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

TDragManager

[Properties (by Name)] [Methods (by Name)] [Events (by Name)]

TDragManager - a class for managing the dragging of controls (eventually to be dropped or docked)

Declaration

Source position: controls.pp line 451

type TDragManager = class(TComponent)

protected

  procedure KeyUp(); virtual; abstract;

  

KeyUp - method for processing a key that is not pressed

  procedure KeyDown(); virtual; abstract;

  

KeyDown - method for handling a key that is pressed down

  procedure CaptureChanged(); virtual; abstract;

  

CaptureChanged - method for use when the identity of the captured control has changed

  procedure MouseMove(); virtual; abstract;

  

MouseMove - method for processing a mouse movement

  procedure MouseUp(); virtual; abstract;

  

MouseUp - method for processing a mouse button that is not pressed

  procedure MouseDown(); virtual; abstract;

  

MouseDown - method for processing a mouse button that is pressed down

public

  constructor Create(); override;

  

Create - constructor for TDragManager: calls inherited Create and sets default drag threshold; sets DragImmediate True

  function IsDragging; virtual; abstract;

  

IsDragging - returns True if dragging is in progress

  function Dragging(); virtual; abstract;

  

Dragging - returns True if the specified control is being dragged

  procedure RegisterDockSite(); virtual; abstract;

  

RegisterDockSite - adds the nominated site to the list or register of docking sites

  procedure DragStart(); virtual; abstract;

  

DragStart - begin the drag

  procedure DragMove(); virtual; abstract;

  

DragMove - method for dragging to specified position (virtual method - needs to be supplied by user)

  procedure DragStop(); virtual; abstract;

  

DragStop - finish the drag

  property DragImmediate: Boolean; [rw]

  

Is the dragging process to start immediately the control receives focus (eg gets captured by mouse)?

  property DragThreshold: Integer; [rw]

  

The threshold amount by which the mouse must move before the dragging process starts.

end;

Inheritance

TDragManager

  

TDragManager - a class for managing the dragging of controls (eventually to be dropped or docked)

|

TComponent

|

TObject

Description

The declaration contains a number of procedure definitions that are 'virtual' and 'abstract'. This means that there is no implementation specified: these essentially represent 'place-holders', and it is the responsibility of the developer of descendant classes to override these methods and implement them as desired.

The latest version of this document can be found at lazarus-ccr.sourceforge.net.