Awesome

enotepad

Clone of MS Notepad using Erlang (wxWidgets)

Motivation

In the process of learning Erlang, I wanted to make some GUI application, so I though I will make a Notepad clone, after all it is just a text control... it wasn't.

Things learned:

• how to use wxWidgets, wx_object and Scintilla
  • using menus, status bar
  • custom dialogs and simple dialogs
  • printing on a printer
• how to make a wxWidgets application using OTP design principles.
• how to build escripts and applications manually
• file handling, creating/removing directories
• dialyzer and types
• how to make releases with systools and with reltool

Requirement

• Erlang >= 19.1

Installation

This program is not intended to be installed, its a learning tool.

Anyway, on Windows there is an installer, but for other systems you must build from source.

Building

This project has been converted to use rebar3 to compile and build the releases.

Extra rebar3 commands and their effects:

reltool    - makes a release using reltool
systools   - makes a release using systools
release    - do not use, this is the default of rebar3 and uses relx which is not supported
clean      - extended clean which deletes more files.
escriptize - This is the default rebar3 escriptize but embeds the app icon within the escript.
winescript - This extedns escriptize to generate special versions for windows

Get more details for winescript using rebar3 help winescript.

Running

You can run enotepad in multiple ways: using Erlang shell, using the built escript and using a generated release.

Using Erlang shell

Using rebar3 shell will start a shell with the required libraries on path, you have multiple options to run it:

Using main like the escript:

Eshell V8.1  (abort with ^G)
1> enotepad:main().
ok
2> enotepad:main(["some_file_name.txt"]).
ok

Using start_link which is used when running under supervisor, but you can use too:

Eshell V8.1  (abort with ^G)
1> enotepad:start_link().
ok
2> enotepad:start_link("some_file_name.txt").
ok

Starting like an application:

Eshell V8.1  (abort with ^G)
1> application:start(wx), application:start(enotepad).
ok
2> application:set_env(enotepad, file, "some_file_name.txt").
ok
3> application:start(enotepad).     <<-- this will load some_file_name.txt
ok

When running like an application, you can stop with application:stop(enotepad) but this is not needed if you just close the window.

Using the escript

This way requires you to have a working installation of Erlang on the path, then just run it by name with optional parameter:

> path/to/enotepad <file_name>

Using a built release

This doesn't require Erlang as it already includes it, just run it by name like the escript, the actual file you run is a facade to hide the erl parameters.