Initial project setup: Qt 6.10.2 TCP client library for Alchemie XPL2 protocol

- Static library (src/) with QML singleton Xpl2Client for TCP communication
- Qt Quick demo app (demo/) with connection UI, command input, and response log

3 files changed, 215 insertions, 0 deletions

diff --git a/demo/CMakeLists.txt b/demo/CMakeLists.txt
new file mode 100644
index 0000000..f85639b
--- /dev/null
+++ b/demo/CMakeLists.txt
@@ -0,0 +1,15 @@
+qt_add_executable(QtXpl2Demo main.cpp)
+
+qt_add_qml_module(
+  QtXpl2Demo
+  URI
+  QtXpl2Demo
+  VERSION
+  1.0
+  QML_FILES
+  Main.qml)
+
+set_target_properties(QtXpl2Demo PROPERTIES RUNTIME_OUTPUT_DIRECTORY
+                                            "${PROJECT_BINARY_DIR}/bin")
+
+target_link_libraries(QtXpl2Demo PRIVATE Qt6::Quick QtXpl2plugin)
diff --git a/demo/Main.qml b/demo/Main.qml
new file mode 100644
index 0000000..82b2573
--- /dev/null
+++ b/demo/Main.qml
@@ -0,0 +1,177 @@
+import QtQuick
+import QtQuick.Controls
+import QtQuick.Layouts
+import Xpl2
+
+ApplicationWindow {
+    id: root
+
+    width: 800
+    height: 600
+    visible: true
+    title: "XPL2 Demo"
+
+    Connections {
+        target: Xpl2Client
+
+        function onConnectedChanged() {
+            log(Xpl2Client.connected ? "Connected" : "Disconnected");
+        }
+
+        function onResponseReceived(response: string) {
+            log("← " + response);
+            responseModel.append({
+                text: response
+            });
+        }
+
+        function onErrorOccurred(error: string) {
+            log("ERROR: " + error);
+        }
+
+        function onStatusMessage(message: string) {
+            log(message);
+        }
+    }
+
+    function log(msg: string) {
+        let ts = new Date().toLocaleTimeString(Qt.locale(), "HH:mm:ss.zzz");
+        logModel.append({
+            text: "[" + ts + "] " + msg
+        });
+        logView.positionViewAtEnd();
+    }
+
+    ColumnLayout {
+        anchors.fill: parent
+        anchors.margins: 16
+        spacing: 12
+
+        // --- Connection ---
+        GroupBox {
+            title: "Connection"
+            Layout.fillWidth: true
+
+            GridLayout {
+                columns: 4
+                anchors.fill: parent
+
+                Label {
+                    text: "Host:"
+                }
+                TextField {
+                    id: hostField
+                    text: Xpl2Client.host
+                    Layout.fillWidth: true
+                    onEditingFinished: Xpl2Client.host = text
+                }
+
+                Label {
+                    text: "Port:"
+                }
+                TextField {
+                    id: portField
+                    text: Xpl2Client.port
+                    implicitWidth: 80
+                    validator: IntValidator {
+                        bottom: 1
+                        top: 65535
+                    }
+                    onEditingFinished: Xpl2Client.port = parseInt(text)
+                }
+
+                Button {
+                    text: Xpl2Client.connected ? "Disconnect" : "Connect"
+                    Layout.columnSpan: 4
+                    Layout.alignment: Qt.AlignRight
+                    onClicked: {
+                        if (Xpl2Client.connected)
+                            Xpl2Client.disconnectFromServer();
+                        else
+                            Xpl2Client.connectToServer();
+                    }
+                }
+            }
+        }
+
+        // --- Send Command ---
+        GroupBox {
+            title: "Command"
+            Layout.fillWidth: true
+            enabled: Xpl2Client.connected
+
+            RowLayout {
+                anchors.fill: parent
+
+                TextField {
+                    id: cmdField
+                    placeholderText: "Enter command…"
+                    Layout.fillWidth: true
+                    onAccepted: sendBtn.clicked()
+                }
+
+                Button {
+                    id: sendBtn
+                    text: "Send"
+                    onClicked: {
+                        if (cmdField.text.length > 0) {
+                            Xpl2Client.sendCommand(cmdField.text);
+                            cmdField.text = "";
+                        }
+                    }
+                }
+            }
+        }
+
+        // --- Responses ---
+        GroupBox {
+            title: "Responses"
+            Layout.fillWidth: true
+            Layout.fillHeight: true
+
+            ListView {
+                id: responseView
+                anchors.fill: parent
+                clip: true
+                model: ListModel {
+                    id: responseModel
+                }
+
+                delegate: Text {
+                    required property string text
+                    width: responseView.width
+                    wrapMode: Text.Wrap
+                    font.family: "monospace"
+                    font.pixelSize: 13
+                    text: model.text
+                }
+            }
+        }
+
+        // --- Debug Log ---
+        GroupBox {
+            title: "Log"
+            Layout.fillWidth: true
+            Layout.preferredHeight: 160
+
+            ListView {
+                id: logView
+                anchors.fill: parent
+                clip: true
+                model: ListModel {
+                    id: logModel
+                }
+
+                delegate: Text {
+                    required property string text
+                    width: logView.width
+                    wrapMode: Text.Wrap
+                    font.family: "monospace"
+                    font.pixelSize: 12
+                    color: "#555"
+                    text: model.text
+                }
+            }
+        }
+    }
+}
diff --git a/demo/main.cpp b/demo/main.cpp
new file mode 100644
index 0000000..64c4f22
--- /dev/null
+++ b/demo/main.cpp
@@ -0,0 +1,23 @@
+/**
+ * @file   main.cpp
+ * @brief  Entry point for the QtXpl2 demo application.
+ */
+#include <QGuiApplication>
+#include <QQmlApplicationEngine>
+
+#include <QtQml/QQmlExtensionPlugin>
+Q_IMPORT_QML_PLUGIN (Xpl2Plugin)
+
+int
+main (int argc, char *argv[])
+{
+  QGuiApplication app (argc, argv);
+
+  QQmlApplicationEngine engine;
+  QObject::connect (
+      &engine, &QQmlApplicationEngine::objectCreationFailed, &app,
+      [] () { QCoreApplication::exit (1); }, Qt::QueuedConnection);
+
+  engine.loadFromModule ("QtXpl2Demo", "Main");
+  return app.exec ();
+}