Qt: Support switching webcams

CHANGES

@@ -6,6 +6,7 @@ Bugfixes:
 Misc:
  - Qt: Add missing HEVC NVENC option (fixes mgba.io/i/1323)
  - Qt: Improve camera initialization
+ - Qt: Support switching webcams
 
 0.7.1: (2019-02-24)
 Bugfixes:

src/platform/qt/InputController.cpp

@@ -15,7 +15,7 @@
 #include <QTimer>
 #include <QWidget>
 #ifdef BUILD_QT_MULTIMEDIA
-#include <QCamera>
+#include <QCameraInfo>
 #include <QVideoSurfaceFormat>
 #endif
 
@@ -98,6 +98,10 @@ InputController::InputController(int playerId, QWidget* topLevel, QObject* paren
 		}
 #ifdef BUILD_QT_MULTIMEDIA
 		if (image->p->m_config->getQtOption("cameraDriver").toInt() == static_cast<int>(CameraDriver::QT_MULTIMEDIA)) {
+			QByteArray camera = image->p->m_config->getQtOption("camera").toByteArray();
+			if (!camera.isNull()) {
+				QMetaObject::invokeMethod(image->p, "setCamera", Q_ARG(QByteArray, camera));
+			}
 			QMetaObject::invokeMethod(image->p, "setupCam");
 		}
 #endif
@@ -691,6 +695,17 @@ void InputController::setCamImage(const QImage& image) {
 	m_image.outOfDate = true;
 }
 
+QList<QPair<QByteArray, QString>> InputController::listCameras() const {
+	QList<QPair<QByteArray, QString>> out;
+#ifdef BUILD_QT_MULTIMEDIA
+	QList<QCameraInfo> cams = QCameraInfo::availableCameras();
+	for (const auto& cam : cams) {
+		out.append(qMakePair(cam.deviceName().toLatin1(), cam.description()));
+	}
+#endif
+	return out;
+}
+
 void InputController::increaseLuminanceLevel() {
 	setLuminanceLevel(m_luxLevel + 1);
 }
@@ -725,7 +740,7 @@ void InputController::setupCam() {
 #ifdef BUILD_QT_MULTIMEDIA
 	if (!m_camera) {
 		m_camera = std::make_unique<QCamera>();
-		connect(m_camera.get(), &QCamera::statusChanged, this, &InputController::prepareCamSettings);
+		connect(m_camera.get(), &QCamera::statusChanged, this, &InputController::prepareCamSettings, Qt::QueuedConnection);
 	}
 	m_camera->setCaptureMode(QCamera::CaptureVideo);
 	m_camera->setViewfinder(&m_videoDumper);
@@ -783,3 +798,17 @@ void InputController::teardownCam() {
 	}
 #endif
 }
+
+void InputController::setCamera(const QByteArray& name) {
+#ifdef BUILD_QT_MULTIMEDIA
+	bool needsRestart = false;
+	if (m_camera) {
+		needsRestart = m_camera->state() == QCamera::ActiveState;
+	}
+	m_camera = std::make_unique<QCamera>(name);
+	connect(m_camera.get(), &QCamera::statusChanged, this, &InputController::prepareCamSettings, Qt::QueuedConnection);
+	if (needsRestart) {
+		setupCam();
+	}
+#endif
+}

src/platform/qt/InputController.h

@@ -96,6 +96,8 @@ public:
 	void stealFocus(QWidget* focus);
 	void releaseFocus(QWidget* focus);
 
+	QList<QPair<QByteArray, QString>> listCameras() const;
+
 	mRumble* rumble();
 	mRotationSource* rotationSource();
 	mImageSource* imageSource() { return &m_image; }
@@ -122,6 +124,8 @@ public slots:
 	void loadCamImage(const QString& path);
 	void setCamImage(const QImage& image);
 
+	void setCamera(const QByteArray& id);
+
 private slots:
 #ifdef BUILD_QT_MULTIMEDIA
 	void prepareCamSettings(QCamera::Status);

src/platform/qt/SettingsView.cpp

@@ -178,12 +178,22 @@ SettingsView::SettingsView(ConfigController* controller, InputController* inputC
 	m_ui.cameraDriver->addItem(tr("None (Still Image)"), static_cast<int>(InputController::CameraDriver::NONE));
 	if (cameraDriver.isNull() || cameraDriver.toInt() == static_cast<int>(InputController::CameraDriver::NONE)) {
 		m_ui.cameraDriver->setCurrentIndex(m_ui.cameraDriver->count() - 1);
+		m_ui.camera->setEnabled(false);
 	}
 
 #ifdef BUILD_QT_MULTIMEDIA
 	m_ui.cameraDriver->addItem(tr("Qt Multimedia"), static_cast<int>(InputController::CameraDriver::QT_MULTIMEDIA));
 	if (!cameraDriver.isNull() && cameraDriver.toInt() == static_cast<int>(InputController::CameraDriver::QT_MULTIMEDIA)) {
 		m_ui.cameraDriver->setCurrentIndex(m_ui.cameraDriver->count() - 1);
+		m_ui.camera->setEnabled(true);
+	}
+	QList<QPair<QByteArray, QString>> cameras = inputController->listCameras();
+	QByteArray currentCamera = m_controller->getQtOption("camera").toByteArray();
+	for (const auto& camera : cameras) {
+		m_ui.camera->addItem(camera.second, camera.first);
+		if (camera.first == currentCamera) {
+			m_ui.camera->setCurrentIndex(m_ui.camera->count() - 1);
+		}
 	}
 #endif
 
@@ -424,6 +434,12 @@ void SettingsView::updateConfig() {
 		emit cameraDriverChanged();
 	}
 
+	QVariant camera = m_ui.camera->itemData(m_ui.camera->currentIndex());
+	if (camera != m_controller->getQtOption("camera")) {
+		m_controller->setQtOption("camera", camera);
+		emit cameraChanged(camera.toByteArray());
+	}
+
 	QLocale language = m_ui.languages->itemData(m_ui.languages->currentIndex()).toLocale();
 	if (language != m_controller->getQtOption("language").toLocale() && !(language.bcp47Name() == QLocale::system().bcp47Name() && m_controller->getQtOption("language").isNull())) {
 		m_controller->setQtOption("language", language.bcp47Name());

src/platform/qt/SettingsView.h

@@ -38,6 +38,7 @@ signals:
 	void audioDriverChanged();
 	void displayDriverChanged();
 	void cameraDriverChanged();
+	void cameraChanged(const QByteArray&);
 	void pathsChanged();
 	void languageChanged();
 	void libraryCleared();

src/platform/qt/SettingsView.ui

@@ -1210,7 +1210,7 @@
        <item row="0" column="0">
         <widget class="QLabel" name="label_29">
          <property name="text">
-          <string>Game Boy model</string>
+          <string>Game Boy model:</string>
          </property>
         </widget>
        </item>
@@ -1246,7 +1246,7 @@
        <item row="1" column="0">
         <widget class="QLabel" name="label_32">
          <property name="text">
-          <string>Super Game Boy model</string>
+          <string>Super Game Boy model:</string>
          </property>
         </widget>
        </item>
@@ -1282,7 +1282,7 @@
        <item row="2" column="0">
         <widget class="QLabel" name="label_33">
          <property name="text">
-          <string>Game Boy Color model</string>
+          <string>Game Boy Color model:</string>
          </property>
         </widget>
        </item>
@@ -1614,6 +1614,26 @@
          </property>
         </widget>
        </item>
+       <item row="10" column="0">
+        <widget class="QLabel" name="label_35">
+         <property name="text">
+          <string>Camera:</string>
+         </property>
+        </widget>
+       </item>
+       <item row="10" column="1">
+        <widget class="QComboBox" name="camera">
+         <property name="enabled">
+          <bool>false</bool>
+         </property>
+         <property name="sizePolicy">
+          <sizepolicy hsizetype="Expanding" vsizetype="Fixed">
+           <horstretch>0</horstretch>
+           <verstretch>0</verstretch>
+          </sizepolicy>
+         </property>
+        </widget>
+       </item>
       </layout>
      </widget>
     </widget>

src/platform/qt/Window.cpp

@@ -441,6 +441,7 @@ void Window::openSettingsWindow() {
 	connect(settingsWindow, &SettingsView::displayDriverChanged, this, &Window::reloadDisplayDriver);
 	connect(settingsWindow, &SettingsView::audioDriverChanged, this, &Window::reloadAudioDriver);
 	connect(settingsWindow, &SettingsView::cameraDriverChanged, this, &Window::mustRestart);
+	connect(settingsWindow, &SettingsView::cameraChanged, &m_inputController, &InputController::setCamera);
 	connect(settingsWindow, &SettingsView::languageChanged, this, &Window::mustRestart);
 	connect(settingsWindow, &SettingsView::pathsChanged, this, &Window::reloadConfig);
 #ifdef USE_SQLITE3