views: [accessibility] Add support for Accessibility Value.

BUG=9604
TEST=point AccExplorer to Edit Bookmark dialog, see if everything has a MSAA information, like: Name, Role, State, Value.

Patch from Thiago Farina <thiago.farina@gmail.com>
Review URL: http://codereview.chromium.org/928001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@42831 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 60 insertions, 10 deletions

diff --git a/views/accessibility/view_accessibility.cc b/views/accessibility/view_accessibility.cc
index f8bf516..32239d1 100644
--- a/views/accessibility/view_accessibility.cc
+++ b/views/accessibility/view_accessibility.cc
@@ -479,7 +479,7 @@ STDMETHODIMP ViewAccessibility::get_accName(VARIANT var_id, BSTR* name) {
   std::wstring temp_name;
 
   if (var_id.lVal == CHILDID_SELF) {
-    // Retrieve the parent view's name.
+    // Retrieve the current view's name.
     view_->GetAccessibleName(&temp_name);
   } else {
     if (!IsValidChild((var_id.lVal - 1), view_)) {
@@ -600,6 +600,39 @@ STDMETHODIMP ViewAccessibility::get_accState(VARIANT var_id, VARIANT* state) {
   return S_OK;
 }
 
+STDMETHODIMP ViewAccessibility::get_accValue(VARIANT var_id, BSTR* value) {
+  if (var_id.vt != VT_I4 || !value) {
+    return E_INVALIDARG;
+  }
+
+  if (!view_) {
+    return E_FAIL;
+  }
+
+  std::wstring temp_value;
+
+  if (var_id.lVal == CHILDID_SELF) {
+    // Retrieve the current view's value.
+    view_->GetAccessibleValue(&temp_value);
+  } else {
+    if (!IsValidChild((var_id.lVal - 1), view_)) {
+      return E_INVALIDARG;
+    }
+    // Retrieve the child view's value.
+    view_->GetChildViewAt(var_id.lVal - 1)->GetAccessibleValue(&temp_value);
+  }
+  if (!temp_value.empty()) {
+    // Return value retrieved.
+    *value = SysAllocString(temp_value.c_str());
+  } else {
+    // If view has no value, fall back into the default implementation.
+    *value = NULL;
+    return E_NOTIMPL;
+  }
+
+  return S_OK;
+}
+
 // Helper functions.
 
 bool ViewAccessibility::IsValidChild(int child_id, views::View* view) const {
@@ -725,12 +758,6 @@ HRESULT ViewAccessibility::accDoDefaultAction(VARIANT var_id) {
   return E_NOTIMPL;
 }
 
-STDMETHODIMP ViewAccessibility::get_accValue(VARIANT var_id, BSTR* value) {
-  if (value)
-    *value = NULL;
-  return E_NOTIMPL;
-}
-
 STDMETHODIMP ViewAccessibility::get_accSelection(VARIANT* selected) {
   if (selected)
     selected->vt = VT_EMPTY;
diff --git a/views/accessibility/view_accessibility.h b/views/accessibility/view_accessibility.h
index 003ce7a..7d95794 100644
--- a/views/accessibility/view_accessibility.h
+++ b/views/accessibility/view_accessibility.h
@@ -81,14 +81,14 @@ class ATL_NO_VTABLE ViewAccessibility
   // Retrieves the current state of the specified object.
   STDMETHODIMP get_accState(VARIANT var_id, VARIANT* state);
 
+  // Retrieves the current value associated with the specified object.
+  STDMETHODIMP get_accValue(VARIANT var_id, BSTR* value);
+
   // Non-supported IAccessible methods.
 
   // Out-dated and can be safely said to be very rarely used.
   STDMETHODIMP accDoDefaultAction(VARIANT var_id);
 
-  // No value associated with views.
-  STDMETHODIMP get_accValue(VARIANT var_id, BSTR* value);
-
   // Selections not applicable to views.
   STDMETHODIMP get_accSelection(VARIANT* selected);
   STDMETHODIMP accSelect(LONG flags_sel, VARIANT var_id);
diff --git a/views/controls/textfield/textfield.cc b/views/controls/textfield/textfield.cc
index d2e2fae..71f66b4 100644
--- a/views/controls/textfield/textfield.cc
+++ b/views/controls/textfield/textfield.cc
@@ -12,6 +12,7 @@
 
 #include "base/keyboard_codes.h"
 #include "base/string_util.h"
+#include "base/utf_string_conversions.h"
 #include "gfx/insets.h"
 #include "views/controls/native/native_view_host.h"
 #include "views/controls/textfield/native_textfield_wrapper.h"
@@ -284,6 +285,18 @@ void Textfield::SetAccessibleName(const std::wstring& name) {
   accessible_name_.assign(name);
 }
 
+bool Textfield::GetAccessibleValue(std::wstring* value) {
+  DCHECK(value);
+  if (!value)
+    return false;
+
+  if (!text_.empty()) {
+    *value = UTF16ToWide(text_);
+    return true;
+  }
+  return false;
+}
+
 void Textfield::SetEnabled(bool enabled) {
   View::SetEnabled(enabled);
   if (native_wrapper_)
diff --git a/views/controls/textfield/textfield.h b/views/controls/textfield/textfield.h
index 4b8076c..7b36547 100644
--- a/views/controls/textfield/textfield.h
+++ b/views/controls/textfield/textfield.h
@@ -226,6 +226,7 @@ class Textfield : public View {
   virtual bool GetAccessibleName(std::wstring* name);
   virtual bool GetAccessibleState(AccessibilityTypes::State* state);
   virtual void SetAccessibleName(const std::wstring& name);
+  virtual bool GetAccessibleValue(std::wstring* value);
 
  protected:
   virtual void Focus();
diff --git a/views/view.h b/views/view.h
index b226c82..0c047d3 100644
--- a/views/view.h
+++ b/views/view.h
@@ -589,6 +589,10 @@ class View : public AcceleratorTarget {
     return false;
   }
 
+  // Returns the current value associated with a view. Sets the input string
+  // appropriately, and returns true if successful.
+  virtual bool GetAccessibleValue(std::wstring* value) { return false; }
+
   // Assigns a keyboard shortcut string description to the given control. Needed
   // as a View does not know which shortcut will be associated with it until it
   // is created to be a certain type.
@@ -599,6 +603,11 @@ class View : public AcceleratorTarget {
   // certain type.
   virtual void SetAccessibleName(const std::wstring& name) {}
 
+  // Assigns a string value to the given control. Needed as a View does not know
+  // which value will be associated with it until it is created to be a
+  // certain type.
+  virtual void SetAccessibleValue(const std::wstring& value) {}
+
   // Returns an instance of a wrapper class implementing the (platform-specific)
   // accessibility interface for a given View. If one exists, it will be
   // re-used, otherwise a new instance will be created.