accessiblebase.cpp

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    static String accessKeyModifiers;
    if (accessKeyModifiers.isNull()) {
        unsigned modifiers = EventHandler::accessKeyModifiers();
        // Follow the same order as Mozilla MSAA implementation:
        // Ctrl+Alt+Shift+Meta+key. MSDN states that keyboard shortcut strings
        // should not be localized and defines the separator as "+".
        if (modifiers & PlatformKeyboardEvent::CtrlKey)
            accessKeyModifiers += "Ctrl+";
        if (modifiers & PlatformKeyboardEvent::AltKey)
            accessKeyModifiers += "Alt+";
        if (modifiers & PlatformKeyboardEvent::ShiftKey)
            accessKeyModifiers += "Shift+";
        if (modifiers & PlatformKeyboardEvent::MetaKey)
            accessKeyModifiers += "Win+";
    }
    *shortcut = BString(accessKeyModifiers + accessKey).release();
    return S_OK;
}

HRESULT STDMETHODCALLTYPE AccessibleBase::accSelect(long, VARIANT)
{
    return E_NOTIMPL;
}

HRESULT STDMETHODCALLTYPE AccessibleBase::get_accSelection(VARIANT*)
{
    return E_NOTIMPL;
}

HRESULT STDMETHODCALLTYPE AccessibleBase::get_accFocus(VARIANT* pvFocusedChild)
{
    if (!pvFocusedChild)
        return E_POINTER;

    ::VariantInit(pvFocusedChild);

    if (!m_object)
        return E_FAIL;

    AccessibilityObject* focusedObj = m_object->focusedUIElement();
    if (!focusedObj)
        return S_FALSE;

    if (focusedObj == m_object) {
        V_VT(pvFocusedChild) = VT_I4;
        V_I4(pvFocusedChild) = CHILDID_SELF;
        return S_OK;
    }

    V_VT(pvFocusedChild) = VT_DISPATCH;
    V_DISPATCH(pvFocusedChild) = wrapper(focusedObj);
    V_DISPATCH(pvFocusedChild)->AddRef();
    return S_OK;
}

HRESULT STDMETHODCALLTYPE AccessibleBase::get_accDefaultAction(VARIANT vChild, BSTR* action)
{
    if (!action)
        return E_POINTER;

    *action = 0;

    AccessibilityObject* childObj;
    HRESULT hr = getAccessibilityObjectForChild(vChild, childObj);

    if (FAILED(hr))
        return hr;

    if (*action = BString(childObj->actionVerb()).release())
        return S_OK;
    return S_FALSE;
}

HRESULT STDMETHODCALLTYPE AccessibleBase::accLocation(long* left, long* top, long* width, long* height, VARIANT vChild)
{
    if (!left || !top || !width || !height)
        return E_POINTER;

    *left = *top = *width = *height = 0;

    AccessibilityObject* childObj;
    HRESULT hr = getAccessibilityObjectForChild(vChild, childObj);

    if (FAILED(hr))
        return hr;

    if (!childObj->documentFrameView())
        return E_FAIL;

    IntRect screenRect(childObj->documentFrameView()->contentsToScreen(childObj->boundingBoxRect()));
    *left = screenRect.x();
    *top = screenRect.y();
    *width = screenRect.width();
    *height = screenRect.height();
    return S_OK;
}

HRESULT STDMETHODCALLTYPE AccessibleBase::accNavigate(long direction, VARIANT vFromChild, VARIANT* pvNavigatedTo)
{
    if (!pvNavigatedTo)
        return E_POINTER;

    ::VariantInit(pvNavigatedTo);

    AccessibilityObject* childObj = 0;

    switch (direction) {
        case NAVDIR_DOWN:
        case NAVDIR_UP:
        case NAVDIR_LEFT:
        case NAVDIR_RIGHT:
            // These directions are not implemented, matching Mozilla and IE.
            return E_NOTIMPL;
        case NAVDIR_LASTCHILD:
        case NAVDIR_FIRSTCHILD:
            // MSDN states that navigating to first/last child can only be from self.
            if (vFromChild.lVal != CHILDID_SELF)
                return E_INVALIDARG;

            if (!m_object)
                return E_FAIL;

            if (direction == NAVDIR_FIRSTCHILD)
                childObj = m_object->firstChild();
            else
                childObj = m_object->lastChild();
            break;
        case NAVDIR_NEXT:
        case NAVDIR_PREVIOUS: {
            // Navigating to next and previous is allowed from self or any of our children.
            HRESULT hr = getAccessibilityObjectForChild(vFromChild, childObj);
            if (FAILED(hr))
                return hr;

            if (direction == NAVDIR_NEXT)
                childObj = childObj->nextSibling();
            else
                childObj = childObj->previousSibling();
            break;
        }
        default:
            ASSERT_NOT_REACHED();
            return E_INVALIDARG;
    }

    if (!childObj)
        return S_FALSE;

    V_VT(pvNavigatedTo) = VT_DISPATCH;
    V_DISPATCH(pvNavigatedTo) = wrapper(childObj);
    V_DISPATCH(pvNavigatedTo)->AddRef();
    return S_OK;
}

HRESULT STDMETHODCALLTYPE AccessibleBase::accHitTest(long x, long y, VARIANT* pvChildAtPoint)
{
    if (!pvChildAtPoint)
        return E_POINTER;

    ::VariantInit(pvChildAtPoint);

    if (!m_object || !m_object->documentFrameView())
        return E_FAIL;

    IntPoint point = m_object->documentFrameView()->screenToContents(IntPoint(x, y));
    AccessibilityObject* childObj = m_object->doAccessibilityHitTest(point);

    if (!childObj) {
        // If we did not hit any child objects, test whether the point hit us, and
        // report that.
        if (!m_object->boundingBoxRect().contains(point))
            return S_FALSE;
        childObj = m_object;
    }

    if (childObj == m_object) {
        V_VT(pvChildAtPoint) = VT_I4;
        V_I4(pvChildAtPoint) = CHILDID_SELF;
    } else {
        V_VT(pvChildAtPoint) = VT_DISPATCH;
        V_DISPATCH(pvChildAtPoint) = static_cast<IDispatch*>(wrapper(childObj));
        V_DISPATCH(pvChildAtPoint)->AddRef();
    }
    return S_OK;
}

HRESULT STDMETHODCALLTYPE AccessibleBase::accDoDefaultAction(VARIANT vChild)
{
    AccessibilityObject* childObj;
    HRESULT hr = getAccessibilityObjectForChild(vChild, childObj);

    if (FAILED(hr))
        return hr;

    if (!childObj->performDefaultAction())
        return S_FALSE;

    return S_OK;
}

// AccessibleBase
String AccessibleBase::name() const
{
    return m_object->title();
}

String AccessibleBase::value() const
{
    return m_object->stringValue();
}

String AccessibleBase::description() const
{
    String desc = m_object->accessibilityDescription();
    if (desc.isNull())
        return desc;

    // From the Mozilla MSAA implementation:
    // "Signal to screen readers that this description is speakable and is not
    // a formatted positional information description. Don't localize the
    // 'Description: ' part of this string, it will be parsed out by assistive
    // technologies."
    return "Description: " + desc;
}

static long MSAARole(AccessibilityRole role)
{
    switch (role) {
        case WebCore::ButtonRole:
            return ROLE_SYSTEM_PUSHBUTTON;
        case WebCore::RadioButtonRole:
            return ROLE_SYSTEM_RADIOBUTTON;
        case WebCore::CheckBoxRole:
            return ROLE_SYSTEM_CHECKBUTTON;
        case WebCore::SliderRole:
            return ROLE_SYSTEM_SLIDER;
        case WebCore::TabGroupRole:
            return ROLE_SYSTEM_PAGETABLIST;
        case WebCore::TextFieldRole:
        case WebCore::TextAreaRole:
        case WebCore::ListMarkerRole:
            return ROLE_SYSTEM_TEXT;
        case WebCore::StaticTextRole:
            return ROLE_SYSTEM_STATICTEXT;
        case WebCore::OutlineRole:
            return ROLE_SYSTEM_OUTLINE;
        case WebCore::ColumnRole:
            return ROLE_SYSTEM_COLUMN;
        case WebCore::RowRole:
            return ROLE_SYSTEM_ROW;
        case WebCore::GroupRole:
            return ROLE_SYSTEM_GROUPING;
        case WebCore::ListRole:
            return ROLE_SYSTEM_LIST;
        case WebCore::TableRole:
            return ROLE_SYSTEM_TABLE;
        case WebCore::LinkRole:
        case WebCore::WebCoreLinkRole:
            return ROLE_SYSTEM_LINK;
        case WebCore::ImageMapRole:
        case WebCore::ImageRole:
            return ROLE_SYSTEM_GRAPHIC;
        default:
            // This is the default role for MSAA.
            return ROLE_SYSTEM_CLIENT;
    }
}

long AccessibleBase::role() const
{
    return MSAARole(m_object->roleValue());
}

HRESULT AccessibleBase::getAccessibilityObjectForChild(VARIANT vChild, AccessibilityObject*& childObj) const
{
    childObj = 0;

    if (!m_object)
        return E_FAIL;

    if (vChild.vt != VT_I4)
        return E_INVALIDARG;

    if (vChild.lVal == CHILDID_SELF)
        childObj = m_object;
    else {
        size_t childIndex = static_cast<size_t>(vChild.lVal - 1);

        if (childIndex >= m_object->children().size())
            return E_FAIL;
        childObj = m_object->children().at(childIndex).get();
    }

    if (!childObj)
        return E_FAIL;

    return S_OK;
}

AccessibleBase* AccessibleBase::wrapper(AccessibilityObject* obj)
{
    AccessibleBase* result = static_cast<AccessibleBase*>(obj->wrapper());
    if (!result)
        result = createInstance(obj);
    return result;
}