So, this is more a question about LV2 development than about Ardour, but…
I’m writing a simple LV2 plugin (no UI, just generic controls for now) that has two file selectors, which show (None) when no file is selected. If i load this plugin in jalv and then load a preset which specifies these files, the corresponding file selector updates to reflect this change. In Ardour the file selectors update immediately on selecting a file, but then still show (None) if the session or preset is saved then reloaded. However the correct files are always loaded and heard, and properly written in the preset’s .ttl file in ~/.lv2
The file selectors are implemented via “patch:writable” + “lv2:Parameter” (atom:Path). The plugin also has separate “control” and “notify” atom ports, both with “atom:supports patch:Message” in the plugin’s .ttl file. When i click the file picker and select a file, i’m seeing the correct “patch:Set” notification on the notify port with the correct filename, and the file gets loaded correctly.
Is there a checklist of stuff i need to verify, so that the UI shows files loaded from a preset/session given by the host?
/* edit */ SOLVED - was forgetting to check the URID atom for LV2_PATCH__Get.