12. Wishlist

• It should be possible to add or remove items from a list with C-k and C-o (suggested by RMS).
• The ‘[INS]’ and ‘[DEL]’ buttons should be replaced by a single dash (‘-’). The dash should be a button that, when invoked, asks whether you want to add or delete an item (RMS wanted to git rid of the ugly buttons, the dash is my idea).
• The menu-choice tag should be prettier, something like the abbreviated menus in Open Look.
• Finish :tab-order.
• Make indentation work with glyphs and proportional fonts.
• Add commands to show overview of object and class hierarchies to the browser.
• Find a way to disable mouse highlight for inactive widgets.
• Find a way to make glyphs look inactive.
• Add property-list widget.
• Add association-list widget.
• Add key-binding widget.
• Add widget widget for editing widget specifications.
• Find clean way to implement variable length list. See TeX-printer-list for an explanation.
• C-h in widget-prompt-value should give type specific help.
• Add a mailto widget.
• C-e e in a fixed size field should go to the end of the text in the field, not the end of the field itself.
• Use an overlay instead of markers to delimit the widget. Create accessors for the end points.
• Clicking on documentation links should call describe-function or widget-browse-other-window and friends directly, instead of going through apropos. If more than one function is valid for the symbol, it should pop up a menu.

12.1 Internals

This (very brief!) section provides a few notes on the internal structure and implementation of Emacs widgets. Avoid relying on this information. (We intend to improve it, but this will take some time.) To the extent that it actually describes APIs, the information will be moved to appropriate sections of the manual in due course.

12.1.1 The Widget and Type Structures

Widgets and types are currently both implemented as lists.

A symbol may be defined as a type name using define-widget. See section Defining New Widgets. A type is a list whose car is a previously defined type name, nil, or (recursively) a type. The car is the class or parent type of the type, and properties which are not specified in the new type will be inherited from ancestors. Probably the only type without a class should be the default type. The cdr of a type is a plist whose keys are widget property keywords.

A type or type name may also be referred to as an unconverted widget.

A converted widget or widget instance is a list whose car is a type name or a type, and whose cdr is a property list. Furthermore, all children of the converted widget must be converted. Finally, in the process of appropriate parts of the list structure are copied to ensure that changes in values of one instance do not affect another’s.

This document was generated on September 25, 2026 using texi2html 1.82.