Add functionality for Delete Template

[unichronic]

ref #1723
I have added the delete functionality for templates. Please check it out if the changes are alright.

Currently after deleting a template it takes 10-15s to disappear from the file list during Folders referesh using FileSystemWatcher.
Do you think that's an issue?

[bjorn]

Thank you for looking into this feature, @unichronic!

Currently after deleting a template it takes 10-15s to disappear from the file list during Folders refresh using FileSystemWatcher.
Do you think that's an issue?

Yes, this is not ideal. It's rather longer than I would expect since the FileSystemWatcher sets mChangedPathsTimer.setInterval(500), meaning it should only take half a second until the list is refreshed. But I think regardless, we should remove the matching entry from the model immediately after successful removal of the file.

I've left two additional comments.

[bjorn]

Consider making a local static isTemplateInUse function, so you can just return true instead of setting and checking an isUse variable.

[unichronic]

done

[bjorn]

Of course, we can't actually delete the template instance when it is still in use, even if the user might be fine with this. By deleting this object, any references to this template will become roaming pointers and can cause crashes or random broken behavior later.

Currently, templates are never unloaded, which is what avoids such issues. I wonder if it hurts to just keep them in memory even if we delete the file.

[unichronic]

done

[unichronic]

Yes, this is not ideal. It's rather longer than I would expect since the FileSystemWatcher sets mChangedPathsTimer.setInterval(500), meaning it should only take half a second until the list is refreshed.

yes, the FileSystemWatcher triggers instantly, but the time to remove depends on the size the project folder since the whole file tree is refreshed everytime. I tried with smaller smaller folder, it was removed instantly. So I think unless the project folder has too many items it won't take that much time (I had my project folder as one of my root folders xD).

Addressed the other comments.