Add HiDPI support for Plymouth boot

debian/postinst

@@ -12,3 +12,10 @@ esac
 ln -s /usr/share/apparmor/extra-profiles/bwrap-userns-restrict /etc/apparmor.d/ || true
 
 #DEBHELPER#
+
+# Plymouth HiDPI support
+
+if [ -x /bin/systemctl ] || [ -x /usr/bin/systemctl ]; then
+    systemctl preset plymouth-hidpi.service || true
+    systemctl enable plymouth-hidpi.service || true
+fi

meson.build

@@ -49,3 +49,10 @@ subdir('skel')
 
 # GTK settings
 subdir('gtk')
+
+# Plymouth HiDPI support
+if get_option('enable-plymouth-hidpi')
+    subdir('plymouth')
+else
+    message('Plymouth HiDPI support disabled.')
+endif

meson_options.txt

@@ -17,3 +17,8 @@ option('default-gsettings-overrides',
        type: 'boolean',
        value: true,
        description: 'Install default Pantheon GSettings Overrides')
+
+option('enable-plymouth-hidpi',
+       type: 'boolean',
+       value: true,
+       description: 'Enable Plymouth HiDPI support.')

plymouth/meson.build

@@ -0,0 +1,14 @@
+# Configure Plymouth for HiDPI screens
+install_data(
+    'plymouth-hidpi.sh',
+    install_dir: get_option('bindir'),
+    install_mode: 'rwxr-xr-x'
+)
+
+configure_file(
+    input: 'plymouth-hidpi.service.in',
+    output: 'plymouth-hidpi.service',
+    configuration: { 'BINDIR': join_paths(get_option('prefix'), get_option('bindir')) },
+    install: true,
+    install_dir: '/etc/systemd/system'
+)

plymouth/plymouth-hidpi.service.in

@@ -0,0 +1,12 @@
+[Unit]
+Description=Configure Plymouth for HiDPI screens
+After=graphical.target
+Requires=graphical.target
+
+[Service]
+Type=oneshot
+ExecStart="@BINDIR@/plymouth-hidpi.sh"
+ExecStartPost=/bin/bash -c 'if [ $? -eq 0 ]; then systemctl disable plymouth-hidpi.service; rm -f /etc/systemd/system/plymouth-hidpi.service @BINDIR@/plymouth-hidpi.sh; fi'
+
+[Install]
+WantedBy=graphical.target

plymouth/plymouth-hidpi.sh

@@ -0,0 +1,66 @@
+#!/bin/bash
+
+CONFIG_FILE="/etc/plymouth/plymouthd.conf"
+
+TIMEOUT_SECONDS=300 # Maximum wait time in seconds
+ELAPSED=0
+
+# Wait until Gala is running or timeout occurs
+while ! pgrep -x "gala" > /dev/null && [ $ELAPSED -lt $TIMEOUT_SECONDS ]; do
+    sleep 5
+    ((ELAPSED += 5))
+done
+
+if [ $ELAPSED -ge $TIMEOUT_SECONDS ]; then
+    echo "Timeout reached while waiting for Gala to start" >&2
+    exit 1
+fi
+
+# Get the active user based on the currently active graphical session
+ACTIVE_USER=$(who | grep -E '(:[0-9]+)' | awk '{print $1}' | head -n 1)
+
+if [[ -z "$ACTIVE_USER" ]]; then
+    logger -t plymouth-hidpi "No active user with a graphical session."
+    exit 1
+fi
+
+USER_HOME=$(eval echo ~$ACTIVE_USER)  # Get the home directory of the active user
+MONITORS_XML="$USER_HOME/.config/monitors.xml"
+
+if [[ ! -f "$MONITORS_XML" ]]; then
+    logger -t plymouth-hidpi "Monitors XML file not found for user: $PRIMARY_USER"
+    exit 1
+fi
+
+PRIMARY_MONITOR_SCALE=$(awk '
+    /<primary>yes<\/primary>/ {print prev; exit}
+    {prev=$0}
+' $MONITORS_XML | grep -oP '<scale>\K[0-9]+')
+# Scale=2 means 2x resolution ('Retina Display' in Apple computers)
+logger -t plymouth-hidpi "Primary monitor scale: '$PRIMARY_MONITOR_SCALE'" 
+
+create_config() {
+    cat <<EOF > "$CONFIG_FILE"
+[Daemon]
+DeviceScale=1
+EOF
+    logger -t plymouth-hidpi "Created new config: '$CONFIG_FILE' with HiDPI setting"
+}
+
+apply_hidpi_setting() {
+    if [[ "$PRIMARY_MONITOR_SCALE" -eq 2 ]]; then
+        if [[ ! -f "$CONFIG_FILE" ]]; then
+            create_config
+
+            # Apply the changes
+            update-initramfs -u
+            logger -t plymouth-hidpi "Updated initramfs after HiDPI change"
+        else
+            logger -t plymouth-hidpi "HiDPI config file already exists, no changes made"
+        fi
+    else
+        logger -t plymouth-hidpi "Skipped HiDPI settings (DPI: $DPI, Threshold: $HIDPI_THRESHOLD)"
+    fi
+}
+
+apply_hidpi_setting