Add build hook to revert the $XDG_CONFIG_HOME variable

Also created the applicationID variable

themeSwitcher.nim

@@ -1,5 +1,6 @@
 from std/osproc import execProcess, ProcessOption, startProcess, waitForExit, close
-from std/os import symlinkExists, getConfigDir, putEnv, `/`
+from std/envvars import existsEnv, getEnv, delEnv, putEnv
+from std/os import symlinkExists, getConfigDir, `/`
 from std/strutils import split, endsWith
 from std/strformat import fmt
 import owlkettle
@@ -9,6 +10,7 @@ const
   iconsDir = "/usr/share/tromjaro-theme-switcher/icons"
   # GTK CSS for overriding the default icon size of buttons
   gtkCSS = "button { -gtk-icon-size: 85px; }"
+  applicationID = "com.tromjaro.ThemeSwitcher"
   themeColors = ["Grey", "Pink", "Green", "Orange", "Purple", "Yellow", "Teal"]
   themeStyles = ["Light", "Nord", "Dark", "Dark-Nord"]
 
@@ -49,19 +51,36 @@ proc setTheme(themeName: string) =
     args=["--channel=xsettings", "--property=/Net/ThemeName", "--create", "--type=string", "--set", themeName])
 
   # Send notification about the theme change
-  sendNotification("com.tromjaro.ThemeSwitcher", "Theme Switcher", fmt"{themeName} theme{panelNotification} is enabled",
+  sendNotification(applicationID, "Theme Switcher", fmt"{themeName} theme{panelNotification} is enabled",
     icon=fmt"{iconsDir}/{themeName}.svg")
 
 
+var
+  oldConfigDir: string
+  oldConfigDirUnset: bool
+  configDirChanged: bool
+
 # Prevent loading GTK theme from ~/.config/gtk-4.0 directory when it is a symlink
 if symlinkExists(getConfigDir() / "gtk-4.0"):
+  if existsEnv("XDG_CONFIG_HOME"):
+    oldConfigDir = getEnv("XDG_CONFIG_HOME")
+  else:
+    oldConfigDirUnset = true
   putEnv("XDG_CONFIG_HOME", "/dev/null")
+  configDirChanged = true
 
 # Display the GTK-4 GUI using owlkettle
 viewable App:
   highlightButton: array[2, string]
   hooks:
     build:
+      # Reset the user's XDG_CONFIG_HOME variable back to what it was before
+      if configDirChanged == true:
+        if oldConfigDirUnset:
+          delEnv("XDG_CONFIG_HOME")
+        else:
+          putEnv("XDG_CONFIG_HOME", oldConfigDir)
+
       let currentTheme: string = execProcess("/usr/bin/xfconf-query",
         args=["--channel=xsettings", "--property=/Net/ThemeName"],
         options={})[0 .. ^2]
@@ -110,4 +129,4 @@ method view(app: AppState): Widget =
                   # Highlight this button
                   app.highlightButton = [themeColor, themeStyle]
 
-brew("com.tromjaro.ThemeSwitcher", gui(App()), icons=[iconsDir], stylesheets=[newStylesheet(gtkCSS)])
+brew(applicationID, gui(App()), icons=[iconsDir], stylesheets=[newStylesheet(gtkCSS)])