Hello BaseView

This is the usage example for the scenic::BaseView class, which simplifies the creation of components that can act as both parents and children in the Scenic view tree.

Note on ExamplePresenter

Includes a simple implementation of fuchsia.ui.policy.Presenter2 which it uses instead of connecting to root_presenter; the topology is analogous to how Peridot's basemgr connects the base_shell to root_presenter.

This configuration requires connecting directly to Scenic; it will not work if there is already a Compositor attached to the default display.

Note on Input Events

For Scenic to deliver input events to Views, it must first receive them from a presenter. It is the presenter's responsibility to set up reception of input events from Zircon and pass them to Scenic. Today, only the root_presenter's implementation is currently configured to do that; ExamplePresenter could do it with extra work.

Both applications (hello_base_view and shadertoy_client) will respond to touchscreen events.

Usage:

• Connect to the root presenter:
  • $ run fuchsia-pkg://fuchsia.com/hello_base_view#meta/hello_base_view.cmx --use_root_presenter
• Set up an example presenter:
  • $ run fuchsia-pkg://fuchsia.com/hello_base_view#meta/hello_base_view.cmx --use_example_presenter
  • For ExamplePresenter, make sure to kill any instances of scenic and root_presenter (use killall).
• Stand up the view provider service, and have it connect to an ambient root_presenter. In this configuration, the hello_base_view application won't put up its own View.
  • $ present_view fuchsia-pkg://fuchsia.com/hello_base_view#meta/hello_base_view.cmx