Add thumbnailer

This enables thumbnail rendering in file managers of .slvs files.

Author: polyfloyd

res/CMakeLists.txt

@@ -203,7 +203,11 @@ else()
         install(FILES freedesktop/solvespace-mime.xml
             DESTINATION ${CMAKE_INSTALL_DATAROOTDIR}/mime/packages
             RENAME      solvespace-slvs.xml)
-        
+
+        install(FILES freedesktop/solvespace.thumbnailer
+            DESTINATION ${CMAKE_INSTALL_DATAROOTDIR}/thumbnailers
+            RENAME      solvespace.thumbnailer)
+
         install(FILES freedesktop/solvespace-scalable.svg
             DESTINATION ${CMAKE_INSTALL_DATAROOTDIR}/icons/hicolor/scalable/apps
             RENAME      solvespace.svg)

res/freedesktop/solvespace.thumbnailer

@@ -0,0 +1,4 @@
+[Thumbnailer Entry]
+TryExec=solvespace-cli
+Exec=solvespace-cli thumbnail --view isometric --size %sx%s --output %o %i
+MimeType=application/x-solvespace