accessible/generic/ImageAccessible.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 "ImageAccessible.h"
   7
   8 #include "nsAccUtils.h"
   9 #include "Role.h"
  10 #include "AccIterator.h"
  11 #include "States.h"
  12
  13 #include "imgIContainer.h"
  14 #include "imgIRequest.h"
  15 #include "nsGenericHTMLElement.h"
  16 #include "nsIDocument.h"
  17 #include "nsIImageLoadingContent.h"
  18 #include "nsIPresShell.h"
  19 #include "nsIServiceManager.h"
  20 #include "nsIDOMHTMLImageElement.h"
  21 #include "nsIPersistentProperties2.h"
  22 #include "nsPIDOMWindow.h"
  23 #include "nsIURI.h"
  24
  25 using namespace mozilla::a11y;
  26
  27 ////////////////////////////////////////////////////////////////////////////////
  28 // ImageAccessible
  29 ////////////////////////////////////////////////////////////////////////////////
  30
  31 ImageAccessible::
  32   ImageAccessible(nsIContent* aContent, DocAccessible* aDoc) :
  33   LinkableAccessible(aContent, aDoc)
  34 {
  35   mType = eImageType;
  36 }
  37
  38 ImageAccessible::~ImageAccessible()
  39 {
  40 }
  41
  42 NS_IMPL_ISUPPORTS_INHERITED(ImageAccessible, Accessible,
  43                             nsIAccessibleImage)
  44
  45 ////////////////////////////////////////////////////////////////////////////////
  46 // Accessible public
  47
  48 uint64_t
  49 ImageAccessible::NativeState()
  50 {
  51   // The state is a bitfield, get our inherited state, then logically OR it with
  52   // states::ANIMATED if this is an animated image.
  53
  54   uint64_t state = LinkableAccessible::NativeState();
  55
  56   nsCOMPtr<nsIImageLoadingContent> content(do_QueryInterface(mContent));
  57   nsCOMPtr<imgIRequest> imageRequest;
  58
  59   if (content)
  60     content->GetRequest(nsIImageLoadingContent::CURRENT_REQUEST,
  61                         getter_AddRefs(imageRequest));
  62
  63   nsCOMPtr<imgIContainer> imgContainer;
  64   if (imageRequest)
  65     imageRequest->GetImage(getter_AddRefs(imgContainer));
  66
  67   if (imgContainer) {
  68     bool animated;
  69     imgContainer->GetAnimated(&animated);
  70     if (animated)
  71       state |= states::ANIMATED;
  72   }
  73
  74   return state;
  75 }
  76
  77 ENameValueFlag
  78 ImageAccessible::NativeName(nsString& aName)
  79 {
  80   bool hasAltAttrib =
  81     mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::alt, aName);
  82   if (!aName.IsEmpty())
  83     return eNameOK;
  84
  85   ENameValueFlag nameFlag = Accessible::NativeName(aName);
  86   if (!aName.IsEmpty())
  87     return nameFlag;
  88
  89   // No accessible name but empty 'alt' attribute is present. If further name
  90   // computation algorithm doesn't provide non empty name then it means
  91   // an empty 'alt' attribute was used to indicate a decorative image (see
  92   // Accessible::Name() method for details).
  93   return hasAltAttrib ? eNoNameOnPurpose : eNameOK;
  94 }
  95
  96 role
  97 ImageAccessible::NativeRole()
  98 {
  99   return roles::GRAPHIC;
 100 }
 101
 102 ////////////////////////////////////////////////////////////////////////////////
 103 // nsIAccessible
 104
 105 uint8_t
 106 ImageAccessible::ActionCount()
 107 {
 108   uint8_t actionCount = LinkableAccessible::ActionCount();
 109   return HasLongDesc() ? actionCount + 1 : actionCount;
 110 }
 111
 112 NS_IMETHODIMP
 113 ImageAccessible::GetActionName(uint8_t aIndex, nsAString& aName)
 114 {
 115   aName.Truncate();
 116
 117   if (IsDefunct())
 118     return NS_ERROR_FAILURE;
 119
 120   if (IsLongDescIndex(aIndex) && HasLongDesc()) {
 121     aName.AssignLiteral("showlongdesc");
 122     return NS_OK;
 123   }
 124   return LinkableAccessible::GetActionName(aIndex, aName);
 125 }
 126
 127 NS_IMETHODIMP
 128 ImageAccessible::DoAction(uint8_t aIndex)
 129 {
 130   if (IsDefunct())
 131     return NS_ERROR_FAILURE;
 132
 133   // Get the long description uri and open in a new window.
 134   if (!IsLongDescIndex(aIndex))
 135     return LinkableAccessible::DoAction(aIndex);
 136
 137   nsCOMPtr<nsIURI> uri = GetLongDescURI();
 138   if (!uri)
 139     return NS_ERROR_INVALID_ARG;
 140
 141   nsAutoCString utf8spec;
 142   uri->GetSpec(utf8spec);
 143   NS_ConvertUTF8toUTF16 spec(utf8spec);
 144
 145   nsIDocument* document = mContent->OwnerDoc();
 146   nsCOMPtr<nsPIDOMWindow> piWindow = document->GetWindow();
 147   nsCOMPtr<nsIDOMWindow> win = do_QueryInterface(piWindow);
 148   NS_ENSURE_STATE(win);
 149
 150   nsCOMPtr<nsIDOMWindow> tmp;
 151   return win->Open(spec, EmptyString(), EmptyString(),
 152                    getter_AddRefs(tmp));
 153 }
 154
 155 ////////////////////////////////////////////////////////////////////////////////
 156 // nsIAccessibleImage
 157
 158 NS_IMETHODIMP
 159 ImageAccessible::GetImagePosition(uint32_t aCoordType, int32_t* aX, int32_t* aY)
 160 {
 161   int32_t width, height;
 162   nsresult rv = GetBounds(aX, aY, &width, &height);
 163   if (NS_FAILED(rv))
 164     return rv;
 165
 166   nsAccUtils::ConvertScreenCoordsTo(aX, aY, aCoordType, this);
 167   return NS_OK;
 168 }
 169
 170 NS_IMETHODIMP
 171 ImageAccessible::GetImageSize(int32_t* aWidth, int32_t* aHeight)
 172 {
 173   int32_t x, y;
 174   return GetBounds(&x, &y, aWidth, aHeight);
 175 }
 176
 177 // Accessible
 178 already_AddRefed<nsIPersistentProperties>
 179 ImageAccessible::NativeAttributes()
 180 {
 181   nsCOMPtr<nsIPersistentProperties> attributes =
 182     LinkableAccessible::NativeAttributes();
 183
 184   nsAutoString src;
 185   mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::src, src);
 186   if (!src.IsEmpty())
 187     nsAccUtils::SetAccAttr(attributes, nsGkAtoms::src, src);
 188
 189   return attributes.forget();
 190 }
 191
 192 ////////////////////////////////////////////////////////////////////////////////
 193 // Private methods
 194
 195 already_AddRefed<nsIURI>
 196 ImageAccessible::GetLongDescURI() const
 197 {
 198   if (mContent->HasAttr(kNameSpaceID_None, nsGkAtoms::longdesc)) {
 199     nsGenericHTMLElement* element =
 200       nsGenericHTMLElement::FromContent(mContent);
 201     if (element) {
 202       nsCOMPtr<nsIURI> uri;
 203       element->GetURIAttr(nsGkAtoms::longdesc, nullptr, getter_AddRefs(uri));
 204       return uri.forget();
 205     }
 206   }
 207
 208   DocAccessible* document = Document();
 209   if (document) {
 210     IDRefsIterator iter(document, mContent, nsGkAtoms::aria_describedby);
 211     while (nsIContent* target = iter.NextElem()) {
 212       if ((target->IsHTML(nsGkAtoms::a) || target->IsHTML(nsGkAtoms::area)) &&
 213           target->HasAttr(kNameSpaceID_None, nsGkAtoms::href)) {
 214         nsGenericHTMLElement* element =
 215           nsGenericHTMLElement::FromContent(target);
 216
 217         nsCOMPtr<nsIURI> uri;
 218         element->GetURIAttr(nsGkAtoms::href, nullptr, getter_AddRefs(uri));
 219         return uri.forget();
 220       }
 221     }
 222   }
 223
 224   return nullptr;
 225 }
 226
 227 bool
 228 ImageAccessible::IsLongDescIndex(uint8_t aIndex)
 229 {
 230   return aIndex == LinkableAccessible::ActionCount();
 231 }
 232