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

CheckMouseButtonDownUp

Checks for mouse click events for the specified control.

Declaration

Source position: controls.pp line 2775

function CheckMouseButtonDownUp(

  const AWinHandle: THandle;

  const AWinControl: TWinControl;

  var LastMouse: TLastMouseInfo;

  const AMousePos: TPoint;

  const AButton: Byte;

  const AMouseDown: Boolean

):Cardinal;

Arguments

AWinHandle

  

Handle for the control where the mouse events were detected.

AWinControl

  

Control with the specified handle.

LastMouse

  

Mouse information for the mouse event examined in the routine.

AMousePos

  

Position where the last mouse event occurred.

AButton

  

Mouse button for the last mouse event.

AMouseDown

  

True if the mouse event is a mouse down event. False for a mouse up event.

Function result

Value used as the Msg member in a mouse message.

Description

CheckMouseButtonDownUp is a Cardinal function used to check for mouse down or up events for the control represented by the handle in AWinHandle. The return value contains the Word value used in the Msg member in a TLMMouse mouse message.

LastMouse contains the most recent mouse event information examined and potentially updated in the method.

CheckMouseButtonDownUp consolidates mouse down events (single, double, triple, and quadruple) into a single value used in a mouse message, and updates LastMouse when needed.

AWinControl contains the control with the handle where the event mouse events occurred.

At run-time, multi-click events are adjusted to the ControlStyle specified in the control (or one of its children) including:

If the target control does not allow one of the multi-click events, the click count in LastMouse is updated accordingly.

At design-time, only Single and Double click mouse events are handled.

CheckMouseButtonDownUp is used in the callback routine for a widgetset class when a mouse event message is created and passed to the class instance.

Version 3.2 Generated 2024-02-25 Home