12.6.28. Flow Object Classes for Online Display

The facilities described in this clause require the online feature.

12.6.28.1. Scroll Flow Object Class

A scroll flow object class is used as the top-level flow object for online display that does not divide output into pages.

It has a single principal port, which accepts displayed flow objects.

The size of the flow object in the direction perpendicular to the filling-direction is determined by the viewing environment.

This flow object has the following characteristics:

12.6.28.2. Multi-mode Flow Object Class

A multi-mode flow object is a flow object with two or more modes of presentation. The flow object can be switched between these modes of presentation in a system-dependent way.

NOTE 117: An implementation might present a menu of the different modes. Alternatively, clicking on the formatted flow object might cycle through the modes.

This flow object is inlined or displayed according to its content and mode of presentation.

This flow object has the following characteristics:

The flow object has one port for each mode. The content of that port specifies the presentation in the corresponding mode. Initially, the flow object shall be displayed using the principal mode.

NOTE 119: For example, an icon which when clicked causes a window to be popped up could be represented by a multi-mode flow object with two ports, the first containing a character flow object representing an icon and the second containing a scroll flow object. In this case, the principal-mode-simultaneous?: characteristic would be true.

12.6.28.3. Link Flow Object Class

A link flow object represents a hypertext link that can be interactively traversed, typically by clicking on the areas representing the flow object and its content. A link has a single principal port, which can contain both inlined and displayed flow objects. Link flow objects can be nested, and the innermost link is effective. It has the following characteristic:

12.6.28.4. Marginalia Flow Object Class

The marginalia flow object class is used to contain flow objects whose resulting areas shall be attachment areas for the line in which the marginalia flow object occurs. See “Attachment Areas”. The marginalia flow object has a single principal port which shall contain only inlined flow objects. A marginalia flow object shall have an ancestor flow object that is of class paragraph.

The behavior when there is more than one marginalia area attached to a single line is system-dependent.

A marginalia flow object has the following characteristics: