Make mga-bg-res a systemd service that uses monitor-probe

Now runs as a systemd service with root privileges, therefore the mga-bg-res C binary is no longer needed.
Uses monitor-probe to find the optimal resolution when X is not yet started, and handles cases where monitor-probe fails by defaulting to 4:3 aspect ratio.

1 files changed, 47 insertions, 0 deletions

diff --git a/mga-bg-res/mga-bg-res.sh b/mga-bg-res/mga-bg-res.sh
new file mode 100755
index 0000000..db937cb
--- /dev/null
+++ b/mga-bg-res/mga-bg-res.sh
@@ -0,0 +1,47 @@
+#!/bin/bash
+
+bgpath="/usr/share/mga/backgrounds"
+theme="Mageia-Default"
+curlink=$(readlink $bgpath/default.jpg)
+
+# If the following tests bail out, default to 4:3 aspect ratio (e.g. 1024x768)
+res="1600x1200"
+
+# Search for the optimal background resolution according to the driver
+DRIVER=$(grep -A 6 'Device' /etc/X11/xorg.conf | grep 'Driver')  # => Driver    "DriverName"
+DRIVER=$(expr "$DRIVER" : '.*"\(.*\)"')  # isolate driver's name
+if [ ! -z "$DRIVER" -a -e /usr/sbin/monitor-probe ]; then
+    res=$(exec /usr/sbin/monitor-probe $DRIVER | grep -m 1 ModeLine)  # => ModeLine "1920x1080" ...
+    res=$(expr "$res" : '.*"\(.*\)".*')  # isolate the resolution
+fi
+
+# Check if the symlink is already good
+if [ "$curlink" = "$bgpath/$theme-$res.jpg" ]; then
+    exit 1
+fi
+
+# Check if this is a supported resolution, if not, find the background with a similar aspect ratio
+if [ ! -e "$bgpath/$theme-$res.jpg" ]; then
+    width=$(echo $res | cut -f1 -d"x")
+    height=$(echo $res | cut -f2 -d"x")
+    # Bash only does integer arithmetic, we multiply everything by 1000 to workaround this
+    ratio=$((1000*$width/$height))
+    declare -A refRatios=( ["1250"]="1280x1024" ["1333"]="1600x1200" ["1600"]="1920x1200"
+                           ["1667"]="1280x768" ["1707"]="1024x600" ["1778"]="1920x1080" )
+    for key in "${!refRatios[@]}"; do
+        if [ $(($ratio % $key)) -lt 25 -o $(($key % $ratio)) -lt 25 ]; then
+            res=${refRatios[$key]}
+            break
+        fi
+    done
+fi
+
+# Check again if the symlink does not already point to this new resolution
+# If not, create a new symlink
+if [ "$curlink" != "$bgpath/$theme-$res.jpg" ]; then
+    if [ -e "$bgpath/$theme-$res.jpg" ]; then
+        ln -sf $bgpath/$theme-$res.jpg $bgpath/default.jpg 
+    else
+        echo -e "Could not find this file: $bgpath/$theme-$res.jpg.\nPlease check that the mageia-theme-Default package is properly installed, or disable the mga-bg-res systemd service if you do not want to force using the Mageia theme."
+    fi
+fi