This allows us to change file layer properties by resummoning the creation dialog.
The patch works in principle, how ever there are two issues:
- The main one is that I don't know how to update the whole canvas afterwards, an important change when having different sized files. EDIT: I figured it out, there needs to be m_view->document()->image()->refreshGraph(); after changing the file layer settings.
- There's no undo command for this, I am not sure how relevant it is to make an undo command for this, considering it is only about pointing to a new file...
- I need someone to check if the creation of "*flayer" makes sense, as the others are sharedpointers.
Other than that, please do a proper code review, because I have no idea what I am doing with nodes :D
Edit: This would fix https://bugs.kde.org/show_bug.cgi?id=380467, which would be the last of the file layer bugs, if I am seeing that correctly :D