WIP: Use CameraView for UM camera feeds

CURA-5821

The original implementation that refreshes a QImage seems to cause
memory overflow on MacOSX and Windows. This is a different
implementation. It doesn't cause memory overflow, but it does consume a
lot of CPU power.

cura/PrinterOutput/NetworkCamera.py

@@ -16,7 +16,6 @@ class NetworkCamera(QObject):
         self._image_request = None
         self._image_reply = None
         self._image = QImage()
-        self._image_id = 0
 
         self._target = target
         self._started = False
@@ -33,15 +32,9 @@ class NetworkCamera(QObject):
         if restart_required:
             self.start()
 
-    @pyqtProperty(QUrl, notify=newImage)
+    @pyqtProperty(QImage, notify=newImage)
     def latestImage(self):
-        self._image_id += 1
+        return self._image
-        # There is an image provider that is called "camera". 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://camera/" + str(self._image_id)
-
-        return QUrl(temp, QUrl.TolerantMode)
 
     @pyqtSlot()
     def start(self):

plugins/UM3NetworkPrinting/resources/qml/MonitorItem.qml

@@ -10,7 +10,7 @@ Component {
         height: maximumHeight;
         width: maximumWidth;
 
-        Image {
+        Cura.CameraView {
             id: cameraImage;
             anchors {
                 horizontalCenter: parent.horizontalCenter;
@@ -21,7 +21,7 @@ Component {
                     OutputDevice.activePrinter.camera.start();
                 }
             }
-            height: Math.floor((sourceSize.height === 0 ? 600 * screenScaleFactor : sourceSize.height) * width / sourceSize.width);
+            height: Math.floor((imageHeight === 0 ? 600 * screenScaleFactor : imageHeight) * width / imageWidth);
             onVisibleChanged: {
                 if (visible) {
                     if (OutputDevice.activePrinter != null && OutputDevice.activePrinter.camera != null) {
@@ -33,14 +33,20 @@ Component {
                     }
                 }
             }
-            source: {
+            width: Math.min(imageWidth === 0 ? 800 * screenScaleFactor : imageWidth, maximumWidth);
-                if (OutputDevice.activePrinter != null && OutputDevice.activePrinter.camera != null && OutputDevice.activePrinter.camera.latestImage) {
-                    return OutputDevice.activePrinter.camera.latestImage;
-                }
-                return "";
-            }
-            width: Math.min(sourceSize.width === 0 ? 800 * screenScaleFactor : sourceSize.width, 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

@@ -5,6 +5,7 @@ import QtQuick 2.2
 import QtQuick.Controls 1.4
 import QtQuick.Controls.Styles 1.4
 import UM 1.3 as UM
+import Cura 1.0 as Cura
 
 Item {
     property var camera: null;
@@ -33,11 +34,11 @@ Item {
         z: 999;
     }
 
-    Image {
+    Cura.CameraView {
         id: cameraImage
         anchors.horizontalCenter: parent.horizontalCenter;
         anchors.verticalCenter: parent.verticalCenter;
-        height: Math.round((sourceSize.height === 0 ? 600 * screenScaleFactor : sourceSize.height) * width / sourceSize.width);
+        height: Math.round((imageHeight === 0 ? 600 * screenScaleFactor : imageHeight) * width / imageWidth);
         onVisibleChanged: {
             if (visible) {
                 if (camera != null) {
@@ -49,13 +50,18 @@ Item {
                 }
             }
         }
-        source: {
+
-            if (camera != null && camera.latestImage != null) {
+        Connections
-                return camera.latestImage;
+        {
+            target: camera
+            onNewImage: {
+                if (cameraImage.visible) {
+                    cameraImage.image = camera.latestImage;
+                    cameraImage.update();
                 }
-            return "";
             }
-        width: Math.min(sourceSize.width === 0 ? 800 * screenScaleFactor : sourceSize.width, maximumWidth);
+        }
+        width: Math.min(imageWidth === 0 ? 800 * screenScaleFactor : imageWidth, maximumWidth);
         z: 1
     }