qtcollider: QSlider: improvements regarding 'step' and rounding

* Implement pixelStep method
* Set default step to 0.
* Whenever in/decrementing, use max(step, pixelStep)
* When value changes, round it to step modified by modifier keys
  (other kits always round to unmodified step)
* Do not round when step itself changes
  (unlike other kits)

* Also, replace all floats with doubles

QtCollider/widgets/QcSlider.cpp

@@ -31,28 +31,49 @@ QC_DECLARE_QWIDGET_FACTORY(QcSlider);
 QcSlider::QcSlider() :
   QtCollider::Style::Client(this),
   _value(0.0),
-  _step(0.01),
+  _step(0.0),
   _hndLen(20)
 {
   setFocusPolicy( Qt::StrongFocus );
   setOrientation( Qt::Vertical );
 }
 
+double QcSlider::pixelStep()
+{
+  using namespace QtCollider::Style;
+
+  QRect contRect( sunkenContentsRect(rect()) );
+  int range = (_ort == Qt::Horizontal) ? contRect.width() : contRect.height();
+  range -= _hndLen;
+
+  if(range > 0)
+      return 1.0 / range;
+  else
+      return 0.0;
+}
+
 void QcSlider::setValue( double val )
 {
+  double step = _step;
+  modifyStep(&step);
+  if (step) val = qRound(val / step) * step;
+
   _value = qBound(0.0, val, 1.0);
+
   update();
 }
 
 void  QcSlider::increment( double factor )
 {
-  setValue( _step * factor + _value );
+  double step = qMax(_step, pixelStep());
+  setValue( step * factor + _value );
   update();
 }
 
 void  QcSlider::decrement( double factor )
 {
-  setValue( - _step * factor + _value );
+  double step = qMax(_step, pixelStep());
+  setValue( - step * factor + _value );
   update();
 }
 
@@ -103,7 +124,9 @@ void QcSlider::mouseMoveEvent ( QMouseEvent *e )
 
 void QcSlider::wheelEvent ( QWheelEvent *e )
 {
-  double dval = e->delta() / 120.0 * _step;
+  double step = qMax(_step, pixelStep());
+  modifyStep(&step);
+  double dval = e->delta() / 120.0 * step;
   setValue( _value + dval );
   Q_EMIT( action() );
 }

QtCollider/widgets/QcSlider.h

@@ -31,10 +31,11 @@
 class QcSlider : public QWidget, QcHelper, QcAbstractStepValue, QtCollider::Style::Client
 {
   Q_OBJECT
-  Q_PROPERTY( float shiftScale READ dummyFloat WRITE setShiftScale );
-  Q_PROPERTY( float ctrlScale READ dummyFloat WRITE setCtrlScale );
-  Q_PROPERTY( float altScale READ dummyFloat WRITE setAltScale );
+  Q_PROPERTY( double shiftScale READ dummyFloat WRITE setShiftScale );
+  Q_PROPERTY( double ctrlScale READ dummyFloat WRITE setCtrlScale );
+  Q_PROPERTY( double altScale READ dummyFloat WRITE setAltScale );
   Q_PROPERTY( double step READ step WRITE setStep )
+  Q_PROPERTY( double pixelStep READ pixelStep )
   Q_PROPERTY( double value READ value WRITE setValue );
   Q_PROPERTY( QColor grooveColor READ grooveColor WRITE setGrooveColor );
   Q_PROPERTY( QColor focusColor READ focusColor WRITE setFocusColor );
@@ -56,6 +57,7 @@ class QcSlider : public QWidget, QcHelper, QcAbstractStepValue, QtCollider::Styl
 
     double step() { return _step; }
     void setStep( double d ) { _step = d; }
+    double pixelStep();
 
     Qt::Orientation orientation() const { return _ort; }
     void setOrientation( int );

SCClassLibrary/QtCollider/QSlider.sc

@@ -54,10 +54,7 @@ QSlider : QAbstractStepValue {
     }
   }
 
-  pixelStep {
-    // FIXME for now we are using step instead
-    ^this.step;
-  }
+  pixelStep { ^this.getProperty(\pixelStep) }
 
   orientation_ { arg aSymbol;
     orientation = aSymbol;