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TImageRequestEvent


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

The TImageRequestEvent type declares the event which occurs when the TThumbnails component needs a thumbnail image to draw. In the event handler the image addressed by the parameter ThumbID has to be loaded and passed on to the variable parameter ImgBuffer. The variable parameters HowToProcess and Markit define how the addressed thumbnail will be processed.

HowToProcess may take one of four values determining whether the thumbnail image is displayed, or an empty slide is presented, or only the frame of the slide is shown, or no slide at all is displayed (see TImageRequestProcessing for more details). If the parameter MarkIt is positive the slide is marked at the top left corner by displaying a marking which corresponds to this parameter. The color of the marking is determined by the property ColorMark.


Last Update: 2012-Oct-20