accessible/src/html/nsHTMLImageAccessible.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* ***** BEGIN LICENSE BLOCK *****
   3  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   4  *
   5  * The contents of this file are subject to the Mozilla Public License Version
   6  * 1.1 (the "License"); you may not use this file except in compliance with
   7  * the License. You may obtain a copy of the License at
   8  * http://www.mozilla.org/MPL/
   9  *
  10  * Software distributed under the License is distributed on an "AS IS" basis,
  11  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  12  * for the specific language governing rights and limitations under the
  13  * License.
  14  *
  15  * The Original Code is mozilla.org code.
  16  *
  17  * The Initial Developer of the Original Code is
  18  * Netscape Communications Corporation.
  19  * Portions created by the Initial Developer are Copyright (C) 1998
  20  * the Initial Developer. All Rights Reserved.
  21  *
  22  * Contributor(s):
  23  *   Author: Aaron Leventhal (aaronl@netscape.com)
  24  *
  25  * Alternatively, the contents of this file may be used under the terms of
  26  * either of the GNU General Public License Version 2 or later (the "GPL"),
  27  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  28  * in which case the provisions of the GPL or the LGPL are applicable instead
  29  * of those above. If you wish to allow use of your version of this file only
  30  * under the terms of either the GPL or the LGPL, and not to allow others to
  31  * use your version of this file under the terms of the MPL, indicate your
  32  * decision by deleting the provisions above and replace them with the notice
  33  * and other provisions required by the GPL or the LGPL. If you do not delete
  34  * the provisions above, a recipient may use your version of this file under
  35  * the terms of any one of the MPL, the GPL or the LGPL.
  36  *
  37  * ***** END LICENSE BLOCK ***** */
  38
  39 #include "nsHTMLImageAccessible.h"
  40
  41 #include "nsAccessibilityAtoms.h"
  42 #include "nsAccUtils.h"
  43
  44 #include "imgIContainer.h"
  45 #include "imgIRequest.h"
  46 #include "nsIDocument.h"
  47 #include "nsIImageLoadingContent.h"
  48 #include "nsILink.h"
  49 #include "nsIPresShell.h"
  50 #include "nsIServiceManager.h"
  51 #include "nsIDOMHTMLImageElement.h"
  52 #include "nsIDOMDocument.h"
  53 #include "nsPIDOMWindow.h"
  54
  55 ////////////////////////////////////////////////////////////////////////////////
  56 // nsHTMLImageAccessible
  57 ////////////////////////////////////////////////////////////////////////////////
  58
  59 nsHTMLImageAccessible::
  60   nsHTMLImageAccessible(nsIContent *aContent, nsIWeakReference *aShell) :
  61   nsLinkableAccessible(aContent, aShell)
  62 {
  63 }
  64
  65 NS_IMPL_ISUPPORTS_INHERITED1(nsHTMLImageAccessible, nsAccessible,
  66                              nsIAccessibleImage)
  67
  68 ////////////////////////////////////////////////////////////////////////////////
  69 // nsAccessible public
  70
  71 nsresult
  72 nsHTMLImageAccessible::GetStateInternal(PRUint32 *aState, PRUint32 *aExtraState)
  73 {
  74   // The state is a bitfield, get our inherited state, then logically OR it with
  75   // STATE_ANIMATED if this is an animated image.
  76
  77   nsresult rv = nsLinkableAccessible::GetStateInternal(aState, aExtraState);
  78   NS_ENSURE_A11Y_SUCCESS(rv, rv);
  79
  80   nsCOMPtr<nsIImageLoadingContent> content(do_QueryInterface(mContent));
  81   nsCOMPtr<imgIRequest> imageRequest;
  82
  83   if (content)
  84     content->GetRequest(nsIImageLoadingContent::CURRENT_REQUEST,
  85                         getter_AddRefs(imageRequest));
  86
  87   nsCOMPtr<imgIContainer> imgContainer;
  88   if (imageRequest)
  89     imageRequest->GetImage(getter_AddRefs(imgContainer));
  90
  91   if (imgContainer) {
  92     PRBool animated;
  93     imgContainer->GetAnimated(&animated);
  94     if (animated)
  95       *aState |= nsIAccessibleStates::STATE_ANIMATED;
  96   }
  97
  98   return NS_OK;
  99 }
 100
 101 nsresult
 102 nsHTMLImageAccessible::GetNameInternal(nsAString& aName)
 103 {
 104   PRBool hasAltAttrib =
 105     mContent->GetAttr(kNameSpaceID_None, nsAccessibilityAtoms::alt, aName);
 106   if (!aName.IsEmpty())
 107     return NS_OK;
 108
 109   nsresult rv = nsAccessible::GetNameInternal(aName);
 110   NS_ENSURE_SUCCESS(rv, rv);
 111
 112   if (aName.IsEmpty() && hasAltAttrib) {
 113     // No accessible name but empty 'alt' attribute is present. If further name
 114     // computation algorithm doesn't provide non empty name then it means
 115     // an empty 'alt' attribute was used to indicate a decorative image (see
 116     // nsIAccessible::name attribute for details).
 117     return NS_OK_EMPTY_NAME;
 118   }
 119
 120   return NS_OK;
 121 }
 122
 123 PRUint32
 124 nsHTMLImageAccessible::NativeRole()
 125 {
 126   return nsIAccessibleRole::ROLE_GRAPHIC;
 127 }
 128
 129 ////////////////////////////////////////////////////////////////////////////////
 130 // nsIAccessible
 131
 132 NS_IMETHODIMP
 133 nsHTMLImageAccessible::GetNumActions(PRUint8 *aNumActions)
 134 {
 135   NS_ENSURE_ARG_POINTER(aNumActions);
 136   *aNumActions = 0;
 137
 138   if (IsDefunct())
 139     return NS_ERROR_FAILURE;
 140
 141   nsresult rv= nsLinkableAccessible::GetNumActions(aNumActions);
 142   NS_ENSURE_SUCCESS(rv, rv);
 143
 144   if (HasLongDesc())
 145     (*aNumActions)++;
 146
 147   return NS_OK;
 148 }
 149
 150 NS_IMETHODIMP
 151 nsHTMLImageAccessible::GetActionName(PRUint8 aIndex, nsAString& aName)
 152 {
 153   aName.Truncate();
 154
 155   if (IsDefunct())
 156     return NS_ERROR_FAILURE;
 157
 158   if (IsValidLongDescIndex(aIndex)) {
 159     aName.AssignLiteral("showlongdesc");
 160     return NS_OK;
 161   }
 162   return nsLinkableAccessible::GetActionName(aIndex, aName);
 163 }
 164
 165 NS_IMETHODIMP
 166 nsHTMLImageAccessible::DoAction(PRUint8 aIndex)
 167 {
 168   if (IsDefunct())
 169     return NS_ERROR_FAILURE;
 170
 171   if (IsValidLongDescIndex(aIndex)) {
 172     //get the long description uri and open in a new window
 173     nsCOMPtr<nsIDOMHTMLImageElement> element(do_QueryInterface(mContent));
 174     NS_ENSURE_TRUE(element, NS_ERROR_FAILURE);
 175
 176     nsAutoString longDesc;
 177     nsresult rv = element->GetLongDesc(longDesc);
 178     NS_ENSURE_SUCCESS(rv, rv);
 179
 180     nsIDocument* document = mContent->GetOwnerDoc();
 181     nsCOMPtr<nsPIDOMWindow> piWindow = document->GetWindow();
 182     nsCOMPtr<nsIDOMWindowInternal> win(do_QueryInterface(piWindow));
 183     NS_ENSURE_TRUE(win, NS_ERROR_FAILURE);
 184     nsCOMPtr<nsIDOMWindow> tmp;
 185     return win->Open(longDesc, EmptyString(), EmptyString(),
 186                      getter_AddRefs(tmp));
 187   }
 188   return nsLinkableAccessible::DoAction(aIndex);
 189 }
 190
 191 ////////////////////////////////////////////////////////////////////////////////
 192 // nsIAccessibleImage
 193
 194 NS_IMETHODIMP
 195 nsHTMLImageAccessible::GetImagePosition(PRUint32 aCoordType,
 196                                         PRInt32 *aX, PRInt32 *aY)
 197 {
 198   PRInt32 width, height;
 199   nsresult rv = GetBounds(aX, aY, &width, &height);
 200   if (NS_FAILED(rv))
 201     return rv;
 202
 203   return nsAccUtils::ConvertScreenCoordsTo(aX, aY, aCoordType, this);
 204 }
 205
 206 NS_IMETHODIMP
 207 nsHTMLImageAccessible::GetImageSize(PRInt32 *aWidth, PRInt32 *aHeight)
 208 {
 209   PRInt32 x, y;
 210   return GetBounds(&x, &y, aWidth, aHeight);
 211 }
 212
 213 // nsAccessible
 214 nsresult
 215 nsHTMLImageAccessible::GetAttributesInternal(nsIPersistentProperties *aAttributes)
 216 {
 217   if (IsDefunct())
 218     return NS_ERROR_FAILURE;
 219
 220   nsresult rv = nsLinkableAccessible::GetAttributesInternal(aAttributes);
 221   NS_ENSURE_SUCCESS(rv, rv);
 222
 223   nsAutoString src;
 224   mContent->GetAttr(kNameSpaceID_None, nsAccessibilityAtoms::src, src);
 225   if (!src.IsEmpty())
 226     nsAccUtils::SetAccAttr(aAttributes, nsAccessibilityAtoms::src, src);
 227
 228   return NS_OK;
 229 }
 230
 231 ////////////////////////////////////////////////////////////////////////////////
 232 // Private methods
 233
 234 PRBool
 235 nsHTMLImageAccessible::HasLongDesc()
 236 {
 237   if (IsDefunct())
 238     return PR_FALSE;
 239
 240   return mContent->HasAttr(kNameSpaceID_None, nsAccessibilityAtoms::longDesc);
 241 }
 242
 243 PRBool
 244 nsHTMLImageAccessible::IsValidLongDescIndex(PRUint8 aIndex)
 245 {
 246   if (!HasLongDesc())
 247     return PR_FALSE;
 248
 249   PRUint8 numActions = 0;
 250   nsresult rv = nsLinkableAccessible::GetNumActions(&numActions);
 251   NS_ENSURE_SUCCESS(rv, PR_FALSE);
 252
 253   return (aIndex == numActions);
 254 }