When determining whether to run an animation, the `TransitionAnimationPlayer`
checks to see if a DOM element is attached to the document. This is done by
checking to see if the element is "contained" by the document body node.
Previously, if the element was inside a shadow DOM, the engine would
determine that the element was not attached, even if the shadow DOM's
host was attached to the document. This commit updates the `containsElement()`
method on `AnimationDriver` implementations to also include shadow DOM
elements as being contained if their shadow host element is contained.
Further, when using CSS keyframes to trigger animations, the styling
was always added to the `head` element of the document, even for
animations on elements within a shadow DOM. This meant that those
elements never receive those styles and the animation would not run.
This commit updates the insertion of these styles so that they are added,
to the element's "root node", which is the nearest shadow DOM host, or the
`head` of the document if the element is not in a shadow DOM.
Closes#25672
PR Close#40134
This patch removes the need to include the Web Animations API Polyfill
(web-animations-js) as a dependency. Angular will now fallback to using
CSS Keyframes in the event that `element.animate` is no longer supported
by the browser.
In the event that an application does use `AnimationBuilder` then the
web-animations-js polyfill is required to enable programmatic,
position-based access to an animation.
Closes#17496
PR Close#22143
Add enough BUILD files to make it possible to
`bazel build packages/core/test`
Also re-format BUILD.bazel files with Buildifier.
Add a CI lint check that they stay formatted.
PR Close#20768
