pin support

src/app/qml/main.qml

@@ -286,9 +286,15 @@ ApplicationWindow {
         
         function onSendError(error) {
             sendProgressDialog.close()
+            pinDialog.close()
             errorDialog.text = error
             errorDialog.open()
         }
+        
+        function onPinRequired(firstAttempt) {
+            pinDialog.isFirstAttempt = firstAttempt
+            pinDialog.open()
+        }
     }
     
     Dialog {
@@ -317,6 +323,112 @@ ApplicationWindow {
         }
     }
     
+    Dialog {
+        id: pinDialog
+        anchors.centerIn: parent
+        modal: true
+        closePolicy: Popup.NoAutoClose
+        title: qsTr("PIN Required")
+        
+        property bool isFirstAttempt: true
+        
+        ColumnLayout {
+            spacing: 12
+            
+            Label {
+                text: pinDialog.isFirstAttempt
+                    ? qsTr("The receiver requires a PIN to accept files.")
+                    : qsTr("Invalid PIN. Please try again.")
+                wrapMode: Text.WordWrap
+                Layout.fillWidth: true
+                color: pinDialog.isFirstAttempt ? palette.text : "red"
+            }
+            
+            TextField {
+                id: pinInput
+                Layout.fillWidth: true
+                placeholderText: qsTr("Enter PIN")
+                echoMode: TextInput.Password
+                focus: true
+                onAccepted: pinDialog.submitPin()
+            }
+        }
+        
+        footer: DialogButtonBox {
+            Button {
+                text: qsTr("Cancel")
+                DialogButtonBox.buttonRole: DialogButtonBox.RejectRole
+            }
+            Button {
+                text: qsTr("Submit")
+                DialogButtonBox.buttonRole: DialogButtonBox.AcceptRole
+                enabled: pinInput.text.length > 0
+            }
+        }
+        
+        onAccepted: submitPin()
+        onRejected: {
+            appController.cancelSend()
+            close()
+        }
+        
+        function submitPin() {
+            if (pinInput.text.length > 0) {
+                appController.retryWithPin(pinInput.text)
+                pinInput.text = ""
+            }
+        }
+        
+        onOpened: {
+            pinInput.text = ""
+            pinInput.forceActiveFocus()
+        }
+    }
+    
+    Dialog {
+        id: setPinDialog
+        anchors.centerIn: parent
+        modal: true
+        title: qsTr("Set Receive PIN")
+        
+        ColumnLayout {
+            spacing: 12
+            
+            Label {
+                text: qsTr("Enter a PIN that senders must provide to transfer files to this device. Leave empty to disable.")
+                wrapMode: Text.WordWrap
+                Layout.fillWidth: true
+            }
+            
+            TextField {
+                id: setPinInput
+                Layout.fillWidth: true
+                placeholderText: qsTr("Enter PIN")
+                onAccepted: setPinDialog.accepted()
+            }
+        }
+        
+        footer: DialogButtonBox {
+            Button {
+                text: qsTr("Cancel")
+                DialogButtonBox.buttonRole: DialogButtonBox.RejectRole
+            }
+            Button {
+                text: qsTr("OK")
+                DialogButtonBox.buttonRole: DialogButtonBox.AcceptRole
+            }
+        }
+        
+        onAccepted: {
+            appController.receivePin = setPinInput.text
+        }
+        
+        onOpened: {
+            setPinInput.text = appController.receivePin
+            setPinInput.forceActiveFocus()
+        }
+    }
+    
     function formatSize(bytes) {
         if (bytes < 1024) return bytes + " B"
         if (bytes < 1024 * 1024) return (bytes / 1024).toFixed(1) + " KB"
@@ -597,6 +709,25 @@ ApplicationWindow {
                         checked: appController.quickSave
                         onCheckedChanged: appController.quickSave = checked
                     }
+                    
+                    Label { text: qsTr("Receive PIN:") }
+                    RowLayout {
+                        Layout.fillWidth: true
+                        Label {
+                            text: appController.receivePin.length > 0 ? qsTr("Enabled") : qsTr("Disabled")
+                            color: appController.receivePin.length > 0 ? "green" : palette.mid
+                        }
+                        Item { Layout.fillWidth: true }
+                        Button {
+                            text: appController.receivePin.length > 0 ? qsTr("Change") : qsTr("Set PIN")
+                            onClicked: setPinDialog.open()
+                        }
+                        Button {
+                            text: qsTr("Remove")
+                            visible: appController.receivePin.length > 0
+                            onClicked: appController.receivePin = ""
+                        }
+                    }
                 }
                 
                 FolderDialog {