SUMMARY Gwenview gives a dialog to edit tags for an image file under Semantic Information If read/write permissions granted on the file (0600), the change occurs and can be seen with getfattr -d ... If only read permissions granted (0400), the change is accepted by Gwenview (and cached?) but it is not changed in the attributes in the filesystem (the change is not seen with getfattr -d ...) The same behaviour happens for changes to the rating and comment fields STEPS TO REPRODUCE 1. Create a read-only image file, open with gwenview and attempt to set a tag. 2. Check the file with getfattr -d .... OBSERVED RESULT Gwenview thinks the tag has been added but the attributes are not changed on the filesystem EXPECTED RESULT Give an error message if the attempt to change details fails DESIRED STATE Do not give an option to change tags for read-only files. SOFTWARE/OS VERSIONS Gwenview 19.12.1 from Neon 5.17 KDE Plasma 5.17.5 KDE Frameworks 5.66.0 Qt 5.13.2 ADDITIONAL INFORMATION This is similar to earlier behaviour in Dolphin 19.04.02, where a change was accepted but the xattr details not changed. With Dolphin 19.08.3, the option to edit tags is not given for read-only files.
As an aside... As images downloaded from a camera are (or are often?) created as read-only files, it may be helpful for Gwenview to display a 'edit' button or link but give a pop up message that the file is read-only. That will help the discoverability of the tagging feature for people new to the application