KNOB

The KNOB widget is used to change a value with a knob. The KNOB widget is transparent per default and it requires a memory device containing a drawn knob to be visible. If the memory device contains transparency, any content can be shown in the background.

Ever since of the release of the ROTARY widget, the KNOB widget has been become obsolete. The new ROTARY widget does not use memory devices.

KNOB
Receives focus	Yes
Skinnable	No
OwnerDraw	No
Uses Memory Devices	Yes
Attached widgets	None

Notification codes

The following events are sent from a KNOB widget to its parent window as part of a WM_NOTIFY_PARENT message:

Message	Description
WM_NOTIFICATION_CLICKED	KNOB has been clicked.
WM_NOTIFICATION_RELEASED	KNOB has been released.
WM_NOTIFICATION_MOVED_OUT	KNOB has been clicked and pointer has been moved out of the KNOB widget without releasing.
WM_NOTIFICATION_VALUE_CHANGED	The value of the KNOB widget has been changed.

Keyboard reaction

The KNOB widget reacts to the following keys if it has the input focus:

Message	Description
GUI_KEY_RIGHT	The KNOB rotates CW.
GUI_KEY_LEFT	The KNOB rotates CCW.
GUI_KEY_LEFT	The KNOB rotates CW.
GUI_KEY_LEFT	The KNOB rotates CCW.