accessible/html/HTMLImageMapAccessible.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 "HTMLImageMapAccessible.h"
   7
   8 #include "ARIAMap.h"
   9 #include "nsAccUtils.h"
  10 #include "DocAccessible-inl.h"
  11 #include "Role.h"
  12
  13 #include "nsIDOMHTMLCollection.h"
  14 #include "nsIServiceManager.h"
  15 #include "nsIDOMElement.h"
  16 #include "nsIDOMHTMLAreaElement.h"
  17 #include "nsIFrame.h"
  18 #include "nsImageFrame.h"
  19 #include "nsImageMap.h"
  20 #include "nsIURI.h"
  21
  22 using namespace mozilla::a11y;
  23
  24 ////////////////////////////////////////////////////////////////////////////////
  25 // HTMLImageMapAccessible
  26 ////////////////////////////////////////////////////////////////////////////////
  27
  28 HTMLImageMapAccessible::
  29   HTMLImageMapAccessible(nsIContent* aContent, DocAccessible* aDoc) :
  30   ImageAccessibleWrap(aContent, aDoc)
  31 {
  32   mType = eImageMapType;
  33 }
  34
  35 ////////////////////////////////////////////////////////////////////////////////
  36 // HTMLImageMapAccessible: nsISupports
  37
  38 NS_IMPL_ISUPPORTS_INHERITED0(HTMLImageMapAccessible, ImageAccessible)
  39
  40 ////////////////////////////////////////////////////////////////////////////////
  41 // HTMLImageMapAccessible: Accessible public
  42
  43 role
  44 HTMLImageMapAccessible::NativeRole()
  45 {
  46   return roles::IMAGE_MAP;
  47 }
  48
  49 ////////////////////////////////////////////////////////////////////////////////
  50 // HTMLImageMapAccessible: HyperLinkAccessible
  51
  52 uint32_t
  53 HTMLImageMapAccessible::AnchorCount()
  54 {
  55   return ChildCount();
  56 }
  57
  58 Accessible*
  59 HTMLImageMapAccessible::AnchorAt(uint32_t aAnchorIndex)
  60 {
  61   return GetChildAt(aAnchorIndex);
  62 }
  63
  64 already_AddRefed<nsIURI>
  65 HTMLImageMapAccessible::AnchorURIAt(uint32_t aAnchorIndex)
  66 {
  67   Accessible* area = GetChildAt(aAnchorIndex);
  68   if (!area)
  69     return nullptr;
  70
  71   nsIContent* linkContent = area->GetContent();
  72   return linkContent ? linkContent->GetHrefURI() : nullptr;
  73 }
  74
  75 ////////////////////////////////////////////////////////////////////////////////
  76 // HTMLImageMapAccessible: public
  77
  78 void
  79 HTMLImageMapAccessible::UpdateChildAreas(bool aDoFireEvents)
  80 {
  81   nsImageFrame* imageFrame = do_QueryFrame(mContent->GetPrimaryFrame());
  82
  83   // If image map is not initialized yet then we trigger one time more later.
  84   nsImageMap* imageMapObj = imageFrame->GetExistingImageMap();
  85   if (!imageMapObj)
  86     return;
  87
  88   bool treeChanged = false;
  89   AutoTreeMutation mut(this);
  90   nsRefPtr<AccReorderEvent> reorderEvent = new AccReorderEvent(this);
  91
  92   // Remove areas that are not a valid part of the image map anymore.
  93   for (int32_t childIdx = mChildren.Length() - 1; childIdx >= 0; childIdx--) {
  94     Accessible* area = mChildren.ElementAt(childIdx);
  95     if (area->GetContent()->GetPrimaryFrame())
  96       continue;
  97
  98     if (aDoFireEvents) {
  99       nsRefPtr<AccHideEvent> event = new AccHideEvent(area, area->GetContent());
 100       mDoc->FireDelayedEvent(event);
 101       reorderEvent->AddSubMutationEvent(event);
 102     }
 103
 104     RemoveChild(area);
 105     treeChanged = true;
 106   }
 107
 108   // Insert new areas into the tree.
 109   uint32_t areaElmCount = imageMapObj->AreaCount();
 110   for (uint32_t idx = 0; idx < areaElmCount; idx++) {
 111     nsIContent* areaContent = imageMapObj->GetAreaAt(idx);
 112
 113     Accessible* area = mChildren.SafeElementAt(idx);
 114     if (!area || area->GetContent() != areaContent) {
 115       nsRefPtr<Accessible> area = new HTMLAreaAccessible(areaContent, mDoc);
 116       mDoc->BindToDocument(area, aria::GetRoleMap(areaContent));
 117
 118       if (!InsertChildAt(idx, area)) {
 119         mDoc->UnbindFromDocument(area);
 120         break;
 121       }
 122
 123       if (aDoFireEvents) {
 124         nsRefPtr<AccShowEvent> event = new AccShowEvent(area, areaContent);
 125         mDoc->FireDelayedEvent(event);
 126         reorderEvent->AddSubMutationEvent(event);
 127       }
 128
 129       treeChanged = true;
 130     }
 131   }
 132
 133   // Fire reorder event if needed.
 134   if (treeChanged && aDoFireEvents)
 135     mDoc->FireDelayedEvent(reorderEvent);
 136
 137   if (!treeChanged)
 138     mut.mInvalidationRequired = false;
 139 }
 140
 141 Accessible*
 142 HTMLImageMapAccessible::GetChildAccessibleFor(const nsINode* aNode) const
 143 {
 144   uint32_t length = mChildren.Length();
 145   for (uint32_t i = 0; i < length; i++) {
 146     Accessible* area = mChildren[i];
 147     if (area->GetContent() == aNode)
 148       return area;
 149   }
 150
 151   return nullptr;
 152 }
 153
 154 ////////////////////////////////////////////////////////////////////////////////
 155 // HTMLImageMapAccessible: Accessible protected
 156
 157 void
 158 HTMLImageMapAccessible::CacheChildren()
 159 {
 160   UpdateChildAreas(false);
 161 }
 162
 163
 164 ////////////////////////////////////////////////////////////////////////////////
 165 // HTMLAreaAccessible
 166 ////////////////////////////////////////////////////////////////////////////////
 167
 168 HTMLAreaAccessible::
 169   HTMLAreaAccessible(nsIContent* aContent, DocAccessible* aDoc) :
 170   HTMLLinkAccessible(aContent, aDoc)
 171 {
 172   // Make HTML area DOM element not accessible. HTML image map accessible
 173   // manages its tree itself.
 174   mStateFlags |= eNotNodeMapEntry;
 175 }
 176
 177 ////////////////////////////////////////////////////////////////////////////////
 178 // HTMLAreaAccessible: Accessible
 179
 180 ENameValueFlag
 181 HTMLAreaAccessible::NativeName(nsString& aName)
 182 {
 183   ENameValueFlag nameFlag = Accessible::NativeName(aName);
 184   if (!aName.IsEmpty())
 185     return nameFlag;
 186
 187   if (!mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::alt, aName))
 188     Value(aName);
 189
 190   return eNameOK;
 191 }
 192
 193 void
 194 HTMLAreaAccessible::Description(nsString& aDescription)
 195 {
 196   aDescription.Truncate();
 197
 198   // Still to do - follow IE's standard here
 199   nsCOMPtr<nsIDOMHTMLAreaElement> area(do_QueryInterface(mContent));
 200   if (area)
 201     area->GetShape(aDescription);
 202 }
 203
 204 ////////////////////////////////////////////////////////////////////////////////
 205 // HTMLAreaAccessible: Accessible public
 206
 207 Accessible*
 208 HTMLAreaAccessible::ChildAtPoint(int32_t aX, int32_t aY,
 209                                  EWhichChildAtPoint aWhichChild)
 210 {
 211   // Don't walk into area accessibles.
 212   return this;
 213 }
 214
 215 ////////////////////////////////////////////////////////////////////////////////
 216 // HTMLImageMapAccessible: HyperLinkAccessible
 217
 218 uint32_t
 219 HTMLAreaAccessible::StartOffset()
 220 {
 221   // Image map accessible is not hypertext accessible therefore
 222   // StartOffset/EndOffset implementations of Accessible doesn't work here.
 223   // We return index in parent because image map contains area links only which
 224   // are embedded objects.
 225   // XXX: image map should be a hypertext accessible.
 226   return IndexInParent();
 227 }
 228
 229 uint32_t
 230 HTMLAreaAccessible::EndOffset()
 231 {
 232   return IndexInParent() + 1;
 233 }
 234
 235 ////////////////////////////////////////////////////////////////////////////////
 236 // HTMLAreaAccessible: Accessible protected
 237
 238 void
 239 HTMLAreaAccessible::CacheChildren()
 240 {
 241   // No children for aria accessible.
 242 }
 243
 244 nsRect
 245 HTMLAreaAccessible::RelativeBounds(nsIFrame** aBoundingFrame) const
 246 {
 247   nsIFrame* frame = GetFrame();
 248   if (!frame)
 249     return nsRect();
 250
 251   nsImageFrame* imageFrame = do_QueryFrame(frame);
 252   nsImageMap* map = imageFrame->GetImageMap();
 253
 254   nsRect bounds;
 255   nsresult rv = map->GetBoundsForAreaContent(mContent, bounds);
 256   if (NS_FAILED(rv))
 257     return nsRect();
 258
 259   // XXX Areas are screwy; they return their rects as a pair of points, one pair
 260   // stored into the width and height.
 261   *aBoundingFrame = frame;
 262   bounds.width -= bounds.x;
 263   bounds.height -= bounds.y;
 264   return bounds;
 265 }