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OnFirstImageRequest


Unit:SDL_thumbnails
Class: TThumbnails
Declaration: property OnFirstImageRequest: TNotifyEvent;

The OnFirstImageRequest event occurs when the thumbnail update cycle starts. 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.

The OnFirstImageRequest event can be used to set for example the screen cursor to crHourGlass in oder to indicate that the loading of the thumbnails may take a while.

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



Last Update: 2012-Oct-20