We maintain offsets for popups, so we can translate
coordinates between surfaces that are attached directly
or indirectly to the same toplevel. Add an api for that.
Make the transform (transfer full).
1. This makes sure we actually reference the transform. Previously we
did not.
2. Most callers create a new transform to pass to us. Now they don't
have to uref it anymore.
CSS does not do exponents, so printing numbers close to 0 as 1.234e-15
does not work.
Also up the accuracy to 17 digits because that's what everyone else
uses.
GTK4 doesn't have WS_CHILD windows anymore, so hWndParent argument
to CreateWindowEx() is always interpreted as the owner window,
not the parent window.
A window with an owner:
* is above the owner in Z-order
* is destroyed when the owner is destroyed
* is hidden when the owner is minimized
This is enforced by the OS.
GTK can only allow this for popup windows.
Desktop window must never[0] be an owner.
[0]: https://devblogs.microsoft.com/oldnewthing/20040224-00/?p=40493
On Windows that call resizes the native window immediately,
and the corresponding GDK event is emitted and processed
before the control is returned to gtk_window_move_resize().
Therefore, update freeze and configure_request_count increment
must happen before the call, not after it.
Popups can't be active or inactive, so emitting GDK events
in response to WM_ACTIVATE makes no sense for these kinds
of GDK surfaces.
The jury is still out on whether we should block (return 0)
or ignore (don't return anything) this message.
Blocking WM_NCACTIVATE (which we currently ignore) is definitely
not an option - it completely breaks input somehow.
1) Handle GDK_SURFACE_POPUP in RegisterGdkClass()
(for now pretend it's the same as GDK_SURFACE_TOPLEVEL)
2) Remove useless code from GDK_SURFACE_TOPLEVEL case in _gdk_win32_display_create_surface()
(now there's just GDK_SURFACE_TOPLEVEL there, no need for a type check)
3) Have a separate case for GDK_SURFACE_POPUP and ensure that
it doesn't get WS_CHILDWINDOW (and neither should GDK_SURFACE_TEMP).
