Desktop ScreenState #

Desktop ScreenState is a Flutter desktop plugin that provides functionality for your application to accurately determine whether the screen is on or off, as well as to detect if it's locked or unlocked.

Platform Support #

macOS #

No changes are required.

Windows #

Make the following changes to the respective files:

windows/runner/flutter_window.h

#ifndef RUNNER_FLUTTER_WINDOW_H_
#define RUNNER_FLUTTER_WINDOW_H_

#include <flutter/dart_project.h>
#include <flutter/flutter_view_controller.h>
+ #include <winuser.h>
#include <memory>

#include "win32_window.h"

// A window that does nothing but host a Flutter view.
class FlutterWindow : public Win32Window {
 public:
  // Creates a new FlutterWindow hosting a Flutter view running |project|.
  explicit FlutterWindow(const flutter::DartProject& project);
  virtual ~FlutterWindow();

 protected:
  // Win32Window:
  bool OnCreate() override;
  void OnDestroy() override;
  LRESULT MessageHandler(HWND window, UINT const message, WPARAM const wparam,
                         LPARAM const lparam) noexcept override;

 private:
  // The project to run.
  flutter::DartProject project_;
+ HPOWERNOTIFY power_notification_handle_ = nullptr;
  // The Flutter instance hosted by this window.
  std::unique_ptr<flutter::FlutterViewController> flutter_controller_;
};

#endif  // RUNNER_FLUTTER_WINDOW_H_

windows/runner/flutter_window.cpp

#include "flutter_window.h"

#include <optional>
+ #include <wtsapi32.h>
#include "flutter/generated_plugin_registrant.h"
+ #pragma comment( lib, "wtsapi32.lib" )

FlutterWindow::FlutterWindow(const flutter::DartProject& project)
    : project_(project) {}

FlutterWindow::~FlutterWindow() {
+ if (power_notification_handle_) {
+ UnregisterPowerSettingNotification(power_notification_handle_);
+ }
}

bool FlutterWindow::OnCreate() {
  if (!Win32Window::OnCreate()) {
    return false;
  }

  RECT frame = GetClientArea();

  // The size here must match the window dimensions to avoid unnecessary surface
  // creation / destruction in the startup path.
  flutter_controller_ = std::make_unique<flutter::FlutterViewController>(
      frame.right - frame.left, frame.bottom - frame.top, project_);
  // Ensure that basic setup of the controller was successful.
  if (!flutter_controller_->engine() || !flutter_controller_->view()) {
    return false;
  }
  RegisterPlugins(flutter_controller_->engine());
  SetChildContent(flutter_controller_->view()->GetNativeWindow());
+ power_notification_handle_ = RegisterPowerSettingNotification(GetHandle(), &GUID_CONSOLE_DISPLAY_STATE, DEVICE_NOTIFY_WINDOW_HANDLE);
+ WTSRegisterSessionNotification(GetHandle(),NOTIFY_FOR_THIS_SESSION);
  return true;
}

void FlutterWindow::OnDestroy() {
  if (flutter_controller_) {
    flutter_controller_ = nullptr;
  }

  Win32Window::OnDestroy();
}

LRESULT
FlutterWindow::MessageHandler(HWND hwnd, UINT const message,
                              WPARAM const wparam,
                              LPARAM const lparam) noexcept {
  // Give Flutter, including plugins, an opportunity to handle window messages.
  if (flutter_controller_) {
    std::optional<LRESULT> result =
        flutter_controller_->HandleTopLevelWindowProc(hwnd, message, wparam,
                                                      lparam);
    if (result) {
      return *result;
    }
  }

  switch (message) {
    case WM_FONTCHANGE:
      flutter_controller_->engine()->ReloadSystemFonts();
      break;
  }

  return Win32Window::MessageHandler(hwnd, message, wparam, lparam);
}

Getting Started #

1. Add desktop_screenstate to your pubspec.yaml.

  desktop_screenstate: $latest_version

2. Then you can use DesktopScreenState.instance.isActive to listen window active event.

final ValueListenable<bool> event = DesktopScreenState.instance.isActive;

final bool active = event.value;

event.addListener(() {
  debugPrint("screen is on or off: ${event.value}");
});

2. You can now utilize DesktopScreenState.instance.state to get the current state of the screen:

final ScreenState state = DesktopScreenState.instance.state;

switch (state) {
  case ScreenState.awaked:
    debugPrint("Screen is on");
    break;
  case ScreenState.sleep:
    debugPrint("Screen is sleep");
    break;
  case ScreenState.locked:
    debugPrint("Screen is locked");
    break;
  case ScreenState.unlocked:
    debugPrint("Screen is unlocked");
    break;
}
The DesktopScreenState instance provides an enum ScreenState with the following possible values:

see LICENSE file