root/Source/core/accessibility/AXScrollView.cpp

DEFINITIONS

1. m_childrenDirty
2. detach
3. create
4. scrollBar
5. isAttachment
6. widgetForAttachmentView
7. updateChildrenIfNecessary
8. updateScrollbars
9. removeChildScrollbar
10. addChildScrollbar
11. clearChildren
12. computeAccessibilityIsIgnored
13. addChildren
14. webAreaObject
15. accessibilityHitTest
16. elementRect
17. documentFrameView
18. parentObject
19. parentObjectIfExists
20. getScrollableAreaIfScrollable
21. scrollTo

/*
 * Copyright (C) 2011 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 AND ITS CONTRIBUTORS "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 OR ITS 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 "core/accessibility/AXScrollView.h"

#include "core/accessibility/AXObjectCache.h"
#include "core/accessibility/AXScrollbar.h"
#include "core/frame/FrameView.h"
#include "core/frame/LocalFrame.h"
#include "core/html/HTMLFrameOwnerElement.h"

namespace WebCore {

AXScrollView::AXScrollView(ScrollView* view)
    : m_scrollView(view)
    , m_childrenDirty(false)
{
}

AXScrollView::~AXScrollView()
{
    ASSERT(isDetached());
}

void AXScrollView::detach()
{
    AXObject::detach();
    m_scrollView = 0;
}

PassRefPtr<AXScrollView> AXScrollView::create(ScrollView* view)
{
    return adoptRef(new AXScrollView(view));
}

AXObject* AXScrollView::scrollBar(AccessibilityOrientation orientation)
{
    updateScrollbars();

    switch (orientation) {
    case AccessibilityOrientationVertical:
        return m_verticalScrollbar ? m_verticalScrollbar.get() : 0;
    case AccessibilityOrientationHorizontal:
        return m_horizontalScrollbar ? m_horizontalScrollbar.get() : 0;
    }

    return 0;
}

// If this is WebKit1 then the native scroll view needs to return the
// AX information (because there are no scroll bar children in the ScrollView object in WK1).
// In WebKit2, the ScrollView object will return the AX information (because there are no platform widgets).
bool AXScrollView::isAttachment() const
{
    return false;
}

Widget* AXScrollView::widgetForAttachmentView() const
{
    return m_scrollView;
}

void AXScrollView::updateChildrenIfNecessary()
{
    if (m_childrenDirty)
        clearChildren();

    if (!m_haveChildren)
        addChildren();

    updateScrollbars();
}

void AXScrollView::updateScrollbars()
{
    if (!m_scrollView)
        return;

    if (m_scrollView->horizontalScrollbar() && !m_horizontalScrollbar) {
        m_horizontalScrollbar = addChildScrollbar(m_scrollView->horizontalScrollbar());
    } else if (!m_scrollView->horizontalScrollbar() && m_horizontalScrollbar) {
        removeChildScrollbar(m_horizontalScrollbar.get());
        m_horizontalScrollbar = nullptr;
    }

    if (m_scrollView->verticalScrollbar() && !m_verticalScrollbar) {
        m_verticalScrollbar = addChildScrollbar(m_scrollView->verticalScrollbar());
    } else if (!m_scrollView->verticalScrollbar() && m_verticalScrollbar) {
        removeChildScrollbar(m_verticalScrollbar.get());
        m_verticalScrollbar = nullptr;
    }
}

void AXScrollView::removeChildScrollbar(AXObject* scrollbar)
{
    size_t pos = m_children.find(scrollbar);
    if (pos != kNotFound) {
        m_children[pos]->detachFromParent();
        m_children.remove(pos);
    }
}

AXScrollbar* AXScrollView::addChildScrollbar(Scrollbar* scrollbar)
{
    if (!scrollbar)
        return 0;

    AXScrollbar* scrollBarObject = toAXScrollbar(axObjectCache()->getOrCreate(scrollbar));
    scrollBarObject->setParent(this);
    m_children.append(scrollBarObject);
    return scrollBarObject;
}

void AXScrollView::clearChildren()
{
    AXObject::clearChildren();
    m_verticalScrollbar = nullptr;
    m_horizontalScrollbar = nullptr;
}

bool AXScrollView::computeAccessibilityIsIgnored() const
{
    AXObject* webArea = webAreaObject();
    if (!webArea)
        return true;

    return webArea->accessibilityIsIgnored();
}

void AXScrollView::addChildren()
{
    ASSERT(!m_haveChildren);
    m_haveChildren = true;

    AXObject* webArea = webAreaObject();
    if (webArea && !webArea->accessibilityIsIgnored())
        m_children.append(webArea);

    updateScrollbars();
}

AXObject* AXScrollView::webAreaObject() const
{
    if (!m_scrollView || !m_scrollView->isFrameView())
        return 0;

    Document* doc = toFrameView(m_scrollView)->frame().document();
    if (!doc || !doc->renderer())
        return 0;

    return axObjectCache()->getOrCreate(doc);
}

AXObject* AXScrollView::accessibilityHitTest(const IntPoint& point) const
{
    AXObject* webArea = webAreaObject();
    if (!webArea)
        return 0;

    if (m_horizontalScrollbar && m_horizontalScrollbar->elementRect().contains(point))
        return m_horizontalScrollbar.get();
    if (m_verticalScrollbar && m_verticalScrollbar->elementRect().contains(point))
        return m_verticalScrollbar.get();

    return webArea->accessibilityHitTest(point);
}

LayoutRect AXScrollView::elementRect() const
{
    if (!m_scrollView)
        return LayoutRect();

    return m_scrollView->frameRect();
}

FrameView* AXScrollView::documentFrameView() const
{
    if (!m_scrollView || !m_scrollView->isFrameView())
        return 0;

    return toFrameView(m_scrollView);
}

AXObject* AXScrollView::parentObject() const
{
    if (!m_scrollView || !m_scrollView->isFrameView())
        return 0;

    HTMLFrameOwnerElement* owner = toFrameView(m_scrollView)->frame().ownerElement();
    if (owner && owner->renderer())
        return axObjectCache()->getOrCreate(owner);

    return 0;
}

AXObject* AXScrollView::parentObjectIfExists() const
{
    if (!m_scrollView || !m_scrollView->isFrameView())
        return 0;

    HTMLFrameOwnerElement* owner = toFrameView(m_scrollView)->frame().ownerElement();
    if (owner && owner->renderer())
        return axObjectCache()->get(owner);

    return 0;
}

ScrollableArea* AXScrollView::getScrollableAreaIfScrollable() const
{
    return m_scrollView;
}

void AXScrollView::scrollTo(const IntPoint& point) const
{
    if (m_scrollView)
        m_scrollView->setScrollPosition(point);
}

} // namespace WebCore