[Overview][Constants][Types][Classes][Procedures and functions][Variables][Index] | Reference for unit 'Controls' (#lcl)

# TControl.OnMouseWheelRight

Event handler signalled for a rightward movement of the mouse wheel.

## Declaration

Source position: controls.pp line 1599

`protected property TControl.OnMouseWheelRight : TMouseWheelUpDownEvent read FOnMouseWheelRight write FOnMouseWheelRight;`

## Description

OnMouseWheelRight is a TMouseWheelUpDownEvent property with the event handler signalled when the mouse wheel is "tilted" towards the right. It is signalled (when assigned) from the DoMouseWheelRight method, and occurs when the LM_MOUSEHWHEEL message is handled in the WMMouseHWheel method.

Applications can implement and assign a TMouseWheelUpDownEvent to perform actions needed when the event has occurred in the control. The arguments to the event handler include:

Sender
  The control for the event notification.
Shift
  The shift modifier in effect when the event occurred.
MousePos
  The coordinates for the mouse pointer when the event occurred.
Handled
  A variable argument which indicates if the wheel event is handled in the routine.

There are several horizontal mouse wheel event handlers, and they are signalled in order until a handler is found that responds to the event notification. These include:

- OnMouseWheelHorz
- Controls handlers added using AddHandler and the chtOnMouseWheelHorz handler type.
- OnMouseWheelLeft or OnMouseWheelRight depending on the WheelDelta - or relative units of movement for the mouse wheel.

OnMouseWheelRight, and the other horizontal mouse wheel event handlers, require a mouse with a tilting scroll wheel to generate the event notification.

## See also

TControl.OnMouseWheelLeft |  | Event handler signalled for a leftward movement of the mouse wheel.
TControl.OnMouseWheelHorz |  | Event handler signalled for a horizontal movement of the mouse wheel.
TControl.OnMouseWheel |  | Event handler for mouse wheel turned.
TMouseWheelUpDownEvent |  | Type of OnMouseWheelUp/Down event handlers.