gh-hugoduncan-library-skills-plugins-emacs-libraries/skills/widget

Emacs Widget Library

Build interactive forms and UI elements in Emacs buffers.

Quick Start

(require 'widget)
(eval-when-compile
  (require 'wid-edit))

(defun my-simple-form ()
  (interactive)
  (switch-to-buffer "*My Form*")
  (kill-all-local-variables)
  (erase-buffer)
  (remove-overlays)

  ;; Create widgets
  (widget-insert "Contact Form\n\n")

  (widget-create 'editable-field
                 :format "Name: %v\n"
                 :size 30)

  (widget-insert "\n")

  (widget-create 'editable-field
                 :format "Email: %v\n"
                 :size 40)

  (widget-insert "\n\n")

  (widget-create 'push-button
                 :notify (lambda (&rest ignore)
                           (message "Form submitted!"))
                 "Submit")

  ;; Enable interaction
  (use-local-map widget-keymap)
  (widget-setup))

Key Widget Types

Text Input:

• editable-field - Single-line text
• text - Multi-line text area

Buttons:

• push-button - Clickable action button
• link - Hyperlink with action

Selection:

• checkbox - Boolean toggle
• radio-button-choice - Single choice from options
• menu-choice - Dropdown selection
• checklist - Multiple selections

Lists:

• editable-list - Dynamic list with add/remove

Essential Functions

;; Create widget
(widget-create TYPE &rest ARGS)

;; Enable widgets (required after creation)
(widget-setup)

;; Get/set values
(widget-value WIDGET)
(widget-value-set WIDGET VALUE)

;; Navigate
(widget-forward)   ; TAB
(widget-backward)  ; S-TAB

;; Properties
(widget-get WIDGET PROPERTY)
(widget-put WIDGET PROPERTY VALUE)

Common Pattern

(defun my-widget-interface ()
  (interactive)
  (let (field1 field2)
    ;; Setup buffer
    (switch-to-buffer "*Interface*")
    (kill-all-local-variables)
    (erase-buffer)
    (remove-overlays)

    ;; Build UI
    (widget-insert "Title\n\n")
    (setq field1 (widget-create 'editable-field "default"))
    (widget-insert "\n")
    (setq field2 (widget-create 'checkbox t))

    ;; Submit button
    (widget-create 'push-button
                   :notify (lambda (&rest _)
                             (message "Values: %S %S"
                                      (widget-value field1)
                                      (widget-value field2)))
                   "Submit")

    ;; Activate
    (use-local-map widget-keymap)
    (widget-setup)))

Using the Skill

Invoke this skill when building:

• Custom configuration interfaces
• Interactive forms
• Settings editors
• Data entry dialogs

The skill provides comprehensive coverage of widget types, API functions, patterns, and real-world examples.

Learning Path

1. Basics - Simple forms with editable-field and push-button
2. Selection - checkbox, radio-button-choice, menu-choice
3. Callbacks - :notify handlers and value retrieval
4. Validation - Input validation and error handling
5. Advanced - Custom widgets and complex interfaces

Resources

• Emacs Info: C-h i m Widget RET
• Source: wid-edit.el in Emacs distribution
• Built-in demo: widget-example (if available)