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#include <qstyle.h>
#include <qstyleoption.h>
#include "Scrollbar.h"
ScrollBar::ScrollBar(QWidget * parent):
QScrollBar(parent)
{
init();
}
ScrollBar::ScrollBar(Qt::Orientation o,
QWidget *parent):
QScrollBar(o, parent)
{
init();
}
ScrollBar::ScrollBar(double minBase, double maxBase,
Qt::Orientation o, QWidget *parent):
QScrollBar(o, parent)
{
init();
setBase(minBase, maxBase);
moveSlider(minBase, maxBase);
}
void ScrollBar::init()
{
d_inverted = orientation() == Qt::Vertical;
d_baseTicks = 1000000;
d_minBase = 0.0;
d_maxBase = 1.0;
moveSlider(d_minBase, d_maxBase);
connect(this, SIGNAL(sliderMoved(int)), SLOT(catchSliderMoved(int)));
connect(this, SIGNAL(valueChanged(int)), SLOT(catchValueChanged(int)));
}
void ScrollBar::setInverted(bool inverted)
{
if ( d_inverted != inverted )
{
d_inverted = inverted;
moveSlider(minSliderValue(), maxSliderValue());
}
}
bool ScrollBar::isInverted() const
{
return d_inverted;
}
void ScrollBar::setBase(double min, double max)
{
if ( min != d_minBase || max != d_maxBase )
{
d_minBase = min;
d_maxBase = max;
moveSlider(minSliderValue(), maxSliderValue());
}
}
void ScrollBar::moveSlider(double min, double max)
{
const int sliderTicks = qRound((max - min) /
(d_maxBase - d_minBase) * d_baseTicks);
// setRange initiates a valueChanged of the scrollbars
// in some situations. So we block
// and unblock the signals.
blockSignals(true);
setRange(sliderTicks / 2, d_baseTicks - sliderTicks / 2);
int steps = sliderTicks / 200;
if ( steps <= 0 )
steps = 1;
#if QT_VERSION < 0x040000
setSteps(steps, sliderTicks);
#else
setSingleStep(steps);
setPageStep(sliderTicks);
#endif
int tick = mapToTick(min + (max - min) / 2);
if ( isInverted() )
tick = d_baseTicks - tick;
#if QT_VERSION < 0x040000
directSetValue(tick);
rangeChange();
#else
setSliderPosition(tick);
#endif
blockSignals(false);
}
double ScrollBar::minBaseValue() const
{
return d_minBase;
}
double ScrollBar::maxBaseValue() const
{
return d_maxBase;
}
void ScrollBar::sliderRange(int value, double &min, double &max) const
{
if ( isInverted() )
value = d_baseTicks - value;
const int visibleTicks = pageStep();
min = mapFromTick(value - visibleTicks / 2);
max = mapFromTick(value + visibleTicks / 2);
}
double ScrollBar::minSliderValue() const
{
double min, dummy;
sliderRange(value(), min, dummy);
return min;
}
double ScrollBar::maxSliderValue() const
{
double max, dummy;
sliderRange(value(), dummy, max);
return max;
}
int ScrollBar::mapToTick(double v) const
{
return (int) ( ( v - d_minBase) / (d_maxBase - d_minBase ) * d_baseTicks );
}
double ScrollBar::mapFromTick(int tick) const
{
return d_minBase + ( d_maxBase - d_minBase ) * tick / d_baseTicks;
}
void ScrollBar::catchValueChanged(int value)
{
double min, max;
sliderRange(value, min, max);
emit valueChanged(orientation(), min, max);
}
void ScrollBar::catchSliderMoved(int value)
{
double min, max;
sliderRange(value, min, max);
emit sliderMoved(orientation(), min, max);
}
int ScrollBar::extent() const
{
#if QT_VERSION < 0x040000
return style().pixelMetric(QStyle::PM_ScrollBarExtent, this);
#else
QStyleOptionSlider opt;
opt.init(this);
opt.subControls = QStyle::SC_None;
opt.activeSubControls = QStyle::SC_None;
opt.orientation = orientation();
opt.minimum = minimum();
opt.maximum = maximum();
opt.sliderPosition = sliderPosition();
opt.sliderValue = value();
opt.singleStep = singleStep();
opt.pageStep = pageStep();
opt.upsideDown = invertedAppearance();
if (orientation() == Qt::Horizontal)
opt.state |= QStyle::State_Horizontal;
return style()->pixelMetric(QStyle::PM_ScrollBarExtent, &opt, this);
#endif
}