Convert TabBar to TabBar<T> and TabBarSelection to TabBarSelection<T>
The TabBarSelection constructor no longer has the odd maxIndex parameter and the selection is initialized by value rather than the index of the selected tab.
TabBar has a Map labels parameter instead of List.
When paging a scrollable list, we were trying to read the render object's size
at a time when we're not allowed to read it. Instead, encode the information
into the repaint limit, which is more correct (and faster) anyway.
This patch also changed ScrollableList2 to use an Iterable instead of an
List for its children. This change lets clients map their underlying
data lazily. If the clients actually have a concrete list, we skip the
extra copy and grab the child list directly.
This patch implements the remaining missing features of ScrollableList2.
It should now be nearly a drop-in replacement for ScrollableList. The
next patch will switch callers over to the new machinery.
ScrollableList2 uses the same pattern as ScrollableGrid, which requires the
client to allocate widgets for every list item but doesn't inflate them unless
they're actually needed for the view. It improves on the original
ScrollableList by not requiring a rebuild of the whole visible portion of the
list when scrolling. In fact, small scrolls can often be handled entirely by
repainting.
We now support (vertically) scrollable grids with viewporting. If the
scroll doesn't reveal any new rows, we execute the scroll with a repaint
(i.e., no layout). If the scroll reveals a new row, we trigger a layout
to change the set of materialized children in the viewport.
This patch make grid layout much more flexible. The behavior is factored
out into a GridDelegate that's modeled after the custom layout
delegates. The patch includes a MaxTileWidthGridDelegate that implements
the old behavior and a FixedColumnCountGridDelegate that implements a
grid layout with a fixed number of columns.
Fixes#1048
When assigning a new overlayPainter, we were detaching the old overlay
painter even if the render object itself wasn't attached. Now we only
twiddle the attach/detach state of the overlay painter when we're
attached ourselves.
Fixes#1047
Require a Key on Input.
Simplify the API for Focus.at() and Focus.moveTo().
Fixes#236.
This will require an e-mail to flutter-dev.
Make Input grab focus onTap not onPointerDown.
Fixes#189.
Complain when you use Focus.at() with two different GlobalKeys that
are both in the tree at the same time.
Fixes#181.
Add dartdocs for Focus.moveTo() and Focus.moveScopeTo().
