This commit adds a badge to the tray icon that displays the number of
unread messages, if there is any. It is implemented by providing
alternative versions of the icon, that replace the default image when a
message is received.
The badge is rendered graphically as a red circle containing the number
of unread messages. Since a different icon file is needed for each
possible number of unread messages, but this number is clearly
unbounded, only the numbers from 1 to 9 are provided. If there are 10 or
more unread messages, a single badge (depicted as "9+") is used.
Resolves#1917
* Clean logs on startup; install server-side testing/linting
* Add eslint config, make all of app/ conform to its demands
* Add Node.js testing and linting to CI
* Lock project to Node.js 7.9.0, used by Electron 1.7.10
* New eslint error: trailing commas in function argumensts
Node 7.9.0 doesn't like trailing commas, but Electron does
* Move electron to devDependency, tell eslint it's built-in
This commit adds a tray icon to the application, shown in the system
tray bar, that can be used to minimise the application window. This
is a common feature on most desktop messaging apps (e.g. Telegram
Desktop or Slack) and allows to save space in the system task bar.
The tray icon provides a context menu that contains a button to
show/hide the application window, and a button to quit the
application. When the tray icon is clicked, the visibility of the
window is toggled. When the close (x) button of the window is
pressed, the application is not terminated but minimised to the tray
icon instead (it can be terminated by using the "Quit" entry in the
File menu or in the context menu of the tray icon).
The tray icon is disabled by default, and two command line arguments
are available to enable it:
--use-tray-icon: enables the tray icon
--start-in-tray: enables the tray icon and the application starts
minimised in the tray bar
Resolves: #1480
