update slider value

components/slider.cpp

@@ -56,7 +56,8 @@ void Handle::mousePressEvent(QMouseEvent *event)
 void Handle::mouseMoveEvent(QMouseEvent *event)
 {
     setRelativePosition(event->globalPos());
-    _slider->update();
+    //_slider->update();
+    _slider->updateValue();
 }
 
 Slider::Slider(QWidget *parent)
@@ -111,7 +112,8 @@ void Slider::mousePressEvent(QMouseEvent *event)
         _handle->setOffset((event->pos() - QPoint(s.width()/2, s.height()/2)) - event->globalPos());
         _handle->setRelativePosition(event->globalPos());
         _drag = true;
-        update();
+        //update();
+        updateValue();
     } else {
         _drag = false;
     }
@@ -122,7 +124,8 @@ void Slider::mouseMoveEvent(QMouseEvent *event)
 {
     if (_drag) {
         _handle->setRelativePosition(event->globalPos());
-        update();
+        //update();
+        updateValue();
     }
     QAbstractSlider::mouseMoveEvent(event);
 }
@@ -132,3 +135,23 @@ void Slider::resizeEvent(QResizeEvent *event)
     _handle->refreshGeometry();
     QAbstractSlider::resizeEvent(event);
 }
+
+void Slider::updateValue()
+{
+    const qreal tot = Qt::Horizontal == _orientation
+            ? geometry().width()-_handle->width()
+            : geometry().height()-_handle->height();
+
+    const qreal r = Qt::Horizontal == _orientation
+            ? _handle->geometry().left() / tot
+            : _handle->geometry().top() / tot;
+
+    // use QStyle::sliderValueFromPosition ??
+
+    setValue((1-r)*minimum()+r*maximum());
+
+    //setSliderPosition((1-r)*minimum()+r*maximum());
+    //triggerAction(QAbstractSlider::SliderMove);
+
+    update();
+}

components/slider.h

@@ -56,7 +56,10 @@ protected:
     void resizeEvent(QResizeEvent *event) Q_DECL_OVERRIDE;
 
 private:
+    friend class Handle;
+
     inline bool isOnTrack(int p, int x) const { return (p >= x-2 && p <= x+2); }
+    void updateValue();
 
     bool            _drag;
     Handle   *const _handle;

examples/sliderexamples.cpp

@@ -1,3 +1,4 @@
+#include <QDebug>
 #include <QVBoxLayout>
 #include <QLineEdit>
 #include "sliderexamples.h"
@@ -48,10 +49,9 @@ SliderExamples::SliderExamples(QWidget *parent)
         widget->setLayout(layout);
 
         Slider *slider = new Slider;
-        QLineEdit *edit = new QLineEdit;
 
         layout->addWidget(slider);
-        layout->addWidget(edit);
+        layout->addWidget(_edit);
         layout->setStretch(0, 1);
         layout->setStretch(1, 1);
 
@@ -65,6 +65,7 @@ SliderExamples::SliderExamples(QWidget *parent)
         frame->setWidget(view);
 
         connect(slider, SIGNAL(valueChanged(int)), this, SLOT(updateValue(int)));
+//        connect(slider, SIGNAL(sliderMoved(int)), this, SLOT(updateValue(int)));
 
         mainLayout->addWidget(frame);
     }