Support IAccessibleHypertext.

content/browser/accessibility/browser_accessibility_win.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/accessibility/browser_accessibility_win.h"
 
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "base/win/scoped_comptr.h"
@@ skipping 1586 matching lines @@
   if (!instance_active_)
     return E_FAIL;
 
   if (!n_characters)
     return E_INVALIDARG;
 
   if (role_ == WebAccessibility::ROLE_TEXT_FIELD ||
       role_ == WebAccessibility::ROLE_TEXTAREA) {
     *n_characters = value_.length();
   } else {
-    *n_characters = name_.length();
+    *n_characters = hypertext_.length();

[dmazzoni, 2011/10/28 17:33:53]

Can this method use TextForIAccessibleText instead?

[David Tseng, 2011/10/28 18:25:15]

Done.

   }
 
   return S_OK;
 }
 
 STDMETHODIMP BrowserAccessibilityWin::get_caretOffset(LONG* offset) {
   if (!instance_active_)
     return E_FAIL;
 
   if (!offset)
@@ skipping 224 matching lines @@
     return E_INVALIDARG;
 
   // TODO(dmazzoni): implement this. We're returning S_OK for now so that
   // screen readers still return partially accurate results rather than
   // completely failing.
   *offset = 0;
   return S_OK;
 }
 
 //
+// IAccessibleHypertext methods.
+//
+
+STDMETHODIMP BrowserAccessibilityWin::get_nHyperlinks(long* hyperlink_count) {
+  if (!instance_active_)
+    return E_FAIL;
+
+  *hyperlink_count = hyperlink_offset_to_index_.size();

[dmazzoni, 2011/10/28 17:33:53]

Need to check all pointer arguments and return E_INVALIDARG if they're null.

[David Tseng, 2011/10/28 18:25:15]

Done.

+  return S_OK;
+}
+
+STDMETHODIMP BrowserAccessibilityWin::get_hyperlink(
+    long index,
+    IAccessibleHyperlink** hyperlink) {
+  if (!instance_active_)
+    return E_FAIL;
+
+  if (index < 0 || index >= static_cast<long>(children().size()) || !hyperlink)

[dmazzoni, 2011/10/28 17:33:53]

You only have an embedded object character for non-static-text children, right?
So does it make sense for this to support getting hyperlinks to static text
children?

Instead of accessing children, could you access hyperlink_offset_to_index_ here?

[David Tseng, 2011/10/28 18:25:15]

The documentation states that clients are supposed to first call
get_hyperlinkIndex to get the hyperlink index corresponding to a provided
offset. That index is then passed into this method.

I guess I could just return the offset as the index in get_hyperlinkIndex and
check for it's existence in the map here.

[dmazzoni, 2011/11/01 05:08:34]

Clients can also call nHyperlinks and iterate over them in order from 0 to
nHyperlinks - 1, right? My concern is that your implementation breaks this -
nHyperlinks returns the number of object children (non-text), but get_hyperlink
returns a hyperlink based on its child index including all children.

+    return E_INVALIDARG;
+
+  *hyperlink = static_cast<IAccessibleHyperlink*>(
+      children_[index]->toBrowserAccessibilityWin()->NewReference());
+  return S_OK;
+}
+
+STDMETHODIMP BrowserAccessibilityWin::get_hyperlinkIndex(long char_index,
+    long* hyperlink_index) {
+  *hyperlink_index = -1;
+
+  if (!instance_active_)
+    return E_FAIL;
+
+  if (char_index < 0 || char_index >= static_cast<long>(hypertext_.size()))
+    return E_INVALIDARG;
+
+  std::map<int32, int32>::iterator it =
+      hyperlink_offset_to_index_.find(char_index);
+  if (it == hyperlink_offset_to_index_.end())
+    return E_FAIL;
+
+  *hyperlink_index = it->second;
+  return S_OK;
+}
+
+//
 // IAccessibleValue methods.
 //
 
 STDMETHODIMP BrowserAccessibilityWin::get_currentValue(VARIANT* value) {
   if (!instance_active_)
     return E_FAIL;
 
   if (!value)
     return E_INVALIDARG;
 
@@ skipping 373 matching lines @@
 // IServiceProvider methods.
 //
 
 STDMETHODIMP BrowserAccessibilityWin::QueryService(
     REFGUID guidService, REFIID riid, void** object) {
   if (!instance_active_)
     return E_FAIL;
 
   if (guidService == IID_IAccessible ||
       guidService == IID_IAccessible2 ||
+      guidService == IID_IAccessibleAction ||
+      guidService == IID_IAccessibleHyperlink ||
+      guidService == IID_IAccessibleHypertext ||
       guidService == IID_IAccessibleImage ||
       guidService == IID_IAccessibleTable ||
       guidService == IID_IAccessibleTable2 ||
       guidService == IID_IAccessibleTableCell ||
       guidService == IID_IAccessibleText ||
       guidService == IID_IAccessibleValue ||
       guidService == IID_ISimpleDOMDocument ||
       guidService == IID_ISimpleDOMNode ||
       guidService == IID_ISimpleDOMText ||
       guidService == GUID_ISimpleDOM) {
     return QueryInterface(riid, object);
   }
 
   *object = NULL;
   return E_FAIL;
 }
 
 //
 // CComObjectRootEx methods.
 //
 
 HRESULT WINAPI BrowserAccessibilityWin::InternalQueryInterface(
     void* this_ptr,
     const _ATL_INTMAP_ENTRY* entries,
     REFIID iid,
     void** object) {
-  if (iid == IID_IAccessibleText) {
-    if (ia_role_ != ROLE_SYSTEM_LINK && ia_role_ != ROLE_SYSTEM_TEXT) {
-      *object = NULL;
-      return E_NOINTERFACE;
-    }
-  } else if (iid == IID_IAccessibleImage) {
+  if (iid == IID_IAccessibleImage) {
     if (ia_role_ != ROLE_SYSTEM_GRAPHIC) {
       *object = NULL;
       return E_NOINTERFACE;
     }
   } else if (iid == IID_IAccessibleTable || iid == IID_IAccessibleTable2) {
     if (ia_role_ != ROLE_SYSTEM_TABLE) {
       *object = NULL;
       return E_NOINTERFACE;
     }
   } else if (iid == IID_IAccessibleTableCell) {
@@ skipping 123 matching lines @@
     // Add a labelled by relationship.
     CComObject<BrowserAccessibilityRelation>* relation;
     HRESULT hr = CComObject<BrowserAccessibilityRelation>::CreateInstance(
         &relation);
     DCHECK(SUCCEEDED(hr));
     relation->AddRef();
     relation->Initialize(this, IA2_RELATION_LABELLED_BY);
     relation->AddTarget(title_elem_id);
     relations_.push_back(relation);
   }
+
+  // Construct the hypertext for this node.
+  hyperlink_offset_to_index_.clear();
+  hypertext_.clear();
+  for (unsigned int i = 0; i < children().size(); ++i) {
+    BrowserAccessibility* child = children()[i];
+    if (child->role() == WebAccessibility::ROLE_STATIC_TEXT) {
+      hypertext_ += child->name();
+    } else {
+      hyperlink_offset_to_index_[hypertext_.size()] = i;
+      hypertext_ += L"\xfffc";

[dmazzoni, 2011/10/28 17:33:53]

Define a constant for this

[David Tseng, 2011/10/28 18:25:15]

Done.

+    }
+  }
 }
 
 void BrowserAccessibilityWin::SendNodeUpdateEvents() {
   // Fire an event when an alert first appears.
   if (role_ == WebAccessibility::ROLE_ALERT && first_time_)
     manager_->NotifyAccessibilityEvent(ViewHostMsg_AccEvent::ALERT, this);
 
   // Fire events if text has changed.
   string16 text = TextForIAccessibleText();
   if (previous_text_ != text) {
@@ skipping 79 matching lines @@
                               base::IntToString16(value));
 }
 
 string16 BrowserAccessibilityWin::Escape(const string16& str) {
   return net::EscapeQueryParamValueUTF8(str, false);
 }
 
 const string16& BrowserAccessibilityWin::TextForIAccessibleText() {
   if (IsEditableText()) {
     return value_;
+  } else if (role_ == WebAccessibility::ROLE_STATIC_TEXT) {
+    return name_;
   } else {
-    return name_;
+    return hypertext_;
   }
 }
 
 void BrowserAccessibilityWin::HandleSpecialTextOffset(
     const string16& text, LONG* offset) {
   if (*offset == IA2_TEXT_OFFSET_LENGTH) {
     *offset = static_cast<LONG>(text.size());
   } else if (*offset == IA2_TEXT_OFFSET_CARET) {
     get_caretOffset(offset);
   }
@@ skipping 487 matching lines @@
   }
 
   // The role should always be set.
   DCHECK(!role_name_.empty() || ia_role_);
 
   // If we didn't explicitly set the IAccessible2 role, make it the same
   // as the MSAA role.
   if (!ia2_role_)
     ia2_role_ = ia_role_;
 }