AnimatedContainer: generalized Container widget that handles animating values

AnimatedContainer: generalized Container widget that handles animating values
when they change via syncFields.

Very early so far. Only supports animating shadow, position, and backgroundColor.

R=abarth@chromium.org

Committed: https://chromium.googlesource.com/external/mojo/+/f66984e72a2b5db0f7c4db4f05829118defe6640

[Matt Perry, 2015-07-08 20:42:12]

mpcomplete@chromium.org changed reviewers:
+ abarth@chromium.org

[Matt Perry, 2015-07-08 20:42:13]

https://codereview.chromium.org/1223073002/diff/1/sky/sdk/example/stocks/lib/...
File sky/sdk/example/stocks/lib/stock_home.dart (right):

https://codereview.chromium.org/1223073002/diff/1/sky/sdk/example/stocks/lib/...
sky/sdk/example/stocks/lib/stock_home.dart:260: Matrix4 transform = new
Matrix4.identity();
Ignore this. I want to use an AnimatedContainer here eventually, but the
Transform here seems to break hit-testing.

[abarth-chromium, 2015-07-08 21:02:05]

https://codereview.chromium.org/1223073002/diff/1/sky/sdk/example/stocks/lib/...
File sky/sdk/example/stocks/lib/stock_home.dart (right):

https://codereview.chromium.org/1223073002/diff/1/sky/sdk/example/stocks/lib/...
sky/sdk/example/stocks/lib/stock_home.dart:260: Matrix4 transform = new
Matrix4.identity();
On 2015/07/08 at 20:42:13, Matt Perry wrote:
> Ignore this. I want to use an AnimatedContainer here eventually, but the
Transform here seems to break hit-testing.

Does that mean you're going to remove this part of the diff before landing?

https://codereview.chromium.org/1223073002/diff/1/sky/sdk/lib/widgets/animate...
File sky/sdk/lib/widgets/animated_container.dart (right):

https://codereview.chromium.org/1223073002/diff/1/sky/sdk/lib/widgets/animate...
sky/sdk/lib/widgets/animated_container.dart:52: }
This seems overly general.  Why not just use explicit properties of
AnimatedContainer instead of using a Map with slots?

[Matt Perry, 2015-07-08 21:41:03]

ready for another look

https://codereview.chromium.org/1223073002/diff/1/sky/sdk/example/stocks/lib/...
File sky/sdk/example/stocks/lib/stock_home.dart (right):

https://codereview.chromium.org/1223073002/diff/1/sky/sdk/example/stocks/lib/...
sky/sdk/example/stocks/lib/stock_home.dart:260: Matrix4 transform = new
Matrix4.identity();
On 2015/07/08 21:02:04, abarth-chromium wrote:
> On 2015/07/08 at 20:42:13, Matt Perry wrote:
> > Ignore this. I want to use an AnimatedContainer here eventually, but the
> Transform here seems to break hit-testing.
> 
> Does that mean you're going to remove this part of the diff before landing?

Yep.

https://codereview.chromium.org/1223073002/diff/1/sky/sdk/lib/widgets/animate...
File sky/sdk/lib/widgets/animated_container.dart (right):

https://codereview.chromium.org/1223073002/diff/1/sky/sdk/lib/widgets/animate...
sky/sdk/lib/widgets/animated_container.dart:52: }
On 2015/07/08 21:02:05, abarth-chromium wrote:
> This seems overly general.  Why not just use explicit properties of
> AnimatedContainer instead of using a Map with slots?

Done.

[abarth-chromium, 2015-07-09 17:51:46]

LGTM

Much better

https://codereview.chromium.org/1223073002/diff/40001/sky/sdk/lib/widgets/ani...
File sky/sdk/lib/widgets/animated_container.dart (right):

https://codereview.chromium.org/1223073002/diff/40001/sky/sdk/lib/widgets/ani...
sky/sdk/lib/widgets/animated_container.dart:29: AnimatedComponent _component;
We shouldn't have an animated component...

[Matt Perry, 2015-07-09 17:59:17]

https://codereview.chromium.org/1223073002/diff/40001/sky/sdk/lib/widgets/ani...
File sky/sdk/lib/widgets/animated_container.dart (right):

https://codereview.chromium.org/1223073002/diff/40001/sky/sdk/lib/widgets/ani...
sky/sdk/lib/widgets/animated_container.dart:29: AnimatedComponent _component;
On 2015/07/09 17:51:46, abarth-chromium wrote:
> We shouldn't have an animated component...

OK. It makes the client code a bit more complicated since they have to watch()
each performance. But I'll try to find a better way around that.

[abarth-chromium, 2015-07-09 18:00:20]

On 2015/07/09 at 17:59:17, mpcomplete wrote:
>
https://codereview.chromium.org/1223073002/diff/40001/sky/sdk/lib/widgets/ani...
> File sky/sdk/lib/widgets/animated_container.dart (right):
> 
>
https://codereview.chromium.org/1223073002/diff/40001/sky/sdk/lib/widgets/ani...
> sky/sdk/lib/widgets/animated_container.dart:29: AnimatedComponent _component;
> On 2015/07/09 17:51:46, abarth-chromium wrote:
> > We shouldn't have an animated component...
> 
> OK. It makes the client code a bit more complicated since they have to watch()
each performance. But I'll try to find a better way around that.

I think it's find to land this as-is and iterate.

[Matt Perry, 2015-07-09 18:12:30]

Committed patchset #3 (id:40001) manually as
f66984e72a2b5db0f7c4db4f05829118defe6640 (presubmit successful).