Managing Multiple Windows (SAP Library - BC SAP Graphics: Programming Interfaces)

Managing Multiple Windows

If a window is open, the graphics program running in it is alive on the workstation. This is true even if the function module that called it has returned.

If two windows running the same graphics program are open, there are two copies of the underlying program running. Each copy handles requests from its own window. If the user closes one of the windows, the other one is still alive.

The ABAP program must be able to handle all of the following window-related functions:

Provide window ID's, when the window is opened.

If you do not do this, the window is named by default. (See the WINID parameter.)

Receive user input from any window.

This means the program must recognize window ID's and which function modules created them. (See the RWNID parameter.)

Send new data to any window. (See the WINID parameter.)

Keep track of windows that are closed.

An ABAP program must not send data to a window that has been closed. The closed window can however be re-opened with the same name.

Provide a function module with the name of a parent window when creating its child. (See the PWDID parameter.)

For a detailed description of parameters and exceptions, see the R/3 system documentation (Tools ® ABAP Workbench, Function library button, or transaction code SE37).

The ABAP program need not maintain the tree of parent-child relationships between windows. This information is maintained on the graphics program side, and does not depend on which graphics programs are running or which function module is waiting for input.

The ABAP program tells the function module how windows are to be closed using the SUPER or PWDID parameters. This information is transmitted to the graphics program. When the online user later exits from the window, the graphics program terminates, closing the window (and possibly its children) as instructed.