Merge pull request #4656 from fieldOfView/fix_network_camera_memory_leak

[3.6] Fix memory leak in print monitor

cura/CameraImageProvider.py

@@ -1,40 +0,0 @@
-# Copyright (c) 2018 Ultimaker B.V.
-# Cura is released under the terms of the LGPLv3 or higher.
-
-from PyQt5.QtGui import QImage
-from PyQt5.QtQuick import QQuickImageProvider
-from PyQt5.QtCore import QSize
-
-from UM.Application import Application
-
-##  Creates screenshots of the current scene.
-class CameraImageProvider(QQuickImageProvider):
-    def __init__(self):
-        super().__init__(QQuickImageProvider.Image)
-
-    ##  Request a new image.
-    #
-    #   The image will be taken using the current camera position.
-    #   Only the actual objects in the scene will get rendered. Not the build
-    #   plate and such!
-    #   \param id The ID for the image to create. This is the requested image
-    #   source, with the "image:" scheme and provider identifier removed. It's
-    #   a Qt thing, they'll provide this parameter.
-    #   \param size The dimensions of the image to scale to.
-    def requestImage(self, id, size):
-        for output_device in Application.getInstance().getOutputDeviceManager().getOutputDevices():
-            try:
-                image = output_device.activePrinter.camera.getImage()
-                if image.isNull():
-                    image = QImage()
-
-                return image, QSize(15, 15)
-            except AttributeError:
-                try:
-                    image = output_device.activeCamera.getImage()
-
-                    return image, QSize(15, 15)
-                except AttributeError:
-                    pass
-
-        return QImage(), QSize(15, 15)

cura/CuraApplication.py

@@ -96,7 +96,6 @@ from . import PrintInformation
 from . import CuraActions
 from cura.Scene import ZOffsetDecorator
 from . import CuraSplashScreen
-from . import CameraImageProvider
 from . import PrintJobPreviewImageProvider
 from . import MachineActionManager
 
@@ -114,6 +113,8 @@ from cura.Settings.CuraFormulaFunctions import CuraFormulaFunctions
 
 from cura.ObjectsModel import ObjectsModel
 
+from cura.PrinterOutput.NetworkMJPGImage import NetworkMJPGImage
+
 from UM.FlameProfiler import pyqtSlot
 from UM.Decorators import override
 
@@ -523,7 +524,6 @@ class CuraApplication(QtApplication):
         CuraApplication.Created = True
 
     def _onEngineCreated(self):
-        self._qml_engine.addImageProvider("camera", CameraImageProvider.CameraImageProvider())
         self._qml_engine.addImageProvider("print_job_preview", PrintJobPreviewImageProvider.PrintJobPreviewImageProvider())
 
     @pyqtProperty(bool)
@@ -947,6 +947,8 @@ class CuraApplication(QtApplication):
         qmlRegisterSingletonType(SimpleModeSettingsManager, "Cura", 1, 0, "SimpleModeSettingsManager", self.getSimpleModeSettingsManager)
         qmlRegisterSingletonType(MachineActionManager.MachineActionManager, "Cura", 1, 0, "MachineActionManager", self.getMachineActionManager)
 
+        qmlRegisterType(NetworkMJPGImage, "Cura", 1, 0, "NetworkMJPGImage")
+
         qmlRegisterSingletonType(ObjectsModel, "Cura", 1, 0, "ObjectsModel", self.getObjectsModel)
         qmlRegisterType(BuildPlateModel, "Cura", 1, 0, "BuildPlateModel")
         qmlRegisterType(MultiBuildPlateModel, "Cura", 1, 0, "MultiBuildPlateModel")
@@ -959,9 +961,6 @@ class CuraApplication(QtApplication):
         qmlRegisterType(QualityManagementModel, "Cura", 1, 0, "QualityManagementModel")
         qmlRegisterType(MachineManagementModel, "Cura", 1, 0, "MachineManagementModel")
 
-        from cura.PrinterOutput.CameraView import CameraView
-        qmlRegisterType(CameraView, "Cura", 1, 0, "CameraView")
-
         qmlRegisterSingletonType(QualityProfilesDropDownMenuModel, "Cura", 1, 0,
                                  "QualityProfilesDropDownMenuModel", self.getQualityProfilesDropDownMenuModel)
         qmlRegisterSingletonType(CustomQualityProfilesDropDownMenuModel, "Cura", 1, 0,

cura/PrinterOutput/CameraView.py

@@ -1,41 +0,0 @@
-# Copyright (c) 2018 Ultimaker B.V.
-# Cura is released under the terms of the LGPLv3 or higher.
-
-from PyQt5.QtCore import pyqtProperty, pyqtSignal
-from PyQt5.QtGui import QImage
-from PyQt5.QtQuick import QQuickPaintedItem
-
-
-#
-# A custom camera view that uses QQuickPaintedItem to present (or "paint") the image frames from a printer's
-# network camera feed.
-#
-class CameraView(QQuickPaintedItem):
-
-    def __init__(self, *args, **kwargs) -> None:
-        super().__init__(*args, **kwargs)
-
-        self._image = QImage()
-
-    imageChanged = pyqtSignal()
-
-    def setImage(self, image: "QImage") -> None:
-        self._image = image
-        self.imageChanged.emit()
-        self.update()
-
-    def getImage(self) -> "QImage":
-        return self._image
-
-    image = pyqtProperty(QImage, fget = getImage, fset = setImage, notify = imageChanged)
-
-    @pyqtProperty(int, notify = imageChanged)
-    def imageWidth(self) -> int:
-        return self._image.width()
-
-    @pyqtProperty(int, notify = imageChanged)
-    def imageHeight(self) -> int:
-        return self._image.height()
-
-    def paint(self, painter):
-        painter.drawImage(self.contentsBoundingRect(), self._image)

cura/PrinterOutput/NetworkCamera.py

@@ -1,112 +0,0 @@
-from UM.Logger import Logger
-
-from PyQt5.QtCore import QUrl, pyqtProperty, pyqtSignal, QObject, pyqtSlot
-from PyQt5.QtGui import QImage
-from PyQt5.QtNetwork import QNetworkRequest, QNetworkReply, QNetworkAccessManager
-
-
-class NetworkCamera(QObject):
-    newImage = pyqtSignal()
-
-    def __init__(self, target = None, parent = None):
-        super().__init__(parent)
-        self._stream_buffer = b""
-        self._stream_buffer_start_index = -1
-        self._manager = None
-        self._image_request = None
-        self._image_reply = None
-        self._image = QImage()
-
-        self._target = target
-        self._started = False
-
-    @pyqtSlot(str)
-    def setTarget(self, target):
-        restart_required = False
-        if self._started:
-            self.stop()
-            restart_required = True
-
-        self._target = target
-
-        if restart_required:
-            self.start()
-
-    @pyqtProperty(QImage, notify=newImage)
-    def latestImage(self):
-        return self._image
-
-    @pyqtSlot()
-    def start(self):
-        # Ensure that previous requests (if any) are stopped.
-        self.stop()
-        if self._target is None:
-            Logger.log("w", "Unable to start camera stream without target!")
-            return
-        self._started = True
-        url = QUrl(self._target)
-        self._image_request = QNetworkRequest(url)
-        if self._manager is None:
-            self._manager = QNetworkAccessManager()
-
-        self._image_reply = self._manager.get(self._image_request)
-        self._image_reply.downloadProgress.connect(self._onStreamDownloadProgress)
-
-    @pyqtSlot()
-    def stop(self):
-        self._stream_buffer = b""
-        self._stream_buffer_start_index = -1
-
-        if self._image_reply:
-            try:
-                # disconnect the signal
-                try:
-                    self._image_reply.downloadProgress.disconnect(self._onStreamDownloadProgress)
-                except Exception:
-                    pass
-                # abort the request if it's not finished
-                if not self._image_reply.isFinished():
-                    self._image_reply.close()
-            except Exception as e:  # RuntimeError
-                pass  # It can happen that the wrapped c++ object is already deleted.
-
-            self._image_reply = None
-            self._image_request = None
-
-        self._manager = None
-
-        self._started = False
-
-    def getImage(self):
-        return self._image
-
-    ##  Ensure that close gets called when object is destroyed
-    def __del__(self):
-        self.stop()
-
-    def _onStreamDownloadProgress(self, bytes_received, bytes_total):
-        # An MJPG stream is (for our purpose) a stream of concatenated JPG images.
-        # JPG images start with the marker 0xFFD8, and end with 0xFFD9
-        if self._image_reply is None:
-            return
-        self._stream_buffer += self._image_reply.readAll()
-
-        if len(self._stream_buffer) > 2000000:  # No single camera frame should be 2 Mb or larger
-            Logger.log("w", "MJPEG buffer exceeds reasonable size. Restarting stream...")
-            self.stop()  # resets stream buffer and start index
-            self.start()
-            return
-
-        if self._stream_buffer_start_index == -1:
-            self._stream_buffer_start_index = self._stream_buffer.indexOf(b'\xff\xd8')
-        stream_buffer_end_index = self._stream_buffer.lastIndexOf(b'\xff\xd9')
-        # If this happens to be more than a single frame, then so be it; the JPG decoder will
-        # ignore the extra data. We do it like this in order not to get a buildup of frames
-
-        if self._stream_buffer_start_index != -1 and stream_buffer_end_index != -1:
-            jpg_data = self._stream_buffer[self._stream_buffer_start_index:stream_buffer_end_index + 2]
-            self._stream_buffer = self._stream_buffer[stream_buffer_end_index + 2:]
-            self._stream_buffer_start_index = -1
-            self._image.loadFromData(jpg_data)
-
-            self.newImage.emit()

cura/PrinterOutput/NetworkMJPGImage.py

@@ -0,0 +1,153 @@
+# Copyright (c) 2018 Aldo Hoeben / fieldOfView
+# NetworkMJPGImage is released under the terms of the LGPLv3 or higher.
+
+from PyQt5.QtCore import QUrl, pyqtProperty, pyqtSignal, pyqtSlot, QRect, QByteArray
+from PyQt5.QtGui import QImage, QPainter
+from PyQt5.QtQuick import QQuickPaintedItem
+from PyQt5.QtNetwork import QNetworkRequest, QNetworkReply, QNetworkAccessManager
+
+from UM.Logger import Logger
+
+#
+# A QQuickPaintedItem that progressively downloads a network mjpeg stream,
+# picks it apart in individual jpeg frames, and paints it.
+#
+class NetworkMJPGImage(QQuickPaintedItem):
+
+    def __init__(self, *args, **kwargs) -> None:
+        super().__init__(*args, **kwargs)
+
+        self._stream_buffer = QByteArray()
+        self._stream_buffer_start_index = -1
+        self._network_manager = None  # type: QNetworkAccessManager
+        self._image_request = None  # type: QNetworkRequest
+        self._image_reply = None  # type: QNetworkReply
+        self._image = QImage()
+        self._image_rect = QRect()
+
+        self._source_url = QUrl()
+        self._started = False
+
+        self._mirror = False
+
+        self.setAntialiasing(True)
+
+    ##  Ensure that close gets called when object is destroyed
+    def __del__(self) -> None:
+        self.stop()
+
+
+    def paint(self, painter: "QPainter") -> None:
+        if self._mirror:
+            painter.drawImage(self.contentsBoundingRect(), self._image.mirrored())
+            return
+
+        painter.drawImage(self.contentsBoundingRect(), self._image)
+
+
+    def setSourceURL(self, source_url: "QUrl") -> None:
+        self._source_url = source_url
+        self.sourceURLChanged.emit()
+        if self._started:
+            self.start()
+
+    def getSourceURL(self) -> "QUrl":
+        return self._source_url
+
+    sourceURLChanged = pyqtSignal()
+    source = pyqtProperty(QUrl, fget = getSourceURL, fset = setSourceURL, notify = sourceURLChanged)
+
+    def setMirror(self, mirror: bool) -> None:
+        if mirror == self._mirror:
+            return
+        self._mirror = mirror
+        self.mirrorChanged.emit()
+        self.update()
+
+    def getMirror(self) -> bool:
+        return self._mirror
+
+    mirrorChanged = pyqtSignal()
+    mirror = pyqtProperty(bool, fget = getMirror, fset = setMirror, notify = mirrorChanged)
+
+    imageSizeChanged = pyqtSignal()
+
+    @pyqtProperty(int, notify = imageSizeChanged)
+    def imageWidth(self) -> int:
+        return self._image.width()
+
+    @pyqtProperty(int, notify = imageSizeChanged)
+    def imageHeight(self) -> int:
+        return self._image.height()
+
+
+    @pyqtSlot()
+    def start(self) -> None:
+        self.stop()  # Ensure that previous requests (if any) are stopped.
+
+        if not self._source_url:
+            Logger.log("w", "Unable to start camera stream without target!")
+            return
+        self._started = True
+
+        self._image_request = QNetworkRequest(self._source_url)
+        if self._network_manager is None:
+            self._network_manager = QNetworkAccessManager()
+
+        self._image_reply = self._network_manager.get(self._image_request)
+        self._image_reply.downloadProgress.connect(self._onStreamDownloadProgress)
+
+    @pyqtSlot()
+    def stop(self) -> None:
+        self._stream_buffer = QByteArray()
+        self._stream_buffer_start_index = -1
+
+        if self._image_reply:
+            try:
+                try:
+                    self._image_reply.downloadProgress.disconnect(self._onStreamDownloadProgress)
+                except Exception:
+                    pass
+
+                if not self._image_reply.isFinished():
+                    self._image_reply.close()
+            except Exception as e:  # RuntimeError
+                pass  # It can happen that the wrapped c++ object is already deleted.
+
+            self._image_reply = None
+            self._image_request = None
+
+        self._network_manager = None
+
+        self._started = False
+
+
+    def _onStreamDownloadProgress(self, bytes_received: int, bytes_total: int) -> None:
+        # An MJPG stream is (for our purpose) a stream of concatenated JPG images.
+        # JPG images start with the marker 0xFFD8, and end with 0xFFD9
+        if self._image_reply is None:
+            return
+        self._stream_buffer += self._image_reply.readAll()
+
+        if len(self._stream_buffer) > 2000000:  # No single camera frame should be 2 Mb or larger
+            Logger.log("w", "MJPEG buffer exceeds reasonable size. Restarting stream...")
+            self.stop()  # resets stream buffer and start index
+            self.start()
+            return
+
+        if self._stream_buffer_start_index == -1:
+            self._stream_buffer_start_index = self._stream_buffer.indexOf(b'\xff\xd8')
+        stream_buffer_end_index = self._stream_buffer.lastIndexOf(b'\xff\xd9')
+        # If this happens to be more than a single frame, then so be it; the JPG decoder will
+        # ignore the extra data. We do it like this in order not to get a buildup of frames
+
+        if self._stream_buffer_start_index != -1 and stream_buffer_end_index != -1:
+            jpg_data = self._stream_buffer[self._stream_buffer_start_index:stream_buffer_end_index + 2]
+            self._stream_buffer = self._stream_buffer[stream_buffer_end_index + 2:]
+            self._stream_buffer_start_index = -1
+            self._image.loadFromData(jpg_data)
+
+            if self._image.rect() != self._image_rect:
+                self.imageSizeChanged.emit()
+
+            self.update()

cura/PrinterOutput/PrintJobOutputModel.py

@@ -54,7 +54,7 @@ class PrintJobOutputModel(QObject):
     @pyqtProperty(QUrl, notify=previewImageChanged)
     def previewImageUrl(self):
         self._preview_image_id += 1
-        # There is an image provider that is called "camera". In order to ensure that the image qml object, that
+        # There is an image provider that is called "print_job_preview". In order to ensure that the image qml object, that
         # requires a QUrl to function, updates correctly we add an increasing number. This causes to see the QUrl
         # as new (instead of relying on cached version and thus forces an update.
         temp = "image://print_job_preview/" + str(self._preview_image_id) + "/" + self._key

cura/PrinterOutput/PrinterOutputModel.py

@@ -1,7 +1,7 @@
 # Copyright (c) 2018 Ultimaker B.V.
 # Cura is released under the terms of the LGPLv3 or higher.
 
-from PyQt5.QtCore import pyqtSignal, pyqtProperty, QObject, QVariant, pyqtSlot
+from PyQt5.QtCore import pyqtSignal, pyqtProperty, QObject, QVariant, pyqtSlot, QUrl
 from typing import List, Dict, Optional
 from UM.Math.Vector import Vector
 from cura.PrinterOutput.ConfigurationModel import ConfigurationModel
@@ -11,7 +11,6 @@ MYPY = False
 if MYPY:
     from cura.PrinterOutput.PrintJobOutputModel import PrintJobOutputModel
     from cura.PrinterOutput.PrinterOutputController import PrinterOutputController
-    from cura.PrinterOutput.NetworkCamera import NetworkCamera
 
 
 class PrinterOutputModel(QObject):
@@ -25,7 +24,7 @@ class PrinterOutputModel(QObject):
     keyChanged = pyqtSignal()
     printerTypeChanged = pyqtSignal()
     buildplateChanged = pyqtSignal()
-    cameraChanged = pyqtSignal()
+    cameraUrlChanged = pyqtSignal()
     configurationChanged = pyqtSignal()
     canUpdateFirmwareChanged = pyqtSignal()
 
@@ -50,16 +49,20 @@ class PrinterOutputModel(QObject):
         self._printer_configuration.extruderConfigurations = [extruder.extruderConfiguration for extruder in
                                                               self._extruders]
 
-        self._camera = None  # type: Optional[NetworkCamera]
+        self._camera_url = QUrl()  # type: QUrl
 
     @pyqtProperty(str, constant = True)
     def firmwareVersion(self) -> str:
         return self._firmware_version
 
-    def setCamera(self, camera: Optional["NetworkCamera"]) -> None:
+    def setCameraUrl(self, camera_url: "QUrl") -> None:
-        if self._camera is not camera:
+        if self._camera_url != camera_url:
-            self._camera = camera
+            self._camera_url = camera_url
-            self.cameraChanged.emit()
+            self.cameraUrlChanged.emit()
+
+    @pyqtProperty(QUrl, fset = setCameraUrl, notify = cameraUrlChanged)
+    def cameraUrl(self) -> "QUrl":
+        return self._camera_url
 
     def updateIsPreheating(self, pre_heating: bool) -> None:
         if self._is_preheating != pre_heating:
@@ -70,10 +73,6 @@ class PrinterOutputModel(QObject):
     def isPreheating(self) -> bool:
         return self._is_preheating
 
-    @pyqtProperty(QObject, notify=cameraChanged)
-    def camera(self) -> Optional["NetworkCamera"]:
-        return self._camera
-
     @pyqtProperty(str, notify = printerTypeChanged)
     def type(self) -> str:
         return self._printer_type

plugins/UM3NetworkPrinting/resources/qml/CameraButton.qml

@@ -31,10 +31,10 @@ Rectangle {
         anchors.fill: parent;
         hoverEnabled: true;
         onClicked: {
-            if (OutputDevice.activeCamera !== null) {
+            if (OutputDevice.activeCameraUrl != "") {
-                OutputDevice.setActiveCamera(null)
+                OutputDevice.setActiveCameraUrl("");
             } else {
-                OutputDevice.setActiveCamera(modelData.camera);
+                OutputDevice.setActiveCameraUrl(modelData.cameraUrl);
             }
         }
     }

plugins/UM3NetworkPrinting/resources/qml/ClusterMonitorItem.qml

@@ -16,7 +16,7 @@ Component {
         height: maximumHeight;
         onVisibleChanged: {
             if (monitorFrame != null && !monitorFrame.visible) {
-                OutputDevice.setActiveCamera(null);
+                OutputDevice.setActiveCameraUrl("");
             }
         }
         width: maximumWidth;
@@ -125,8 +125,8 @@ Component {
 
         PrinterVideoStream {
             anchors.fill: parent;
-            camera: OutputDevice.activeCamera;
+            cameraUrl: OutputDevice.activeCameraUrl;
-            visible: OutputDevice.activeCamera != null;
+            visible: OutputDevice.activeCameraUrl != "";
         }
     }
 }

plugins/UM3NetworkPrinting/resources/qml/MonitorItem.qml

@@ -10,43 +10,36 @@ Component {
         height: maximumHeight;
         width: maximumWidth;
 
-        Cura.CameraView {
+        Cura.NetworkMJPGImage {
             id: cameraImage;
             anchors {
                 horizontalCenter: parent.horizontalCenter;
                 verticalCenter: parent.verticalCenter;
             }
             Component.onCompleted: {
-                if (OutputDevice.activePrinter != null && OutputDevice.activePrinter.camera != null) {
+                if (OutputDevice.activePrinter != null && OutputDevice.activePrinter.cameraUrl != null) {
-                    OutputDevice.activePrinter.camera.start();
+                    cameraImage.start();
                 }
             }
             height: Math.floor((imageHeight === 0 ? 600 * screenScaleFactor : imageHeight) * width / imageWidth);
             onVisibleChanged: {
                 if (visible) {
-                    if (OutputDevice.activePrinter != null && OutputDevice.activePrinter.camera != null) {
+                    if (OutputDevice.activePrinter != null && OutputDevice.activePrinter.cameraUrl != null) {
-                        OutputDevice.activePrinter.camera.start();
+                        cameraImage.start();
                     }
                 } else {
-                    if (OutputDevice.activePrinter != null && OutputDevice.activePrinter.camera != null) {
+                    if (OutputDevice.activePrinter != null && OutputDevice.activePrinter.cameraUrl != null) {
-                        OutputDevice.activePrinter.camera.stop();
+                        cameraImage.stop();
                     }
                 }
             }
+            source: {
+                if (OutputDevice.activePrinter != null && OutputDevice.activePrinter.cameraUrl != null) {
+                    return OutputDevice.activePrinter.cameraUrl;
+                }
+            }
             width: Math.min(imageWidth === 0 ? 800 * screenScaleFactor : imageWidth, maximumWidth);
             z: 1;
-
-            Connections
-            {
-                target: OutputDevice.activePrinter.camera;
-                onNewImage:
-                {
-                    if (cameraImage.visible) {
-                        cameraImage.image = OutputDevice.activePrinter.camera.latestImage;
-                        cameraImage.update();
-                    }
-                }
-            }
         }
     }
 }

plugins/UM3NetworkPrinting/resources/qml/PrinterVideoStream.qml

@@ -8,7 +8,7 @@ import UM 1.3 as UM
 import Cura 1.0 as Cura
 
 Item {
-    property var camera: null;
+    property var cameraUrl: "";
 
     Rectangle {
         anchors.fill:parent;
@@ -18,7 +18,7 @@ Item {
 
     MouseArea {
         anchors.fill: parent;
-        onClicked: OutputDevice.setActiveCamera(null);
+        onClicked: OutputDevice.setActiveCameraUrl("");
         z: 0;
     }
 
@@ -34,33 +34,23 @@ Item {
         z: 999;
     }
 
-    Cura.CameraView {
+    Cura.NetworkMJPGImage {
         id: cameraImage
         anchors.horizontalCenter: parent.horizontalCenter;
         anchors.verticalCenter: parent.verticalCenter;
         height: Math.round((imageHeight === 0 ? 600 * screenScaleFactor : imageHeight) * width / imageWidth);
         onVisibleChanged: {
             if (visible) {
-                if (camera != null) {
+                if (cameraUrl != "") {
-                    camera.start();
+                    start();
                 }
             } else {
-                if (camera != null) {
+                if (cameraUrl != "") {
-                    camera.stop();
+                    stop();
-                }
-            }
-        }
-
-        Connections
-        {
-            target: camera
-            onNewImage: {
-                if (cameraImage.visible) {
-                    cameraImage.image = camera.latestImage;
-                    cameraImage.update();
                 }
             }
         }
+        source: cameraUrl
         width: Math.min(imageWidth === 0 ? 800 * screenScaleFactor : imageWidth, maximumWidth);
         z: 1
     }
@@ -68,7 +58,7 @@ Item {
     MouseArea {
         anchors.fill: cameraImage;
         onClicked: {
-            OutputDevice.setActiveCamera(null);
+            OutputDevice.setActiveCameraUrl("");
         }
         z: 1;
     }

plugins/UM3NetworkPrinting/src/ClusterUM3OutputDevice.py

@@ -22,7 +22,6 @@ from cura.PrinterOutput.ExtruderConfigurationModel import ExtruderConfigurationM
 from cura.PrinterOutput.NetworkedPrinterOutputDevice import NetworkedPrinterOutputDevice, AuthState
 from cura.PrinterOutput.PrinterOutputModel import PrinterOutputModel
 from cura.PrinterOutput.MaterialOutputModel import MaterialOutputModel
-from cura.PrinterOutput.NetworkCamera import NetworkCamera
 
 from .ClusterUM3PrinterOutputController import ClusterUM3PrinterOutputController
 from .SendMaterialJob import SendMaterialJob
@@ -47,7 +46,7 @@ i18n_catalog = i18nCatalog("cura")
 class ClusterUM3OutputDevice(NetworkedPrinterOutputDevice):
     printJobsChanged = pyqtSignal()
     activePrinterChanged = pyqtSignal()
-    activeCameraChanged = pyqtSignal()
+    activeCameraUrlChanged = pyqtSignal()
     receivedPrintJobsChanged = pyqtSignal()
 
     # This is a bit of a hack, as the notify can only use signals that are defined by the class that they are in.
@@ -100,7 +99,7 @@ class ClusterUM3OutputDevice(NetworkedPrinterOutputDevice):
         self._latest_reply_handler = None  # type: Optional[QNetworkReply]
         self._sending_job = None
 
-        self._active_camera = None # type: Optional[NetworkCamera]
+        self._active_camera_url = QUrl()  # type: QUrl
 
     def requestWrite(self, nodes: List[SceneNode], file_name: Optional[str] = None, limit_mimetypes: bool = False, file_handler: Optional[FileHandler] = None, **kwargs: str) -> None:
         self.writeStarted.emit(self)
@@ -264,30 +263,21 @@ class ClusterUM3OutputDevice(NetworkedPrinterOutputDevice):
     def activePrinter(self) -> Optional[PrinterOutputModel]:
         return self._active_printer
 
-    @pyqtProperty(QObject, notify=activeCameraChanged)
-    def activeCamera(self) -> Optional[NetworkCamera]:
-        return self._active_camera
-
     @pyqtSlot(QObject)
     def setActivePrinter(self, printer: Optional[PrinterOutputModel]) -> None:
         if self._active_printer != printer:
-            if self._active_printer and self._active_printer.camera:
-                self._active_printer.camera.stop()
             self._active_printer = printer
             self.activePrinterChanged.emit()
 
-    @pyqtSlot(QObject)
+    @pyqtProperty(QUrl, notify = activeCameraUrlChanged)
-    def setActiveCamera(self, camera: Optional[NetworkCamera]) -> None:
+    def activeCameraUrl(self) -> "QUrl":
-        if self._active_camera != camera:
+        return self._active_camera_url
-            if self._active_camera:
-                self._active_camera.stop()
 
-            self._active_camera = camera
+    @pyqtSlot(QUrl)
-
+    def setActiveCameraUrl(self, camera_url: "QUrl") -> None:
-            if self._active_camera:
+        if self._active_camera_url != camera_url:
-                self._active_camera.start()
+            self._active_camera_url = camera_url
-
+            self.activeCameraUrlChanged.emit()
-            self.activeCameraChanged.emit()
 
     def _onPostPrintJobFinished(self, reply: QNetworkReply) -> None:
         if self._progress_message:
@@ -548,7 +538,7 @@ class ClusterUM3OutputDevice(NetworkedPrinterOutputDevice):
     def _createPrinterModel(self, data: Dict[str, Any]) -> PrinterOutputModel:
         printer = PrinterOutputModel(output_controller = ClusterUM3PrinterOutputController(self),
                                      number_of_extruders = self._number_of_extruders)
-        printer.setCamera(NetworkCamera("http://" + data["ip_address"] + ":8080/?action=stream"))
+        printer.setCameraUrl(QUrl("http://" + data["ip_address"] + ":8080/?action=stream"))
         self._printers.append(printer)
         return printer
 

plugins/UM3NetworkPrinting/src/LegacyUM3OutputDevice.py

@@ -7,7 +7,6 @@ from cura.PrinterOutput.NetworkedPrinterOutputDevice import NetworkedPrinterOutp
 from cura.PrinterOutput.PrinterOutputModel import PrinterOutputModel
 from cura.PrinterOutput.PrintJobOutputModel import PrintJobOutputModel
 from cura.PrinterOutput.MaterialOutputModel import MaterialOutputModel
-from cura.PrinterOutput.NetworkCamera import NetworkCamera
 
 from cura.Settings.ContainerManager import ContainerManager
 from cura.Settings.ExtruderManager import ExtruderManager
@@ -18,7 +17,7 @@ from UM.i18n import i18nCatalog
 from UM.Message import Message
 
 from PyQt5.QtNetwork import QNetworkRequest
-from PyQt5.QtCore import QTimer
+from PyQt5.QtCore import QTimer, QUrl
 from PyQt5.QtWidgets import QMessageBox
 
 from .LegacyUM3PrinterOutputController import LegacyUM3PrinterOutputController
@@ -568,7 +567,7 @@ class LegacyUM3OutputDevice(NetworkedPrinterOutputDevice):
                 # Quickest way to get the firmware version is to grab it from the zeroconf.
                 firmware_version = self._properties.get(b"firmware_version", b"").decode("utf-8")
                 self._printers = [PrinterOutputModel(output_controller=self._output_controller, number_of_extruders=self._number_of_extruders, firmware_version=firmware_version)]
-                self._printers[0].setCamera(NetworkCamera("http://" + self._address + ":8080/?action=stream"))
+                self._printers[0].setCameraUrl(QUrl("http://" + self._address + ":8080/?action=stream"))
                 for extruder in self._printers[0].extruders:
                     extruder.activeMaterialChanged.connect(self.materialIdChanged)
                     extruder.hotendIDChanged.connect(self.hotendIdChanged)