add doc on creating a panel using emacs facility

* COMMENT -*- mode: org -*-

#+Date: 2019-10-08

Time-stamp: <2021-08-08>

Time-stamp: <2023-08-16>

#+STARTUP: content

* notes                                                               :entry:

** 2019-04-01 zero-el a Chinese IM framework in emacs; FSM              :doc:

  https://docs.travis-ci.com/user/customizing-the-build#build-matrix

  Testing Your Project on Multiple Operating Systems - Travis CI

  https://docs.travis-ci.com/user/multi-os/

** 2023-08-16 architecture                                         :arch:doc:

see https://blog.emacsos.com/zero-el.html#org8e45833

#+BEGIN_SRC text

	   emacs zero-input-mode

		   |

		   |

	     zero-input-pinyin

		  /\

		 /  \

		/    \

	       /      \

	 dbus /        \ dbus

	     /          \                         

	    /            \ 

	   /              \ 

	  /                \

  zero-pinyin-service     zero-panel

#+END_SRC

* later                                                               :entry:

* current                                                             :entry:

** 

** 2023-08-16 create a panel using emacs facility.

make it work in terminal emacs.

- yasnippet when select snippet can show a dropdown list.

- check the arch. how is dbus message sent to different component?

  zero-input call zero-panel service directly from emacs lisp code.

  so I only need to register a new service and select which service to publish

  message to. this is not as flexible.

  try this instead:

  still use the same service name and spec.

  in emacs lisp, allow user to stop (kill) existing service and choose which

  panel service to start.

  worry about this later. first make it work in terminal emacs.

- create a zero-panel service in raw emacs.

  ~/.emacs.d/site-lisp/yasnippet/dropdown-list.el

  According to Jaeyoun Chung, "overlay code stolen from company-mode.el."

  search: emacs lisp which overlay drop down menu to use?

  which one does pyim use?

  GitHub - tumashu/pyim: 一个 emacs 中文输入法，支持全拼，双拼，五笔，仓颉和Rime，pyim 是 GNU elpa 包。

  https://github.com/tumashu/pyim

  GNU ELPA - pyim

  https://elpa.gnu.org/packages/pyim.html

  让选词框跟随光标

  https://github.com/tumashu/pyim#%E8%AE%A9%E9%80%89%E8%AF%8D%E6%A1%86%E8%B7%9F%E9%9A%8F%E5%85%89%E6%A0%87

  overlay solutions to show candidates

  - popup

    (require 'popup)

    GitHub - auto-complete/popup-el: Visual Popup Interface Library for Emacs

    https://github.com/auto-complete/popup-el

    popup is in melpa.

    last release is 20221231.1634

  - popon

    (require 'popon)

    akib/emacs-popon: "Pop" floating text "on" a window - emacs-popon - Codeberg.org

    https://codeberg.org/akib/emacs-popon

    It is not on GNU elpa or melpa. out.

  - posframe

    (require 'posframe)

    GitHub - tumashu/posframe: Pop a posframe (just a child-frame) at point, posframe is a **GNU ELPA** package!

    https://github.com/tumashu/posframe

    GNU ELPA - posframe

    https://elpa.gnu.org/packages/posframe.html

    posframe is both in GNU elpa and melpa.

  none is included in emacs.

- evaluate which overlay solution has best performance and is easy to use.

  I will try both popup and posframe.

  just show the same thing as zero-panel-client-demo.

  see test code in ./test-popup.el

** 2021-08-08 create a panel for wayland display server.

currently zero-panel doesn't position itself correctly in wayland on debian 11

bullseye.

- 2023-08-16 panel flash on GNOME 40 Wayland in RHEL 9.

  see ~/projects/zero-panel/operational

  There are two problems of zero-panel on Wayland.

  1. zero-panel window keeps getting focus and unfocused. e.g. flashing.

  2. zero-panel window is not positioned at emacs (point) location.

** 2020-02-23 support typing ±, ≥, ≤ easier.

when user type +-, it is converted to ±.

use a flag to control conversion.

(require 'popup)

(setq popup (popup-create (point) 10 10))

(popup-set-list popup '("Foo" "Bar" "Baz"))

(popup-draw popup)

;; do something here

(popup-delete popup)