/*

  This file is part of serialplot.

  serialplot 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.

  serialplot 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 serialplot.  If not, see <http://www.gnu.org/licenses/>.

*/

#include <QEvent>

#include <QMouseEvent>

#include <QPainter>

#include <qwt_scale_widget.h>

#include <qwt_scale_map.h>

#include <qwt_scale_div.h>

#include <math.h>

#include "scalepicker.h"

// minimum size for pick (in pixels)

#define MIN_PICK_SIZE (2)

#define SNAP_DISTANCE (5)

class PlotOverlay : public QwtWidgetOverlay

{

public:

    PlotOverlay(QWidget* widget, ScalePicker* picker);

protected:

    virtual void drawOverlay(QPainter*) const;

private:

    ScalePicker* _picker;

};

PlotOverlay::PlotOverlay(QWidget* widget, ScalePicker* picker) :

    QwtWidgetOverlay(widget)

{

    _picker = picker;

            pressed = false;

            if (started)

            {

                // finalize

                started = false;

                emit picked(firstPos, pos);

            }

        }

        return true;

    }

    else if (event->type() == QEvent::Leave)

    {

        scaleOverlay->updateOverlay();

        return true;

    }

    else

    {

        return QObject::eventFilter(object, event);

    }

}

void ScalePicker::drawPlotOverlay(QPainter* painter)

{

    if (started)

    {

        painter->save();

        painter->setPen(_pen);

        QRect rect;

        if (_scaleWidget->alignment() == QwtScaleDraw::BottomScale ||

            _scaleWidget->alignment() == QwtScaleDraw::TopScale)

        {

            int height = painter->device()->height();

            rect = QRect(posCanvasPx(firstPosPx), 0, currentPosPx-firstPosPx, height);

        }

        else // vertical

        {

            int width = painter->device()->width();

            rect = QRect(0, posCanvasPx(firstPosPx), width, currentPosPx-firstPosPx);

        }

        painter->drawRect(rect);

        painter->restore();

    }

}

void ScalePicker::drawScaleOverlay(QPainter* painter)

{

    painter->save();

    {

        int width = painter->device()->width();

        {

    painter->restore();

}

void ScalePicker::setPen(QPen pen)

{

    _pen = pen;

}

// convert the position of the click to the plot coordinates

double ScalePicker::position(double posPx)

{

    return _scaleWidget->scaleDraw()->scaleMap().invTransform(posPx);

}

int ScalePicker::positionPx(QMouseEvent* mouseEvent)

{

    double pos;

    if (_scaleWidget->alignment() == QwtScaleDraw::BottomScale ||

        _scaleWidget->alignment() == QwtScaleDraw::TopScale)

    {

        pos = mouseEvent->pos().x();

    }

    else // left or right scale

    {

        pos = mouseEvent->pos().y();

    }

    return pos;

}

/*

 * Scale widget and canvas widget is not always aligned. Especially

 * when zooming scaleWidget moves around. This causes irregularities

 * when drawing the tracker lines. This function maps scale widgets

 * pixel coordinate to canvas' coordinate.

 */

double ScalePicker::posCanvasPx(double pos)

{

    // assumption: scale.width < canvas.width && scale.x > canvas.x

    if (_scaleWidget->alignment() == QwtScaleDraw::BottomScale ||

        _scaleWidget->alignment() == QwtScaleDraw::TopScale)

    {

        return pos + (_scaleWidget->x() - _canvas->x());

    }

    else // left or right scale

    {

        return pos + (_scaleWidget->y() - _canvas->y());

    }

/*

  This file is part of serialplot.

  serialplot 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.

  serialplot 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 serialplot.  If not, see <http://www.gnu.org/licenses/>.

*/

#ifndef SCALEPICKER_H

#define SCALEPICKER_H

#include <QObject>

#include <QMouseEvent>

#include <QPen>

#include <QWidget>

#include <QList>

#include <qwt_scale_widget.h>

#include <qwt_widget_overlay.h>

class ScalePicker : public QObject

{

    Q_OBJECT

public:

    ScalePicker(QwtScaleWidget* scaleWidget, QWidget* canvas);

    virtual bool eventFilter(QObject*, QEvent*);

    void drawPlotOverlay(QPainter*); // called from ScalePickerOverlay

    void drawScaleOverlay(QPainter*); // called from ScaleOverlay

    void setPen(QPen pen);

signals:

    void pickStarted(double pos);

    void picking(double firstPos, double lastPos);

    void picked(double firstPos, double lastPos);

private:

    QwtScaleWidget* _scaleWidget;

    QWidget* _canvas;

    QwtWidgetOverlay* pickerOverlay; // will be PlotOverlay

    QwtWidgetOverlay* scaleOverlay;  // will be ScaleOverlay

    QPen _pen;

    bool pressed;

    bool started;

    double firstPos; // converted to plot coordinates

    double firstPosPx; // pixel coordinates

    double currentPosPx; // current position in pixel coordinates

    QList<int> snapPoints;

    double position(double); // returns the axis mouse position relative to plot coordinates

    int positionPx(QMouseEvent*); // returns the axis mouse position in pixels

    double posCanvasPx(double pos); // returns the given position in canvas coordinates

private slots:

    void updateSnapPoints();

};

#endif // SCALEPICKER_H