replace slim with lightdm

This will be a breaking change for existing users.

After running the new tasks to install and enable LightDM, disable Slim:

    # systemctl disable slim.service

LightDM uses `~/.xprofile` instead of `~/.xinitrc`. Move all of the
contents from `~/.xinitrc` to `~/.xprofile`, except for the `exec` line.
In your `~/.xinitrc` you can source your new `~/.xprofile` so that it is
still functional in case you find yourself using it again.

https://wiki.archlinux.org/index.php/Xprofile
3a75c5d454

On the next reboot you'll be greeted by LightDM. Slim can then be
uninstalled.

    # pacman --remove slim

README.md

@@ -52,11 +52,7 @@ tasks to be skipped.
 ## Tagging
 
 All tasks are tagged with their role, allowing them to be skipped by tag in
-addition to modifying `playbook.yml`. For instance, a system could be built
-excluding the entire `media` role and the `slim` section of the `x`
-role.
-
-    # ansible-playbook -i localhost playbook.yml --skip-tags "media,slim"
+addition to modifying `playbook.yml`.
 
 ## AUR
 

playbook.yml

@@ -11,7 +11,7 @@
     - { role: ssd, tags: ['ssd'] }
     - { role: fonts, tags: ['fonts'] }
     - { role: x, tags: ['x'] }
-    - { role: slim, tags: ['slim'] }
+    - { role: lightdm, tags: ['lightdm'] }
     - { role: i3, tags: ['i3'] }
     - { role: iptables, tags: ['iptables'] }
     - { role: nettools, tags: ['nettools'] }

roles/lightdm/tasks/main.yml

@@ -0,0 +1,33 @@
+---
+- name: Install LightDM
+  pacman: name={{ item }} state=present
+  with_items:
+      - lightdm
+      - lightdm-gtk-greeter
+
+- name: Enable LightDM
+  service: name=lightdm.service enabled=yes
+
+- name: Create background dir
+  file: path=/usr/share/backgrounds state=directory
+
+- name: Push LightDM greeter background
+  copy: src=onosendai.jpg dest=/usr/share/backgrounds/onosendai.jpg
+
+- name: Specify LightDM greeter background
+  lineinfile: dest=/etc/lightdm/lightdm-gtk-greeter.conf
+              regexp="^background="
+              state=present
+              line="background=/usr/share/backgrounds/onosendai.jpg"
+
+- name: Hide user images
+  lineinfile: dest=/etc/lightdm/lightdm-gtk-greeter.conf
+              regexp="^hide-user-image="
+              state=present
+              line="hide-user-image=true"
+
+- name: Force LightDM greeter theme
+  lineinfile: dest=/usr/share/xgreeters/lightdm-gtk-greeter.desktop
+              regexp="^Exec="
+              state=present
+              line="Exec=env GTK_THEME=Adwaita:dark lightdm-gtk-greeter"

roles/slim/meta/main.yml

@@ -1,3 +0,0 @@
----
-dependencies:
-  - { role: fonts }

roles/slim/tasks/main.yml

@@ -1,27 +0,0 @@
----
-- name: Install SLiM
-  pacman: name=slim state=present
-
-- name: Enable SLiM
-  service: name=slim.service enabled=yes
-
-- name: Set the SLiM login shell
-  lineinfile: dest=/etc/slim.conf
-              regexp=^login_cmd
-              state=present
-              line="login_cmd   exec {{ user.shell }} --login ~/.xinitrc %session"
-
-- name: Configure SLiM to properly log logins to utmp and wtmp
-  lineinfile: dest=/etc/slim.conf
-              regexp=^sessionstart_cmd
-              state=present
-              line="sessionstart_cmd   /usr/bin/sessreg -a -l tty$(fgconsole) %user"
-
-- name: Configure SLiM to properly log logouts to utmp and wtmp
-  lineinfile: dest=/etc/slim.conf
-              regexp=^sessionstop_cmd
-              state=present
-              line="sessionstop_cmd   /usr/bin/sessreg -d -l tty$(fgconsole) %user"
-
-- name: Push SLiM background
-  copy: src=onosendai.jpg dest=/usr/share/slim/themes/default/background.jpg