widget: clicking on the scrollbar indicator shouldn't jump

Signed-off-by: Dominik Honnef <dominik@honnef.co>

widget/list.go

@@ -58,8 +58,12 @@ func (s *Scrollbar) Layout(gtx layout.Context, axis layout.Axis, viewportStart,
 			Y: int(event.Position.Y),
 		})
 		normalizedPos := float32(pos.X) / trackHeight
+		// Clicking on the indicator should not jump to that position on the track. The user might've just intended to
+		// drag and changed their mind.
+		if !(normalizedPos >= viewportStart && normalizedPos <= viewportEnd) {
 			s.delta += normalizedPos - viewportStart
 		}
+	}
 
 	// Offset to account for any drags.
 	for _, event := range s.drag.Events(gtx.Metric, gtx, gesture.Axis(axis)) {