Creating Pictures

Instances of the Control class provide the createPictureIndirect method, which creates a short binary that contains an instruction concerning the window to be copied.

When the binary is assigned to a Picture control property, the picture is created using the current image of the requested window.

The createPictureIndirect method improves JADE thin client mode performance, as it does not have to pass large binary large objects (blobs) back and forth between the presentation client and the application server when creating a bitmap for the receiver control.

If you use the Control::createPicture method in JADE thin client mode, the picture image would be created on the presentation client and brought back to the application server. Assigning the picture then causes the image to be sent back to the presentation client and to be cached, which could involve significant delays and overheads for a reasonable-size image. Using the createPictureIndirect method, a small binary is sent instead and the image data itself is not transported between the presentation client and the application server.

For more details, see Chapter 2 of the JADE Encyclopaedia of Classes.