/*

 * Copyright (C) 2008, 2009, 2010 Apple Inc. All Rights Reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY

 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY

 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 

 */

#include "config.h"

#include "AXObjectCache.h"

#include "AccessibilityObject.h"

#include "Chrome.h"

#include "Document.h"

#include "Page.h"

#include "RenderObject.h"

using namespace std;

namespace WebCore {

void AXObjectCache::detachWrapper(AccessibilityObject* obj)

{

    // On Windows, AccessibilityObjects are created when get_accChildCount is

    // called, but they are not wrapped until get_accChild is called, so this

    // object may not have a wrapper.

    if (AccessibilityObjectWrapper* wrapper = obj->wrapper())

        wrapper->detach();

}

void AXObjectCache::attachWrapper(AccessibilityObject*)

{

    // On Windows, AccessibilityObjects are wrapped when the accessibility

    // software requests them via get_accChild.

}

void AXObjectCache::handleScrolledToAnchor(const Node* anchorNode)

{

    // The anchor node may not be accessible. Post the notification for the

    // first accessible object.

    postPlatformNotification(AccessibilityObject::firstAccessibleObjectFromNode(anchorNode), AXScrolledToAnchor);

}

void AXObjectCache::postPlatformNotification(AccessibilityObject* obj, AXNotification notification)

{

    if (!obj)

        return;

    Document* document = obj->document();

    if (!document)

        return;

    Page* page = document->page();

    if (!page || !page->chrome()->platformPageClient())

        return;

    DWORD msaaEvent;

    switch (notification) {

        case AXFocusedUIElementChanged:

        case AXActiveDescendantChanged:

            msaaEvent = EVENT_OBJECT_FOCUS;

            break;

        case AXScrolledToAnchor:

            msaaEvent = EVENT_SYSTEM_SCROLLINGSTART;

            break;

        case AXValueChanged:

        case AXMenuListValueChanged:

            msaaEvent = EVENT_OBJECT_VALUECHANGE;

            break;

        default:

            return;

    }

    // Windows will end up calling get_accChild() on the root accessible

    // object for the WebView, passing the child ID that we specify below. We

    // negate the AXID so we know that the caller is passing the ID of an

    // element, not the index of a child element.

    ASSERT(obj->axObjectID() >= 1);

    ASSERT(obj->axObjectID() <= numeric_limits<LONG>::max());

    NotifyWinEvent(msaaEvent, page->chrome()->platformPageClient(), OBJID_CLIENT, -static_cast<LONG>(obj->axObjectID()));

}

AXID AXObjectCache::platformGenerateAXID() const

{

    static AXID lastUsedID = 0;

    // Generate a new ID. Windows accessibility relies on a positive AXID,

    // ranging from 1 to LONG_MAX.

    AXID objID = lastUsedID;

    do {

        ++objID;

        objID %= std::numeric_limits<LONG>::max();

    } while (objID == 0 || HashTraits<AXID>::isDeletedValue(objID) || m_idsInUse.contains(objID));

    ASSERT(objID >= 1 && objID <= std::numeric_limits<LONG>::max());

    lastUsedID = objID;

    return objID;

}

void AXObjectCache::handleFocusedUIElementChanged(RenderObject*, RenderObject* newFocusedRenderer)

{

    if (!newFocusedRenderer)

        return;

    Page* page = newFocusedRenderer->document()->page();

    if (!page || !page->chrome()->platformPageClient())

        return;

    AccessibilityObject* focusedObject = focusedUIElementForPage(page);

    if (!focusedObject)

        return;

    ASSERT(!focusedObject->accessibilityIsIgnored());

    postPlatformNotification(focusedObject, AXFocusedUIElementChanged);

}

} // namespace WebCore