nheko/include/SlidingStackWidget.h

/*
 * nheko Copyright (C) 2017  Konstantinos Sideris <siderisk@auth.gr>
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 */

#pragma once

#include <QDebug>
#include <QEasingCurve>
#include <QParallelAnimationGroup>
#include <QPropertyAnimation>
#include <QStackedWidget>
#include <QWidget>

/*
 * SlidingStackWidget allows smooth side shifting of widgets,
 * in addition to the hard switching from one to another offered
 * by QStackedWidget.
 */

class SlidingStackWidget : public QStackedWidget
{
        Q_OBJECT

public:
        // Defines the animation direction.
        enum class AnimationDirection { LEFT_TO_RIGHT, RIGHT_TO_LEFT, AUTOMATIC };

        SlidingStackWidget(QWidget *parent);
        ~SlidingStackWidget();

public slots:
        // Move to the next widget.
        void slideInNext();

        // Move to the previous widget.
        void slideInPrevious();

        // Move to a widget by index.
        void slideInIndex(int index, AnimationDirection direction = AnimationDirection::AUTOMATIC);

        int getWidgetIndex(QWidget *widget);
signals:
        // Internal signal to alert the engine for the animation's end.
        void animationFinished();

protected slots:
        // Internal slot to handle the end of the animation.
        void onAnimationFinished();

protected:
        // The method that does the main work for the widget transition.
        void slideInWidget(QWidget *widget,
                           AnimationDirection direction = AnimationDirection::AUTOMATIC);

        // Indicates whether or not the animation is active.
        bool active_;

        // The widget currently displayed.
        QWidget *window_;

        // The speed of the animation in milliseconds.
        int speed_;

        // The animation type.
        QEasingCurve::Type animation_type_;

        // Current widget's index.
        int now_;

        // Reference point.
        QPoint current_position_;

        // Next widget's to show index.
        int next_;
};