/*

 * Copyright (C) 2003, 2004, 2005, 2006 Apple Computer, 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 COMPUTER, 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 COMPUTER, 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.

 */

#import "config.h"

#import "AXObjectCache.h"

#import "Document.h"

#import "FoundationExtras.h"

#import "RenderObject.h"

#import "WebCoreAXObject.h"

#import "WebCoreViewFactory.h"

// The simple Cocoa calls in this file don't throw exceptions.

namespace WebCore {

struct TextMarkerData  {

    AXID axID;

    Node* node;

    int offset;

    EAffinity affinity;

};

bool AXObjectCache::gAccessibilityEnabled = false;

AXObjectCache::~AXObjectCache()

{

    HashMap<RenderObject*, WebCoreAXObject*>::iterator end = m_objects.end();

    for (HashMap<RenderObject*, WebCoreAXObject*>::iterator it = m_objects.begin(); it != end; ++it) {

        WebCoreAXObject* obj = (*it).second;

        [obj detach];

        HardRelease(obj);

    }

}

WebCoreAXObject* AXObjectCache::get(RenderObject* renderer)

{

    WebCoreAXObject* obj = m_objects.get(renderer);

    if (obj)

        return obj;

    obj = [[WebCoreAXObject alloc] initWithRenderer:renderer];

    HardRetainWithNSRelease(obj);

    m_objects.set(renderer, obj);

    return obj;

}

void AXObjectCache::remove(RenderObject* renderer)

{

    HashMap<RenderObject*, WebCoreAXObject*>::iterator it = m_objects.find(renderer);

    if (it == m_objects.end())

        return;

    WebCoreAXObject* obj = (*it).second;

    [obj detach];

    HardRelease(obj);

    m_objects.remove(it);

    ASSERT(m_objects.size() >= m_idsInUse.size());

}

AXID AXObjectCache::getAXID(WebCoreAXObject* obj)

{

    // check for already-assigned ID

    AXID objID = [obj axObjectID];

    if (objID) {

        ASSERT(m_idsInUse.contains(objID));

        return objID;

    }

    // generate a new ID

    static AXID lastUsedID = 0;

    objID = lastUsedID;

    do

        ++objID;

    while (objID == 0 || objID == AXIDHashTraits::deletedValue() || m_idsInUse.contains(objID));

    m_idsInUse.add(objID);

    lastUsedID = objID;

    [obj setAXObjectID:objID];

    return objID;

}

void AXObjectCache::removeAXID(WebCoreAXObject* obj)

{

    AXID objID = [obj axObjectID];

    if (objID == 0)

        return;

    ASSERT(objID != AXIDHashTraits::deletedValue());

    ASSERT(m_idsInUse.contains(objID));

    [obj setAXObjectID:0];

    m_idsInUse.remove(objID);

}

WebCoreTextMarker* AXObjectCache::textMarkerForVisiblePosition(const VisiblePosition& visiblePos)

{

    Position deepPos = visiblePos.deepEquivalent();

    Node* domNode = deepPos.node();

    ASSERT(domNode);

    if (!domNode)

        return nil;

    // locate the renderer, which must exist for a visible dom node

    RenderObject* renderer = domNode->renderer();

    ASSERT(renderer);

    // find or create an accessibility object for this renderer

    WebCoreAXObject* obj = get(renderer);

    // create a text marker, adding an ID for the WebCoreAXObject if needed

    TextMarkerData textMarkerData;

    textMarkerData.axID = getAXID(obj);

    textMarkerData.node = domNode;

    textMarkerData.offset = deepPos.offset();

    textMarkerData.affinity = visiblePos.affinity();

    return [[WebCoreViewFactory sharedFactory] textMarkerWithBytes:&textMarkerData length:sizeof(textMarkerData)]; 

}

VisiblePosition AXObjectCache::visiblePositionForTextMarker(WebCoreTextMarker* textMarker)

{

    TextMarkerData textMarkerData;

    if (![[WebCoreViewFactory sharedFactory] getBytes:&textMarkerData fromTextMarker:textMarker length:sizeof(textMarkerData)])

        return VisiblePosition();

    // return empty position if the text marker is no longer valid

    if (!m_idsInUse.contains(textMarkerData.axID))

        return VisiblePosition();

    // generate a VisiblePosition from the data we stored earlier

    VisiblePosition visiblePos = VisiblePosition(textMarkerData.node, textMarkerData.offset, textMarkerData.affinity);

    // make sure the node and offset still match (catches stale markers). affinity is not critical for this.

    Position deepPos = visiblePos.deepEquivalent();

    if (deepPos.node() != textMarkerData.node || deepPos.offset() != textMarkerData.offset)

        return VisiblePosition();

    return visiblePos;

}

void AXObjectCache::childrenChanged(RenderObject* renderer)

{

    WebCoreAXObject* obj = m_objects.get(renderer);

    if (obj)

        [obj childrenChanged];

}

void AXObjectCache::postNotification(RenderObject* renderer, const String& message)

{

    if (!renderer)

        return;

    // notifications for text input objects are sent to that object

    // all others are sent to the top WebArea

    WebCoreAXObject* obj = [get(renderer) observableObject];

    if (obj)

        NSAccessibilityPostNotification(obj, message);

    else

        NSAccessibilityPostNotification(get(renderer->document()->renderer()), message);

}

void AXObjectCache::postNotificationToElement(RenderObject* renderer, const String& message)

{

    // send the notification to the specified element itself, not one of its ancestors

    if (renderer)

        NSAccessibilityPostNotification(get(renderer), message);

}

void AXObjectCache::handleFocusedUIElementChanged()

{

    [[WebCoreViewFactory sharedFactory] accessibilityHandleFocusChanged];

}

}