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 "DocAccessible-inl.h"
   9 #include "LocalAccessible-inl.h"
  10 #include "nsAccUtils.h"
  11 #include "mozilla/a11y/Role.h"
  12 #include "AccAttributes.h"
  13 #include "AccIterator.h"
  14 #include "CacheConstants.h"
  15 #include "States.h"
  16
  17 #include "imgIRequest.h"
  18 #include "nsGenericHTMLElement.h"
  19 #include "mozilla/dom/BrowsingContext.h"
  20 #include "mozilla/dom/Document.h"
  21 #include "mozilla/dom/MutationEventBinding.h"
  22 #include "nsContentUtils.h"
  23 #include "nsIImageLoadingContent.h"
  24 #include "nsPIDOMWindow.h"
  25 #include "nsIURI.h"
  26
  27 namespace mozilla::a11y {
  28
  29 NS_IMPL_ISUPPORTS_INHERITED(ImageAccessible, LinkableAccessible,
  30                             imgINotificationObserver)
  31
  32 ////////////////////////////////////////////////////////////////////////////////
  33 // ImageAccessible
  34 ////////////////////////////////////////////////////////////////////////////////
  35
  36 ImageAccessible::ImageAccessible(nsIContent* aContent, DocAccessible* aDoc)
  37     : LinkableAccessible(aContent, aDoc),
  38       mImageRequestStatus(imgIRequest::STATUS_NONE) {
  39   mType = eImageType;
  40   nsCOMPtr<nsIImageLoadingContent> content(do_QueryInterface(mContent));
  41   if (content) {
  42     content->AddNativeObserver(this);
  43     nsCOMPtr<imgIRequest> imageRequest;
  44     content->GetRequest(nsIImageLoadingContent::CURRENT_REQUEST,
  45                         getter_AddRefs(imageRequest));
  46     if (imageRequest) {
  47       imageRequest->GetImageStatus(&mImageRequestStatus);
  48     }
  49   }
  50 }
  51
  52 ImageAccessible::~ImageAccessible() {}
  53
  54 ////////////////////////////////////////////////////////////////////////////////
  55 // LocalAccessible public
  56
  57 void ImageAccessible::Shutdown() {
  58   nsCOMPtr<nsIImageLoadingContent> content(do_QueryInterface(mContent));
  59   if (content) {
  60     content->RemoveNativeObserver(this);
  61   }
  62
  63   LinkableAccessible::Shutdown();
  64 }
  65
  66 uint64_t ImageAccessible::NativeState() const {
  67   // The state is a bitfield, get our inherited state, then logically OR it with
  68   // states::ANIMATED if this is an animated image.
  69
  70   uint64_t state = LinkableAccessible::NativeState();
  71
  72   if (mImageRequestStatus & imgIRequest::STATUS_IS_ANIMATED) {
  73     state |= states::ANIMATED;
  74   }
  75
  76   if (!(mImageRequestStatus & imgIRequest::STATUS_SIZE_AVAILABLE)) {
  77     nsIFrame* frame = GetFrame();
  78     MOZ_ASSERT(!frame || frame->AccessibleType() == eImageType ||
  79                frame->AccessibleType() == a11y::eHTMLImageMapType);
  80     if (frame && !frame->HasAnyStateBits(IMAGE_SIZECONSTRAINED)) {
  81       // The size of this image hasn't been constrained and we haven't loaded
  82       // enough of the image to know its size yet. This means it currently
  83       // has 0 width and height.
  84       state |= states::INVISIBLE;
  85     }
  86   }
  87
  88   return state;
  89 }
  90
  91 ENameValueFlag ImageAccessible::NativeName(nsString& aName) const {
  92   mContent->AsElement()->GetAttr(nsGkAtoms::alt, aName);
  93   if (!aName.IsEmpty()) return eNameOK;
  94
  95   ENameValueFlag nameFlag = LocalAccessible::NativeName(aName);
  96   if (!aName.IsEmpty()) return nameFlag;
  97
  98   return eNameOK;
  99 }
 100
 101 role ImageAccessible::NativeRole() const { return roles::GRAPHIC; }
 102
 103 void ImageAccessible::DOMAttributeChanged(int32_t aNameSpaceID,
 104                                           nsAtom* aAttribute, int32_t aModType,
 105                                           const nsAttrValue* aOldValue,
 106                                           uint64_t aOldState) {
 107   LinkableAccessible::DOMAttributeChanged(aNameSpaceID, aAttribute, aModType,
 108                                           aOldValue, aOldState);
 109
 110   if (aAttribute == nsGkAtoms::longdesc &&
 111       (aModType == dom::MutationEvent_Binding::ADDITION ||
 112        aModType == dom::MutationEvent_Binding::REMOVAL)) {
 113     mDoc->QueueCacheUpdate(this, CacheDomain::Actions);
 114   }
 115 }
 116
 117 ////////////////////////////////////////////////////////////////////////////////
 118 // LocalAccessible
 119
 120 uint8_t ImageAccessible::ActionCount() const {
 121   uint8_t actionCount = LinkableAccessible::ActionCount();
 122   return HasLongDesc() ? actionCount + 1 : actionCount;
 123 }
 124
 125 void ImageAccessible::ActionNameAt(uint8_t aIndex, nsAString& aName) {
 126   aName.Truncate();
 127   if (IsLongDescIndex(aIndex) && HasLongDesc()) {
 128     aName.AssignLiteral("showlongdesc");
 129   } else {
 130     LinkableAccessible::ActionNameAt(aIndex, aName);
 131   }
 132 }
 133
 134 bool ImageAccessible::DoAction(uint8_t aIndex) const {
 135   // Get the long description uri and open in a new window.
 136   if (!IsLongDescIndex(aIndex)) return LinkableAccessible::DoAction(aIndex);
 137
 138   nsCOMPtr<nsIURI> uri = GetLongDescURI();
 139   if (!uri) return false;
 140
 141   nsAutoCString utf8spec;
 142   uri->GetSpec(utf8spec);
 143   NS_ConvertUTF8toUTF16 spec(utf8spec);
 144
 145   dom::Document* document = mContent->OwnerDoc();
 146   nsCOMPtr<nsPIDOMWindowOuter> piWindow = document->GetWindow();
 147   if (!piWindow) return false;
 148
 149   RefPtr<dom::BrowsingContext> tmp;
 150   return NS_SUCCEEDED(piWindow->Open(spec, u""_ns, u""_ns,
 151                                      /* aLoadInfo = */ nullptr,
 152                                      /* aForceNoOpener = */ false,
 153                                      getter_AddRefs(tmp)));
 154 }
 155
 156 ////////////////////////////////////////////////////////////////////////////////
 157 // ImageAccessible
 158
 159 LayoutDeviceIntPoint ImageAccessible::Position(uint32_t aCoordType) {
 160   LayoutDeviceIntPoint point = Bounds().TopLeft();
 161   nsAccUtils::ConvertScreenCoordsTo(&point.x.value, &point.y.value, aCoordType,
 162                                     this);
 163   return point;
 164 }
 165
 166 LayoutDeviceIntSize ImageAccessible::Size() { return Bounds().Size(); }
 167
 168 // LocalAccessible
 169 already_AddRefed<AccAttributes> ImageAccessible::NativeAttributes() {
 170   RefPtr<AccAttributes> attributes = LinkableAccessible::NativeAttributes();
 171
 172   nsString src;
 173   mContent->AsElement()->GetAttr(nsGkAtoms::src, src);
 174   if (!src.IsEmpty()) attributes->SetAttribute(nsGkAtoms::src, std::move(src));
 175
 176   return attributes.forget();
 177 }
 178
 179 ////////////////////////////////////////////////////////////////////////////////
 180 // Private methods
 181
 182 already_AddRefed<nsIURI> ImageAccessible::GetLongDescURI() const {
 183   if (mContent->AsElement()->HasAttr(nsGkAtoms::longdesc)) {
 184     // To check if longdesc contains an invalid url.
 185     nsAutoString longdesc;
 186     mContent->AsElement()->GetAttr(nsGkAtoms::longdesc, longdesc);
 187     if (longdesc.FindChar(' ') != -1 || longdesc.FindChar('\t') != -1 ||
 188         longdesc.FindChar('\r') != -1 || longdesc.FindChar('\n') != -1) {
 189       return nullptr;
 190     }
 191     nsCOMPtr<nsIURI> uri;
 192     nsContentUtils::NewURIWithDocumentCharset(getter_AddRefs(uri), longdesc,
 193                                               mContent->OwnerDoc(),
 194                                               mContent->GetBaseURI());
 195     return uri.forget();
 196   }
 197
 198   DocAccessible* document = Document();
 199   if (document) {
 200     IDRefsIterator iter(document, mContent, nsGkAtoms::aria_describedby);
 201     while (nsIContent* target = iter.NextElem()) {
 202       if ((target->IsHTMLElement(nsGkAtoms::a) ||
 203            target->IsHTMLElement(nsGkAtoms::area)) &&
 204           target->AsElement()->HasAttr(nsGkAtoms::href)) {
 205         nsGenericHTMLElement* element = nsGenericHTMLElement::FromNode(target);
 206
 207         nsCOMPtr<nsIURI> uri;
 208         element->GetURIAttr(nsGkAtoms::href, nullptr, getter_AddRefs(uri));
 209         return uri.forget();
 210       }
 211     }
 212   }
 213
 214   return nullptr;
 215 }
 216
 217 bool ImageAccessible::IsLongDescIndex(uint8_t aIndex) const {
 218   return aIndex == LinkableAccessible::ActionCount();
 219 }
 220
 221 ////////////////////////////////////////////////////////////////////////////////
 222 // imgINotificationObserver
 223
 224 void ImageAccessible::Notify(imgIRequest* aRequest, int32_t aType,
 225                              const nsIntRect* aData) {
 226   if (aType != imgINotificationObserver::FRAME_COMPLETE &&
 227       aType != imgINotificationObserver::LOAD_COMPLETE &&
 228       aType != imgINotificationObserver::DECODE_COMPLETE) {
 229     // We should update our state if the whole image was decoded,
 230     // or the first frame in the case of a gif.
 231     return;
 232   }
 233
 234   if (IsDefunct() || !mParent) {
 235     return;
 236   }
 237
 238   uint32_t status = imgIRequest::STATUS_NONE;
 239   aRequest->GetImageStatus(&status);
 240
 241   if ((status ^ mImageRequestStatus) & imgIRequest::STATUS_SIZE_AVAILABLE) {
 242     nsIFrame* frame = GetFrame();
 243     if (frame && !frame->HasAnyStateBits(IMAGE_SIZECONSTRAINED)) {
 244       RefPtr<AccEvent> event = new AccStateChangeEvent(
 245           this, states::INVISIBLE,
 246           !(status & imgIRequest::STATUS_SIZE_AVAILABLE));
 247       mDoc->FireDelayedEvent(event);
 248     }
 249   }
 250
 251   if ((status ^ mImageRequestStatus) & imgIRequest::STATUS_IS_ANIMATED) {
 252     RefPtr<AccEvent> event = new AccStateChangeEvent(
 253         this, states::ANIMATED, (status & imgIRequest::STATUS_IS_ANIMATED));
 254     mDoc->FireDelayedEvent(event);
 255   }
 256
 257   mImageRequestStatus = status;
 258 }
 259
 260 }  // namespace mozilla::a11y