TCustomImageList.Overlay procedure
Assigns the specified image to the given overlay position for the image list.
Declaration
procedure Overlay(AIndex: Integer; Overlay: TOverlay)Arguments
AIndex | Ordinal position of the image used as an overlay. |
Overlay | Ordinal position in the internal array where the image index is stored. |
Description
Overlay is a procedure which makes an image in the image list an
overlay. An overlay image is drawn transparently over another image. An image
list can have up 15 images designated as overlay images (0 is reserved for
none).
AIndex contains the position in the image list for the image to
use as an overlay image.
Overlay is a
TOverlay value that indicates the position
in Overlays where the value in AIndex is stored.
The Overlay method tells the image list that the image in AIndex is an overlay image referenced using the value in the Overlay parameter instead of the ordinal position in the image list.
Overlay sets the value in the HasOverlays property to True
when AIndex contains a valid index position in the image list. Otherwise, the
image indexes in each of the positions in Overlays are re-examined to
determine the value for HasOverlays. Any element in Overlays with a value
other than -1 has an assigned overlay image index.
Use the DrawOverlay method to draw an image along with a specific
overlay image.
Use ClearOverlays to reset the image indexes stored in Overlays to
the unused value (-1).
See also
An experiment, built from development snapshots. Not the official Free Pascal or Lazarus documentation.