Michael Goderbauer d17ae25034 Do not schedule animation if already at the target value (#11503)
* Do not schedule animation if already at the target value

* Partially fixes https://github.com/flutter/flutter/issues/11495.
* Also includes a fix for Cupertino button to always run the tap animation even if the finger is immediately lifted from the screen (uncovered by a test failure).

* refactorings

* more tests

* test clearifications

* remove Listener

* fix lints

* fix async issue
2017-08-04 10:42:08 -07:00
..