slider: implemented value ladder

Allows finer control over value changes.

app/widget/slider/sliderlabel.cpp

@@ -57,66 +57,25 @@ SliderLabel::SliderLabel(QWidget *parent) :
 void SliderLabel::mousePressEvent(QMouseEvent *e)
 {
   if (e->modifiers() & Qt::AltModifier) {
-
     emit RequestReset();
-
   } else {
-
-#if defined(Q_OS_MAC)
-    CGAssociateMouseAndMouseCursorPosition(false);
-    CGDisplayHideCursor(kCGDirectMainDisplay);
-    CGGetLastMouseDelta(nullptr, nullptr);
-#else
-    drag_start_ = QCursor::pos();
-
-    static_cast<QGuiApplication*>(QApplication::instance())->setOverrideCursor(Qt::BlankCursor);
-#endif
-
-    emit drag_start();
-
     dragging_ = true;
-
+    emit LabelPressed();
   }
 }
 
 void SliderLabel::mouseMoveEvent(QMouseEvent *)
 {
   if (dragging_) {
-
-    int32_t x_mvmt, y_mvmt;
-
-    // Keep cursor in the same position
-#if defined(Q_OS_MAC)
-    CGGetLastMouseDelta(&x_mvmt, &y_mvmt);
-#else
-    QPoint current_pos = QCursor::pos();
-
-    x_mvmt = current_pos.x() - drag_start_.x();
-    y_mvmt = drag_start_.y() - current_pos.y();
-
-    QCursor::setPos(drag_start_);
-#endif
-
-    emit dragged(x_mvmt + y_mvmt);
-
+    emit LabelMoved();
   }
 }
 
 void SliderLabel::mouseReleaseEvent(QMouseEvent *)
 {
   if (dragging_) {
-
-#if defined(Q_OS_MAC)
-    CGAssociateMouseAndMouseCursorPosition(true);
-    CGDisplayShowCursor(kCGDirectMainDisplay);
-#else
-    static_cast<QGuiApplication*>(QApplication::instance())->restoreOverrideCursor();
-#endif
-
-    emit drag_stop();
-
+    emit LabelReleased();
     dragging_ = false;
-
   }
 }