1.182.1 Send methods

visual ->contained_in: visual

Succeeds if I'm contained in the argument visual object. This method walks up the visualisation contained hierarchy using‘Visual visual<-contained_in’. A visual is defined to be contained in itself.

visual ->destroy:

Invokes object->free on the visual and all parts of this visual that are not protected. This method may be used to destroy an entire tree of visual objects.

First, it collects all visuals that are part of it and not protected or part of a protected visual using visual<-contains. Then it will send free to all collected visuals. This method takes care of the fact that freeing one visual might result in the destruction of others.

See also

- object->free
- visual<-contains
- object->protect
- window->destroy

visual ->report: kind={status,inform,progress,done,warning,error,fatal}, format=[char_array], argument=any ...

The method visual->report provides a general mechanism to present short descriptions of status, warnings or errors to the application user. This method is integrated with the general error reporting mechanism (see object->error and class error.

If no visual object is available to send the report to, object->report may be used.

The first argument describes the type of the message to be reported. The type is an indication on how serious the message is and thus how much attention it should attract from the application user. Its values are:

status

Information on progress, status change of the system, etc. such information should not attract much attention. By default, PCE will format the message at an appropriate location. If no such location can be found the message is ignored

inform

The user requested information and this is the reply. Handled as status, but if no appropriate location can be found it will invoke display->inform.

progress

Indicates progress in ongoing computation. Feedback is generally similar to status, but followed by a graphical->flush to take immediate effect.

done

Terminates a (sequence of) visual->report: progress messages.

warning

The user probably made a minor mistake for which a simple alert such as provided by graphical->alert suffices. If there is an appropriate location for the message it will be formatted there.

error

Something serious went wrong and the user needs to be informed of this. For example a file could not be read or written.

The remaining arguments are a format specification and format arguments. See string->format for details on PCE's formatting capabilities.

The method visual->report performs the following steps:

1. Ask for a visual that might be able to report the message using visual<-report_to.
2. If such an object exists and @reportee equals @nil, bind @reportee to the receiver of the visual->report message. @reportee thus points to the original visual object that received the visual->report message.
3. Invoke visual->report with the same argument on the object. The method visual->report is redefined by various subclasses. The most important are: label->report, frame->report and‘display visual->report’.

   See also

   - object->report
   - @reportee
   - object->error
   - string->format
   - graphical->alert

visual ->reset:

This method sends visual->reset to all visual objects it contains (recursively). visual->reset is automatically invoked from the host-language after an abort to the hostlanguage toplevel. Various subclasses of visual implement this method to reset parameters such as status, event-focus, etc.

Bugs: Recovery after a crash or abort is not very save. The consistency of the objectbase may be violated, gesture objects often cannot be tracked and reset, etc.

See also

window->reset