Error message dialog added for X11VMC error

main.qml

@@ -29,6 +29,11 @@ Item {
     // virtscreen.py backend.
     Backend {
         id: backend
+        onVncStateChanged: {
+            if (backend.vncState == Backend.ERROR) {
+                autostart = false;
+            }
+        }
     }
 
     // Timer object and function
@@ -128,12 +133,24 @@ Item {
         menu: Menu {
             MenuItem {
                 id: vncStateText
-                text: !backend.virtScreenCreated ? "Enable Virtual Screen first." :
+                text: !backend.virtScreenCreated ? "Enable Virtual Screen first" :
-                      backend.vncState == Backend.OFF ? "Turn on VNC Server in the VNC tab." :
+                      backend.vncState == Backend.OFF ? "Turn on VNC Server in the VNC tab" :
+                      backend.vncState == Backend.ERROR ? "Error occurred" :
                       backend.vncState == Backend.WAITING ? "VNC Server is waiting for a client..." :
-                      backend.vncState == Backend.CONNECTED ? "Connected." :
+                      backend.vncState == Backend.CONNECTED ? "Connected" :
                       "Server state error!"
             }
+            MenuItem {
+                id: errorText
+                visible: (text)
+                text: ""
+                Component.onCompleted : {
+                    backend.onError.connect(function(errMsg) {
+                        errorText.text = "";
+                        errorText.text = errMsg;
+                    });
+                }
+            }
             MenuItem {
                 separator: true
             }

qml/AppWindow.qml

@@ -221,6 +221,29 @@ ApplicationWindow {
         onRejected: passwordFIeld.text = ""
     }
 
+    Dialog {
+        id: errorDialog
+        title: "Error"
+        focus: true
+        modal: true
+        standardButtons: Dialog.Ok
+        x: (parent.width - width) / 2
+        y: (parent.width - height) / 2 //(window.height) / 2 
+        width: popupWidth
+        ColumnLayout {
+            anchors.fill: parent
+            Text {
+                horizontalAlignment: Text.AlignHCenter
+                text: errorText.text
+                onTextChanged: {
+                    if (text) {
+                        errorDialog.open();
+                    }
+                }
+            }
+        }
+    }
+
     Loader {
         id: preferenceLoader
         active: false

qml/preferenceDialog.qml

@@ -9,7 +9,7 @@ Dialog {
     focus: true
     modal: true
     visible: true
-    standardButtons: Dialog.Ok | Dialog.Cancel
+    standardButtons: Dialog.Ok
     x: (window.width - width) / 2
     y: (window.width - height) / 2 
     width: popupWidth

virtscreen.py

@@ -353,22 +353,20 @@ class Backend(QObject):
     class VNCState:
         """ Enum to indicate a state of the VNC server """
         OFF = 0
-        WAITING = 1
+        ERROR = 1
-        CONNECTED = 2
+        WAITING = 2
+        CONNECTED = 3
 
     Q_ENUMS(VNCState)
     # Virtual screen properties
-    xrandr: XRandR
+    xrandr: XRandR = XRandR()
     _virtScreenCreated: bool = False
-    screens: List[DisplayProperty]
+    _virtScreenIndex: int = xrandr.virt_idx
-    _virtScreenIndex: int
     # VNC server properties
     _vncUsePassword: bool = False
     _vncState: VNCState = VNCState.OFF
     # Primary screen and mouse posistion
     _primaryProp: DisplayProperty
-    cursor_x: int
-    cursor_y: int
     vncServer: ProcessProtocol
 
     # Signals
@@ -376,15 +374,12 @@ class Backend(QObject):
     onVirtScreenIndexChanged = pyqtSignal(int)
     onVncUsePasswordChanged = pyqtSignal(bool)
     onVncStateChanged = pyqtSignal(VNCState)
-    onVncAutoStartChanged = pyqtSignal(bool)
     onIPAddressesChanged = pyqtSignal()
     onDisplaySettingClosed = pyqtSignal()
+    onError = pyqtSignal(str)
 
     def __init__(self, parent=None):
         super(Backend, self).__init__(parent)
-        # create objects
-        self.xrandr = XRandR()
-        self._virtScreenIndex = self.xrandr.virt_idx
         
     # Qt properties
     @pyqtProperty(str, constant=True)
@@ -534,6 +529,9 @@ class Backend(QObject):
                 print("VNC disconnected.")
                 self.vncState = self.VNCState.WAITING
         def _onEnded(exitCode):
+            if exitCode is not 0:
+                self.vncState = self.VNCState.ERROR
+                self.onError.emit('X11VNC: Error occurred.')
             print("VNC Exited.")
             self.vncState = self.VNCState.OFF
             atexit.unregister(self.stopVNC)