Windows Application to Presentation Manager Application

DDE support between Windows applications and Presentation Manager applications requires that the DDEServer be linked with the Presentation Manager DDE APIs. Both DDE messages and data formats are translated during the data exchange between Presentation Manager and any given VDM running a Windows application. This process consists of a protected mode DDEServer, a Windows DDE ServerAgent, as described above, and a Presentation Manager DDE ServerAgent. The Presentation Manager DDE ServerAgent is a mirror to the Windows DDE ServerAgent. The ServerAgent is responsible for routing all DDE messages beyond the confines of Presentation Manager to the DDEServer. The ServerAgent communicates with the DDEServer via named pipes.

The DDE process between Presentation Manager applications and Windows applications may be represented as in Figure "DDE Process between Presentation Manager and Windows".

The following data formats are translated between the Presentation Manager environment and the Windows environment:

Bitmaps:

Windows DIB format to/from OS/2 BITMAPINFO2 and Presentation Manager BITMAPINFO to/from Windows DIB format.

Pre-Windows 3.0 format to Windows DIB format to/from Presentation Manager BITMAPINFO.

Metafiles are converted to Window DIB format prior to being translated as above.

PM metafiles are first converted to Window DIB format prior to being translated as above, and are then forwarded to the global clipboard.

Codepage translation is provided in both directions, if required.

Any data format which is not supported by the global DDEServer translation routines, can still be used on a local base, that means within the same VDM.

The Presentation Manager DDE ServerAgent will reside as a utility in a Productivity folder on the Workplace Shell. Where there is a demand to provide DDE support between Presentation Manager applications and Windows applications, the Presentation Manager DDE ServerAgent should be placed in the Workplace Startup folder. The DDE ServerAgent runs only as a minimized icon. To shut down global DDE, the Presentation Manager DDE ServerAgent must be terminated through the Window List.

If a seamless Windows session is started, the DDE ServerAgent will automatically be started, so that this particular Windows application can automatically use DDE. Otherwise, it would appear to be isolated and this would confuse the novice user.

Existing DDE support between Presentation Manager applications remains essentially unchanged. Where DDE is only used between Presentation Manager applications, the DDEServer should be deactivated to improve performance.