// 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;

using fuchsia.ui.views;

/// This interface is exposed to all Module instances in a story. It allows to
/// create Link instances and run more Module instances.
[Discoverable]
protocol ModuleContext {
    /// Starts a new Module instance and adds it to the story. The Module to
    /// execute is identified by the contents of [intent] and the Module instance
    /// is given a [name] in the scope of the starting Module instance. The view
    /// for the Module is given to the story shell for display.
    ///
    /// Providing a [surface_relation] advises the StoryShell how to layout
    /// surfaces that the new module creates. If [surface_relation] is null then
    /// a default relation is used.
    ///
    /// If the method is called again with the same [name] by the same Module
    /// instance, but with different arguments, the existing Module instance is
    /// restarted with the changed arguments. If the other arguments don't
    /// change, just an additional ModuleController connection is made.
    AddModuleToStory(string name, Intent intent,
                     request<ModuleController> module_controller,
                     SurfaceRelation? surface_relation)
        -> (StartModuleStatus status);

    /// Like AddModuleToStory(), but passes a [view_token] explicitly to embed
    /// the view of the requested Module instance in the view of the requesting
    /// Module instance, instead of relying on the story shell for display. If a
    /// Module instance with the same [name] and [intent] is already running,
    /// [view_token] is destroyed.
    [Transitional]
    EmbedModule(string name, Intent intent,
                request<ModuleController> module_controller,
                fuchsia.ui.views.ViewToken view_token)
        -> (StartModuleStatus status);

    /// When a module calls [RemoveSelfFromStory()] the framework will stop the
    /// module and remove it from the story. If there are no more running modules
    /// in the story the story will be deleted.
    RemoveSelfFromStory();
};

/// Communicates the status of an Intent to a Module.
enum StartModuleStatus {
    SUCCESS = 0;
    NO_MODULES_FOUND = 1;
};

/// This interface defines the protocol over which a Module can communicate about
/// an ongoing activity to the framework. It is provided to Modules via
/// ModuleContext.StartOngoingActivity().
protocol OngoingActivity {
};

enum OngoingActivityType {
    UNSPECIFIED = 0;
    VIDEO = 1;
    AUDIO = 2;
};