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

# TDragManager

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

The abstract base class for managing the dragging of controls (to be dropped or docked).

## Declaration

Source position: controls.pp line 465

`type TDragManager = class(TComponent)`
`protected`
`procedure KeyUp(); virtual; abstract;` |  | Handler for keyboard key released.
`procedure KeyDown(); virtual; abstract;` |  | Handler for keyboard key pressed.
`procedure CaptureChanged(); virtual; abstract;` |  | Aborts the dragging operation, when the capturing control really has changed.
`procedure MouseMove(); virtual; abstract;` |  | Generates the visual feedback when the mouse moves.
`procedure MouseUp(); virtual; abstract;` |  | Ends dragging.
`procedure MouseDown(); virtual; abstract;` |  | Nop.
`public`
`constructor Create(); override;` |  | Initializes the Delphi default dragging parameters.
`function IsDragging; virtual; abstract;` |  | True if dragging is in progress.
`function Dragging(); virtual; abstract;` |  | True if the specified control is being dragged.
`procedure RegisterDockSite(); virtual; abstract;` |  | Adds or removes the control to the list or register of docking sites.
`procedure DragStart(); virtual; abstract;` |  | Starts dragging.
`procedure DragMove(); virtual; abstract;` |  | Updates the visual dragging feedback.
`procedure DragStop(); virtual; abstract;` |  | Ends dragging.
`property DragImmediate: Boolean; [rw]` |  | Start dragging immediately, on MouseDown? (default value)
`property DragThreshold: Integer; [rw]` |  | The threshold amount by which the mouse must move before non-immediate dragging starts. (default 5 pixels)
`end;`

## Inheritance

`TDragManager` |  | The abstract base class for managing the dragging of controls (to be dropped or docked).
`TComponent,IUnknown,IInterfaceComponentReference`
`TPersistent`
`TObject`

## Description

This is the OO version of the Delphi drag manager, implemented in TDragManagerDefault.

[entire review DoDi 2010-02-16]

## See also

TDragManagerDefault |  | The default DragManager class.

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