QtAV/examples/player/Slider.cpp

/*  smplayer, GUI front-end for mplayer.
    Copyright (C) 2006-2010 Ricardo Villalba <rvm@escomposlinux.org>

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) version 3, or any
    later version accepted by the membership of KDE e.V. (or its
    successor approved by the membership of KDE e.V.), Trolltech ASA
    (or its successors, if any) and the KDE Free Qt Foundation, which shall
    act as a proxy defined in Section 6 of version 3 of the license.

    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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public 
    License along with this library.  If not, see <http://www.gnu.org/licenses/>.
*/

#define CODE_FOR_CLICK 1 // 0 = old code, 1 = code copied from QSlider, 2 = button swap

#include "Slider.h"
#include <QApplication>
#include <QMouseEvent>

#if CODE_FOR_CLICK <= 1
#include <QStyle>
#if CODE_FOR_CLICK == 1
#include <QStyleOption>
#endif
#endif

#if QT_VERSION < 0x040300
#define initStyleOption initStyleOption_Qt430
#endif //QT_VERSION


Slider::Slider(QWidget *parent):
    QSlider(parent)
{
    setOrientation(Qt::Horizontal);
    setMouseTracking(true); //mouseMoveEvent without press.
}

Slider::~Slider()
{
}

#if CODE_FOR_CLICK == 1
// Function copied from qslider.cpp
inline int Slider::pick(const QPoint &pt) const
{
    return orientation() == Qt::Horizontal ? pt.x() : pt.y();
}

// Function copied from qslider.cpp and modified to make it compile
void Slider::initStyleOption_Qt430(QStyleOptionSlider *option) const
{
    if (!option)
        return;

    option->initFrom(this);
    option->subControls = QStyle::SC_None;
    option->activeSubControls = QStyle::SC_None;
    option->orientation = orientation();
    option->maximum = maximum();
    option->minimum = minimum();
    option->tickPosition = (QSlider::TickPosition) tickPosition();
    option->tickInterval = tickInterval();
    option->upsideDown = (orientation() == Qt::Horizontal) ?
                     (invertedAppearance() != (option->direction == Qt::RightToLeft))
                     : (!invertedAppearance());
    option->direction = Qt::LeftToRight; // we use the upsideDown option instead
    option->sliderPosition = sliderPosition();
    option->sliderValue = value();
    option->singleStep = singleStep();
    option->pageStep = pageStep();
    if (orientation() == Qt::Horizontal)
        option->state |= QStyle::State_Horizontal;
}

// Function copied from qslider.cpp and modified to make it compile
int Slider::pixelPosToRangeValue(int pos) const
{
    QStyleOptionSlider opt;
    initStyleOption(&opt);
    QRect gr = style()->subControlRect(QStyle::CC_Slider, &opt, QStyle::SC_SliderGroove, this);
    QRect sr = style()->subControlRect(QStyle::CC_Slider, &opt, QStyle::SC_SliderHandle, this);
    int sliderMin, sliderMax, sliderLength;
    if (orientation() == Qt::Horizontal) {
        sliderLength = sr.width();
        sliderMin = gr.x();
        sliderMax = gr.right() - sliderLength + 1;
    } else {
        sliderLength = sr.height();
        sliderMin = gr.y();
        sliderMax = gr.bottom() - sliderLength + 1;
    }
    return QStyle::sliderValueFromPosition(minimum(), maximum(), pos - sliderMin,
                                           sliderMax - sliderMin, opt.upsideDown);
}

void Slider::enterEvent(QEvent *event)
{
    emit onEnter();
    QSlider::enterEvent(event);
}

void Slider::leaveEvent(QEvent *e)
{
    emit onLeave();
    QSlider::leaveEvent(e);
}

void Slider::mouseMoveEvent(QMouseEvent *e)
{
    const int o = style()->pixelMetric(QStyle::PM_SliderLength ) - 1;
    int v = QStyle::sliderValueFromPosition(minimum(), maximum(), e->pos().x()-o/2, width()-o, false);
    emit onHover(e->x(), v);
    QSlider::mouseMoveEvent(e);
}

// Based on code from qslider.cpp
void Slider::mousePressEvent(QMouseEvent *e)
{
    qDebug("pressed (%d, %d)", e->pos().x(), e->pos().y());
	if (e->button() == Qt::LeftButton) {
        QStyleOptionSlider opt;
        initStyleOption(&opt);
        const QRect sliderRect = style()->subControlRect(QStyle::CC_Slider, &opt, QStyle::SC_SliderHandle, this);
        const QPoint center = sliderRect.center() - sliderRect.topLeft();
        // to take half of the slider off for the setSliderPosition call we use the center - topLeft

        if (!sliderRect.contains(e->pos())) {
            qDebug("accept");
            e->accept();

            int v = pixelPosToRangeValue(pick(e->pos() - center));
            setSliderPosition(v);
            triggerAction(SliderMove);
            setRepeatAction(SliderNoAction);
            emit sliderMoved(v);//TODO: ok?
            emit sliderPressed(); //TODO: ok?
        } else {
            QSlider::mousePressEvent(e);
		}
	} else {
		QSlider::mousePressEvent(e);
	}
}
#endif // CODE_FOR_CLICK == 1
#if CODE_FOR_CLICK == 2
void Slider::mousePressEvent(QMouseEvent *e)
{
	// Swaps middle button click with left click
	if (e->button() == Qt::LeftButton) {
		QMouseEvent ev2(QEvent::MouseButtonRelease, e->pos(), e->globalPos(), Qt::MidButton, Qt::MidButton, e->modifiers());
		QSlider::mousePressEvent(&ev2);
    } else if (e->button() == Qt::MidButton) {
		QMouseEvent ev2(QEvent::MouseButtonRelease, e->pos(), e->globalPos(), Qt::LeftButton, Qt::LeftButton, e->modifiers());
		QSlider::mousePressEvent(&ev2);
	}
	else {
		QSlider::mousePressEvent(e);
	}
}
#endif // CODE_FOR_CLICK == 2
#if CODE_FOR_CLICK == 0
void Slider::mousePressEvent(QMouseEvent *e)
{
	// FIXME:
	// The code doesn't work well with right to left layout,
	// so it's disabled.
	if (qApp->isRightToLeft()) {
		QSlider::mousePressEvent(e);
		return;
	}

	int range = maximum()-minimum();
	int pos = (e->x() * range) / width();
	//qDebug( "width: %d x: %d", width(), e->x());
	//qDebug( "range: %d pos: %d value: %d", range, pos, value());

	// Calculate how many positions takes the slider handle
    int metric = qApp->style()->pixelMetric(QStyle::PM_SliderLength);
    double one_tick_pixels = (double)width() / range;
    int slider_handle_positions = (int)(metric / one_tick_pixels);

	/*
	qDebug("metric: %d", metric );
	qDebug("one_tick_pixels :%f", one_tick_pixels);
	qDebug("width() :%d", width());
	qDebug("slider_handle_positions: %d", slider_handle_positions);
	*/

	if (abs(pos - value()) > slider_handle_positions) { 
		setValue(pos);
        emit sliderMoved(pos);
	} else {
		QSlider::mousePressEvent(e);
	}
}
#endif