Cleanup monitoringPrint stuff by properly passing things as properties

Instead of relying on the property magically being propagated from the
root object, which causes crashes.

Contributes to CURA-3964

resources/qml/Cura.qml

@@ -18,14 +18,14 @@ UM.MainWindow
     //: Cura application window title
     title: catalog.i18nc("@title:window","Cura");
     viewportRect: Qt.rect(0, 0, (base.width - sidebar.width) / base.width, 1.0)
-    property bool monitoringPrint: false
+    property bool showPrintMonitor: false
 
     Connections
     {
         target: Printer
         onShowPrintMonitor:
         {
-            monitoringPrint = show;
+            base.showPrintMonitor = show;
         }
     }
 
@@ -388,6 +388,9 @@ UM.MainWindow
                 anchors.left:parent.left
                 anchors.right: parent.right
                 anchors.top: parent.top
+                monitoringPrint: base.showPrintMonitor
+                onStartMonitoringPrint: base.showPrintMonitor = true
+                onStopMonitoringPrint: base.showPrintMonitor = false
             }
 
             Sidebar
@@ -402,6 +405,7 @@ UM.MainWindow
                 }
                 z: 1
                 width: UM.Theme.getSize("sidebar").width;
+                monitoringPrint: base.showPrintMonitor
             }
 
             Button
@@ -451,7 +455,7 @@ UM.MainWindow
             Loader
             {
                 sourceComponent: Cura.MachineManager.printerOutputDevices.length > 0 ? Cura.MachineManager.printerOutputDevices[0].monitorItem: null
-                visible: base.monitoringPrint
+                visible: base.showPrintMonitor
                 anchors.horizontalCenter: parent.horizontalCenter
                 anchors.verticalCenter: parent.verticalCenter
                 anchors.horizontalCenterOffset: - UM.Theme.getSize("sidebar").width / 2

resources/qml/Sidebar.qml

@@ -22,6 +22,8 @@ Rectangle
     property bool printerAcceptsCommands: printerConnected && Cura.MachineManager.printerOutputDevices[0].acceptsCommands
     property int backendState: UM.Backend.state;
 
+    property bool monitoringPrint: false
+
     color: UM.Theme.getColor("sidebar")
     UM.I18nCatalog { id: catalog; name:"cura"}
 

resources/qml/Topbar.qml

@@ -20,6 +20,9 @@ Rectangle
 
     property bool printerConnected: Cura.MachineManager.printerOutputDevices.length != 0
     property bool printerAcceptsCommands: printerConnected && Cura.MachineManager.printerOutputDevices[0].acceptsCommands
+    property bool monitoringPrint: false
+    signal startMonitoringPrint()
+    signal stopMonitoringPrint()
 
     Row
     {
@@ -32,13 +35,13 @@ Rectangle
         {
             id: showSettings
             height: UM.Theme.getSize("sidebar_header").height
-            onClicked: monitoringPrint = false
+            onClicked: base.stopMonitoringPrint()
             iconSource: UM.Theme.getIcon("tab_settings");
             property color overlayColor: "transparent"
             property string overlayIconSource: ""
             text: "Prepare"
             checkable: true
-            checked: !monitoringPrint
+            checked: !base.monitoringPrint
             exclusiveGroup: sidebarHeaderBarGroup
 
             style:  UM.Theme.styles.topbar_header_tab
@@ -48,7 +51,7 @@ Rectangle
         {
             id: showMonitor
             height: UM.Theme.getSize("sidebar_header").height
-            onClicked: monitoringPrint = true
+            onClicked: base.startMonitoringPrint()
             text: "Print"
             iconSource: printerConnected ? UM.Theme.getIcon("tab_monitor_with_status") : UM.Theme.getIcon("tab_monitor")
             property color overlayColor:
@@ -122,7 +125,7 @@ Rectangle
             }
 
             checkable: true
-            checked: monitoringPrint
+            checked: base.monitoringPrint
             exclusiveGroup: sidebarHeaderBarGroup
 
             style:  UM.Theme.styles.topbar_header_tab
@@ -205,4 +208,4 @@ Rectangle
 
         menu: PrinterMenu { }
     }
-}
+}