Window screen edge reservation relies on Window::showOnScreenEdge()
getting called when the screen edge can't be reserved. That makes screen
edge code not easy to follow.
This change makes ScreenEdges::reserve() indicate if a screen edge has
been successfully reserved and delegate error handling to the user.
In most cases, if a screen edge has not been successfully hidden, you
just need to avoid calling hideClient() and wait until the next moment
when the window can be hidden again. Note that it differs from the
current behavior but it's for a good reason. If the panel can't be
hidden now, the panel has no idea how to handle it; only the compositor
knows when it can be hidden again.
Currently, the normal window lifecycle looks as follows: create Window,
wait until it's shown, add it to Workspace, wait until it's closed,
create a Deleted, copy properties from the original window to the
deleted one, destroy the original window, wait until the last deleted
window reference is dropped.
There are a couple of issues with this design: we can't nicely
encapsulate X11 or Wayland specific implementation details if they need
to be accessed for closed windows; manual copying of properties is
cumbersome and error prone and we've had a dozen of cases where effects
worked incorrectly because some properties had not been copied.
The goal of this patch is to drop Deleted and extend the lifetime of the
original window, but with a special state set: Window::isDeleted().
The main danger is that somebody can try to do something with deleted
windows that they should not do, but on the other hand, such code needs
to be guarded with relevant checks too.
It's needed to work around the cleanup logic of decorations.
Currently, decorations have a valid QObject parent and they're managed
using std::shared_ptr. That's not a perfect combination, but changing it
is also going to be an involved task because the QObject parent is used
to look up the Window.
In long term, it won't matter since we want to get rid of Deleted.
For what it's worth, it restores the order in which Deleted and normal
windows used to be destroyed prior to
995d509e45.
Window::depth and Window::hasAlpha make no sense on Wayland. The main
reason why we can't rid of them completely yet are X11Window and
Unmanaged.
This change makes WaylandWindow initialize depth to 32 by default to
make wayland window subclasses less boilerplaty.
Things such as Output, InputDevice and so on are made to be
multi-purpose. In order to make this separation more clear, this change
moves that code in the core directory. Some things still link to the
abstraction level above (kwin), they can be tackled in future refactors.
Ideally code in core/ should depend either on other code in core/ or
system libs.
With fractional scaling integer based logical geometry may not match
device pixels. Once we have a floating point base we can fix that. This
also is
important for our X11 scale override, with a scale of 2 we could
get logical sizes with halves.
We already have all input being floating point, this doubles down on it
for all remaining geometry.
- Outputs remain integer to ensure that any screen on the right remains
aligned.
- Placement also remains integer based for now.
- Repainting is untouched as we always expand outwards
(QRectF::toAdjustedRect().
- Decoration is untouched for now
- Rules are integer in the config, but floating in the adjusting/API
This should also be fine.
At some point we'll add a method to snap to the device pixel
grid. Effectively `round(value * dpr) / dpr` though right now things
mostly work.
This also gets rid of a lot of hacks for QRect right and bottom which
are very
confusing.
Parts to watch out in the port are:
QRectF::contains now includes edges
QRectF::right and bottom are now sane so previous hacks have to be
removed
QRectF(QPoint, QPoint) behaves differently for the same reason
QRectF::center too
In test results some adjusted values which are the result of
QRect.center because using QRectF's center should behave the same to the
user.
