Nothing really changes, because both ListView and GridView still keep
self->item_manager around, but it's set up to point at the base's item
manager.
This way we can slowly move things to GtkListBase that need the item
manager (like trackers).
- Handle anchor as align + top/bottom
This fixes behavior for cells that are higher than the view
- Add gtk_list_view_adjustment_is_flipped()
This should fix RTL handling of horizontal lists
- Fix scrolling
This should make scrolling more reliable, particularly on short lists
that are only a few pages long.
I couldn't come up with a better way to automatically inherit the scope
in the builder list item factory that didn't involve a magic
incantation in the XML file. And I do not want developers to know magic
incantations to do a thing that should pretty much always be done.
This implements all the keybindings from GtkTreeView that can be
supported.
It does not implement expand-all, because supporting that means
causing the TreeListModel to emit lots of create_model vfuncs which in
turn would cause many items-changed signal which in turn would cause
many signal handlers to run which in turn would make "expand-all" very
reentrant, and I'm uneasy about supporting that.
For the mouse, just add a click gesture to the expander icon that toggles
expanded state.
Focus in the listitem now works like this:
1. If any child can take focus, do not ever attempt
to take focus.
2. Otherwise, if this item is selectable or activatable,
allow focusing this widget.
This makes sure every item in a list is focusable for
activation and selection handling, but no useless widgets
get focused and moving focus is as fast as possible.
It's quite a bit faster now, but the code is also a bit more awkward.
Pain points:
- GtkTreeListModel cannot be created in UI files because it needs
a CreateModelFunc.
Using a signal for this doesn't work because autoexpand wants to
expand the model before the signal handler is connected.
- The list item factory usage is still awkward. It's bearable here
because the list items are very simple, but still.
This is a container widget that takes over all the duties of tree
expanding and collapsing.
It has to be a container so it can capture keybindings while focus is
inside the listitem.
So far, this widget does not allow interacting with it, but it shows the
expander arrow in its correct state.
Also, testlistview uses this widget now instead of implementing
expanding itself.
Implement measuring and allocating items - which makes the items appear
when drawing and allows interacting with the items.
However, the gridview still does not allow any user interaction
(including scrolling).
Due to the many different ways to set factories, it makes sense to
expose them as custom objects.
This makes the actual APIs for the list widgets simpler, because they
can just have a regular "factory" property.
As a convenience function, gtk_list_view_new_with_factory() was added
to make this whole approach easy to use from C.
Shift-clicking to extend selections now also works, imitating the
behavior of normal clicking and Windows Explorer (but not treeview):
1. We track the last selected item (normally, not via extend-clicking).
2. When shift-selecting, we modify the range from the last selected item
to this item the same way we modify the regular item when not using
shift:
2a. If Ctrl is not pressed, we select the range and unselect everything
else.
2b. If Ctrl is pressed, we make the range have the same selection state
as the last selected item:
- If the last selected item is selected, select the range.
- If the last selected item is not selected, unselect the range.
