Method onCursor

gui/scrollbar.go:225–243

onCursor receives subscribed cursor events for the scroll bar button

(evname string, ev interface{})

// onCursor receives subscribed cursor events for the scroll bar button
func (button *scrollBarButton) onCursor(evname string, ev interface{}) {

	e := ev.(*window.CursorEvent)
	if !button.pressed {
		return
	}
	if button.sb.vertical {
		dy := button.mouseY - e.Ypos
		py := button.Position().Y
		button.SetPositionY(math32.Clamp(py-dy, 0, button.sb.content.Height-button.Size))
	} else {
		dx := button.mouseX - e.Xpos
		px := button.Position().X
		button.SetPositionX(math32.Clamp(px-dx, 0, button.sb.content.Width-button.Size))
	}
	button.mouseX = e.Xpos
	button.mouseY = e.Ypos
	button.sb.Dispatch(OnChange, nil)
}