accessiblebase.cpp

linux下开源浏览器WebKit的源码,市面上的很多商用浏览器都是移植自WebKit

/*
 * Copyright (C) 2008 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 "WebKitDLL.h"
#include "AccessibleBase.h"

#include <oleacc.h>
#include <WebCore/AccessibilityObject.h>
#include <WebCore/AXObjectCache.h>
#include <WebCore/BString.h>
#include <WebCore/Element.h>
#include <WebCore/EventHandler.h>
#include <WebCore/FrameView.h>
#include <WebCore/HostWindow.h>
#include <WebCore/HTMLNames.h>
#include <WebCore/HTMLFrameElementBase.h>
#include <WebCore/HTMLInputElement.h>
#include <WebCore/IntRect.h>
#include <WebCore/PlatformKeyboardEvent.h>
#include <WebCore/RenderFrame.h>
#include <WebCore/RenderObject.h>
#include <WebCore/RenderView.h>
#include "WebView.h"
#include <wtf/RefPtr.h>

using namespace WebCore;

AccessibleBase::AccessibleBase(AccessibilityObject* obj)
    : AccessibilityObjectWrapper(obj)
    , m_refCount(0)
{
    ASSERT_ARG(obj, obj);
    m_object->setWrapper(this);
    ++gClassCount;
    gClassNameCount.add("AccessibleBase");
}

AccessibleBase::~AccessibleBase()
{
    --gClassCount;
    gClassNameCount.remove("AccessibleBase");
}

AccessibleBase* AccessibleBase::createInstance(AccessibilityObject* obj)
{
    ASSERT_ARG(obj, obj);

    return new AccessibleBase(obj);
}

// IUnknown
HRESULT STDMETHODCALLTYPE AccessibleBase::QueryInterface(REFIID riid, void** ppvObject)
{
    if (IsEqualGUID(riid, __uuidof(IAccessible)))
        *ppvObject = this;
    else if (IsEqualGUID(riid, __uuidof(IDispatch)))
        *ppvObject = this;
    else if (IsEqualGUID(riid, __uuidof(IUnknown)))
        *ppvObject = this;
    else {
        *ppvObject = 0;
        return E_NOINTERFACE;
    }
    AddRef();
    return S_OK;
}

ULONG STDMETHODCALLTYPE AccessibleBase::Release(void)
{
    ASSERT(m_refCount > 0);
    if (--m_refCount)
        return m_refCount;
    delete this;
    return 0;
}

// IAccessible
HRESULT STDMETHODCALLTYPE AccessibleBase::get_accParent(IDispatch** parent)
{
    *parent = 0;

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

    return WebView::AccessibleObjectFromWindow(m_object->topDocumentFrameView()->hostWindow()->platformWindow(),
        OBJID_WINDOW, __uuidof(IAccessible), reinterpret_cast<void**>(parent));
}

HRESULT STDMETHODCALLTYPE AccessibleBase::get_accChildCount(long* count)
{
    if (!m_object)
        return E_FAIL;
    if (!count)
        return E_POINTER;
    *count = static_cast<long>(m_object->children().size());
    return S_OK;
}

HRESULT STDMETHODCALLTYPE AccessibleBase::get_accChild(VARIANT vChild, IDispatch** ppChild)
{
    if (!ppChild)
        return E_POINTER;

    *ppChild = 0;

    AccessibilityObject* childObj;

    HRESULT hr = getAccessibilityObjectForChild(vChild, childObj);
    if (FAILED(hr))
        return hr;

    *ppChild = static_cast<IDispatch*>(wrapper(childObj));
    (*ppChild)->AddRef();
    return S_OK;
}

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

    *name = 0;

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

    if (FAILED(hr))
        return hr;

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

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

    *value = 0;

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

    if (FAILED(hr))
        return hr;

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

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

    *description = 0;

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

    if (FAILED(hr))
        return hr;

    // TODO: Description, for SELECT subitems, should be a string describing
    // the position of the item in its group and of the group in the list (see
    // Firefox).
    if (*description = BString(wrapper(childObj)->description()).release())
        return S_OK;
    return S_FALSE;
}

HRESULT STDMETHODCALLTYPE AccessibleBase::get_accRole(VARIANT vChild, VARIANT* pvRole)
{
    if (!pvRole)
        return E_POINTER;

    ::VariantInit(pvRole);

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

    if (FAILED(hr))
        return hr;

    pvRole->vt = VT_I4;
    pvRole->lVal = wrapper(childObj)->role();
    return S_OK;
}

HRESULT STDMETHODCALLTYPE AccessibleBase::get_accState(VARIANT vChild, VARIANT* pvState)
{
    if (!pvState)
        return E_POINTER;

    ::VariantInit(pvState);

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

    if (FAILED(hr))
        return hr;

    pvState->vt = VT_I4;
    pvState->lVal = 0;

    if (childObj->isAnchor())
        pvState->lVal |= STATE_SYSTEM_LINKED;

    if (childObj->isHovered())
        pvState->lVal |= STATE_SYSTEM_HOTTRACKED;

    if (!childObj->isEnabled())
        pvState->lVal |= STATE_SYSTEM_UNAVAILABLE;

    if (childObj->isReadOnly())
        pvState->lVal |= STATE_SYSTEM_READONLY;

    if (childObj->isOffScreen())
        pvState->lVal |= STATE_SYSTEM_OFFSCREEN;

    if (childObj->isMultiSelect())
        pvState->lVal |= STATE_SYSTEM_MULTISELECTABLE;

    if (childObj->isPasswordField())
        pvState->lVal |= STATE_SYSTEM_PROTECTED;

    if (childObj->isIndeterminate())
        pvState->lVal |= STATE_SYSTEM_INDETERMINATE;

    if (childObj->isChecked())
        pvState->lVal |= STATE_SYSTEM_CHECKED;

    if (childObj->isPressed())
        pvState->lVal |= STATE_SYSTEM_PRESSED;

    if (childObj->isFocused())
        pvState->lVal |= STATE_SYSTEM_FOCUSED;

    if (childObj->isVisited())
        pvState->lVal |= STATE_SYSTEM_TRAVERSED;

    if (childObj->canSetFocusAttribute())
        pvState->lVal |= STATE_SYSTEM_FOCUSABLE;

    // TODO: Add selected and selectable states.

    return S_OK;
}

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

    *helpText = 0;

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

    if (FAILED(hr))
        return hr;

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

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

    *shortcut = 0;

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

    if (FAILED(hr))
        return hr;

    String accessKey = childObj->accessKey();
    if (accessKey.isNull())
        return S_FALSE;