This patch makes that work using 1 of 2 options:
1. Add all missing enums to the switch statement
or
2. Cast the switch argument to a uint to avoid having to do that (mostly
for GdkEventType).
I even found a bug while doing that: clearing a GtkImage with a surface
did not notify thae surface property.
The reason for enabling this flag even though it is tedious at times is
that it is very useful when adding values to an enum, because it makes
GTK immediately warn about all the switch statements where this enum is
relevant.
And I expect changes to enums to be frequent during the GTK4 development
cycle.
We now rely on toplevels receiving and forwarding all the events
the windowing should be able to handle. Event masks are no longer a
way to determine whether an event is deliverable ot a widget.
Events will always be delivered in the three captured/target/bubbled
phases, widgets can now just attach GtkEventControllers and let those
handle the events.
5bb12474d9 removed the dnd window movement code to let
the gdk backends handle the window movement instead. While this
works for X11/wayland the win32 backend still uses the unmanaged
interface and expects the window movement to be handled on the gtk
side. This restores the functionality in case the dnd is unmanaged.
This fixes the drag window on Windows being stuck in the top left
corner instead of following the drag position.
https://bugzilla.gnome.org/show_bug.cgi?id=781737
Instead of creating a GtkWindow, connecting to ::draw and drawing the
surface in there, then adding that window to another GtkWindow... just
use a GtkImage. This also gets rid of a bunch of utility functions used
only in gtk_drag_set_icon_surface.
Switch code to use gdk_display_is_composited() instead.
The new code also doesn't use a vfunc to query the property but rather
requires the backend to call set_composited()/set_rgba() to change the
value.
And with it, gtk_widget_get_visual() and gtk_widget_set_visual() are
gone.
We now always use the RGBA visual (if available) and otherwise fall back
to the system visual.
In non-composited environments, we were ending up with all-black
drag icons, because nothing was drawing the background of our new
toplevel. Fix this by drawing background when we are not composited.
We don't do this when composited, since we want to allow transparent
icons.
The documentation clearly says that the widget is not destroyed,
but we were in fact failing to keep it alive, since it was still
a child or the icon_window when we destroy that. Fix this by
reparenting the icon_widget out before. Also, deal with the
possibility that the application might destroy the widget
halfway through, for whatever reason.
We should conform to a minimal set of reasons for the gtk side to emit
a better GtkDragResult than GTK_DRAG_RESULT_ERROR. This fixes the notebook
tab DnD feature, where we rely on GTK_DRAG_RESULT_NO_TARGET.
In the wayland side, unfortunately we can't honor either NO_TARGET nor
USER_CANCELLED, we don't know of the latter, so we could return false
positives on the former.
https://bugzilla.gnome.org/show_bug.cgi?id=761954
Grabbing must stay a bit longer until all other backends than x11/wayland
catch up with GDK DnD, so ignore deprecation flags are used on those. The
uses of GdkDeviceManager can be entirely avoided though.
When this is in use, there's essentially a bunch of dead code here.
When all backends are ported, we'll be able to remove grab/cursor
management plus a bunch of source-side event handlers.
I hadn't noticed the :drop() pseudo state in the CSS4 Selectors
spec when I added this a while ago. This commit renames
GTK_STATE_FLAG_DND to GTK_STATE_FLAG_DROP_ACTIVE and adds
:drop(active) as equivalent to the :dnd pseudo state.
Remove some now unused includes and dead code, and rename
gtk_drag_set_icon_window to gtk_drag_set_icon_widget_internal,
since it is no longer restricted to toplevel windows.
Under Wayland, the compositor does it, so there is no need
for us to move the window ourselves. For X11, we are now
doing the animation from the X11 backend. Trigger that by
calling gdk_drag_drop_done().
What changes here is that we have to keep the icon_window
alive for as long as the drag context exists. Use a weak
reference to do so.
When we start a drag cancel animation, we can just keep the existing
window. The reset was only necessary to convert from cursor icon to
window and we removed the cursor handling.
The Wayland dnd surface must remain in place until the drag
is over. Setting it directly as the hardcoded window of the
widget we construct carries the danger that it might get
destroyed prematurely, e.g. when the application calls
gtk_drag_set_icon_name more than once and we recreate the
widget.
Instead, create a dedicated toplevel, and reparent the widget
into it. To keep the code simple, we use the same approach
under X11 as well, and make it the responsibility of the
GDK dnd code to keep the window position updated. We already
pass the current pointer position to gdk_drag_motion, which
makes this very easy.
As a side-effect of these changes, it is now possible to use
non-toplevel widgets as drag icons.
https://bugzilla.gnome.org/show_bug.cgi?id=748763
The size of icons is a property that is relevant to who is rendering the
icon, not to the icon itself.
Example: Starting a DND operation from an entry icon should cause the
icon to resize (from the entr icon's size to the DND icon size).
