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.
Make sure the APIs follow a predictable path:
setup
bind
rebind/update (0-N times)
unbind
teardown
This is the first step towards providing multiple different factories.
... and replace the anchor tracking with a tracker.
Trackers track an item through the list across changes and ensure that
this item (and potentially siblings before/after it) are always backed
by a GtkListItem and that if the item gets removed a replacement gets
chosen.
This is now used for tracking the anchor but can also be used to add
trackers for the cursor later.
Remove a bunch of API from the headers that isn't used anymore and then
refactor code to not call it anymore.
In particular, get rid of GtkListItemManagerChange and replace it with a
GHashTable.
This is implemented by using actions, which are a neat trick to get to
allow the ListItem to call functions on the ListView without actually
needing to be aware of it.
This way, newly displayed rows don't play an unselect animation (text
fading in) when they are unselected, but the row was previously used for
a selected item.
Instead of just destroying all items and then recreating them (or even
hide()ing and then show()ing them again (or even even repositioning
them in the widget tree)), just try to reust them in the order they are.
This works surprisingly well when scrolling and most/all widgets
just moved.
We reorder widgets start to end, so when reusing a list item, we
correctly know the previous sibling for that list item, but not the
next sibling yet. We just know the widget it should ultimately be in
front of.
So we can do a more correct guess of the list item's place in the widget
tree if we think about where to place an item like this.
Actually using this change will come in the next commit.
Previously, we were recreating all widgets every time the list item was
rebound, which caused a lot of extra work every time we scrolled.
Now we keep the widgets around and only set their properties again when
the item changes.
