Thank you.
When I wrote my post, I was using the already compiled package LazMapViewer.pkg, v0.2.5, available on the SVN of sourceForge (
https://sourceforge.net/p/lazarus-ccr/svn/HEAD/tree/components/lazmapviewer/, that seems not taking into account new versions of source file.
This package v0.2.5 seems to no provide the recent evolutions of the code with "DrawPreviewTiles".
After posting my post, I managed to have the demo work, but it is a turn around :
- de-installing the lazmapviewer package v0.2.5 from the IDE
- regenerating the IDE to complety delete it-
- recompiling the demo code generated errors as no LazMapViewer element were available
- then I added all the source code of lazmapviewer source folder to the demo project (
https://sourceforge.net/p/lazarus-ccr/svn/HEAD/tree/components/lazmapviewer/source/)
- recompiling now the code, and it works
But this is not satisfactory .... because your process should be the correct one, but I have a problem ...
"the package from the sourceforge site via svn or zip snapshot, open the file "lazmapviewer.pkg.lpkl" in Lazarus "
-> this file "lazmapviewer.pkg.lpkl" is not available on sourceforge ?!?