alacritty: add config with color switching, use as terminal in i3

.config/alacritty/alacritty.yml

@@ -0,0 +1,19 @@
+# See: /usr/share/doc/alacritty/example/alacritty.yml
+
+env:
+  TERM: xterm-256color
+
+colors:
+  primary:
+    background: '#424242'
+    foreground: '#eeeeee'
+
+font:
+  size: 13.5
+  normal:
+    family: Fantasque Sans Mono
+
+key_bindings:
+   - key: F6
+     mods: Control|Shift
+     command: { program: "/bin/sh", args: ["-c", "~/.config/alacritty/switch_bg.py"] }

.config/alacritty/switch_bg.py

@@ -0,0 +1,15 @@
+#!/usr/bin/python3
+
+import os
+
+path = os.path.join(os.getenv('HOME'), '.config/alacritty/alacritty.yml')
+with open(path, 'r+') as f:
+    cfg = f.read()
+    if "    background: '#424242'" in cfg:
+        cfg = cfg.replace("    background: '#424242'", "    background: '#fafafa'")
+        cfg = cfg.replace("    foreground: '#eeeeee'", "    foreground: '#424242'")
+    else:
+        cfg = cfg.replace("    background: '#fafafa'", "    background: '#424242'")
+        cfg = cfg.replace("    foreground: '#424242'", "    foreground: '#eeeeee'")
+    f.seek(0)
+    f.write(cfg)

.config/i3/config

@@ -22,7 +22,7 @@ bindsym XF86MonBrightnessUp exec --no-startup-id xbacklight -inc 3
 floating_modifier $mod
 
 # start a terminal
-bindsym $mod+Shift+Return exec "emacsclient -n -c --eval '(vterm)'"
+bindsym $mod+Shift+Return exec alacritty
 
 # start new Emacs frame
 bindsym $mod+e exec "emacsclient -n -c"