Glyphs

InterViews Glyph objects provide the usual user interface widgets like buttons, scrollbars, pulldown menus, string editors, etc. (They also provide a limited graphical capability; since they don't have a general editing framework the glyph graphics are mostly useful for static pictures, e.g. a graphic inside a button.) We use glyphs to implement layout, look-and-feel, and controls/displays for application programs.

The main technical advantages of glyphs are:

• lightweight: they use less memory than other equivalent widget sets, so they are fast.
• multiple look-and-feel styles: every program supports OpenLook, Motif or SGIMotif styles, selectable by a command line flag at startup.

The ultimate reference for glyphs is the "InterViews Reference Manual Version 3.1" (no frames) dated December 14, 1992. It is included in the InterViews source tree under iv/src/man/refman/refman.PS. Here we will provide supplementary information and more practical hints.

Some of the more important glyph classes are:

• Glyph: base class for all glyph objects
• MonoGlyph: wrapper to override some aspect of a glyph
• PolyGlyph: wrapper for list of glyphs
• InputHandler: glyph that receives input (mouse or keys)
• Action: object to provide callback functions for input handling glyphs (used by buttons, menus, etc.)
• Style: keep track of X resources, command line flags and programmer-defined parameters with default values
• Observable/Observer: provide automatic update of displays when a data value changes
• Window, Display: X Window basic objects
• WidgetKit: object factory to create common user interface objects with a concrete look-and-feel (beveled frames, menus, buttons, scrollers)
• LayoutKit: object factory to create objects that manage the physical layout of one or more glyphs (boxes and glue)
• DialogKit: object factory for dialoglike objects. Field editors and file choosers.

The basic glyph demo program is idemo, included in the InterViews source tree under iv/src/bin/idemo/. It features pulldown menus, text labels (normal and rotated), push buttons, check boxes, radio buttons, palette buttons, field (text) editors, scrollbars and a panner. By using the flags -openlook, -motif or -sgimotif at program startup you can see the same glyphs under each different look-and-feel discipline.

We also have a few other glyph-based derived classes and example programs in the ivtools package. These are examples of glyph usage and/or subclasses that extend the basic glyph functionality in some way. Most of these are contained in the IVGlyph library within ivtools.

• "forms" objects: display and edit common simple types. These use an observable/observer relationship to keep display updated to current value.
  • BoundedValue is a constrained float value. BoundedValueObserver is a simple textual display of the value. MeterObserver is a scrolling display of the value. BoundedValueEditor is an editor for a value using textual input or a movable scrollbar
  • ObservableBoolean is a true/false value. BooleanObserver is a simple textual display of the value. CheckBooleanEditor and PaletteBooleanEditor modify the value via checkbox or palette button
  • ObservableEnum is an enumerated value. EnumObserver is its simple textual display. MenuEnumEditor, RadioEnumEditor and CycleEnumEditor modify the enumerated value via menus, radio buttons or previous/next buttons
  • similarly for ObservableText, TextObserver, ObsTextEditor
• CharFieldEditor: field editor that calls update on every keystroke
• GFieldEditor: a purely Glyph field editor without Interactors (hence can be scrolled within another glyph.)
• OpenFileChooser: a file chooser more suited for derivation. Subclasses are ImportChooser, PrintChooser, ExportChooser, and SaveAsChooser
• StrChooser: dialog for choosing one from a list of strings
• EivTextEditor: contributed glyph for editing largish quantities of text within an application
• Scrollable: a glyph that can scroll other glyphs within its body
• Fig31: graphic-like figure glyphs. Fig31Line, Fig31Rectangle, Fig31Circle, Fig31Ellipse, Fig31Open_BSpline, Fig31Closed_BSpline, Fig31Polygon. These were designed to mimic the basic Unidraw graphic objects, but there are no tools for drawing them; they are usually created programatically.

Glyphs are compiled with different options and namespace than Unidraw objects. See the different rules used in the Imakefiles. This can lead to conflicts but we have developed ways of integrating glyphs with Unidraw that work in our examples.

The layout model for glyphs is based on the TeX boxes and glue model. ...

back to ivtools technical info