src/swipl-devel/packages/xpce/man/refmanual/md/application.md

In rswipl: Embed 'SWI'-'Prolog'

class application {#class-application}

An application object defines a collection of cooperating frame objects. Applications are new as of XPCE version 4.9, and therefore do not yet have a stable definition. It is however assumed that the current implementation will only be enhanced with new, compatible, features.

Applications are designed to deal with the following issues:

• Find frames belonging to the application Using the <-member method, frames that constitute an application can find each other. See also frame<->name and graphical<-application.

• Define the scope of modal frames Frames may be defined modal over the other frames in the application. See frame ->modal.

• Define general application properties XPCE itself uses applications of <-kind: service to realise the programming environment, and avoid the environment from tracing and debugging itself.

Normally, applications are created explicitely, often as global named objects. Frames are attached to it using the application initialisation argument application:

:- pce_global(@my_application, make_my_application).

make_my_application(App) :-
    new(App, application(mine)),
    ...

    ...
    new(F, frame('My title',
                 application := @my_application)),
    ...

Instance variables {#class-application-instvars}

• application<->kind: {user,service} If user, (default), the methods and predicates called as a result of event-handling by windows and frames of the application can be debugged. If service, all Prolog and XPCE activity will be run in system mode to avoid debugging the XPCE environments tools, while trying to debug the user application.

  Timer objects are not covered by this flag as they do not belong to an application. They provide the timer->service method to turn them into a service.

• application<-members: chain Chain holding member frames. This chain is maintained by ->delete and ->append.

• application-modal: chain Frame that currently acts as modal window for the application. This implies that no window in another frame object can receive events. See also frame->modal.

• application<->name: name Identifier name of the application. Currently not used.

Send methods {#class-application-send}

• application->append: frame Add frame to the application. See also frame ->application, and the application argument of frame ->initialise.

• application->delete: frame Remove frame from the application. Associating a frame with another application object will automatically delete it from the application it was a <-member of. This method may be redefined to keep track of the applications, but must call the super-implementation.

• application->initialise: name Create an application with the given name. The application is added to the chain object @applications.

• application->reset Implementation of visual <-reset. Removes any possible <-modal frame object.

• application->unlink Destroying an application will invoke frame ->destroy on all <-members.

Get methods {#class-application-get}

• application<-contains: -> chain Implementation of visual <-contains, returning <-members.

• application<-member: name -> frame Find a member frame object with given frame <-name.

rswipl documentation built on June 16, 2026, 5:07 p.m.