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

# TControlCanvas

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

Base class which provides a canvas property used in graphic controls.

## Declaration

Source position: controls.pp line 356

`type TControlCanvas = class(TCanvas)`
`protected`
`procedure CreateHandle; override;` |  | Ensures that a handle exists for the class instance.
`function GetDefaultColor(); override;` |  | Gets the color value used for clDefault.
`public`
`constructor Create;` |  | Constructor for the class instance.
`destructor Destroy; override;` |  | Destructor for the class instance.
`procedure FreeHandle; override;` |  | Frees the Handle for the control canvas, and its device context when assigned.
`function ControlIsPainting;` |  | Indicates if the Control has called but not completed its Paint method.
`property Control: TControl; [rw]` |  | The Control object for which the Canvas is used.
`end;`

## Inheritance

`TControlCanvas` |  | Base class which provides a canvas property used in graphic controls.
`TCanvas` |  | Implements a drawing surface for a visual control or bitmap image.
`TFPCustomCanvas`
?
`TObject`

## Description

TControlCanvas is a TCanvas descendant that implements the base class which provides a canvas used in graphic controls. TControlCanvas extends the ancestor class by including a property representing the TControl associated with the canvas, a window handle for the associated control, and the device context for the handle.

TControlCanvas is used in the implementation of classes like TGraphicControl and TCustomControl, and other visual controls.

## See also

TCanvas |  | Implements a drawing surface for a visual control or bitmap image.
TGraphicControl |  | TGraphicControl is the base class for all lightweight controls.
TCustomControl |  | The base class for windowed controls which paint themselves.