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 "nsIFrame.h"
  14 #include "nsImageFrame.h"
  15 #include "nsImageMap.h"
  16 #include "nsIURI.h"
  17 #include "nsLayoutUtils.h"
  18 #include "mozilla/dom/HTMLAreaElement.h"
  19
  20 using namespace mozilla::a11y;
  21
  22 ////////////////////////////////////////////////////////////////////////////////
  23 // HTMLImageMapAccessible
  24 ////////////////////////////////////////////////////////////////////////////////
  25
  26 HTMLImageMapAccessible::HTMLImageMapAccessible(nsIContent* aContent,
  27                                                DocAccessible* aDoc)
  28     : ImageAccessibleWrap(aContent, aDoc) {
  29   mType = eImageMapType;
  30
  31   UpdateChildAreas(false);
  32 }
  33
  34 ////////////////////////////////////////////////////////////////////////////////
  35 // HTMLImageMapAccessible: LocalAccessible public
  36
  37 role HTMLImageMapAccessible::NativeRole() const { return roles::IMAGE_MAP; }
  38
  39 ////////////////////////////////////////////////////////////////////////////////
  40 // HTMLImageMapAccessible: HyperLinkAccessible
  41
  42 uint32_t HTMLImageMapAccessible::AnchorCount() { return ChildCount(); }
  43
  44 LocalAccessible* HTMLImageMapAccessible::AnchorAt(uint32_t aAnchorIndex) {
  45   return LocalChildAt(aAnchorIndex);
  46 }
  47
  48 already_AddRefed<nsIURI> HTMLImageMapAccessible::AnchorURIAt(
  49     uint32_t aAnchorIndex) const {
  50   LocalAccessible* area = LocalChildAt(aAnchorIndex);
  51   if (!area) return nullptr;
  52
  53   nsIContent* linkContent = area->GetContent();
  54   return linkContent ? linkContent->GetHrefURI() : nullptr;
  55 }
  56
  57 ////////////////////////////////////////////////////////////////////////////////
  58 // HTMLImageMapAccessible: public
  59
  60 void HTMLImageMapAccessible::UpdateChildAreas(bool aDoFireEvents) {
  61   nsImageFrame* imageFrame = do_QueryFrame(mContent->GetPrimaryFrame());
  62
  63   // If image map is not initialized yet then we trigger one time more later.
  64   nsImageMap* imageMapObj = imageFrame->GetExistingImageMap();
  65   if (!imageMapObj) return;
  66
  67   TreeMutation mt(this, TreeMutation::kNoEvents & !aDoFireEvents);
  68
  69   // Remove areas that are not a valid part of the image map anymore.
  70   for (int32_t childIdx = mChildren.Length() - 1; childIdx >= 0; childIdx--) {
  71     LocalAccessible* area = mChildren.ElementAt(childIdx);
  72     if (area->GetContent()->GetPrimaryFrame()) continue;
  73
  74     mt.BeforeRemoval(area);
  75     RemoveChild(area);
  76   }
  77
  78   // Insert new areas into the tree.
  79   uint32_t areaElmCount = imageMapObj->AreaCount();
  80   for (uint32_t idx = 0; idx < areaElmCount; idx++) {
  81     nsIContent* areaContent = imageMapObj->GetAreaAt(idx);
  82     LocalAccessible* area = mChildren.SafeElementAt(idx);
  83     if (!area || area->GetContent() != areaContent) {
  84       RefPtr<LocalAccessible> area = new HTMLAreaAccessible(areaContent, mDoc);
  85       mDoc->BindToDocument(area, aria::GetRoleMap(areaContent->AsElement()));
  86
  87       if (!InsertChildAt(idx, area)) {
  88         mDoc->UnbindFromDocument(area);
  89         break;
  90       }
  91
  92       mt.AfterInsertion(area);
  93     }
  94   }
  95
  96   mt.Done();
  97 }
  98
  99 LocalAccessible* HTMLImageMapAccessible::GetChildAccessibleFor(
 100     const nsINode* aNode) const {
 101   uint32_t length = mChildren.Length();
 102   for (uint32_t i = 0; i < length; i++) {
 103     LocalAccessible* area = mChildren[i];
 104     if (area->GetContent() == aNode) return area;
 105   }
 106
 107   return nullptr;
 108 }
 109
 110 ////////////////////////////////////////////////////////////////////////////////
 111 // HTMLAreaAccessible
 112 ////////////////////////////////////////////////////////////////////////////////
 113
 114 HTMLAreaAccessible::HTMLAreaAccessible(nsIContent* aContent,
 115                                        DocAccessible* aDoc)
 116     : HTMLLinkAccessible(aContent, aDoc) {
 117   // Make HTML area DOM element not accessible. HTML image map accessible
 118   // manages its tree itself.
 119   mStateFlags |= eNotNodeMapEntry;
 120 }
 121
 122 ////////////////////////////////////////////////////////////////////////////////
 123 // HTMLAreaAccessible: LocalAccessible
 124
 125 ENameValueFlag HTMLAreaAccessible::NativeName(nsString& aName) const {
 126   ENameValueFlag nameFlag = LocalAccessible::NativeName(aName);
 127   if (!aName.IsEmpty()) return nameFlag;
 128
 129   if (!mContent->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::alt,
 130                                       aName)) {
 131     Value(aName);
 132   }
 133
 134   return eNameOK;
 135 }
 136
 137 void HTMLAreaAccessible::Description(nsString& aDescription) const {
 138   aDescription.Truncate();
 139
 140   // Still to do - follow IE's standard here
 141   RefPtr<dom::HTMLAreaElement> area =
 142       dom::HTMLAreaElement::FromNodeOrNull(mContent);
 143   if (area) area->GetShape(aDescription);
 144 }
 145
 146 ////////////////////////////////////////////////////////////////////////////////
 147 // HTMLAreaAccessible: LocalAccessible public
 148
 149 LocalAccessible* HTMLAreaAccessible::LocalChildAtPoint(
 150     int32_t aX, int32_t aY, EWhichChildAtPoint aWhichChild) {
 151   // Don't walk into area accessibles.
 152   return this;
 153 }
 154
 155 ////////////////////////////////////////////////////////////////////////////////
 156 // HTMLImageMapAccessible: HyperLinkAccessible
 157
 158 uint32_t HTMLAreaAccessible::StartOffset() {
 159   // Image map accessible is not hypertext accessible therefore
 160   // StartOffset/EndOffset implementations of LocalAccessible doesn't work here.
 161   // We return index in parent because image map contains area links only which
 162   // are embedded objects.
 163   // XXX: image map should be a hypertext accessible.
 164   return IndexInParent();
 165 }
 166
 167 uint32_t HTMLAreaAccessible::EndOffset() { return IndexInParent() + 1; }
 168
 169 nsRect HTMLAreaAccessible::RelativeBounds(nsIFrame** aBoundingFrame) const {
 170   nsIFrame* frame = GetFrame();
 171   if (!frame) return nsRect();
 172
 173   nsImageFrame* imageFrame = do_QueryFrame(frame);
 174   nsImageMap* map = imageFrame->GetImageMap();
 175
 176   nsRect bounds;
 177   nsresult rv = map->GetBoundsForAreaContent(mContent, bounds);
 178
 179   if (NS_FAILED(rv)) return nsRect();
 180
 181   // XXX Areas are screwy; they return their rects as a pair of points, one pair
 182   // stored into the width and height.
 183   *aBoundingFrame = frame;
 184   bounds.SizeTo(bounds.Width() - bounds.X(), bounds.Height() - bounds.Y());
 185   return bounds;
 186 }
 187
 188 nsRect HTMLAreaAccessible::ParentRelativeBounds() {
 189   nsIFrame* boundingFrame = nullptr;
 190   nsRect relativeBoundsRect = RelativeBounds(&boundingFrame);
 191
 192   nsIFrame* parentBoundingFrame = nullptr;
 193   if (mParent) {
 194     parentBoundingFrame = mParent->GetFrame();
 195   }
 196
 197   if (!parentBoundingFrame) {
 198     // if we can't get the bounding frame, use the pres shell root for the
 199     // bounding frame RelativeBounds returned
 200     parentBoundingFrame =
 201         nsLayoutUtils::GetContainingBlockForClientRect(boundingFrame);
 202   }
 203
 204   nsLayoutUtils::TransformRect(boundingFrame, parentBoundingFrame,
 205                                relativeBoundsRect);
 206
 207   return relativeBoundsRect;
 208 }