This function gets the icon associated with a .
desktop file that was previously installed by the dynamic launcher portal.
The desktop_file_id must be prefixed with the caller's app ID followed by a "." and suffixed with ".desktop".
| this |
a [class@Portal] |
| desktop_file_id |
the .desktop file name |
| out_icon_format |
return location for icon format string, one of "png", "jpeg", "svg" |
| out_icon_size |
return location for icon size |
|
the icon in a format recognized by deserialize, or null with throws set |