VuoSliderWithLabels.cc

Go to the documentation of this file.

 
#include "VuoSliderWithLabels.hh"
 
const int VuoSliderWithLabels::minimumHeight = 37; // @todo: Figure this out programatically
const int VuoSliderWithLabels::extraVSpaceForTicks = 11;
 
VuoSliderWithLabels::VuoSliderWithLabels(QWidget *parent) :
    QSlider(parent)
{
    setTickInterval(1);
    setDisplayTicks(false);
 
    minLabel = NULL;
    maxLabel = NULL;
}
 
void VuoSliderWithLabels::initialize()
{
    if (!minLabel)
        minLabel = new QLabel(this);
 
    if (!maxLabel)
        maxLabel = new QLabel(this);
 
    QStyleOptionSlider slider;
    slider.initFrom(this);
 
    QFont labelFont = minLabel->font();
    labelFont.setPointSize(9);
 
    minLabel->setFont(labelFont);
    minLabel->setText(getLabelTextForValue(minimum()));
 
    maxLabel->setFont(labelFont);
    // Append some extra space to account for a max label that might grow and shrink,
    // since once it shrinks it can't reliably be expanded.
    maxLabel->setText(getLabelTextForValue(maximum()).append("  "));
 
    if (displayTicks)
    {
        for (map<int, QLabel *>::iterator i = intermediateLabels.begin(); i != intermediateLabels.end(); ++i)
        {
            // Clear the text of previously initialized labels that are no longer relevant for the updated range.
            int labelIndex = i->first;
            QLabel *label = i->second;
            if (labelIndex <= minimum() || labelIndex >= maximum())
            {
                // Don't actually make the label empty, though, since once it shrinks it can't reliably be expanded.
                QString placeholderText = "          ";
                label->setText(placeholderText);
            }
        }
 
        for (int i = minimum()+1; i < maximum(); ++i)
        {
            if (intermediateLabels.find(i) == intermediateLabels.end())
                intermediateLabels[i] = new QLabel(this);
 
            intermediateLabels[i]->setFont(minLabel->font());
            intermediateLabels[i]->setText(getLabelTextForValue(i));
        }
    }
 
    setTickPosition(displayTicks? QSlider::TicksBelow : QSlider::NoTicks);
    setMinimumSize(QSize(0, VuoSliderWithLabels::minimumHeight + (displayTicks? extraVSpaceForTicks : 0)));
}
 
void VuoSliderWithLabels::paintEvent(QPaintEvent *e)
{
    QStyleOptionSlider slider;
    slider.initFrom(this);
 
    int sliderAvailableHorizontalSpace = style()->pixelMetric(QStyle::PM_SliderSpaceAvailable, &slider, this);
    int sliderLeft = QStyle::sliderPositionFromValue(minimum(), maximum(), minimum(), sliderAvailableHorizontalSpace);
    int sliderRight = width();
 
    int labelVerticalOffset = style()->pixelMetric(QStyle::PM_SliderThickness, &slider, this) + (displayTicks? extraVSpaceForTicks : 0) + 10;
 
    minLabel->move(QPoint(sliderLeft, labelVerticalOffset));
    maxLabel->move(QPoint(min(sliderRight - maxLabel->sizeHint().width() + 6,
                              QStyle::sliderPositionFromValue(minimum(), maximum(), maximum(), sliderAvailableHorizontalSpace)),
                          labelVerticalOffset));
 
    if (displayTicks)
    {
        for (int i = minimum()+tickInterval(); i < maximum(); ++i)
        {
            int labelHorizontalOffset = QStyle::sliderPositionFromValue(minimum(), maximum(), i, sliderAvailableHorizontalSpace);
            intermediateLabels[i]->move(labelHorizontalOffset, labelVerticalOffset);
        }
    }
 
    QSlider::paintEvent(e);
}
 
QString VuoSliderWithLabels::getLabelTextForValue(int value)
{
    return labelTextForValue[value];
}
 
void VuoSliderWithLabels::setLabelTextForValue(int value, QString text)
{
    this->labelTextForValue[value] = text;
}
 
void VuoSliderWithLabels::setDisplayTicks(bool display)
{
    this->displayTicks = display;
}