Note: This page includes content based on the F1 documentation for Centura development. It may be partially converted to support APF development, but should be regarded to be of uncertain actuality. It is provided as is. Eventually, it should be replaced by documentation available from within Visual Studio.
Const.PM_DataItemZoom
The Const.PM_DataItemZoom message is sent to a data item when the user requests to zoom to the object referenced by the item.
| Name | Description |
|---|---|
| nWhat = wParam | Standard method parameter. Possible values are Const.METHOD_Inquire, Const.METHOD_Execute, Const.METHOD_GetType |
| lParam | Unused |
When nWhat = Const.METHOD_Inquire, TRUE is returned if the data item has a reference, there is a default window registered for the reference, and that window's data source is available. Otherwise, FALSE is returned.
When nWhat = Const.METHOD_Execute, TRUE is returned if the default window for the reference was successfully created, FALSE otherwise.
For the zoom functionality to work, there must be a default window (also called "LU home page") registered for the logical unit and view that is referenced by the data item. Applications should call Component.WindowRegister to register a default window.
The framework responds to the zoom request by initiating the data transfer object with the current data item, and then creating the default window. The default window may then process the information in DataTransfer to e.g. populate with the correct record.
For instance, if the user invokes zoom from a "customer id" field containing the value "102", the default window can use this information (that's been placed in DataTransfer by the framework) to populate with customer 102.