ash/ambient/ambient_ui_launcher.h

// Copyright 2023 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef ASH_AMBIENT_AMBIENT_UI_LAUNCHER_H_
#define ASH_AMBIENT_AMBIENT_UI_LAUNCHER_H_

#include <memory>

#include "ash/ambient/ambient_photo_controller.h"
#include "ash/ambient/metrics/ambient_session_metrics_recorder.h"
#include "ash/ambient/model/ambient_backend_model.h"
#include "base/functional/callback_forward.h"
#include "ui/views/view.h"

namespace ash {

class AmbientUiSettings;

// AmbientUiLauncher is used to start ambient UIs. Every implementation of
// this abstract class is tied a particular UI (slideshow, animation etc) but it
// is able to launch multiple ambient UI sessions.
//
// Where each ambient UI session starts when the `Initialize` method is called
// for the first time and ends when the `Finalize` method is called.
class AmbientUiLauncher {
 public:
  using InitializationCallback = base::OnceCallback<void(bool success)>;

  class Observer : public base::CheckedObserver {
   public:
    virtual void OnReadyStateChanged(bool is_ready) {}
  };

  virtual ~AmbientUiLauncher() = default;

  // Do any asynchronous initialization before launching the UI. This method is
  // only expected to be run once per ambient UI session.
  virtual void Initialize(InitializationCallback on_done) = 0;

  // After Initialize() is complete, we call this method to create the view,
  // this can be called multiple times during an ambient UI session in case
  // there are multiple screens.
  //
  // Must only be called between a successful `Initialize()` and `Finalize()`
  // call.
  virtual std::unique_ptr<views::View> CreateView() = 0;

  // Stop any processing and ends the current ambient session. This method is
  // only expected to run once to end the ambient UI session.
  virtual void Finalize() = 0;

  // TODO(esum): Remove when we get rid of the ambient backend model dependency
  // from the ambient controller and PhotoView.
  virtual AmbientBackendModel* GetAmbientBackendModel() = 0;

  // TODO(pzliu): Remove when we get rid of the ambient photo controller
  // dependency from the ambient controller.
  virtual AmbientPhotoController* GetAmbientPhotoController() = 0;

  // Returns whether an ambient UI session is ready to be started and the
  // `Intiailize` method can be called. Note: This can potentially disable
  // ambient mode until the next lock/unlock event if this is false on the lock
  // screen.
  bool IsReady();

  void SetObserver(Observer* observer);

  // Always returns a non-null value. Defaults to
  // `AmbientConsumerSessionMetricsDelegate`, but UI launchers that want to
  // customize the standard set of metrics that recorded for all ambient UIs
  // may override with their own implementation here.
  virtual std::unique_ptr<AmbientSessionMetricsRecorder::Delegate>
  CreateMetricsDelegate(AmbientUiSettings current_ui_settings);

 protected:
  // Sets the ready state and notifies the observer whenvever the reader state
  // changes.
  void SetReadyState(bool is_ready);

 private:
  raw_ptr<Observer> observer_ = nullptr;

  // The ready state of the launcher, indicates whether the launcher is ready to
  // be shown or not.
  bool is_ready_ = true;
};

}  // namespace ash

#endif  // ASH_AMBIENT_AMBIENT_UI_LAUNCHER_H_