blob: 0e1dbda9cce0e3d3059640b6e894d24e17154328 [file] [log] [blame]
// Copyright 2018 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
library fuchsia.ui.app;
using fuchsia.sys;
// NOTE: This is likely not the ViewProvider you are looking for! This is
// the new ViewProvider interface that will be deprecating the old one soon.
// The old ViewProvider is in fuchsia.ui.viewsv1.ViewProvider.
// TODO(SCN-589): Remove this when old ViewProvider is deleted.
//
// ViewProvider is the standard mechanism for two modules to each obtain half
// of a shared eventpair token. The shared token is a capability allowing the
// modules to ask Scenic to create a ViewHolder/View pair. The resulting
// View and ViewHolder are linked together until either one is destroyed.
//
// Modules are free to use any other mechanism to agree upon the shared
// eventpair token, and use this to create the linked ViewHolder/View.
// ViewProvider is given for the convenience of clients that don't require
// a more complex implementation.
[Discoverable]
interface ViewProvider {
// Creates a new View under the control of the ViewProvider.
//
// |token| is one half of the shared eventpair which will bind the new View
// to its associated ViewHolder. The ViewProvider will use |token| to
// create its internal View representation. The caller is expected to use
// its half to create corresponding ViewHolder object.
//
// |incoming_services| allows clients to request services from the
// ViewProvider implementation. |outgoing_services| allows clients to
// provide services of their own to the ViewProvider implementation.
//
// Clients can embed a ViewHolder (and by proxy the paired View) into their
// scene graph by using |Node.AddChild()|. The ViewHolder cannot itself
// have any children. A ViewProvider implementation can nest scene objects
// within its View by using |View.AddChild()|. The View itself
// cannot be a child of anything.
//
// Modules can use these mechanisms to establish a distributed,
// inter-process scene graph.
1: CreateView(handle<eventpair> token,
request<fuchsia.sys.ServiceProvider>? incoming_services,
fuchsia.sys.ServiceProvider? outgoing_services);
};