runtime/flutter_runner/session_connection.h

// Copyright 2017 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef TOPAZ_RUNTIME_FLUTTER_RUNNER_SESSION_CONNECTION_H_
#define TOPAZ_RUNTIME_FLUTTER_RUNNER_SESSION_CONNECTION_H_

#include <lib/fit/function.h>
#include <trace/event.h>
#include <lib/zx/eventpair.h>

#include "flutter/flow/compositor_context.h"
#include "flutter/flow/scene_update_context.h"
#include "flutter/fml/macros.h"
#include "lib/fidl/cpp/interface_handle.h"
#include "lib/fidl/cpp/optional.h"
#include "lib/ui/scenic/cpp/resources.h"
#include "lib/ui/scenic/cpp/session.h"
#include "vulkan_surface_producer.h"

namespace flutter {

using OnMetricsUpdate = fit::function<void(const fuchsia::ui::gfx::Metrics&)>;
using OnSizeChangeHint =
    fit::function<void(float width_change_factor, float height_change_factor)>;

// The component residing on the GPU thread that is responsible for
// maintaining the Scenic session connection and presenting node updates.
class SessionConnection final {
 public:
  SessionConnection(std::string debug_label,
#ifndef SCENIC_VIEWS2
                    zx::eventpair import_token,
#else
                    zx::eventpair view_token,
#endif
                    fidl::InterfaceHandle<fuchsia::ui::scenic::Session> session,
                    fit::closure session_error_callback,
                    zx_handle_t vsync_event_handle);

  ~SessionConnection();

  bool has_metrics() const { return scene_update_context_.has_metrics(); }

  const fuchsia::ui::gfx::MetricsPtr& metrics() const {
    return scene_update_context_.metrics();
  }

  void set_metrics(const fuchsia::ui::gfx::Metrics& metrics) {
    fuchsia::ui::gfx::Metrics metrics_copy;
    metrics.Clone(&metrics_copy);
    scene_update_context_.set_metrics(
        fidl::MakeOptional(std::move(metrics_copy)));
  }

  flow::SceneUpdateContext& scene_update_context() {
    return scene_update_context_;
  }

#ifndef SCENIC_VIEWS2
  scenic::ImportNode& root_node() { return root_node_; }
#else
  scenic::ContainerNode& root_node() { return root_node_; }
  scenic::View* root_view() { return &root_view_; }
#endif

  void Present(flow::CompositorContext::ScopedFrame& frame);

  void OnSessionSizeChangeHint(float width_change_factor,
                               float height_change_factor);

 private:
  const std::string debug_label_;
  scenic::Session session_wrapper_;

#ifndef SCENIC_VIEWS2
  scenic::ImportNode root_node_;
#else
  scenic::View root_view_;
  scenic::EntityNode root_node_;
#endif

  std::unique_ptr<VulkanSurfaceProducer> surface_producer_;
  flow::SceneUpdateContext scene_update_context_;
  zx_handle_t vsync_event_handle_;

  // A flow event trace id for following |Session::Present| calls into
  // Scenic.  This will be incremented each |Session::Present| call.  By
  // convention, the Scenic side will also contain its own trace id that
  // begins at 0, and is incremented each |Session::Present| call.
  uint64_t next_present_trace_id_ = 0;

  void EnqueueClearOps();

  void PresentSession();

  static void ToggleSignal(zx_handle_t handle, bool raise);

  FML_DISALLOW_COPY_AND_ASSIGN(SessionConnection);
};

}  // namespace flutter

#endif  // TOPAZ_RUNTIME_FLUTTER_RUNNER_SESSION_CONNECTION_H_