Caching Pictures and Forms
The Picture::cachePictures property has meaning only when the picture object is attached to a physical window.
By default, setting the picture properties of a Picture or JadeMask control at run time causes those pictures to be stored in the cache file of the application server and the cache file of the presentation client unless the UseCacheFile parameter in the [JadeThinClient] section of the JADE initialization file is set to false.
However, you can set this property to false in situations where you do not require this caching because the picture is only ever downloaded once and will therefore unnecessarily add entries to those cache files. Examples of where you could set this property to false are as follows.
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Using the Control::createPicture method to create a dynamic runtime image that is then displayed. (See "Creating Pictures", in the following subsection, for more details about picture creation.)
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Displaying a customer invoice that was scanned in.
Setting the cachePictures property to false affects the following.
In addition, you can use the CacheEntryTimeout parameter in the [JadeAppServer] section or the CacheEntryTimeout parameter in the [JadeThinClient] section of the JADE initialization file to control the number of days entries are held in the cache file on the application server or presentation client before being discarded. This parameter provides control over cache file entries that become orphaned when forms and pictures are removed from the JADE system.
By default, a form that has not been created or a picture that has not been displayed within the last 30 days is discarded. You can set this parameter to zero (0) if you want forms and pictures to remain indefinitely in the cache file on the presentation client. In addition, the Window class drawPictureAt and drawPictureIn methods cache the pictures that are drawn on the presentation client.
