accessible/src/html/nsHTMLLinkAccessible.cpp

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   3  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
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  15  * The Original Code is mozilla.org code.
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  17  * The Initial Developer of the Original Code is
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  20  * the Initial Developer. All Rights Reserved.
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  22  * Contributor(s):
  23  *   Aaron Leventhal <aleventh@us.ibm.com> (original author)
  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"),
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  38  * ***** END LICENSE BLOCK ***** */
  39
  40 #include "nsHTMLLinkAccessible.h"
  41
  42 #include "nsILink.h"
  43
  44 ////////////////////////////////////////////////////////////////////////////////
  45 // nsHTMLLinkAccessible
  46
  47 nsHTMLLinkAccessible::nsHTMLLinkAccessible(nsIDOMNode* aDomNode,
  48                                            nsIWeakReference* aShell):
  49   nsHyperTextAccessibleWrap(aDomNode, aShell)
  50 {
  51 }
  52
  53 // Expose nsIAccessibleHyperLink unconditionally
  54 NS_IMPL_ISUPPORTS_INHERITED1(nsHTMLLinkAccessible, nsHyperTextAccessibleWrap,
  55                              nsIAccessibleHyperLink)
  56
  57 ////////////////////////////////////////////////////////////////////////////////
  58 // nsIAccessible
  59
  60 NS_IMETHODIMP
  61 nsHTMLLinkAccessible::GetName(nsAString& aName)
  62 {
  63   aName.Truncate();
  64
  65   if (IsDefunct())
  66     return NS_ERROR_FAILURE;
  67
  68   nsCOMPtr<nsIContent> content(do_QueryInterface(mDOMNode));
  69   nsresult rv = AppendFlatStringFromSubtree(content, &aName);
  70   NS_ENSURE_SUCCESS(rv, rv);
  71
  72   if (aName.IsEmpty()) {
  73     // Probably an image without alt or title inside, try to get the name on
  74     // the link by usual way.
  75     return GetHTMLName(aName, PR_FALSE);
  76   }
  77
  78   return NS_OK;
  79 }
  80
  81 NS_IMETHODIMP
  82 nsHTMLLinkAccessible::GetRole(PRUint32 *aRole)
  83 {
  84   NS_ENSURE_ARG_POINTER(aRole);
  85
  86   *aRole = nsIAccessibleRole::ROLE_LINK;
  87   return NS_OK;
  88 }
  89
  90 NS_IMETHODIMP
  91 nsHTMLLinkAccessible::GetState(PRUint32 *aState, PRUint32 *aExtraState)
  92 {
  93   nsresult rv = nsHyperTextAccessibleWrap::GetState(aState, aExtraState);
  94   NS_ENSURE_SUCCESS(rv, rv);
  95   if (!mDOMNode)
  96     return NS_OK;
  97
  98   *aState  &= ~nsIAccessibleStates::STATE_READONLY;
  99
 100   nsCOMPtr<nsIContent> content(do_QueryInterface(mDOMNode));
 101   if (content && content->HasAttr(kNameSpaceID_None,
 102                                   nsAccessibilityAtoms::name)) {
 103     // This is how we indicate it is a named anchor
 104     // In other words, this anchor can be selected as a location :)
 105     // There is no other better state to use to indicate this.
 106     *aState |= nsIAccessibleStates::STATE_SELECTABLE;
 107   }
 108
 109   nsCOMPtr<nsILink> link = do_QueryInterface(mDOMNode);
 110   NS_ENSURE_STATE(link);
 111
 112   nsLinkState linkState;
 113   link->GetLinkState(linkState);
 114   if (linkState == eLinkState_NotLink || linkState == eLinkState_Unknown) {
 115     // This is a either named anchor (a link with also a name attribute) or
 116     // it doesn't have any attributes. Check if 'click' event handler is
 117     // registered, otherwise bail out.
 118     PRBool isOnclick = nsAccUtils::HasListener(content,
 119                                                NS_LITERAL_STRING("click"));
 120     if (!isOnclick)
 121       return NS_OK;
 122   }
 123
 124   *aState |= nsIAccessibleStates::STATE_LINKED;
 125
 126   if (linkState == eLinkState_Visited)
 127     *aState |= nsIAccessibleStates::STATE_TRAVERSED;
 128
 129   return NS_OK;
 130 }
 131
 132 NS_IMETHODIMP
 133 nsHTMLLinkAccessible::GetValue(nsAString& aValue)
 134 {
 135   aValue.Truncate();
 136
 137   nsresult rv = nsHyperTextAccessible::GetValue(aValue);
 138   NS_ENSURE_SUCCESS(rv, rv);
 139
 140   if (!aValue.IsEmpty())
 141     return NS_OK;
 142
 143   nsCOMPtr<nsIPresShell> presShell(do_QueryReferent(mWeakShell));
 144   if (mDOMNode && presShell)
 145     return presShell->GetLinkLocation(mDOMNode, aValue);
 146
 147   return NS_OK;
 148 }
 149
 150 NS_IMETHODIMP
 151 nsHTMLLinkAccessible::GetNumActions(PRUint8 *aNumActions)
 152 {
 153   NS_ENSURE_ARG_POINTER(aNumActions);
 154
 155   if (!IsLinked())
 156     return nsHyperTextAccessible::GetNumActions(aNumActions);
 157
 158   *aNumActions = 1;
 159   return NS_OK;
 160 }
 161
 162 NS_IMETHODIMP
 163 nsHTMLLinkAccessible::GetActionName(PRUint8 aIndex, nsAString& aName)
 164 {
 165   aName.Truncate();
 166
 167   if (!IsLinked())
 168     return nsHyperTextAccessible::GetActionName(aIndex, aName);
 169
 170   // Action 0 (default action): Jump to link
 171   if (aIndex != eAction_Jump)
 172     return NS_ERROR_INVALID_ARG;
 173
 174   aName.AssignLiteral("jump");
 175   return NS_OK;
 176 }
 177
 178 NS_IMETHODIMP
 179 nsHTMLLinkAccessible::DoAction(PRUint8 aIndex)
 180 {
 181   if (!IsLinked())
 182     return nsHyperTextAccessible::DoAction(aIndex);
 183
 184   // Action 0 (default action): Jump to link
 185   if (aIndex != eAction_Jump)
 186     return NS_ERROR_INVALID_ARG;
 187
 188   if (IsDefunct())
 189     return NS_ERROR_FAILURE;
 190
 191   nsCOMPtr<nsIContent> content(do_QueryInterface(mDOMNode));
 192   return DoCommand(content);
 193 }
 194
 195 ////////////////////////////////////////////////////////////////////////////////
 196 // nsIAccessibleHyperLink
 197
 198 NS_IMETHODIMP
 199 nsHTMLLinkAccessible::GetURI(PRInt32 aIndex, nsIURI **aURI)
 200 {
 201   NS_ENSURE_ARG_POINTER(aURI);
 202   *aURI = nsnull;
 203
 204   if (aIndex != 0)
 205     return NS_ERROR_INVALID_ARG;
 206
 207   nsCOMPtr<nsILink> link(do_QueryInterface(mDOMNode));
 208   NS_ENSURE_STATE(link);
 209
 210   return link->GetHrefURI(aURI);
 211 }
 212
 213 ////////////////////////////////////////////////////////////////////////////////
 214 // Protected members
 215
 216 PRBool
 217 nsHTMLLinkAccessible::IsLinked()
 218 {
 219   nsCOMPtr<nsILink> link(do_QueryInterface(mDOMNode));
 220   if (!link)
 221     return PR_FALSE;
 222
 223   nsLinkState linkState;
 224   nsresult rv = link->GetLinkState(linkState);
 225
 226   return NS_SUCCEEDED(rv) && linkState != eLinkState_NotLink &&
 227          linkState != eLinkState_Unknown;
 228 }