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 "EventTree.h"
  10 #include "mozilla/a11y/Role.h"
  11
  12 #include "nsCoreUtils.h"
  13 #include "nsIFrame.h"
  14 #include "nsImageFrame.h"
  15 #include "nsImageMap.h"
  16 #include "nsLayoutUtils.h"
  17 #include "mozilla/dom/HTMLAreaElement.h"
  18
  19 using namespace mozilla::a11y;
  20
  21 ////////////////////////////////////////////////////////////////////////////////
  22 // HTMLImageMapAccessible
  23 ////////////////////////////////////////////////////////////////////////////////
  24
  25 HTMLImageMapAccessible::HTMLImageMapAccessible(nsIContent* aContent,
  26                                                DocAccessible* aDoc)
  27     : ImageAccessible(aContent, aDoc) {
  28   mType = eImageMapType;
  29
  30   UpdateChildAreas(false);
  31 }
  32
  33 ////////////////////////////////////////////////////////////////////////////////
  34 // HTMLImageMapAccessible: LocalAccessible public
  35
  36 role HTMLImageMapAccessible::NativeRole() const { return roles::IMAGE_MAP; }
  37
  38 ////////////////////////////////////////////////////////////////////////////////
  39 // HTMLImageMapAccessible: public
  40
  41 void HTMLImageMapAccessible::UpdateChildAreas(bool aDoFireEvents) {
  42   if (!mContent || !mContent->GetPrimaryFrame()) {
  43     return;
  44   }
  45   nsImageFrame* imageFrame = do_QueryFrame(mContent->GetPrimaryFrame());
  46
  47   // If image map is not initialized yet then we trigger one time more later.
  48   nsImageMap* imageMapObj = imageFrame->GetExistingImageMap();
  49   if (!imageMapObj) return;
  50
  51   TreeMutation mt(this, TreeMutation::kNoEvents & !aDoFireEvents);
  52
  53   // Remove areas that are not a valid part of the image map anymore.
  54   for (int32_t childIdx = mChildren.Length() - 1; childIdx >= 0; childIdx--) {
  55     LocalAccessible* area = mChildren.ElementAt(childIdx);
  56     if (area->GetContent()->GetPrimaryFrame()) continue;
  57
  58     mt.BeforeRemoval(area);
  59     RemoveChild(area);
  60   }
  61
  62   // Insert new areas into the tree.
  63   uint32_t areaElmCount = imageMapObj->AreaCount();
  64   for (uint32_t idx = 0; idx < areaElmCount; idx++) {
  65     nsIContent* areaContent = imageMapObj->GetAreaAt(idx);
  66     LocalAccessible* area = mChildren.SafeElementAt(idx);
  67     if (!area || area->GetContent() != areaContent) {
  68       RefPtr<LocalAccessible> area = new HTMLAreaAccessible(areaContent, mDoc);
  69       mDoc->BindToDocument(area, aria::GetRoleMap(areaContent->AsElement()));
  70
  71       if (!InsertChildAt(idx, area)) {
  72         mDoc->UnbindFromDocument(area);
  73         break;
  74       }
  75
  76       mt.AfterInsertion(area);
  77     }
  78   }
  79
  80   mt.Done();
  81 }
  82
  83 LocalAccessible* HTMLImageMapAccessible::GetChildAccessibleFor(
  84     const nsINode* aNode) const {
  85   uint32_t length = mChildren.Length();
  86   for (uint32_t i = 0; i < length; i++) {
  87     LocalAccessible* area = mChildren[i];
  88     if (area->GetContent() == aNode) return area;
  89   }
  90
  91   return nullptr;
  92 }
  93
  94 ////////////////////////////////////////////////////////////////////////////////
  95 // HTMLAreaAccessible
  96 ////////////////////////////////////////////////////////////////////////////////
  97
  98 HTMLAreaAccessible::HTMLAreaAccessible(nsIContent* aContent,
  99                                        DocAccessible* aDoc)
 100     : HTMLLinkAccessible(aContent, aDoc) {
 101   // Make HTML area DOM element not accessible. HTML image map accessible
 102   // manages its tree itself.
 103   mStateFlags |= eNotNodeMapEntry;
 104 }
 105
 106 ////////////////////////////////////////////////////////////////////////////////
 107 // HTMLAreaAccessible: LocalAccessible
 108
 109 role HTMLAreaAccessible::NativeRole() const {
 110   // A link element without an href attribute and without a click listener
 111   // should be reported as a generic.
 112   if (mContent->IsElement()) {
 113     dom::Element* element = mContent->AsElement();
 114     if (!element->HasAttr(nsGkAtoms::href) &&
 115         !nsCoreUtils::HasClickListener(element)) {
 116       return roles::TEXT;
 117     }
 118   }
 119   return HTMLLinkAccessible::NativeRole();
 120 }
 121
 122 ENameValueFlag HTMLAreaAccessible::NativeName(nsString& aName) const {
 123   ENameValueFlag nameFlag = LocalAccessible::NativeName(aName);
 124   if (!aName.IsEmpty()) return nameFlag;
 125
 126   if (!mContent->AsElement()->GetAttr(nsGkAtoms::alt, aName)) {
 127     Value(aName);
 128   }
 129
 130   return eNameOK;
 131 }
 132
 133 void HTMLAreaAccessible::Description(nsString& aDescription) const {
 134   aDescription.Truncate();
 135
 136   // Still to do - follow IE's standard here
 137   RefPtr<dom::HTMLAreaElement> area =
 138       dom::HTMLAreaElement::FromNodeOrNull(mContent);
 139   if (area) area->GetShape(aDescription);
 140 }
 141
 142 ////////////////////////////////////////////////////////////////////////////////
 143 // HTMLAreaAccessible: LocalAccessible public
 144
 145 LocalAccessible* HTMLAreaAccessible::LocalChildAtPoint(
 146     int32_t aX, int32_t aY, EWhichChildAtPoint aWhichChild) {
 147   // Don't walk into area accessibles.
 148   return this;
 149 }
 150
 151 ////////////////////////////////////////////////////////////////////////////////
 152 // HTMLImageMapAccessible: HyperLinkAccessible
 153
 154 uint32_t HTMLAreaAccessible::StartOffset() {
 155   // Image map accessible is not hypertext accessible therefore
 156   // StartOffset/EndOffset implementations of LocalAccessible doesn't work here.
 157   // We return index in parent because image map contains area links only which
 158   // are embedded objects.
 159   // XXX: image map should be a hypertext accessible.
 160   return IndexInParent();
 161 }
 162
 163 uint32_t HTMLAreaAccessible::EndOffset() { return IndexInParent() + 1; }
 164
 165 nsRect HTMLAreaAccessible::RelativeBounds(nsIFrame** aBoundingFrame) const {
 166   nsIFrame* frame = GetFrame();
 167   if (!frame) return nsRect();
 168
 169   nsImageFrame* imageFrame = do_QueryFrame(frame);
 170   nsImageMap* map = imageFrame->GetImageMap();
 171
 172   nsRect bounds;
 173   nsresult rv = map->GetBoundsForAreaContent(mContent, bounds);
 174
 175   if (NS_FAILED(rv)) return nsRect();
 176
 177   // XXX Areas are screwy; they return their rects as a pair of points, one pair
 178   // stored into the width and height.
 179   *aBoundingFrame = frame;
 180   bounds.SizeTo(bounds.Width() - bounds.X(), bounds.Height() - bounds.Y());
 181   return bounds;
 182 }
 183
 184 nsRect HTMLAreaAccessible::ParentRelativeBounds() {
 185   nsIFrame* boundingFrame = nullptr;
 186   nsRect relativeBoundsRect = RelativeBounds(&boundingFrame);
 187   if (MOZ_UNLIKELY(!boundingFrame)) {
 188     // Area is not attached to an image map?
 189     return nsRect();
 190   }
 191
 192   // The relative bounds returned above are relative to this area's
 193   // image map, which is technically already "parent relative".
 194   // Because area elements are `display:none` to layout, they can't
 195   // have transforms or other styling applied directly, and so we
 196   // don't apply any additional transforms here. Any transform
 197   // at the image map layer will be taken care of when computing bounds
 198   // in the parent process.
 199   return relativeBoundsRect;
 200 }