X-Git-Url: https://sigrok.org/gitweb/?a=blobdiff_plain;f=pv%2Fview%2Fviewport.cpp;h=d9be32c996ee142b44603d1c9097a9bcde93295a;hb=08d9c3caec0a3ad1c624af685f948e17b91d278a;hp=2150182f543dd4a52eb974f3352198e8b2b24b66;hpb=8e21a82cac5eb399dc7158da4b34c664cb4958cd;p=pulseview.git

diff --git a/pv/view/viewport.cpp b/pv/view/viewport.cpp
index 2150182f..d9be32c9 100644
--- a/pv/view/viewport.cpp
+++ b/pv/view/viewport.cpp
@@ -36,7 +36,6 @@ using std::abs;
 using std::back_inserter;
 using std::copy;
 using std::dynamic_pointer_cast;
-using std::isnan;
 using std::max;
 using std::min;
 using std::none_of;
@@ -83,7 +82,8 @@ void Viewport::drag()
 
 void Viewport::drag_by(const QPoint &delta)
 {
-	if (isnan(drag_offset_))
+	// Use std::isnan() instead of isnan(), the latter can cause issues.
+	if (std::isnan(drag_offset_))
 		return;
 
 	view_.set_scale_offset(view_.scale(), drag_offset_ -
@@ -195,18 +195,27 @@ void Viewport::mouseDoubleClickEvent(QMouseEvent *event)
 		view_.zoom(-2.0, event->x());
 }
 
-void Viewport::wheelEvent(QWheelEvent *event)
+void Viewport::wheelEvent(QWheelEvent *e)
 {
-	assert(event);
-
-	if (event->orientation() == Qt::Vertical) {
-		// Vertical scrolling is interpreted as zooming in/out
-		view_.zoom(event->delta() / 120, event->x());
-	} else if (event->orientation() == Qt::Horizontal) {
+	assert(e);
+
+	if (e->orientation() == Qt::Vertical)
+	{
+		if (e->modifiers() & Qt::ControlModifier) {
+			// Vertical scrolling with the control key pressed
+			// is intrepretted as vertical scrolling
+			view_.set_v_offset(-view_.owner_visual_v_offset() -
+				(e->delta() * height()) / (8 * 120));
+		} else {
+			// Vertical scrolling is interpreted as zooming in/out
+			view_.zoom(e->delta() / 120, e->x());
+		}
+	}
+	else if (e->orientation() == Qt::Horizontal)
+	{
 		// Horizontal scrolling is interpreted as moving left/right
 		view_.set_scale_offset(view_.scale(),
-				       event->delta() * view_.scale()
-				       + view_.offset());
+			e->delta() * view_.scale() + view_.offset());
 	}
 }