Add notifications and document configuration variables

README.md

@@ -39,6 +39,16 @@ In rare cases it might be neccessary to run automirror more than once so that xr
     configured to mirror the primary display with **scaling**  so that the primary display fills
     the entire screen. The scaling does not care about aspect ratios!
 
+## CONFIGURATION
+
+automirror can be configured via environment variables:
+
+  * `AUTOMIRROR_PRIMARY_DISPLAY`:
+    Defaults to `LVDS1`. If this display is present than always configure all other displays to mirror that one.
+
+  * `AUTOMIRROR_NOTIFY_COMMAND`:
+    Defaults to use notify-send(1). Can be set to a command that will be called with a single argument containing a multi-line string. Set to `true` to disable notifications.
+
 ## DEVELOPMENT
 
 Please add test cases under `testdata` for everything you want to have covered.

automirror.desktop

@@ -7,5 +7,5 @@ GenericName=Automatic Display Mirror
 Exec=automirror
 Icon=automirror
 Terminal=false
-Categories=Graphics;
+Categories=Utility;
 Comment=Automatically configure attached monitors for screen mirroring

automirror.sh

@@ -4,7 +4,8 @@ set -e -E -u
 XRANDR_STATUS_PROGRAM=${XRANDR_STATUS_PROGRAM:-xrandr}
 XRANDR_SET_PROGRAM=${XRANDR_SET_PROGRAM:-xrandr}
 
-PRIMARY_DISPLAY=${PRIMARY_DISPLAY:-LVDS1}
+PRIMARY_DISPLAY=${AUTOMIRROR_PRIMARY_DISPLAY:-LVDS1}
+NOTIFY_SEND=( ${AUTOMIRROR_NOTIFY_COMMAND:-notify-send -a automirror -i automirror "Automatic Mirror Configuration"} )
 
 # force called programs to english output
 LANG=C LC_ALL=C
@@ -36,9 +37,11 @@ function get_highest_display {
 
 xrandr_current="$($XRANDR_STATUS_PROGRAM)"
 
-# find connected displays
+# find connected displays by filtering those that are connected and have a size set in millimeters (mm)
 connected_displays=( $(sed -n -e 's/^\(.*\) connected.*mm$/\1/p' <<<"$xrandr_current") )
+
 # See http://stackoverflow.com/a/1252191/2042547 for how to use sed to replace newlines
+# display_list is a list of displays with their maximum/optimum pixel and physical dimensions
 display_list="$(sed ':a;N;$!ba;s/\n   / /g' <<<"$xrandr_current" | sed -n -e 's/^\([A-Z0-9_-]\+\) connected.* \([0-9]\+\)mm.* \([0-9]\+\)mm.* \([0-9]\+\)x\([0-9]\+\)[ 0-9\.\*]\++.*$/\1 \2 \3 \4 \5/p' )"
 : ${connected_displays[@]}
 : "$display_list"
@@ -49,7 +52,7 @@ $xrandr_current"
 fi
 
 
-# if primary display is active then that is our frame buffer size
+# if the primary display is NOT connected then use the highest display as primary
 if [[ "${connected_displays[*]}" != *$PRIMARY_DISPLAY* ]] ; then
     PRIMARY_DISPLAY=$(get_highest_display "$display_list")
 fi
@@ -58,17 +61,25 @@ frame_buffer_resolution=$(get_display_resolution $PRIMARY_DISPLAY "$display_list
 : $frame_buffer_resolution
 
 xrandr_set_args=( --fb $frame_buffer_resolution )
+notify_string=""
 if (( ${#connected_displays[@]} == 1 )) ; then
     xrandr_set_args+=( --output $connected_displays --mode $frame_buffer_resolution --scale 1x1 )
+    notify_string="$connected_displays reset to $frame_buffer_resolution"
 else
     other_display_list="$(grep -v ^$PRIMARY_DISPLAY <<<"$display_list")"
     $XRANDR_SET_PROGRAM $(while read display junk ; do echo " --output $display --scale 1x1 --off" ; done <<<"$other_display_list")
     xrandr_set_args+=( --output $PRIMARY_DISPLAY --mode $frame_buffer_resolution --scale 1x1 )
+    notify_string="$PRIMARY_DISPLAY is primary at $frame_buffer_resolution"
     while read display junk ; do
-        xrandr_set_args+=( --output $display --same-as $PRIMARY_DISPLAY --mode $(get_display_resolution $display "$other_display_list") --scale-from $frame_buffer_resolution  )
+        mode="$(get_display_resolution $display "$other_display_list")"
+        xrandr_set_args+=( --output $display --same-as $PRIMARY_DISPLAY --mode "$mode" --scale-from $frame_buffer_resolution  )
+        notify_string="$notify_string\n$display is scaled mirror at $mode"
     done <<<"$other_display_list"
 fi
 
 #logger -s -t "$0" -- Running $XRANDR_SET_PROGRAM "${xrandr_set_args[@]}"
 
 $XRANDR_SET_PROGRAM "${xrandr_set_args[@]}"
+ret=$?
+"${NOTIFY_SEND[@]}" "$notify_string"
+exit $ret

debian/control

@@ -8,7 +8,7 @@ Build-Depends: debhelper (>= 9)
 
 Package: automirror
 Architecture: all
-Depends: ${misc:Depends}, x11-xserver-utils
+Depends: ${misc:Depends}, x11-xserver-utils, libnotify-bin
 Description: Automatically mirror X screen onto available monitors
  What it does:
   * LVDS1 is primary output if enabled, everything else will be mirror