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OnImageRequest


Unit:SDL_thumbnails
Class: TThumbnails
Declaration: property OnImageRequest: TImageRequestEvent;
{TImageRequestEvent = procedure (Sender: TObject; ThumbID: integer; var HowToProcess: TImageRequestProcessing; var MarkIt: integer; var ImgBuffer: TBitMap) of object;}

The OnImageRequest event is triggered whenever the component has to display a thumbnail image. Thus when painting the thumbnails on the canvas the sequence of events is as follows:
1 x OnFirstImageRequest,
p x OnImageRequest, and
1 x OnLastImageRequest,
with p being less than or equal to NumSlidesHoriz * NumSlidesVert.

More details on how to use the OnImageRequest event can be found in the description of the TImageRequestEvent type.

Example: This event is used in the following example programs (see http://www.lohninger.com/examples.html for downloading the code): slides, jpg_browser



Last Update: 2023-Dec-13