The layouting was becoming too complex to maintain and to introduce
new features. Was even buggy, the fuzzer was constantly finding
bugs, which took hours to workaround.
Problem with the old layout engine is that there was a catch 22, between
Items driving the separators, and separators driving the anchors.
The new layout is much simpler, both in implementation and conceptually.
There's simply a recursive hierarchy of Item elements. An Item can either
have a QWidget to show, or be a ItemContainer, which contains Item children,
and so forth. Each ItemContainer is either vertical or horizontal. That's enough
to represent the "nested multi-splitter" concept which KDDW uses.
After each item insertion/deletion/resize, the separators are regenerated. They
are essentially dumb now.
TODO:
- Separators are drawn, but are not interactive yet
- There's 5 tests failing
- LayoutSaver scalling functionality
Each subset is identified by its "affinity name".
See DockWidget/MainWindow setAffinityName property.
Patch contributed by Andras Mantia, I've changed it to deal in
terms of affinity names instead of unique names.
After a restore with relative sizes the items might not be on a pixel
perfect position regarding to their anchors. Make sure they are after
the restore is complete.
Same for restore.
This is better API as LayoutSaver shouldn't be concerned about
QSettings. It also assumed the user only had a single layout, which
is normally not the case.
And finally, storing escaped json in .ini files is not very elegant.
QDataStream is opaque and is not good for validation.
With this intermediate format we'll be able to:
- manipulate stuff
- validate that the saved layout is correct, before restoring it
- decide about some restore heuristics which would have been impossible
because before we needed to restore as we read the stream, now we can
look at the state before restoring it
LayoutSaver isn't using the new format yet, but the LayoutSaver::Layout
is already useful to debug some bogus saved states
Implemented as a property it's better that the LayoutSaver
doesn't carry state about this. Then we would need to remove dock
widgets from the list if they are deleted. Also not a important
enough feature to be on the DockWidget public interface.
