contrib: add an example of how to start displaying images automatically

Add an example of how an am7xxx-autodisplay functionality might be
implemented: some udev rules call a script which resizes the screen and
then call am7xxx-play.

diff --git a/contrib/99-am7xxx-autodisplay.rules b/contrib/99-am7xxx-autodisplay.rules
new file mode 100644 (file)
index 0000000..fc58472
--- /dev/null
+++ b/contrib/99-am7xxx-autodisplay.rules
@@ -0,0 +1,3 @@
+# Example rules to show how to run a program when the device is plugged in or out
+ACTION=="add", SUBSYSTEM=="usb", ATTRS{idVendor}=="1de1", ATTRS{idProduct}=="c101", MODE="0660", GROUP="plugdev", RUN+="am7xxx-autodisplay.sh start"
+ACTION=="remove", SUBSYSTEM=="usb", ENV{ID_VENDOR_ID}=="1de1", ENV{ID_MODEL_ID}=="c101", RUN+="am7xxx-autodisplay.sh stop"

diff --git a/contrib/am7xxx-autodisplay.sh b/contrib/am7xxx-autodisplay.sh
new file mode 100755 (executable)
index 0000000..9d5199d
--- /dev/null
+++ b/contrib/am7xxx-autodisplay.sh
@@ -0,0 +1,49 @@
+#!/bin/sh
+#
+# am7xxx-autodisplay - resize the screen and run am7xxx-play
+#
+# Copyright (C) 2012  Antonio Ospite <ospite@studenti.unina.it>
+#
+# This program is free software. It comes without any warranty, to
+# the extent permitted by applicable law. You can redistribute it
+# and/or modify it under the terms of the Do What The Fuck You Want
+# To Public License, Version 2, as published by Sam Hocevar. See
+# http://sam.zoy.org/wtfpl/COPYING for more details.
+
+# This is just an example script to show how to resize the screen before
+# running am7xxx-play, this can be called also from a udev script.
+#
+# Resizing the screen may be needed if the am7xxx device has problems
+# displaying a certain resolution.
+#
+# For example on some devices the firmware fails to display images of
+# resolution 800x469 resulting from scaled down 1024x600 screens, in
+# cases like this, resizing the screen can be a viable workaround.
+
+USER=ao2
+
+RESOLUTION_PROJECTOR=800x600
+RESOLUTION_ORIGINAL=1024x600
+
+AM7XXX_PLAY=am7xxx-play
+
+# needed when running xrandr as root from udev rules,
+# see https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/660901
+export XAUTHORITY=$(find /var/run/gdm3/ -type f -path "*${USER}*" 2> /dev/null)
+
+export DISPLAY=:0.0
+
+case $1 in
+  start)
+    xrandr --size $RESOLUTION_PROJECTOR && \
+      $AM7XXX_PLAY -f x11grab -i $DISPLAY
+    ;;
+
+  stop)
+    xrandr --size $RESOLUTION_ORIGINAL
+    ;;
+
+  *)
+    { echo "usage: $(basename $0) <start|stop>" 1>&2; exit 1; }
+    ;;
+esac