View source for 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.

{| class="wikitable" style="float:right; margin-left: 10px; background-color: #f9f9f9; width: 15%;"
! colspan="2" style="font-weight:bold; font-size:17px; font-family:Arial, Helvetica, sans-serif !important;; background-color:#ceceff;" | KNOB
|-
| colspan="2" | [[File:Knob.png | center]]
|-
| style="font-weight:bold; font-size:12px; font-family:Arial, Helvetica, sans-serif !important;;" | Receives focus
| style="font-size:12px; font-family:Arial, Helvetica, sans-serif !important;;" | Yes
|-
| style="font-weight:bold; font-size:12px; font-family:Arial, Helvetica, sans-serif !important;;" | Skinnable
| style="font-size:12px; font-family:Arial, Helvetica, sans-serif !important;;" | No
|-
| style="font-weight:bold; font-size:12px; font-family:Arial, Helvetica, sans-serif !important;;" | OwnerDraw
| style="font-size:12px; font-family:Arial, Helvetica, sans-serif !important;;" | No
|-
| style="font-weight:bold; font-size:12px; font-family:Arial, Helvetica, sans-serif !important;;" | Uses Memory Devices
| style="font-size:12px; font-family:Arial, Helvetica, sans-serif !important;;" | Yes
|-
| style="font-weight:bold; font-size:12px; font-family:Arial, Helvetica, sans-serif !important;;" | Attached widgets
| style="font-size:12px; font-family:Arial, Helvetica, sans-serif !important;;" | None
|}

== Notification codes ==

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

{| class="wikitable" style="width: 30%;"
|-
! Message !! Description
|-
| style="font-family: monospace,monospace; width: 40%;" | WM_NOTIFICATION_CLICKED
| KNOB has been clicked.
|-
| style="font-family: monospace,monospace; width: 40%;" | WM_NOTIFICATION_RELEASED
| KNOB has been released.
|-
| style="font-family: monospace,monospace; width: 40%;" | WM_NOTIFICATION_MOVED_OUT
| KNOB has been clicked and pointer has been moved out of the KNOB widget without releasing.
|-
| style="font-family: monospace,monospace; width: 40%;" | 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:

{| class="wikitable" style="width: 30%;"
|-
! Message !! Description
|-
| style="font-family: monospace,monospace; width: 40%;" | GUI_KEY_RIGHT
| The KNOB rotates CW.
|-
| style="font-family: monospace,monospace; width: 40%;" | GUI_KEY_LEFT
| The KNOB rotates CCW.
|-
| style="font-family: monospace,monospace; width: 40%;" | GUI_KEY_LEFT
| The KNOB rotates CW.
|-
| style="font-family: monospace,monospace; width: 40%;" | GUI_KEY_LEFT
| The KNOB rotates CCW.
|}