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(kTextMime));
  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, kTextMime)) {
  69       *_retval = true;
  70     }
  71 #if NOT_NOW
  72     // pinkerton
  73     // no one uses this flavor right now, so it's just slowing things down. If
  74     // anyone cares I can put it back in.
  75     else if (toFlavor.Equals(kAOLMailMime))
  76       *_retval = true;
  77 #endif
  78   }
  79   return NS_OK;
  80
  81 }  // CanConvert
  82
  83 //
  84 // Convert
  85 //
  86 // Convert data from one flavor to another. The data is wrapped in primitive
  87 // objects so that it is accessible from JS. Currently, this only accepts HTML
  88 // input, so anything else is invalid.
  89 //
  90 // XXX This method copies the data WAAAAY too many time for my liking. Grrrrrr.
  91 // Mostly it's because
  92 // XXX we _must_ put things into nsStrings so that the parser will accept it.
  93 // Lame lame lame lame. We
  94 // XXX also can't just get raw unicode out of the nsString, so we have to
  95 // allocate heap to get
  96 // XXX unicode out of the string. Lame lame lame.
  97 //
  98 NS_IMETHODIMP
  99 nsHTMLFormatConverter::Convert(const char* aFromDataFlavor,
 100                                nsISupports* aFromData,
 101                                const char* aToDataFlavor,
 102                                nsISupports** aToData) {
 103   if (!aToData) return NS_ERROR_INVALID_ARG;
 104
 105   nsresult rv = NS_OK;
 106   *aToData = nullptr;
 107
 108   if (!nsCRT::strcmp(aFromDataFlavor, kHTMLMime)) {
 109     nsAutoCString toFlavor(aToDataFlavor);
 110
 111     // HTML on clipboard is going to always be double byte so it will be in a
 112     // primitive class of nsISupportsString. Also, since the data is in two byte
 113     // chunks the length represents the length in 1-byte chars, so we need to
 114     // divide by two.
 115     nsCOMPtr<nsISupportsString> dataWrapper0(do_QueryInterface(aFromData));
 116     if (!dataWrapper0) {
 117       return NS_ERROR_INVALID_ARG;
 118     }
 119
 120     nsAutoString dataStr;
 121     dataWrapper0->GetData(dataStr);  // COPY #1
 122     // note: conversion to text/plain is done inside the clipboard. we do not
 123     // need to worry about it here.
 124     if (toFlavor.Equals(kHTMLMime) || toFlavor.Equals(kTextMime)) {
 125       nsresult res;
 126       if (toFlavor.Equals(kHTMLMime)) {
 127         int32_t dataLen = dataStr.Length() * 2;
 128         nsPrimitiveHelpers::CreatePrimitiveForData(toFlavor, dataStr.get(),
 129                                                    dataLen, aToData);
 130       } else {
 131         nsAutoString outStr;
 132         res = ConvertFromHTMLToUnicode(dataStr, outStr);
 133         if (NS_SUCCEEDED(res)) {
 134           int32_t dataLen = outStr.Length() * 2;
 135           nsPrimitiveHelpers::CreatePrimitiveForData(toFlavor, outStr.get(),
 136                                                      dataLen, aToData);
 137         }
 138       }
 139     }  // else if HTML or Unicode
 140     else if (toFlavor.Equals(kAOLMailMime)) {
 141       nsAutoString outStr;
 142       if (NS_SUCCEEDED(ConvertFromHTMLToAOLMail(dataStr, outStr))) {
 143         int32_t dataLen = outStr.Length() * 2;
 144         nsPrimitiveHelpers::CreatePrimitiveForData(toFlavor, outStr.get(),
 145                                                    dataLen, aToData);
 146       }
 147     }  // else if AOL mail
 148     else {
 149       rv = NS_ERROR_FAILURE;
 150     }
 151   }  // if we got html mime
 152   else
 153     rv = NS_ERROR_FAILURE;
 154
 155   return rv;
 156
 157 }  // Convert
 158
 159 //
 160 // ConvertFromHTMLToUnicode
 161 //
 162 // Takes HTML and converts it to plain text but in unicode.
 163 //
 164 NS_IMETHODIMP
 165 nsHTMLFormatConverter::ConvertFromHTMLToUnicode(const nsAutoString& aFromStr,
 166                                                 nsAutoString& aToStr) {
 167   return nsContentUtils::ConvertToPlainText(
 168       aFromStr, aToStr,
 169       nsIDocumentEncoder::OutputSelectionOnly |
 170           nsIDocumentEncoder::OutputAbsoluteLinks |
 171           nsIDocumentEncoder::OutputNoScriptContent |
 172           nsIDocumentEncoder::OutputNoFramesContent,
 173       0);
 174 }  // ConvertFromHTMLToUnicode
 175
 176 NS_IMETHODIMP
 177 nsHTMLFormatConverter::ConvertFromHTMLToAOLMail(const nsAutoString& aFromStr,
 178                                                 nsAutoString& aToStr) {
 179   aToStr.AssignLiteral("<HTML>");
 180   aToStr.Append(aFromStr);
 181   aToStr.AppendLiteral("</HTML>");
 182
 183   return NS_OK;
 184 }