Creates a panel object launcher in MATE desktop

create_launcher.sh

#!/usr/bin/env bash

addPanelItem() {
    PANEL_PATH=~/.config/mate/panel2.d/default/launchers/
    
    echo -ne $1

    filename=$(basename -- "$1")
    extension="${filename##*.}"
    filename="${filename%.*}"
    
    PANEL_FILE="${PANEL_PATH}${filename}.desktop"

    if [[ -f "$PANEL_FILE" ]]; then
        echo -e "\texists"
        return 1
    fi
    
    # Determine next object index
    N=$(dconf read /org/mate/panel/general/object-id-list|sed 's/,/\n/g'|grep "'object-[0-9][0-9]*'"|grep -o "[0-9]*"|sort -nr|head -n1
)
    ((N++))
    POSITION=$((75+N*50))

    # Custom name or base filename    
    if [[ $2 == "" ]]; then
        NAME=$filename
    else 
        NAME=$2
    fi

    # Custom icon or default launcher icon
    if [[ $3 == "" ]]; then
        ICON="mate-panel-launcher"
    else 
        ICON=$3
    fi

    # Terminal
    if [[ $4 == "" ]]; then
        TERMINAL="false"
    else 
        TERMINAL="true"
    fi

    cat <<EOF > $PANEL_FILE
#!/usr/bin/env xdg-open
[Desktop Entry]
Version=1.0
Type=Application
Terminal=$TERMINAL
Icon=$ICON
Exec=$1
Name=$NAME
EOF

    dconf load / << EOF
[org/mate/panel/objects/object-${N}]
launcher-location='${filename}.desktop'
object-type='launcher'
panel-right-stick=false
position=$POSITION
toplevel-id='top'
EOF
    if [ $? -ne 0 ]; then 
        echo -e "\tfailed to create panel object"
        return 1
    fi
    
    LIST=$(dconf read /org/mate/panel/general/object-id-list | sed -rne "s/(.*)'\]/\1', 'object-${N}']/gip")

    dconf write /org/mate/panel/general/object-id-list "$LIST"
    if [ $? -ne 0 ]; then 
        echo -e "\tfailed to add panel object to the list"
        return 1
    fi

    echo -e "\tcreated"

    return 0    
}

#addPanelItem "application" ["title"] ["icon"] [runInTerminal]
# "application" is mandatory, rest is optional
addPanelItem "$HOME/bin/brightness.py" "Brightness" "/usr/share/icons/mate/scalable/status/display-brightness-symbolic.svg"

# You might need to run `killall -s SIGUSR1 mate-panel` if the panel was not updating