IFRPageEvents Interface

IFRPageEvents interface in the ABBYY FineReader Engine API — Client-side callback interface for reporting events (OnPageProcessed, OnProgress, OnRegionProcessed, OnWarning) from an FRPage to listeners.

This is a callback interface that is used for reporting events from the FRPage object to the listeners. This interface is implemented on the client-side. See the detailed implementation advice for your development tool in Working with Connectable Objects. A brief description is below:

C++ users will need to implement the IFRPageEvents interface, obtain a connection point (Windows), and “advise” object implementing the interface to the FRPage object. As the interface is derived from the IUnknown interface, the client object should also implement the IUnknown methods.

Visual Basic users that want to receive notifications from the FRPage object should declare it WithEvents and implement the procedures similar to the following:

Public WithEvents page As FREngine.FRPage
Private Sub page_OnPageProcessed(ByVal sender As FRPage, _
                                 ByVal stage As PageProcessingStageEnum)
...
End Sub

An object receiving notifications through this interface’s methods may do the following inside the methods’ implementation:

• Report percentage of document analysis, recognition, and export.
• Report recognizer tips and warnings to the user.
• Report information about completion of the operation.
• In Windows: Process any system messages to help prevent the application from appearing unresponsive during long operations. This can be helpful in applications with a user interface.

Methods

Name	Description
OnPageProcessed	Delivers to the client information about page processing completed.
OnProgress	Delivers to the client information about approximate percentage of the current operation (analysis, recognition, and export).
OnRegionProcessed	Delivers to the client information about region which is processed.
OnWarning	Delivers to the client tips and warnings which occurred during processing.

Remarks

In Linux: This interface does not work if the Engine object is loaded as an out-of-process server.

See also

FRPage

Working with Connectable Objects