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

# TCustomGrid.DoMouseWheelUp

Handles a mouse wheel up movement for the grid control.

## Declaration

Source position: grids.pas line 1038

`protected function TCustomGrid.DoMouseWheelUp(`
`Shift: TShiftState;`
`MousePos: TPoint`
`):Boolean; override;`

## Arguments

`Shift` |  | Shift, Alt, Ctrl modifier for the mouse wheel action.
`MousePos` |  | TPoint instance with the coordinates for the mouse pointer.

## Function result

True if the mouse wheel operation was handled in the method.

## Description

DoMouseWheelUp is an overridden method in TCustomGrid called when the mouse wheel is scrolled upward. It calls the inherited method on entry to signal the OnMouseWheelUp event handler (when assigned). The return value is set to True if the action was handled in OnMouseWheelUp.

If the action is not handled in OnMouseWheelUp, the GridMouseWheel method is called to scroll to the previous selectable area in the control using the specified Shift modifier. When Shift contains ssCtrl (Ctrl key), the horizontal position is updated instead of the vertical. The return value is set to True when the action is handled in this manner.

Use MouseWheelOption to specify whether mouse wheel operations are applied to the grid cursor (selection / editing) or the visible area for the control.

See DoMouseWheelDown for the actions performed when the mouse wheel is scrolled in the downward direction.

DoMouseWheelUp is called from the inherited DoMouseWheel method when an OnMouseWheel event handler was not found, or it did not handle the notification.

## See also

TCustomGrid.MouseWheelOption |  | Sets the mouse wheel behavior for the grid control.
TCustomGrid.GridMouseWheel |  | Performs actions to apply a mouse wheel message to the grid control.
TCustomGrid.DoMouseWheelDown |  | Handles a mouse wheel down movement for the grid control.
TControl.DoMouseWheelUp |  | Signals the OnMouseWheelUp handler.
TControl.OnMouseWheelUp |  | Event handler signalled for an upward movement of the mouse wheel.
TShiftState