155
 156 }  // Convert
 157
 158 //
 159 // ConvertFromHTMLToUnicode
 160 //
 161 // Takes HTML and converts it to plain text but in unicode.
 162 //
 163 NS_IMETHODIMP
 164 nsHTMLFormatConverter::ConvertFromHTMLToUnicode(const nsAutoString& aFromStr,
 165                                                 nsAutoString& aToStr) {
 166   return nsContentUtils::ConvertToPlainText(
 167       aFromStr, aToStr,
 168       nsIDocumentEncoder::OutputSelectionOnly |
 169           nsIDocumentEncoder::OutputAbsoluteLinks |
 170           nsIDocumentEncoder::OutputNoScriptContent |
 171           nsIDocumentEncoder::OutputNoFramesContent,
 172       0);
 173 }  // ConvertFromHTMLToUnicode
 174
 175 NS_IMETHODIMP
 176 nsHTMLFormatConverter::ConvertFromHTMLToAOLMail(const nsAutoString& aFromStr,
 177                                                 nsAutoString& aToStr) {
 178   aToStr.AssignLiteral("<HTML>");
 179   aToStr.Append(aFromStr);
 180   aToStr.AppendLiteral("</HTML>");
 181
 182   return NS_OK;
 183 }