[camera_windows] Support camera on windows desktop platform (flutter#…

…4641)

This PR adds a Windows Desktop implementation of [camera plugin](https://pub.dev/packages/camera) using Media Foundation and CaptureEngine interface.

The implementation supports multiple cameras, video preview, and capturing photos and videos. Works with camera plugin and [camera example](https://pub.dev/packages/camera/example).

The current implementation uses FlutterDesktopPixelBuffer, but could be switched to use shared textures or Platform views after those are supported.

Unit tests are partially done; for the CaptureControllerImpl class all falilure code paths are not yet covered.

Still missing some features, like exposure and focus controls. These can be done later with interfaces IAMCameraControl and IAMVideoProcAmp,

Resolves flutter#41709: [camera] Add Windows support

packages/camera/camera_windows/.gitignore

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+.DS_Store
+.dart_tool/
+
+.packages
+.pub/
+
+build/

packages/camera/camera_windows/.metadata

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+# This file tracks properties of this Flutter project.
+# Used by Flutter tool to assess capabilities and perform upgrades etc.
+#
+# This file should be version controlled and should not be manually edited.
+
+version:
+  revision: 18116933e77adc82f80866c928266a5b4f1ed645
+  channel: stable
+
+project_type: plugin

packages/camera/camera_windows/AUTHORS

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+# Below is a list of people and organizations that have contributed
+# to the Flutter project. Names should be added to the list like so:
+#
+#   Name/Organization <email address>
+
+Google Inc.
+Joonas Kerttula <joonas.kerttula@codemate.com>
+Codemate Ltd.

packages/camera/camera_windows/CHANGELOG.md

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+## 0.1.0
+
+* Initial release

packages/camera/camera_windows/LICENSE

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+Copyright 2013 The Flutter Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
+      disclaimer in the documentation and/or other materials provided
+      with the distribution.
+    * Neither the name of Google Inc. nor the names of its
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

packages/camera/camera_windows/README.md

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+# Camera Windows Plugin
+
+The Windows implementation of [`camera`][camera].
+
+*Note*: This plugin is under development.
+See [missing implementations and limitations](#missing-features-on-the-windows-platform).
+
+## Usage
+
+### Depend on the package
+
+This package is not an [endorsed][endorsed-federated-plugin]
+implementation of the [`camera`][camera] plugin, so you'll need to
+[add it explicitly][install].
+
+## Missing features on the Windows platform
+
+### Device orientation
+
+Device orientation detection
+is not yet implemented: [issue #97540][device-orientation-issue].
+
+### Pause and Resume video recording
+
+Pausing and resuming the video recording
+is not supported due to Windows API limitations.
+
+### Exposure mode, point and offset
+
+Support for explosure mode and offset
+is not yet implemented: [issue #97537][camera-control-issue].
+
+Exposure points are not supported due to
+limitations of the Windows API.
+
+### Focus mode and point
+
+Support for explosure mode and offset
+is not yet implemented: [issue #97537][camera-control-issue].
+
+### Flash mode
+
+Support for flash mode is not yet implemented: [issue #97537][camera-control-issue].
+
+Focus points are not supported due to
+current limitations of the Windows API.
+
+### Streaming of frames
+
+Support for image streaming is not yet implemented: [issue #97542][image-streams-issue].
+
+## Error handling
+
+Camera errors can be listened using the platform's `onCameraError` method.
+
+Listening to errors is important, and in certain situations,
+disposing of the camera is the only way to reset the situation.
+
+<!-- Links -->
+
+[camera]: https://pub.dev/packages/camera
+[endorsed-federated-plugin]: https://flutter.dev/docs/development/packages-and-plugins/developing-packages#endorsed-federated-plugin
+[install]: https://pub.dev/packages/camera_windows/install
+[camera-control-issue]: https://github.com/flutter/flutter/issues/97537
+[device-orientation-issue]: https://github.com/flutter/flutter/issues/97540
+[image-streams-issue]: https://github.com/flutter/flutter/issues/97542

packages/camera/camera_windows/example/.gitignore

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+# Miscellaneous
+*.class
+*.log
+*.pyc
+*.swp
+.DS_Store
+.atom/
+.buildlog/
+.history
+.svn/
+
+# IntelliJ related
+*.iml
+*.ipr
+*.iws
+.idea/
+
+# The .vscode folder contains launch configuration and tasks you configure in
+# VS Code which you may wish to be included in version control, so this line
+# is commented out by default.
+#.vscode/
+
+# Flutter/Dart/Pub related
+**/doc/api/
+**/ios/Flutter/.last_build_id
+.dart_tool/
+.flutter-plugins
+.flutter-plugins-dependencies
+.packages
+.pub-cache/
+.pub/
+/build/
+
+# Web related
+lib/generated_plugin_registrant.dart
+
+# Symbolication related
+app.*.symbols
+
+# Obfuscation related
+app.*.map.json
+
+# Android Studio will place build artifacts here
+/android/app/debug
+/android/app/profile
+/android/app/release

packages/camera/camera_windows/example/.metadata

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+# This file tracks properties of this Flutter project.
+# Used by Flutter tool to assess capabilities and perform upgrades etc.
+#
+# This file should be version controlled and should not be manually edited.
+
+version:
+  revision: 18116933e77adc82f80866c928266a5b4f1ed645
+  channel: stable
+
+project_type: app

packages/camera/camera_windows/example/README.md

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+# camera_windows_example
+
+Demonstrates how to use the camera_windows plugin.

packages/camera/camera_windows/example/integration_test/camera_test.dart

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+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:async';
+import 'package:async/async.dart';
+import 'package:camera_platform_interface/camera_platform_interface.dart';
+import 'package:flutter/services.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:integration_test/integration_test.dart';
+
+// Note that these integration tests do not currently cover
+// most features and code paths, as they can only be tested if
+// one or more cameras are available in the test environment.
+// Native unit tests with better coverage are available at
+// the native part of the plugin implementation.
+
+void main() {
+  IntegrationTestWidgetsFlutterBinding.ensureInitialized();
+
+  group('initializeCamera', () {
+    testWidgets('throws exception if camera is not created',
+        (WidgetTester _) async {
+      final CameraPlatform camera = CameraPlatform.instance;
+
+      expect(() async => await camera.initializeCamera(1234),
+          throwsA(isA<CameraException>()));
+    });
+  });
+
+  group('takePicture', () {
+    testWidgets('throws exception if camera is not created',
+        (WidgetTester _) async {
+      final CameraPlatform camera = CameraPlatform.instance;
+
+      expect(() async => await camera.takePicture(1234),
+          throwsA(isA<PlatformException>()));
+    });
+  });
+
+  group('startVideoRecording', () {
+    testWidgets('throws exception if camera is not created',
+        (WidgetTester _) async {
+      final CameraPlatform camera = CameraPlatform.instance;
+
+      expect(() async => await camera.startVideoRecording(1234),
+          throwsA(isA<PlatformException>()));
+    });
+  });
+
+  group('stopVideoRecording', () {
+    testWidgets('throws exception if camera is not created',
+        (WidgetTester _) async {
+      final CameraPlatform camera = CameraPlatform.instance;
+
+      expect(() async => await camera.stopVideoRecording(1234),
+          throwsA(isA<PlatformException>()));
+    });
+  });
+
+  group('pausePreview', () {
+    testWidgets('throws exception if camera is not created',
+        (WidgetTester _) async {
+      final CameraPlatform camera = CameraPlatform.instance;
+
+      expect(() async => await camera.pausePreview(1234),
+          throwsA(isA<PlatformException>()));
+    });
+  });
+
+  group('resumePreview', () {
+    testWidgets('throws exception if camera is not created',
+        (WidgetTester _) async {
+      final CameraPlatform camera = CameraPlatform.instance;
+
+      expect(() async => await camera.resumePreview(1234),
+          throwsA(isA<PlatformException>()));
+    });
+  });
+
+  group('onDeviceOrientationChanged', () {
+    testWidgets('emits the initial DeviceOrientationChangedEvent',
+        (WidgetTester _) async {
+      final Stream<DeviceOrientationChangedEvent> eventStream =
+          CameraPlatform.instance.onDeviceOrientationChanged();
+
+      final StreamQueue<DeviceOrientationChangedEvent> streamQueue =
+          StreamQueue<DeviceOrientationChangedEvent>(eventStream);
+
+      expect(
+        await streamQueue.next,
+        equals(
+          const DeviceOrientationChangedEvent(
+            DeviceOrientation.landscapeRight,
+          ),
+        ),
+      );
+    });
+  });
+}