src/ui/lib/display/get_hardware_display_controller.cc

// Copyright 2020 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.

#include "src/ui/lib/display/get_hardware_display_controller.h"

#include <lib/fdio/directory.h>
#include <lib/fit/bridge.h>
#include <lib/syslog/cpp/macros.h>
#include <zircon/status.h>

#include <memory>

namespace ui_display {

fit::promise<DisplayControllerHandles> GetHardwareDisplayController(
    std::shared_ptr<fuchsia::hardware::display::ProviderPtr> provider) {
  // Create the device and interface channels.
  zx::channel device_server, device_client;
  zx_status_t status = zx::channel::create(0, &device_server, &device_client);
  if (status != ZX_OK) {
    FX_LOGS(ERROR) << "Failed to create device channel: " << zx_status_get_string(status);
    return fit::make_ok_promise(DisplayControllerHandles{});
  }

  zx::channel ctrl_server, ctrl_client;
  status = zx::channel::create(0, &ctrl_server, &ctrl_client);
  if (status != ZX_OK) {
    FX_LOGS(ERROR) << "Failed to create controller channel: " << zx_status_get_string(status);
    return fit::make_ok_promise(DisplayControllerHandles{});
  }

  // A reference to |provider| is retained in the closure, to keep the connection open until the
  // response is received.
  fit::bridge<DisplayControllerHandles> dc_handles_bridge;
  (*provider)->OpenController(
      std::move(device_server),
      ::fidl::InterfaceRequest<fuchsia::hardware::display::Controller>(std::move(ctrl_server)),
      [provider, completer = std::move(dc_handles_bridge.completer),
       device_client = std::move(device_client),
       ctrl_client = std::move(ctrl_client)](zx_status_t status) mutable {
        if (status != ZX_OK) {
          FX_LOGS(ERROR) << "GetHardwareDisplayController() provider responded with status: "
                         << zx_status_get_string(status);
          completer.complete_ok(DisplayControllerHandles{});
          return;
        }

        DisplayControllerHandles handles{
            ::fidl::InterfaceHandle<fuchsia::hardware::display::Controller>(std::move(ctrl_client)),
            std::move(device_client)};
        completer.complete_ok(std::move(handles));
      });

  return dc_handles_bridge.consumer.promise();
}

fit::promise<DisplayControllerHandles> GetHardwareDisplayController() {
  const char* kSvcPath = "/svc/fuchsia.hardware.display.Provider";
  auto provider = std::make_shared<fuchsia::hardware::display::ProviderPtr>();
  zx_status_t status =
      fdio_service_connect(kSvcPath, provider->NewRequest().TakeChannel().release());
  if (status != ZX_OK) {
    FX_LOGS(ERROR) << "GetHardwareDisplayController() failed to connect to " << kSvcPath
                   << " with status: " << status;
    return fit::make_result_promise<DisplayControllerHandles>(fit::error());
  }
  return GetHardwareDisplayController(std::move(provider));
}

}  // namespace ui_display