Source/web/BackForwardClientImpl.cpp

/*
 * Copyright (C) 2009 Google Inc. All rights reserved.
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 * modification, are permitted provided that the following conditions are
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 * in the documentation and/or other materials provided with the
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 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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#include "config.h"
#include "BackForwardClientImpl.h"

#include "WebViewClient.h"
#include "WebViewImpl.h"
#include "core/history/HistoryItem.h"
#include "wtf/text/StringConcatenate.h"

using namespace WebCore;

namespace WebKit {

const char backForwardNavigationScheme[] = "chrome-back-forward";

BackForwardClientImpl::BackForwardClientImpl(WebViewImpl* webView)
    : m_webView(webView)
{
}

BackForwardClientImpl::~BackForwardClientImpl()
{
}

void BackForwardClientImpl::addItem(PassRefPtr<HistoryItem> item)
{
    m_currentItem = item;

    // If WebCore adds a new HistoryItem, it means this is a new navigation (ie,
    // not a reload or back/forward).
    m_webView->observeNewNavigation();

    if (m_webView->client())
        m_webView->client()->didAddHistoryItem();
}

void BackForwardClientImpl::goToItem(HistoryItem* item)
{
    m_currentItem = item;

    if (m_pendingHistoryItem == item)
        m_pendingHistoryItem = 0;
}

HistoryItem* BackForwardClientImpl::itemAtIndex(int index)
{
    if (!m_webView->client())
        return 0;

    if (!index)
        return m_currentItem.get();

    if (index > forwardListCount() || -index > backListCount())
        return 0;

    // Since we don't keep the entire back/forward list, we have no way to
    // properly implement this method.  We return a dummy entry instead that we
    // intercept in our FrameLoaderClient implementation in case WebCore asks
    // to navigate to this HistoryItem.

    // FIXME: We should change WebCore to handle history.{back,forward,go}
    // differently.  It should perhaps just ask the FrameLoaderClient to
    // perform those navigations.

    String urlString = String(backForwardNavigationScheme) + "://go/" + String::number(index);
    m_pendingHistoryItem = HistoryItem::create(urlString);
    return m_pendingHistoryItem.get();
}

int BackForwardClientImpl::backListCount()
{
    if (!m_webView->client())
        return 0;

    return m_webView->client()->historyBackListCount();
}

int BackForwardClientImpl::forwardListCount()
{
    if (!m_webView->client())
        return 0;

    return m_webView->client()->historyForwardListCount();
}

bool BackForwardClientImpl::isActive()
{
    return m_webView->client();
}

void BackForwardClientImpl::close()
{
    m_currentItem = 0;
    m_pendingHistoryItem = 0;
}

} // namespace WebKit