Instead of randomly changing tiles, the listitemmanager gains a split
vfunc that listview and gridview implement so they can keep their tile
areas intact. The listitemmanager will now conform to these rules:
1. Never delete a tile.
This ensures that all areas stay intact.
2. Never change the n_items of a tile other than setting them to 0.
This causes "empty" areas to appear, but listview/gridview can
easily check for them by checking for tile->n_items == 0.
gtk_list_tile_gc() will get rid of them.
3. Adding items always creates new tiles that are added with empty area.
That way they don't interrupt any existing machinery until the next
allocation.
4. Adding/removing widgets has no effect on areas
This is useful in particular when scrolling where new widgets are
moving between tiles. When the manager moves the widgets, it may
split some areas, but will not remove any existing tiles, so the
whole area stays intact and the list can deal with further scroll
events before an allocation.
This improve the situation for #3334
Instead of the custom size property, use the new tile size.
Also introduce the ability to split tiles, so that gridview can split a
layout that would look like (question mark denoting cells without a
widget, which in this case would be a single tile)
█ █ █ ? ?
? ? ? ? ?
? ? ? ? ?
? ? ?
into 3 rectangular tiles like so:
█ █ █ A A
B B B B B
B B B B B
C C C
This of course also means we need to be able to merge those tiles again
when cells got added/deleted or the gridview was resized. For that job,
gtk_list_tile_gc() exists now, which removes tiles without items and
merges adjacent tiles without widgets.
* Instead of using a gpointer to refer to it, use the GtkListTile type.
* Use gtk_list_tile_get_foo() instead of
gtk_list_item_manager_get_tile_foo() naming.
Just to help static analysis out.
self->n_columns can't ever be 0, since
we clamp it between min_columns and
max_columns, with min_columns always
being at least one.
Rubberband does not work when initiated past the last row
(warning is printed "Could not start rubberbanding: No item).
Clamp y at the max height of the widgets in the gridview
Fixes: #3462
The function gtk_grid_view_get_items_in_rect() erroneously calculates
columns less than 0 and greater than n_columns when the user attempts
to rubberband all the way to the left or right respectively. This
causes the rubberband to persistent and creates unexpected behavior.
Limit the rows to a minimum of 0 and maximum of n_columns - 1.
Fixes: https://gitlab.gnome.org/GNOME/gtk/-/issues/3445
In a list with a visible scrollbar, the scrollbar usually becomes
invisible when the numbers of items is less than the required amount
to scroll. If, however, the list is emptied all at once,
the scrollbar remains. This happens because when there's an empty
list gtk_list_view_size_allocate() returns early before the scrollbar
adjustment is updated.
Given that the list is empty, simply reset the adjustment values
to zero.
Fixes: https://gitlab.gnome.org/GNOME/gtk/-/issues/4370
Those property features don't seem to be in use anywhere.
They are redundant since the docs cover the same information
and more. They also created unnecessary translation work.
Closes#4904
Remove a boatload of "or %NULL" from nullable parameters
and return values. gi-docgen generates suitable text from
the annotation that we don't need to duplicate.
This adds a few missing nullable annotations too.
Match GtkListBox, so it's possible to use the same styles for them.
Update GtkListView and GtkGridView docs to reflect that, fix a few gtk-doc
formatting leftovers along the way.
Removed sentence that claimed the view will wrap the model in a
GtkSingleSelection, as it's no longer true. Fixed the code example in
GtkListView for the same reason. Fixed a small typo in GtkDropDown docs.
Now that both arguments to the _new_with_factory() constructors
are nullable, there's no good reason to keep a separate _new()
around. Just make gtk_list_view_new() and gtk_grid_view_new()
take both a model and a factory.
Change the apis in GtkListView, GtkColumnView and
GtkGridView to be explicitly about GtkSelectionModel,
to make it obvious that the widgets handle selection.
Update all users.
As things currently stand, we get events for focus changes
before the widget is allocated, and try to scroll in response.
Therefore, leaving n_columns at 0 until size-allocate leads
to plenty of division-by-zero. Just set it to 1 initially
to avoid that. This is a workaround for #3025.
Make both gtk_grid_view_new and gtk_grid_view_new_with_factory
take a model as first argument, and make all arguments
allow-none and transfer full.
Update all callers.
Instead of storing the active items as we go, compute the affected items
whenever the rubberband changes and in particular when the rubberband
ends.
That way, the rubberband is guaranteed to select a rectangle even
after scrolling very far.
This is achieved by having a get_items_in_rect() vfunc that selects all
the items in the rubberbanded rectangle and returns them as a bitset.
We are currently not robust against model changes or
widget invalidations, so we can actually end up in
situations where we run out of items here. Handle
the failure a bit more gracefully, by returning NULL.
This is good enough to make scrolling work okish most
of the time. We still need a proper fix to handle
other situations.
The new names are
GtkListView - listview row
GtkGridView - gridview child
GtkColumView - columnview header
columnview listview row
Adwaita css has been updated to preserve
existing styles.
Fixes: #2818
