TCustomImage class

In unit ExtCtrls

Implements the base class for TImage.

Declaration

pascal

TCustomImage = class(TGraphicControl)

Inheritance

Descends from it: TDBImage TImage

Description

TCustomImage is a TGraphicControl descendent, and the base class for TImage. It is a lightweight and fast class used to display a graphic image using one of the image formats supported in the LCL. This includes:

Bitmap
Pixmap
PNG
JPEG
GIF
TIFF
Icon

Use the Picture property to assign, load or save an image using one of the supported formats.

The Canvas property is used to render the graphic image in Picture, or to perform custom drawing operations on the image.

Use properties in the class instance to control how the image is rendered, including: AntialiasingMode, Center, Stretch, Transparent, and Proportional.

Do not create instances of TCustomImage; use the TImage descendant instead.

Use TImageList when a list of images with scaling capabilities is needed.

Properties

`Canvas`	public	Canvas used to draw the image.
`HasGraphic`	public
`AntialiasingMode`	public	Indicates if anti-aliasing is used when rendering the image.
`Align`	public	Specifies the placement of the control on its Parent control.
`AutoSize`	public	Allows automatic adjustment of the size for the control, according to its content.
`Center`	public	Indicates if the image should be centered.
`KeepOriginXWhenClipped`	public	Preserves the Left coordinate when a clipped image is centered.
`KeepOriginYWhenClipped`	public	Preserves the Top coordinate when a clipped image is centered.
`Constraints`	public	Contains the minimum and maximum Width and Height for the control.
`ImageIndex`	public
`ImageWidth`	public
`Images`	public
`Picture`	public	Contains the image displayed in the control.
`Visible`	public	Allows the control, and all of its children, to be displayed or hidden.
`Stretch`	public	Indicates if the image is resized to the client area for the control.
`StretchOutEnabled`	public	Allows the image to be resized proportionally when the image drawing area is expanded.
`StretchInEnabled`	public	Allows the image to be resized proportionally when the image drawing area is shrunk.
`Transparent`	public	Indicates if the image has a clear, non-opaque background.
`Proportional`	public	True if image is proportional.

Methods

`WSRegisterClass`	protected	Registers the class with the widgetset.
`PictureChanged`	protected	Performs actions needed when the Picture property has been changed.
`CalculatePreferredSize`	protected	Gets the preferred width and height used as the default size for the control.
`GetControlClassDefaultSize`	protected	Gets the default size for a new instance of the class type.
`Paint`	protected	Draws the image to the control canvas.
`Create`	public	Constructor for the class instance.
`Destroy`	public	Destructor for the class instance.
`DestRect`	public	Gets the rectangle where the image is painted.
`Invalidate`	public	Causes the control to be repainted.

Events

`OnClick`	public	Notification handler for mouse clicks.
`OnMouseDown`	public	Event handler signalled when a mouse down event is handled for the control.
`OnMouseEnter`	public	Event handler signalled when the mouse pointer has entered the control.
`OnMouseLeave`	public	Event handler signalled when the mouse pointer has left the control.
`OnMouseMove`	public	Event handler signalled when the mouse pointer is moved in the control.
`OnMouseUp`	public	Event handler signalled when a mouse up event is handled for the control.
`OnMouseWheel`	public	Event handler for mouse wheel turned.
`OnMouseWheelDown`	public	Event handler signalled for a downward movement of the mouse wheel.
`OnMouseWheelUp`	public	Event handler signalled for an upward movement of the mouse wheel.
`OnPictureChanged`	public	Event handler signalled when Picture is changed.
`OnPaintBackground`	public	Event handler signalled to draw the background for the image.