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

11 files changed, 420 insertions, 0 deletions

diff --git a/.clang-format b/.clang-format
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index 0000000..a6cc54a
--- /dev/null
+++ b/.clang-format
@@ -0,0 +1 @@
+BasedOnStyle: GNU
diff --git a/.gitignore b/.gitignore
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index 0000000..1a33617
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,8 @@
+# IDE / editor
+.qmlls.ini
+.qtcreator
+.cache
+
+# Build output
+build
+compile_commands.json
diff --git a/.qmlformat.ini b/.qmlformat.ini
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index 0000000..f32994e
--- /dev/null
+++ b/.qmlformat.ini
@@ -0,0 +1,10 @@
+[General]
+IndentWidth=4
+MaxColumnWidth=80
+NewlineType=unix
+NormalizeOrder=true
+ObjectsSpacing=true
+FunctionsSpacing=true
+SemicolonRule=always
+SortImports=false
+UseTabs=false
diff --git a/CMakeLists.txt b/CMakeLists.txt
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index 0000000..bcb1f62
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,30 @@
+cmake_minimum_required(VERSION 3.16)
+project(QtXpl2 LANGUAGES CXX)
+
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
+
+find_package(Qt6 6.10.2 REQUIRED COMPONENTS Core Network Qml Quick)
+qt_standard_project_setup()
+qt_policy(SET QTP0001 NEW)
+
+# QML import path so Qt Creator / qmlls can resolve modules.
+list(APPEND QML_IMPORT_PATH "${PROJECT_BINARY_DIR}/qml")
+set(QML_IMPORT_PATH
+    "${QML_IMPORT_PATH}"
+    CACHE STRING "" FORCE)
+
+# Generate .qmlls.ini for QML language server
+set(QT_QML_GENERATE_QMLLS_INI
+    ON
+    CACHE BOOL "")
+
+# Let the demo executable find the library at run time.
+set(CMAKE_BUILD_RPATH "${PROJECT_BINARY_DIR}/qml/Xpl2")
+
+add_subdirectory(src)
+
+if(PROJECT_IS_TOP_LEVEL)
+  add_subdirectory(demo)
+endif()
diff --git a/demo/CMakeLists.txt b/demo/CMakeLists.txt
new file mode 100644
index 0000000..f85639b
--- /dev/null
+++ b/demo/CMakeLists.txt
@@ -0,0 +1,15 @@
+qt_add_executable(QtXpl2Demo main.cpp)
+
+qt_add_qml_module(
+  QtXpl2Demo
+  URI
+  QtXpl2Demo
+  VERSION
+  1.0
+  QML_FILES
+  Main.qml)
+
+set_target_properties(QtXpl2Demo PROPERTIES RUNTIME_OUTPUT_DIRECTORY
+                                            "${PROJECT_BINARY_DIR}/bin")
+
+target_link_libraries(QtXpl2Demo PRIVATE Qt6::Quick QtXpl2plugin)
diff --git a/demo/Main.qml b/demo/Main.qml
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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
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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 ();
+}
diff --git a/docs/protocol.pdf b/docs/protocol.pdf
new file mode 100644
index 0000000..0bf0bb4
--- /dev/null
+++ b/docs/protocol.pdf
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
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index 0000000..3339013
--- /dev/null
+++ b/src/CMakeLists.txt
@@ -0,0 +1,17 @@
+qt_add_library(QtXpl2 STATIC)
+
+qt_add_qml_module(
+  QtXpl2
+  URI
+  Xpl2
+  VERSION
+  1.0
+  SOURCES
+  Xpl2Client.h
+  Xpl2Client.cpp
+  OUTPUT_DIRECTORY
+  "${PROJECT_BINARY_DIR}/qml/Xpl2")
+
+target_compile_features(QtXpl2 PRIVATE cxx_std_17)
+
+target_link_libraries(QtXpl2 PRIVATE Qt6::Core Qt6::Network Qt6::Quick)
diff --git a/src/Xpl2Client.cpp b/src/Xpl2Client.cpp
new file mode 100644
index 0000000..db53792
--- /dev/null
+++ b/src/Xpl2Client.cpp
@@ -0,0 +1,86 @@
+/**
+ * @file   Xpl2Client.cpp
+ * @brief  TCP client for the Alchemie XPL2 printhead protocol.
+ */
+#include "Xpl2Client.h"
+
+Xpl2Client::Xpl2Client(QObject *parent) : QObject(parent) {
+  connect(&m_socket, &QTcpSocket::connected, this, &Xpl2Client::onConnected);
+  connect(&m_socket, &QTcpSocket::disconnected, this,
+          &Xpl2Client::onDisconnected);
+  connect(&m_socket, &QTcpSocket::readyRead, this, &Xpl2Client::onReadyRead);
+  connect(&m_socket, &QAbstractSocket::errorOccurred, this,
+          &Xpl2Client::onErrorOccurred);
+}
+
+QString Xpl2Client::host() const { return m_host; }
+
+void Xpl2Client::setHost(const QString &host) {
+  if (m_host == host)
+    return;
+  m_host = host;
+  emit hostChanged();
+}
+
+quint16 Xpl2Client::port() const { return m_port; }
+
+void Xpl2Client::setPort(quint16 port) {
+  if (m_port == port)
+    return;
+  m_port = port;
+  emit portChanged();
+}
+
+bool Xpl2Client::isConnected() const {
+  return m_socket.state() == QAbstractSocket::ConnectedState;
+}
+
+void Xpl2Client::connectToServer() {
+  if (isConnected()) {
+    emit statusMessage(QStringLiteral("Already connected"));
+    return;
+  }
+  emit statusMessage(
+      QStringLiteral("Connecting to %1:%2…").arg(m_host).arg(m_port));
+  m_socket.connectToHost(m_host, m_port);
+}
+
+void Xpl2Client::disconnectFromServer() {
+  if (!isConnected())
+    return;
+  m_socket.disconnectFromHost();
+}
+
+void Xpl2Client::sendCommand(const QString &command) {
+  if (!isConnected()) {
+    emit errorOccurred(QStringLiteral("Not connected"));
+    return;
+  }
+  QByteArray data = command.toUtf8() + '\n';
+  m_socket.write(data);
+  emit statusMessage(QStringLiteral("Sent: %1").arg(command));
+}
+
+void Xpl2Client::onConnected() {
+  emit connectedChanged();
+  emit statusMessage(QStringLiteral("Connected to %1:%2")
+                         .arg(m_socket.peerName())
+                         .arg(m_socket.peerPort()));
+}
+
+void Xpl2Client::onDisconnected() {
+  emit connectedChanged();
+  emit statusMessage(QStringLiteral("Disconnected"));
+}
+
+void Xpl2Client::onReadyRead() {
+  while (m_socket.canReadLine()) {
+    QString line = QString::fromUtf8(m_socket.readLine()).trimmed();
+    emit responseReceived(line);
+  }
+}
+
+void Xpl2Client::onErrorOccurred(QAbstractSocket::SocketError error) {
+  Q_UNUSED(error)
+  emit errorOccurred(m_socket.errorString());
+}
diff --git a/src/Xpl2Client.h b/src/Xpl2Client.h
new file mode 100644
index 0000000..f052962
--- /dev/null
+++ b/src/Xpl2Client.h
@@ -0,0 +1,53 @@
+/**
+ * @file   Xpl2Client.h
+ * @brief  TCP client for the Alchemie XPL2 printhead protocol.
+ */
+#pragma once
+
+#include <QObject>
+#include <QQmlEngine>
+#include <QTcpSocket>
+
+class Xpl2Client : public QObject {
+  Q_OBJECT
+  QML_ELEMENT
+  QML_SINGLETON
+
+  Q_PROPERTY(QString host READ host WRITE setHost NOTIFY hostChanged)
+  Q_PROPERTY(quint16 port READ port WRITE setPort NOTIFY portChanged)
+  Q_PROPERTY(bool connected READ isConnected NOTIFY connectedChanged)
+
+public:
+  explicit Xpl2Client(QObject *parent = nullptr);
+
+  QString host() const;
+  void setHost(const QString &host);
+
+  quint16 port() const;
+  void setPort(quint16 port);
+
+  bool isConnected() const;
+
+  Q_INVOKABLE void connectToServer();
+  Q_INVOKABLE void disconnectFromServer();
+  Q_INVOKABLE void sendCommand(const QString &command);
+
+signals:
+  void hostChanged();
+  void portChanged();
+  void connectedChanged();
+  void responseReceived(const QString &response);
+  void errorOccurred(const QString &error);
+  void statusMessage(const QString &message);
+
+private slots:
+  void onConnected();
+  void onDisconnected();
+  void onReadyRead();
+  void onErrorOccurred(QAbstractSocket::SocketError error);
+
+private:
+  QTcpSocket m_socket;
+  QString m_host = QStringLiteral("127.0.0.1");
+  quint16 m_port = 5000;
+};