/* This file is part of the KDE libraries
    Copyright (C) 2006 Olivier Goffart <ogoffart at kde.org>

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License version 2 as published by the Free Software Foundation.

    This library 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
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public License
    along with this library; see the file COPYING.LIB.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301, USA.
*/


#ifndef KASSISTANTDIALOG_H
#define KASSISTANTDIALOG_H

#include <kpagedialog.h>

/**
 * This class provides a framework for assistant dialogs.
 *
 * The use of this class is the same as KWizard in KDE3.
 * You should use the word "assistant" instead of "wizard" both in the source 
 * and translatable strings.
 *
 * An assistant dialog consists of a sequence of pages.
 * Its purpose is to guide the user (assist) through a process step by step.
 * Assistant dialogs are useful for complex or infrequently occurring tasks 
 * that people may find difficult to learn or do.
 * Sometimes a task requires too many input fields to fit them on a single dialog.
 *
 * KAssistantDialog provides page titles and displays Next, Back, Finish, Cancel, 
 * and Help push buttons, as appropriate to the current position in the page sequence.
 * The Finish Button has the code KDialog::User1, The Next button is KDialog::User2 
 * and the Back button is KDialog::User3.
 * The help button may be hidden using showButton(KDialog::Help, false)
 *
 * Create and populate dialog pages that inherit from QWidget and add them 
 * to the assistant dialog using addPage().
 *
 * The functions next() and back() are virtual and may be reimplemented to
 * override the default actions of the next and back buttons.
 *
 * \image html kassistantdialog.png "KDE Assistant Dialog"
 *
 * @author Olivier Goffart <ogoffart at kde.org>
 */
class KDEUI_EXPORT KAssistantDialog : public KPageDialog
{
    Q_OBJECT
    public:
        /**
         * Construct a new assistant dialog with @p parent as parent.
         * @param parent is the parent of the widget. 
         * @flags the window flags to give to the assistant dialog. The
         * default of zero is usually what you want.
         */
        explicit KAssistantDialog(QWidget *parent=0, Qt::WindowFlags flags=0);
        virtual ~KAssistantDialog();

        /**
         * Specify if the content of the page is valid, and if the next button may be enabled on this page.
         * By default all pages are valid.
         *
         * This will disable or enable the next button on the specified page
         *
         * @param page the page on which the next button will be enabled/disable
         * @param enable if true the next button will be enabled, if false it will be disabled
         */
        void setValid(KPageWidgetItem* page, bool enable);

        /**
         * return if a page is valid
         * @see setValid
         * @param page the page to check the validity of
         */
        bool isValid(KPageWidgetItem *page) const;

        /**
         * Specify whether a page is appropriate.
         *
         * A page is considered inappropriate if it should not be shown due to 
         * the contents of other pages making it inappropriate.
         *
         * A page which is inappropriate will not be shown.
         *
         * The last page in an assistant dialog should always be appropriate
         * @param page the page to set as appropriate
         * @param appropriate flag indicating the appropriateness of the page.
         * If @p appropriate is true, then @p page is appropriate and will be
         * shown in the assistant dialog. If false, @p page will not be shown.
         */
        void setAppropriate(KPageWidgetItem *page, bool appropriate);

        /**
         * Check if a page is appropriate for use in the assistant dialog.
         * @param page is the page to check the appropriateness of.
         * @return true if @p page is appropriate, false if it is not
         */
        bool isAppropriate(KPageWidgetItem *page) const;


    public Q_SLOTS:
        /**
         * Called when the user clicks the Back button.
         *
         * This function will show the preceding relevant page in the sequence.
         * Do nothing if the current page is the first page in the sequence.
         */
        virtual void back();

        /**
         * Called when the user clicks the Next/Finish button.
         *
         * This function will show the next relevant page in the sequence.
         * If the current page is the last page, it will call accept()
         */
        virtual void next();

    protected:
        /**
         * Construct an assistant dialog from a single widget.
         * @param widget the widget to construct the dialog with
         * @param parent the parent of the assistant dialog
         * @flags the window flags to use when creating the widget. The default
         * of zero is usually fine.
         *
         * Calls the KPageDialog(KPageWidget *widget, QWidget *parent, Qt::WindowFlags flags) constructor
         */
        explicit KAssistantDialog(KPageWidget *widget, QWidget *parent=0, Qt::WindowFlags flags=0);

        virtual void showEvent(QShowEvent * event);

    private:
        class Private;
        Private * const d;

        Q_PRIVATE_SLOT( d, void _k_slotUpdateButtons() )

        Q_DISABLE_COPY( KAssistantDialog )
};


#endif