From 9d62acd01a6b09dda6cb810f0f9b89e34dfeb94b Mon Sep 17 00:00:00 2001
From: Jakob Odersky <jakob@odersky.com>
Date: Wed, 26 Dec 2018 10:22:33 +0100
Subject: Lock screen: use fixed script that locks screen before sleep

---
 home/.config/i3/config |  2 +-
 home/bin/lock          | 55 +++++++++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 53 insertions(+), 4 deletions(-)

diff --git a/home/.config/i3/config b/home/.config/i3/config
index 71a91ee..2908ac6 100644
--- a/home/.config/i3/config
+++ b/home/.config/i3/config
@@ -273,7 +273,7 @@ bindsym $mod+r mode "resize"
 #
 # Session and power management
 #
-    exec --no-startup-id xss-lock -- ~/bin/lock
+    exec --no-startup-id xss-lock --transfer-sleep-lock -- ~/bin/lock
     set $mode_system [0-3] monitor, (l) lock, (e) logout, (s) suspend, (r) reboot, (S) shutdown
     mode "$mode_system" {
         bindsym 0 exec --no-startup-id ~/bin/setup mirror, mode "default"
diff --git a/home/bin/lock b/home/bin/lock
index f75f4cb..8f336bd 100755
--- a/home/bin/lock
+++ b/home/bin/lock
@@ -1,7 +1,56 @@
 #!/bin/bash
 
+# Example locker script -- demonstrates how to use the --transfer-sleep-lock
+# option with i3lock's forking mode to delay sleep until the screen is locked.
+
+## CONFIGURATION ##############################################################
+
 screenshot="$XDG_RUNTIME_DIR/.screen.png"
 
-scrot "$screenshot" \
-    && convert "$screenshot" -scale 5% -scale 2000% "$screenshot"
-i3lock --nofork --image="$screenshot" --ignore-empty-password
+# Options to pass to i3lock
+i3lock_options="--image=$screenshot --ignore-empty-password"
+
+
+# Run before starting the locker
+pre_lock() {
+    scrot "$screenshot" \
+	&& convert "$screenshot" -scale 5% -scale 2000% "$screenshot"
+    #mpc pause
+    return
+}
+
+# Run after the locker exits
+post_lock() {
+    return
+}
+
+###############################################################################
+
+pre_lock
+
+# We set a trap to kill the locker if we get killed, then start the locker and
+# wait for it to exit. The waiting is not that straightforward when the locker
+# forks, so we use this polling only if we have a sleep lock to deal with.
+if [[ -e /dev/fd/${XSS_SLEEP_LOCK_FD:--1} ]]; then
+    kill_i3lock() {
+        pkill -xu $EUID "$@" i3lock
+    }
+
+    trap kill_i3lock TERM INT
+
+    # we have to make sure the locker does not inherit a copy of the lock fd
+    i3lock $i3lock_options {XSS_SLEEP_LOCK_FD}<&-
+
+    # now close our fd (only remaining copy) to indicate we're ready to sleep
+    exec {XSS_SLEEP_LOCK_FD}<&-
+
+    while kill_i3lock -0; do
+        sleep 0.5
+    done
+else
+    trap 'kill %%' TERM INT
+    i3lock -n $i3lock_options &
+    wait
+fi
+
+post_lock
-- 
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