accessible/src/base/nsBaseWidgetAccessible.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  *   John Gaunt (jgaunt@netscape.com)
  24  *   Alexander Surkov <surkov.alexander@gmail.com>
  25  *
  26  * Alternatively, the contents of this file may be used under the terms of
  27  * either of the GNU General Public License Version 2 or later (the "GPL"),
  28  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  29  * in which case the provisions of the GPL or the LGPL are applicable instead
  30  * of those above. If you wish to allow use of your version of this file only
  31  * under the terms of either the GPL or the LGPL, and not to allow others to
  32  * use your version of this file under the terms of the MPL, indicate your
  33  * decision by deleting the provisions above and replace them with the notice
  34  * and other provisions required by the GPL or the LGPL. If you do not delete
  35  * the provisions above, a recipient may use your version of this file under
  36  * the terms of any one of the MPL, the GPL or the LGPL.
  37  *
  38  * ***** END LICENSE BLOCK ***** */
  39
  40 #include "nsBaseWidgetAccessible.h"
  41 #include "nsAccessibilityAtoms.h"
  42 #include "nsIAccessibilityService.h"
  43 #include "nsIAccessibleDocument.h"
  44 #include "nsAccessibleWrap.h"
  45 #include "nsCoreUtils.h"
  46 #include "nsIDOMNSHTMLElement.h"
  47 #include "nsGUIEvent.h"
  48 #include "nsHyperTextAccessibleWrap.h"
  49 #include "nsILink.h"
  50 #include "nsIFrame.h"
  51 #include "nsINameSpaceManager.h"
  52 #include "nsPresContext.h"
  53 #include "nsIPresShell.h"
  54 #include "nsIServiceManager.h"
  55 #include "nsIURI.h"
  56
  57 //-------------
  58 // nsLeafAccessible
  59 //-------------
  60
  61 nsLeafAccessible::nsLeafAccessible(nsIDOMNode* aNode, nsIWeakReference* aShell):
  62 nsAccessibleWrap(aNode, aShell)
  63 {
  64 }
  65
  66 NS_IMPL_ISUPPORTS_INHERITED0(nsLeafAccessible, nsAccessible)
  67
  68 /* nsIAccessible getFirstChild (); */
  69 NS_IMETHODIMP nsLeafAccessible::GetFirstChild(nsIAccessible **_retval)
  70 {
  71   *_retval = nsnull;
  72   return NS_OK;
  73 }
  74
  75 /* nsIAccessible getLastChild (); */
  76 NS_IMETHODIMP nsLeafAccessible::GetLastChild(nsIAccessible **_retval)
  77 {
  78   *_retval = nsnull;
  79   return NS_OK;
  80 }
  81
  82 /* long getAccChildCount (); */
  83 NS_IMETHODIMP nsLeafAccessible::GetChildCount(PRInt32 *_retval)
  84 {
  85   *_retval = 0;
  86   return NS_OK;
  87 }
  88
  89 /* readonly attribute boolean allowsAnonChildAccessibles; */
  90 NS_IMETHODIMP
  91 nsLeafAccessible::GetAllowsAnonChildAccessibles(PRBool *aAllowsAnonChildren)
  92 {
  93   *aAllowsAnonChildren = PR_FALSE;
  94   return NS_OK;
  95 }
  96
  97 ////////////////////////////////////////////////////////////////////////////////
  98 // nsLinkableAccessible
  99
 100 nsLinkableAccessible::
 101   nsLinkableAccessible(nsIDOMNode* aNode, nsIWeakReference* aShell) :
 102   nsHyperTextAccessibleWrap(aNode, aShell),
 103   mActionContent(nsnull),
 104   mIsLink(PR_FALSE),
 105   mIsOnclick(PR_FALSE)
 106 {
 107 }
 108
 109 NS_IMPL_ISUPPORTS_INHERITED0(nsLinkableAccessible, nsHyperTextAccessibleWrap)
 110
 111 ////////////////////////////////////////////////////////////////////////////////
 112 // nsLinkableAccessible. nsIAccessible
 113
 114 NS_IMETHODIMP
 115 nsLinkableAccessible::TakeFocus()
 116 {
 117   nsCOMPtr<nsIAccessible> actionAcc = GetActionAccessible();
 118   if (actionAcc)
 119     return actionAcc->TakeFocus();
 120
 121   return nsHyperTextAccessibleWrap::TakeFocus();
 122 }
 123
 124 nsresult
 125 nsLinkableAccessible::GetStateInternal(PRUint32 *aState, PRUint32 *aExtraState)
 126 {
 127   nsresult rv = nsHyperTextAccessibleWrap::GetStateInternal(aState,
 128                                                             aExtraState);
 129   NS_ENSURE_A11Y_SUCCESS(rv, rv);
 130
 131   if (mIsLink) {
 132     *aState |= nsIAccessibleStates::STATE_LINKED;
 133     nsCOMPtr<nsIAccessible> actionAcc = GetActionAccessible();
 134     if (nsAccUtils::State(actionAcc) & nsIAccessibleStates::STATE_TRAVERSED)
 135       *aState |= nsIAccessibleStates::STATE_TRAVERSED;
 136   }
 137
 138   return NS_OK;
 139 }
 140
 141 NS_IMETHODIMP
 142 nsLinkableAccessible::GetValue(nsAString& aValue)
 143 {
 144   aValue.Truncate();
 145
 146   nsHyperTextAccessible::GetValue(aValue);
 147   if (!aValue.IsEmpty())
 148     return NS_OK;
 149
 150   if (mIsLink) {
 151     nsCOMPtr<nsIAccessible> actionAcc = GetActionAccessible();
 152     if (actionAcc)
 153       return actionAcc->GetValue(aValue);
 154   }
 155
 156   return NS_ERROR_NOT_IMPLEMENTED;
 157 }
 158
 159
 160 NS_IMETHODIMP
 161 nsLinkableAccessible::GetNumActions(PRUint8 *aNumActions)
 162 {
 163   NS_ENSURE_ARG_POINTER(aNumActions);
 164
 165   *aNumActions = mActionContent ? 1 : 0;
 166   return NS_OK;
 167 }
 168
 169 NS_IMETHODIMP
 170 nsLinkableAccessible::GetActionName(PRUint8 aIndex, nsAString& aName)
 171 {
 172   aName.Truncate();
 173
 174   // Action 0 (default action): Jump to link
 175   if (aIndex == eAction_Jump) {
 176     if (mIsLink) {
 177       aName.AssignLiteral("jump");
 178       return NS_OK;
 179     }
 180     else if (mIsOnclick) {
 181       aName.AssignLiteral("click");
 182       return NS_OK;
 183     }
 184     return NS_ERROR_NOT_IMPLEMENTED;
 185   }
 186   return NS_ERROR_INVALID_ARG;
 187 }
 188
 189 NS_IMETHODIMP
 190 nsLinkableAccessible::DoAction(PRUint8 aIndex)
 191 {
 192   if (aIndex != eAction_Jump)
 193     return NS_ERROR_INVALID_ARG;
 194
 195   nsCOMPtr<nsIAccessible> actionAcc = GetActionAccessible();
 196   if (actionAcc)
 197     return actionAcc->DoAction(aIndex);
 198
 199   return nsHyperTextAccessibleWrap::DoAction(aIndex);
 200 }
 201
 202 NS_IMETHODIMP
 203 nsLinkableAccessible::GetKeyboardShortcut(nsAString& aKeyboardShortcut)
 204 {
 205   aKeyboardShortcut.Truncate();
 206
 207   nsCOMPtr<nsIAccessible> actionAcc = GetActionAccessible();
 208   if (actionAcc)
 209     return actionAcc->GetKeyboardShortcut(aKeyboardShortcut);
 210
 211   return nsAccessible::GetKeyboardShortcut(aKeyboardShortcut);
 212 }
 213
 214 ////////////////////////////////////////////////////////////////////////////////
 215 // nsLinkableAccessible. nsIAccessibleHyperLink
 216
 217 NS_IMETHODIMP
 218 nsLinkableAccessible::GetURI(PRInt32 aIndex, nsIURI **aURI)
 219 {
 220   if (mIsLink) {
 221     nsCOMPtr<nsIAccessible> actionAcc = GetActionAccessible();
 222     if (actionAcc) {
 223       nsCOMPtr<nsIAccessibleHyperLink> hyperLinkAcc =
 224         do_QueryInterface(actionAcc);
 225       NS_ASSERTION(hyperLinkAcc,
 226                    "nsIAccessibleHyperLink isn't implemented.");
 227
 228       if (hyperLinkAcc)
 229         return hyperLinkAcc->GetURI(aIndex, aURI);
 230     }
 231   }
 232
 233   return NS_ERROR_INVALID_ARG;
 234 }
 235
 236 ////////////////////////////////////////////////////////////////////////////////
 237 // nsLinkableAccessible. nsAccessNode
 238
 239 nsresult
 240 nsLinkableAccessible::Init()
 241 {
 242   CacheActionContent();
 243   return nsHyperTextAccessibleWrap::Init();
 244 }
 245
 246 nsresult
 247 nsLinkableAccessible::Shutdown()
 248 {
 249   mActionContent = nsnull;
 250   return nsHyperTextAccessibleWrap::Shutdown();
 251 }
 252
 253 ////////////////////////////////////////////////////////////////////////////////
 254 // nsLinkableAccessible
 255
 256 void
 257 nsLinkableAccessible::CacheActionContent()
 258 {
 259   nsCOMPtr<nsIContent> walkUpContent(do_QueryInterface(mDOMNode));
 260   PRBool isOnclick = nsCoreUtils::HasListener(walkUpContent,
 261                                               NS_LITERAL_STRING("click"));
 262
 263   if (isOnclick) {
 264     mActionContent = walkUpContent;
 265     mIsOnclick = PR_TRUE;
 266     return;
 267   }
 268
 269   while ((walkUpContent = walkUpContent->GetParent())) {
 270     isOnclick = nsCoreUtils::HasListener(walkUpContent,
 271                                          NS_LITERAL_STRING("click"));
 272
 273     nsCOMPtr<nsIDOMNode> walkUpNode(do_QueryInterface(walkUpContent));
 274
 275     nsCOMPtr<nsIAccessible> walkUpAcc;
 276     GetAccService()->GetAccessibleInWeakShell(walkUpNode, mWeakShell,
 277                                               getter_AddRefs(walkUpAcc));
 278
 279     if (nsAccUtils::Role(walkUpAcc) == nsIAccessibleRole::ROLE_LINK &&
 280         nsAccUtils::State(walkUpAcc) & nsIAccessibleStates::STATE_LINKED) {
 281       mIsLink = PR_TRUE;
 282       mActionContent = walkUpContent;
 283       return;
 284     }
 285
 286     if (isOnclick) {
 287       mActionContent = walkUpContent;
 288       mIsOnclick = PR_TRUE;
 289       return;
 290     }
 291   }
 292 }
 293
 294 already_AddRefed<nsIAccessible>
 295 nsLinkableAccessible::GetActionAccessible()
 296 {
 297   // Return accessible for the action content if it's different from node of
 298   // this accessible. If the action accessible is not null then it is used to
 299   // redirect methods calls otherwise we use method implementation from the
 300   // base class.
 301   nsCOMPtr<nsIDOMNode> actionNode(do_QueryInterface(mActionContent));
 302   if (!actionNode || mDOMNode == actionNode)
 303     return nsnull;
 304
 305   nsIAccessible *accessible = nsnull;
 306   GetAccService()->GetAccessibleInWeakShell(actionNode, mWeakShell,
 307                                             &accessible);
 308   return accessible;
 309 }
 310
 311 //---------------------
 312 // nsEnumRoleAccessible
 313 //---------------------
 314
 315 nsEnumRoleAccessible::nsEnumRoleAccessible(nsIDOMNode* aNode, nsIWeakReference* aShell, PRUint32 aRole) :
 316   nsAccessibleWrap(aNode, aShell),
 317   mRole(aRole)
 318 {
 319 }
 320
 321 NS_IMPL_ISUPPORTS_INHERITED0(nsEnumRoleAccessible, nsAccessible)