Scripting Marble from the shell using D-BUS

MarbleWidget and MarbleMap provide their full amount of methods as a D-BUS Interface. Therefore you can easily create a shell-script to control Marble using the qdbus command line tool.

Before you start you need to find out the PID of the Marble process: In your script you can do it like this.

marble_pid="$(pidof marble)"

Then you can pass this PID to the actual qdbus call

qdbus org.kde.marble-$marble_pid /MarbleWidget

This call returns a list of all the methods that MarbleWidget supports. From this list you can choose the one that you'd like to call, e.g.

qdbus org.kde.marble-$marble_pid /MarbleWidget org.kde.MarbleWidget.zoomIn

to zoom into the map. Note that for function calls you shouldn't pass the brackets "()".

As a convenient tool you can use qdbusviewer to get a graphical list of the interfaces and methods that get provided through D-BUS.

Further examples

To shorten the following dbus calls, we use

marble_pid="$(pidof marble)"
alias MCALL='qdbus org.kde.marble-${marble_pid} /MarbleWidget'

Changing map themes can be done via

MCALL org.kde.MarbleWidget.setMapThemeId "earth/srtm/srtm.dgml"
MCALL org.kde.MarbleWidget.setMapThemeId "earth/openstreetmap/openstreetmap.dgml"

Move to a place, specified by longitude and latitude

MCALL org.kde.MarbleWidget.centerOn 8.8 53.2

Set the zoom

MCALL org.kde.MarbleWidget.zoomView 2000

Note that the range of values passed to zoomView is defined in the .dgml files, eg for marble/data/maps/earth/openstreetmap/openstreetmap.dgml the range is from 900 to 4000, while for bluemarble it is from 900 to 2400.

It is also possible to retrieve parameters from marble, e.g.

MCALL org.freedesktop.DBus.Properties.Get org.kde.MarbleWidget latitude
MCALL org.freedesktop.DBus.Properties.Get org.kde.MarbleWidget longitude
MCALL org.freedesktop.DBus.Properties.Get org.kde.MarbleWidget zoom

to get the current latitude, longitude or zoom.

Note that one has to go through org.freedesktop.DBus.Properties.Get as latitude is not a method, but a property.

Things which (currently) don't work

Opening a gpx file should work via

MCALL org.kde.MarbleWidget.openGpxFile /tmp/test.gpx

but gives: "Invalid number of parameters". This might be a bug on the qdbus side.

Trouble shooting

No MarbleWidget or MarbleMap

Problem: Neither the MarbleMap nor the MarbleWidget interfaces are available in my installation, and qdbus complains:

org.freedesktop.DBus.Error.UnknownObject (No such object path '/MarbleWidget')

Solution: The D-BUS interface is only available in Marble trunk (and eventually in Marble >= 0.8). Additionally you need to make sure that the "BUILD_WITH_DBUS" cmake flag is set to "ON" once you are building Marble from the source code:

cmake -DBUILD_WITH_DBUS=ON ../marble

This page was last edited on 10 March 2016, at 21:01. Content is available under Creative Commons License SA 4.0 unless otherwise noted.