This introduces the concept of an Anchor, which you can use to link
transitions together. I've used this in the Fitness and Stocks apps to
link the FAB and SnackBar to animate together by sharing the
SlideTransition.
I also fixed the Scaffold hit testing code to apply sub-widget
transforms, so it works with Transformed nodes.
Now it wont crash on save, but it still doesn't display
the error message in a snackbar and this also doesn't
wire up the enter/go key to actually do anything.
We'll need to implement performEditorAction on our
InputConnection implementation to catch this key and
pass it along to dart.
Our Input control needs to get more powerful to handle things
like this, including filtering of input.
The code was crashing by triggering a bug in the SnackBar
which didn't assert for actions, but crashed when they
were not null.
Partial fix for https://github.com/domokit/sky_engine/issues/543
@abarth
This patch converts sky.Paint to be a pure Dart object, which means we don't
need to open a weak handle to sky.Paint. Avoiding the weak handle reduces the
amount of weak handle callbacks we need to process at the end of GC and
therefore reduces jank.
Added a ScrollListener listener to Scrollable. The ScrollListener runs each time the Scrollable's scrollOffset changes. This can be used to keep overlay widgets in sync with a Scrollable below them.
Removed the Scrollable ScrollClient API. It was no longer used and was clumsy to use as a ScrollListener.
Added global function findScrollableAncestor() to scrollable.dart.
Added examples/widgets/overlay_geometry.dart. The app's Scaffold is contained by a Stack. The Stack is used to display green overlay "Markers" at the corners of the most recently selected list item and where the corresponding tap occurred. The app uses widget.localToGlobal() to compute the global overlay positions of the markers. The ScrollListener is used to keep the markers' positions up to date.
Using ImageResource solves two problems:
1) Listeners can be notified synchronously when the sky.Image is already
available. This change removes flash of 0x0 layout when moving an
already-cached image around in the render tree.
2) In the future, when we support animated images, we can notify listeners
multiple times whenever a new image is available.
This patch simplifies the SkPicture we generate for Skia. Instead of drawing
everything into a nested SkPicture, we now draw everything into the top-level
picture, which requires us to apply the device scale factor in Dart.
