/***************************************************************************
 *   Copyright (C) 2006 by Peter Penz (<peter.penz@gmx.at>)                *
 *   Copyright (C) 2006 by Aaron J. Seigo (<aseigo@kde.org>)               *
 *   Copyright (C) 2006 by Patrice Tremblay                                *
 *                                                                         *
 *   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 URLNAVIGATOR_H
#define URLNAVIGATOR_H

#include <kurl.h>
#include <QWidget>
#include <QLinkedList>

class QHBoxLayout;
class QLabel;
class QLineEdit;
class QMouseEvent;
class QToolButton;

class KUrl;
class KFileItem;
class KUrlComboBox;

class BookmarkSelector;
class UrlNavigatorButton;
class ProtocolCombo;

/**
 * @brief Navigation bar which contains the current shown URL.
 *
 * The URL navigator offers two modes:
 * - Editable:     Represents the 'classic' mode, where the current URL
 *                 is editable inside a line editor.
 * - Non editable: The URL is represented by a number of buttons, where
 *                 clicking on a button results in activating the URL
 *                 the button represents. This mode also supports drag
 *                 and drop of items.
 *
 * The mode can be changed by a toggle button located on the left side of
 * the navigator.
 *
 * The URL navigator also remembers the URL history and allows to go
 * back and forward within this history.
*/

typedef QLinkedList<KUrl> UrlStack;

class UrlNavigator : public QWidget
{
    Q_OBJECT

public:
    /**
     * @brief Represents the history element of an URL.
     *
     * A history element contains the URL, the name of the current file
     * (the 'current file' is the file where the cursor is located) and
     * the x- and y-position of the content.
     */
    class HistoryElem {
    public:
        HistoryElem();
        HistoryElem(const KUrl& url);
        ~HistoryElem(); // non virtual

        const KUrl& url() const { return m_url; }

        void setCurrentFileName(const QString& name) { m_currentFileName = name; }
        const QString& currentFileName() const { return m_currentFileName; }

        void setContentsX(int x) { m_contentsX = x; }
        int contentsX() const { return m_contentsX; }

        void setContentsY(int y) { m_contentsY = y; }
        int contentsY() const { return m_contentsY; }

    private:
        KUrl m_url;
        QString m_currentFileName;
        int m_contentsX;
        int m_contentsY;
    };

    UrlNavigator(const KUrl& url, QWidget* parent);
    virtual ~UrlNavigator();

    /** Returns the current active URL. */
    const KUrl& url() const;

    /** Returns the portion of the current active URL up to the button at index. */
    KUrl url(int index) const;

    /**
     * Returns the complete URL history. The index 0 indicates the oldest
     * history element.
     * @param index     Output parameter which indicates the current
     *                  index of the location.
     */
    const QLinkedList<HistoryElem>& history(int& index) const;

    /**
     * Goes back one step in the URL history. The signals
     * UrlNavigator::urlChanged and UrlNavigator::historyChanged
     * are submitted.
     */
    void goBack();

    /**
     * Goes forward one step in the URL history. The signals
     * UrlNavigator::urlChanged and UrlNavigator::historyChanged
     * are submitted.
     */
    void goForward();

    /**
     * Goes up one step of the URL path. The signals
     * UrlNavigator::urlChanged and UrlNavigator::historyChanged
     * are submitted.
     */
    void goUp();

    /**
     * Goes to the home URL. The signals UrlNavigator::urlChanged
     * and UrlNavigator::historyChanged are submitted.
     */
    void goHome();

    /**
     * @return True, if the URL is editable by the user within a line editor.
     *         If false is returned, each part of the URL is presented by a button
     *         for fast navigation.
     */
    bool isUrlEditable() const;

    /**
     * Switches to the edit mode and assures that the keyboard focus
     * is assigned.
     */
    void editUrl(bool editOrBrowse); //TODO: switch to an enum

    /**
     * Set the URL navigator to the active mode, if \a active
     * is true. The active mode is default. Using the URL navigator
     * in the inactive mode is useful when having split views,
     * where the inactive view is indicated by a an inactive URL
     * navigator visually.
     */
    void setActive(bool active);

    /**
     * Returns true, if the URL navigator is in the active mode.
     * @see UrlNavigator::setActive()
     */
    bool isActive() const { return m_active; }

    /**
     * Sets whether or not to show hidden files in lists
     */
    void setShowHiddenFiles( bool show );

    /**
     * Returns true if the URL navigator is set to show hidden files
     */
    bool showHiddenFiles() { return m_showHiddenFiles; }

    /**
     * Handles the dropping of the URLs \a urls to the given
     * destination \a destination and emits the signal urlsDropped.
     */
    void dropUrls(const KUrl::List& urls,
                  const KUrl& destination);

public slots:
    /**
     * Sets the current active URL.
     * The signals UrlNavigator::urlChanged and UrlNavigator::historyChanged
     * are submitted.
     */
    void setUrl(const KUrl& url);

    /**
     * Activates the URL navigator (UrlNavigator::isActive() will return true)
     * and emits the signal 'activationChanged()'.
     */
    void requestActivation();

    /**
     * Stores the coordinates of the contents into
     * the current history element.
     */
    void storeContentsPosition(int x, int y);

signals:
    /**
     * Is emitted, if the URL navigator has been activated by
     * a user interaction.
     */
    void activated();

    /**
     * Is emitted, if the URL has been changed e. g. by
     * the user.
     * @see setUrl()
     */
    void urlChanged(const KUrl& url);

    /**
     * Is emitted, if the history has been changed. Usually
     * the history is changed if a new URL has been selected.
     */
    void historyChanged();

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

protected:
    /**
     * If the Escape key is pressed, the navigation bar should switch
     * to the browse mode.
     */
    virtual void keyReleaseEvent(QKeyEvent* event);

    /**
     * Paste the clipboard content as URL, if the middle mouse
     * button has been clicked.
     */
    virtual void mouseReleaseEvent(QMouseEvent* event);

private slots:
    void slotReturnPressed(const QString& text);
    void slotUrlActivated(const KUrl& url);
    void slotRemoteHostActivated();
    void slotProtocolChanged(const QString& protocol);
    void slotRedirection(const KUrl&, const KUrl&);

    /**
     * Switches the navigation bar between the breadcrumb view and the
     * traditional view (see setUrlEditable()) and is connected to the clicked signal
     * of the navigation bar button.
     */
    void switchView();

private:
    /**
     * Allows to edit the Url of the navigation bar if \a editable
     * is true. If \a editable is false, each part of
     * the Url is presented by a button for a fast navigation.
     */
    void setUrlEditable(bool editable);

    /**
     * Updates the history element with the current file item
     * and the contents position.
     */
    void updateHistoryElem();
    void updateContent();

    /**
     * Updates all buttons to have one button for each part of the
     * path \a path. Existing buttons, which are available by m_navButtons,
     * are reused if possible. If the path is longer, new buttons will be
     * created, if the path is shorter, the remaining buttons will be deleted.
     * @param startIndex    Start index of path part (/), where the buttons
     *                      should be created for each following part.
     */
    void updateButtons(const QString& path, int startIndex);

    /**
     * Deletes all URL navigator buttons. m_navButtons is
     * empty after this operation.
     */
    void deleteButtons();

    /**
     * Appends the widget at the end of the URL navigator. It is assured
     * that the filler widget remains as last widget to fill the remaining
     * width.
     */
    void appendWidget(QWidget* widget);

private:
    bool m_active;
    bool m_showHiddenFiles;
    int m_historyIndex;

    QHBoxLayout* m_layout;

    QLinkedList<HistoryElem> m_history;
    QToolButton* m_toggleButton;
    BookmarkSelector* m_bookmarkSelector;
    KUrlComboBox* m_pathBox;
    ProtocolCombo* m_protocols;
    QLabel* m_protocolSeparator;
    QLineEdit* m_host;
    QLinkedList<UrlNavigatorButton*> m_navButtons;
    QWidget* m_filler;
    //UrlStack m_urls;
};

#endif