blob: e883d8e2560139c5d2a5039bfbc721d743e7b9ac [file] [log] [blame]
// Copyright 2016 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.modular;
/// This file has interfaces for 2 pieces of information: (1) The story
/// that is currently in focus and (2) stories that are visible to the
/// user. Names of interfaces follow the usual patterns:
/// {Focus,VisibleStories}Controller is used by session shell to update
/// information whenever changes take place.
/// FocusProvider is used by session shell to
/// query and get updates on which story is in focus on which device
/// and visible stories on this device.
/// Implemented by sessionmgr. Given to session shell through its namespace.
// NOTE(alhaad): The information about visible stories can be used by
// sessionmgr to stop / pause stories that are not visible to the
// user.
protocol FocusController {
// Sets the focus on this device.
Set(string? focused_story_id);
WatchRequest(FocusRequestWatcher watcher);
/// Implemented by session shell. OnFocusRequest() gets called whenever there
/// is a new request to change focus on this device. Requests can be
/// made via FocusProvider.Request().
protocol FocusRequestWatcher {
OnFocusRequest(string story_id);
/// Implemented by sessionmgr. Given to session shell and session agents through
/// their namespace. Focus is persisted on the ledger.
protocol FocusProvider {
/// Returns the stories that are focused across all devices.
Query() -> (vector<FocusInfo> focused_stories);
/// Watches for change in focus on any of the user's devices.
Watch(FocusWatcher watcher);
/// Requests session shell to change focus on this device. If session shell
/// responds to this request, focus shall be taken away from
/// previously focused story and an update will be sent on
/// FocusWatcher.OnFocusChange(). If `story_id` is NULL, the timeline
/// is brought back into focus.
// TODO(alhaad): Consider making this available for remote devices as
// well.
Request(string? story_id);
/// Implemented by anyone who is interested in getting updates when focus
/// changes.
protocol FocusWatcher {
OnFocusChange(FocusInfo? focus_info);
/// Specifies the focused story of a device.
struct FocusInfo {
/// The id of the device.
string device_id;
/// The id of the focused story. If null, no stories are focused.
string? focused_story_id;
/// The time the focused story on the device `device_id` was last
/// changed. 0 if no focus has ever been set for device `device_id`.
uint64 last_focus_change_timestamp;