/***************************************************************************
 *   Copyright (C) 2006 by Peter Penz <peter.penz@gmx.at>                  *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA            *
 ***************************************************************************/

#ifndef TREEVIEWSIDEBARPAGE_H
#define TREEVIEWSIDEBARPAGE_H

#include <kurl.h>
#include <sidebarpage.h>

class KDirLister;
class DolphinModel;

class DolphinSortFilterProxyModel;
class SidebarTreeView;
class QModelIndex;

/**
 * @brief Shows a tree view of the directories starting from
 *        the currently selected place.
 *
 * The tree view is always synchronized with the currently active view
 * from the main window.
 */
class TreeViewSidebarPage : public SidebarPage
{
    Q_OBJECT

public:
    TreeViewSidebarPage(QWidget* parent = 0);
    virtual ~TreeViewSidebarPage();

    /** @see QWidget::sizeHint() */
    virtual QSize sizeHint() const;

    void setShowHiddenFiles(bool show);
    bool showHiddenFiles() const;

signals:
    /**
     * Is emitted if the an URL change is requested.
     */
    void changeUrl(const KUrl& url, Qt::MouseButtons buttons);

    /**
     * This signal is emitted when the sidebar requests a change in the
     * current selection. The file-management view recieving this signal is
     * not required to select all listed files, limiting the selection to
     * e.g. the current folder. The new selection will be reported via the
     * setSelection slot.
     */
    void changeSelection(const KFileItemList& selection);

    /**
     * This signal is emitted whenever a drop action on this widget needs the
     * MainWindow's attention.
     */
    void urlsDropped(const KUrl::List& urls, const KUrl& destination);

public slots:
    /**
     * Changes the current selection inside the tree to \a url.
     */
    virtual void setUrl(const KUrl& url);

protected:
    /** @see QWidget::showEvent() */
    virtual void showEvent(QShowEvent* event);

    /** @see QWidget::contextMenuEvent() */
    virtual void contextMenuEvent(QContextMenuEvent* event);

private slots:
    /**
     * Updates the active view to the URL
     * which is given by the item with the index \a index.
     */
    void updateActiveView(const QModelIndex& index);

    /**
     * Is emitted if the URLs \a urls have been dropped
     * to the index \a index. */
    void dropUrls(const KUrl::List& urls,
                  const QModelIndex& index);

    /**
     * Invokes expandToLeafDir() asynchronously (the expanding
     * may not be done in the context of this slot).
     */
    void triggerExpanding();

    /**
     * Invokes loadSubTree() asynchronously (the loading
     * may not be done in the context of this slot).
     */
    void triggerLoadSubTree();

    /**
     * Expands all directories to make m_leafDir visible and
     * adjusts the selection.
     */
    void expandToLeafDir();

    /**
     * Loads the sub tree to make m_leafDir visible. Is invoked
     * indirectly by loadTree() after the directory lister has
     * finished loading the root items.
     */
    void loadSubTree();

    /**
     * Assures that the leaf folder gets visible.
     */
    void scrollToLeaf();

    void updateMouseButtons();

private:
    /**
     * Initializes the base URL of the tree and expands all
     * directories until \a url.
     * @param url  URL of the leaf directory that should get expanded.
     */
    void loadTree(const KUrl& url);

    /**
     * Selects the current leaf directory m_leafDir and assures
     * that the directory is visible if the leaf has been set by
     * TreeViewSidebarPage::setUrl().
     */
    void selectLeafDirectory();

private:
    bool m_setLeafVisible;
    Qt::MouseButtons m_mouseButtons;
    KDirLister* m_dirLister;
    DolphinModel* m_dolphinModel;
    DolphinSortFilterProxyModel* m_proxyModel;
    SidebarTreeView* m_treeView;
    KUrl m_leafDir;
};

#endif // TREEVIEWSIDEBARPAGE_H