Display coordinates of centroid of map in box using QGIS

Question

I am customising a layout map to print it in PDF with QGIS. I have a Box where i would like to automatically display the coordinates of the center of the map if possible.

How can I do it?

I am guessing I have to edit the following.

Answer 1

Get them with:

map_get(item_variables('Map 1'),'map_extent_center')

which returns a <geometry: Point>. Then extract x and y values as you like, for example:

'X-Centroid: ' ||
x(centroid(map_get(item_variables('Map 1'),'map_extent')))
|| ' - ' ||
'Y-Centroid: ' ||
y(centroid(map_get(item_variables('Map 1'),'map_extent')))

Replace Map 1 with the name of your map in print layout.

Answer 2

To get the result in DMS, try this expression construction:

[%
'B: ' ||
to_dms(y(transform(centroid(map_get(item_variables('Map 1'),'map_extent')), map_get(item_variables('Map 1'),'map_crs'), 'EPSG:4326')), 'y' , 2, 'aligned')
|| '\n' ||
'L: ' ||
to_dms(x(transform(centroid(map_get(item_variables('Map 1'),'map_extent')), map_get(item_variables('Map 1'),'map_crs'), 'EPSG:4326')), 'x' , 2, 'aligned')
%]