Instead of determining the focus item through item tree traversal and
pointer comparison and storing the intermediate indices in the
components in the tree, remember the focus item by a pair of
VWeak<ComponentVTable, Dyn> and item_index: usize.
This speeds up determining the focus item as well as delivering events,
which can now be done directly after retrieving an ItemRef with
get_item_ref.
This also fixes the duplicate line edit focus in the 7gui cells
test case.
Draw rounded rectangles using a distance function. This removes the need
to use lyon to tesselate the rounded corners and as a bonus it gives
anti-aliased borders.
Similar to the mouse_grabber, we use a VisitChildrenResult field to
track the focus item within a component. Unlike the mouse grabber
however, it is set/cleared using dedicated focus events.
The key event now routes the key event directly to the focus item.
The focus can be requested via set_focus_item on a window, which the
TextItem does.
In the future the TextInput will request focus on mouse click,for
example.
Pass the outer-most component through to ItemVTable's input_event.
For the purpose of disambiguating this component from any nested
component instantiated by a repeater or so, it's called the
app_component.
The ComponentVTable takes a reference to a ComponentRefPin instead of a
ComponentRefPin by value, as the vtable macro gets confused otherwise
and thinks it's a self argument.
When selecting to the left, the anchor remains to the right of the cursor.
When deleting such a selection, we fetch the cursor and anchor using a helper
method, which ensures that the anchor is to the left of the cursor.
Finally when setting the cursor then to the anchor, we need to also
set the anchor, since both were swapped.
This also add an automated test for this scenario.
We really shouldn't require specifying a color for every Text {} element just in order
to see *some* text.
For Rectangle OTOH transparent is a good default (and thus for Color), hence
this change just to Text.
Right now the constructor bit is also a bit repetitive, this could
perhaps be folded into BuiltinItem to generate the ffi, default impl and
forward to an init function if it exists.
