To keep the scope of this CL as small of possible I'm leaving the actual
implementation of the platform view mechanics to a following CL.
This CL introduces:
* A PlatformViewsController class which will be responsible for creating,
resizing, and disposing platform views.
* A PlatformViewRegistry which is exposed through the PluginRegistry
and allows plugins to register factories for platform views.
Android plugin code will add support for a new platform view type by
implementing PlatformViewFactory, and registering a factory with the
registry, e.g:
```java
registrar.platformViewRegistry().registerViewFactory(
'webview',
new FlutterWebViewFactory()
);
```
On the Dart side, the framework will ask the engine to create new
platform views by sending a create message over the platformviews method
channel with the unique platform view type id, dimensions, and a unique
id allocated by the framework for the new platform view instance.
The platformviews method channel is also used for resizing and disposing
platform views.
We have a use for this for the internal messaging plugin. Instead of rolling our own, it made sense to add it here especially since it has the mirror functionality (wrap).
Sometimes, plugin instances need access to the `FlutterView`.
They can currently cast the `messenger()`, but that's fragile.
This adds API support for getting the view from the registry.
Matt Carroll
Jason Simmons
Dan Field
Ian Hickson
Michael Goderbauer
Kirill Nikolaev
amirh
Mehmet Fidanboylu
Sarah Zakarias
Mikkel Nygaard Ravn
Ali Bitek
Zachary Anderson
Chinmay Garde
Todd Volkert