README

This plugin for RoundCubeMail version 1.7, patches dark mode for the mail editor and the mail viewer. I think the quality is close to what you get in Thunderbird.

It also includes a customized version of the Inter font made by Rasmus Andersson from Scandinavia, released under SIL Open Font License version 1.1.
https://github.com/rsms/inter/ and https://rsms.me/inter/

It extends the mail editor dark mode work done by Dhiego Cassiano Fogaça Barbosa, which is released under Apache License version 2.0.
https://github.com/modscleo4/roundcube-plugin-dark-html

Inter font

The configurable option use_scandinavian_inter_font lets you choose whether to use the modified Inter font.

When used in the mail editor, the Inter font is added to the available_fonts option and set as default in the default_font option.

A note about custom fonts in the message editor. Even though the font is available in the message css, the @font face is most likely stripped by the receiving mail servers with the result that the message receiver will see an alternative font unless the message receiver has an inter font installed, in which case the message receiver should see the Inter font though not the Scandinavian version.

Dark mode prerequisites

This plugin assumes that RCM adds and removes the dark-mode class on the html element, specifying whether dark mode is enabled or not:

• For the web program itself
• For the mail viewer iframe
• For the mail viewer window or tab
• For the mail editor iframe (TinyMCE)

Mail viewer

The configurable option invert_implementation lets you choose which inverting implementation to use.

I am still playing with the colour implementation.

Known bugs

Minor: Sometimes there is a white flash when a mail is selected, but I think that I have found all the relevant css that can cause this.

I am inclined not to view this as a bug, because it looks like this is coming from white or bright background in the message itself, and the flash is caused by the delay between loading the message and the plugin inverting the message HTML elements.

Minor: Not all the css and js is minified.

Mail editor (TinyMCE)

RCM does not set the dark-mode class on the html element when the mail editor is created/initialised, the plugin fixes that.

RCM does however set the dark-mode class on the html element when the user toggles between dark and light mode.

Fix css

The message editor css is fixed by creating a new css file containing the existing css from skins/elastic/styles/embed.min.css and some additional css. The RCM configuration setting editor_css_location is set with the path to the new combined css file, which causes RCM to use that file when it initialises the mail editor (TinyMCE).

Known bugs

Minor: Not all the css is minified.

File permissions

Because files are written, the following file permissions are required:

chmod  u+w  plugins/rpc_rcm_patches/skin/elastic

Examples

Message editor

Message viewer

The same message in RoundCubeMail and Thunderbird

Installation

Basic steps to install this plugin:

• Download code from GitHub (https://github.com/rpc-scandinavia/RpcRoundCubeMailPatches)
• Extract files, and copy directory rpc_rcm_patches to plugins
• Enable plugin in config/config.inc.php by adding rpc_rcm_patches to $config['plugins'] array
• Copy configuration file plugins/rpc_rcm_patches/config.inc.php.dist to plugins/rpc_rcm_patches/config.inc.php and modify as needed
• Allow plugin to create css file: chmod u+w plugins/rpc_rcm_patches/skin/elastic

René Paw Christensen
https://rpc-scandinavia.dk/