diff --git a/CodeGenerator/codegenerator.cpp b/CodeGenerator/codegenerator.cpp
index f6e8976..351375d 100644
--- a/CodeGenerator/codegenerator.cpp
+++ b/CodeGenerator/codegenerator.cpp
@@ -44,6 +44,19 @@ GeneratedFunction* GeneratedCodeStorage::addFunction(const QString& name)
     return function;
 }
 
+GeneratedFunction* GeneratedCodeStorage::addFunction(GeneratedFunction* function)
+{
+    function->setParent(this);
+    m_functions.append(function);
+    return function;
+}
+
+void GeneratedCodeStorage::removeFunction(GeneratedFunction* function)
+{
+    function->deleteLater();
+    m_functions.removeOne(function);
+}
+
 QObject* Serializer::load(const QDomElement& element, QObject* parent)
 {
     QString className = element.attribute("class");
@@ -81,7 +94,13 @@ QObject* Serializer::load(const QDomElement& element, QObject* parent)
                 if (!propertyElement.isNull())
                 {
                     // Deserialize the element
-                    if (property.userType() == qMetaTypeId<QObjectList>())
+                    if (property.isEnumType())
+                    {
+                        QMetaEnum metaEnum = property.enumerator();
+                        Q_ASSERT(metaEnum.isValid());
+                        property.write(deserializedObject, metaEnum.keyToValue(propertyElement.text().toLatin1().data()));
+                    }
+                    else if (property.userType() == qMetaTypeId<QObjectList>())
                     {
                         QObjectList objectList;
                         QDomNodeList children = propertyElement.childNodes();
@@ -135,7 +154,13 @@ void Serializer::store(QObject* object, QDomElement& element)
                 propertyElement.setAttribute("name", property.name());
 
                 QVariant value = property.read(object);
-                if (value.canConvert<QObjectList>())
+                if (property.isEnumType())
+                {
+                    QMetaEnum metaEnum = property.enumerator();
+                    Q_ASSERT(metaEnum.isValid());
+                    propertyElement.appendChild(propertyElement.ownerDocument().createTextNode(metaEnum.valueToKey(value.toInt())));
+                }
+                else if (value.canConvert<QObjectList>())
                 {
                     QObjectList objectList = value.value<QObjectList>();
                     for (QObject* currentObject : objectList)
@@ -154,6 +179,15 @@ void Serializer::store(QObject* object, QDomElement& element)
     }
 }
 
+QObject* Serializer::clone(QObject* object, QObject* parent)
+{
+    QDomDocument document;
+    QDomElement rootElement = document.createElement("root");
+    document.appendChild(rootElement);
+    Serializer::store(object, rootElement);
+    return Serializer::load(rootElement, parent);
+}
+
 CodeGenerator::CodeGenerator(QObject* parent) :
     BaseClass(parent)
 {
@@ -231,4 +265,509 @@ void GeneratedFunction::setFunctionDescription(const QString& functionDescriptio
     m_functionDescription = functionDescription;
 }
 
+GeneratedFunction* GeneratedFunction::clone(QObject* parent)
+{
+    return qobject_cast<GeneratedFunction*>(Serializer::clone(this, parent));
+}
+
+bool GeneratedFunction::hasField(GeneratedBase::FieldType fieldType) const
+{
+    switch (fieldType)
+    {
+        case FieldType::Name:
+        case FieldType::ItemType:
+        case FieldType::DataType:
+        case FieldType::Description:
+            return true;
+
+        case FieldType::Value:
+            return false;
+
+        default:
+            break;
+    }
+
+    return false;
+}
+
+QVariant GeneratedFunction::readField(GeneratedBase::FieldType fieldType) const
+{
+    switch (fieldType)
+    {
+        case FieldType::Name:
+            return m_functionName;
+        case FieldType::ItemType:
+            return int(m_functionType);
+        case FieldType::DataType:
+            return int(m_returnType);
+        case FieldType::Description:
+            return m_functionDescription;
+
+        case FieldType::Value:
+        default:
+            break;
+    }
+
+    return QVariant();
+}
+
+void GeneratedFunction::writeField(GeneratedBase::FieldType fieldType, QVariant value)
+{
+    switch (fieldType)
+    {
+        case FieldType::Name:
+            m_functionName = value.toString();
+            break;
+        case FieldType::ItemType:
+            m_functionType = static_cast<FunctionType>(value.toInt());
+            break;
+        case FieldType::DataType:
+            m_returnType = static_cast<DataType>(value.toInt());
+            break;
+        case FieldType::Description:
+            m_functionDescription = value.toString();
+            break;
+
+        case FieldType::Value:
+        default:
+            break;
+    }
+}
+
+void GeneratedFunction::fillComboBox(QComboBox* comboBox, GeneratedBase::FieldType fieldType)
+{
+    switch (fieldType)
+    {
+        case FieldType::ItemType:
+            Serializer::fillComboBox(comboBox, m_functionType);
+            break;
+        case FieldType::DataType:
+            Serializer::fillComboBox(comboBox, m_returnType);
+            break;
+
+        default:
+            break;
+    }
+}
+
+bool GeneratedFunction::canHaveSubitems() const
+{
+    return true;
+}
+
+GeneratedFunction::DataType GeneratedFunction::getReturnType() const
+{
+    return m_returnType;
+}
+
+void GeneratedFunction::setReturnType(DataType returnType)
+{
+    m_returnType = returnType;
+}
+
+GeneratedAction::GeneratedAction(QObject* parent) :
+    BaseClass(parent),
+    m_actionType(CreateObject)
+{
+
+}
+
+bool GeneratedAction::hasField(FieldType fieldType) const
+{
+    switch (fieldType)
+    {
+        case FieldType::Name:
+            return m_actionType == CreateObject;
+        case FieldType::ItemType:
+            return true;
+        case FieldType::DataType:
+            return hasField(FieldType::Name) && !m_variableName.isEmpty();
+        case FieldType::Description:
+            return m_actionType == Code;
+
+        default:
+            break;
+    }
+
+    return false;
+}
+
+QVariant GeneratedAction::readField(GeneratedBase::FieldType fieldType) const
+{
+    switch (fieldType)
+    {
+        case FieldType::Name:
+            return m_variableName;
+        case FieldType::ItemType:
+            return int(m_actionType);
+        case FieldType::DataType:
+            return int(m_variableType);
+        case FieldType::Description:
+            return m_code;
+
+        default:
+            break;
+    }
+
+    return QVariant();
+}
+
+void GeneratedAction::writeField(GeneratedBase::FieldType fieldType, QVariant value)
+{
+    switch (fieldType)
+    {
+        case FieldType::Name:
+            m_variableName = value.toString();
+            break;
+        case FieldType::ItemType:
+            m_actionType = static_cast<ActionType>(value.toInt());
+            break;
+        case FieldType::DataType:
+            m_variableType = static_cast<DataType>(value.toInt());
+            break;
+        case FieldType::Description:
+            m_code = value.toString();
+            break;
+
+        default:
+            break;
+    }
+}
+
+void GeneratedAction::fillComboBox(QComboBox* comboBox, FieldType fieldType)
+{
+    switch (fieldType)
+    {
+        case FieldType::ItemType:
+            Serializer::fillComboBox(comboBox, m_actionType);
+            break;
+        case FieldType::DataType:
+            Serializer::fillComboBox(comboBox, m_variableType);
+            break;
+
+        default:
+            break;
+    }
+}
+
+bool GeneratedAction::canHaveSubitems() const
+{
+    switch (m_actionType)
+    {
+        case Parameters:
+        case CreateObject:
+            return true;
+
+        default:
+            break;
+    }
+
+    return false;
+}
+
+GeneratedAction::ActionType GeneratedAction::getActionType() const
+{
+    return m_actionType;
+}
+
+void GeneratedAction::setActionType(ActionType actionType)
+{
+    m_actionType = actionType;
+
+    if (!canHaveSubitems())
+    {
+        clearItems();
+    }
+}
+
+QString GeneratedAction::getVariableName() const
+{
+    return m_variableName;
+}
+
+void GeneratedAction::setVariableName(const QString& variableName)
+{
+    m_variableName = variableName;
+}
+
+GeneratedAction::DataType GeneratedAction::getVariableType() const
+{
+    return m_variableType;
+}
+
+void GeneratedAction::setVariableType(DataType variableType)
+{
+    m_variableType = variableType;
+}
+
+QString GeneratedAction::getCode() const
+{
+    return m_code;
+}
+
+void GeneratedAction::setCode(const QString& code)
+{
+    m_code = code;
+}
+
+QObjectList GeneratedBase::getItems() const
+{
+    return m_items;
+}
+
+void GeneratedBase::setItems(const QObjectList& items)
+{
+    m_items = items;
+}
+
+void GeneratedBase::addItem(QObject* object)
+{
+    object->setParent(this);
+    m_items.append(object);
+}
+
+void GeneratedBase::removeItem(QObject* object)
+{
+    object->deleteLater();
+    m_items.removeAll(object);
+}
+
+void GeneratedBase::clearItems()
+{
+    qDeleteAll(m_items);
+    m_items.clear();
+}
+
+GeneratedPDFObject::GeneratedPDFObject(QObject* parent) :
+    BaseClass(parent)
+{
+
+}
+
+bool GeneratedPDFObject::hasField(GeneratedBase::FieldType fieldType) const
+{
+    switch (fieldType)
+    {
+        case FieldType::Name:
+            return m_objectType == DictionaryItemSimple || m_objectType == DictionaryItemComplex;
+        case FieldType::ItemType:
+            return true;
+        case FieldType::Value:
+            return m_objectType == Object || m_objectType == ArraySimple || m_objectType == DictionaryItemSimple;
+
+        default:
+            break;
+    }
+
+    return false;
+}
+
+QVariant GeneratedPDFObject::readField(GeneratedBase::FieldType fieldType) const
+{
+    switch (fieldType)
+    {
+        case FieldType::Name:
+            return m_dictionaryItemName;
+        case FieldType::ItemType:
+            return int(m_objectType);
+        case FieldType::Value:
+            return m_value;
+
+        default:
+            break;
+    }
+
+    return QVariant();
+}
+
+void GeneratedPDFObject::writeField(GeneratedBase::FieldType fieldType, QVariant value)
+{
+    switch (fieldType)
+    {
+        case FieldType::Name:
+            m_dictionaryItemName = value.toString();
+            break;
+        case FieldType::ItemType:
+            m_objectType = static_cast<ObjectType>(value.toInt());
+            break;
+        case FieldType::Value:
+            m_value = value.toString();
+            break;
+
+        default:
+            break;
+    }
+}
+
+void GeneratedPDFObject::fillComboBox(QComboBox* comboBox, GeneratedBase::FieldType fieldType)
+{
+    switch (fieldType)
+    {
+        case FieldType::ItemType:
+            Serializer::fillComboBox(comboBox, m_objectType);
+            break;
+
+        default:
+            break;
+    }
+}
+
+bool GeneratedPDFObject::canHaveSubitems() const
+{
+    switch (m_objectType)
+    {
+        case ArrayComplex:
+        case Dictionary:
+        case DictionaryItemComplex:
+            return true;
+
+        default:
+            break;
+    }
+
+    return false;
+}
+
+QString GeneratedPDFObject::getValue() const
+{
+    return m_value;
+}
+
+void GeneratedPDFObject::setValue(const QString& value)
+{
+    m_value = value;
+}
+
+GeneratedPDFObject::ObjectType GeneratedPDFObject::getObjectType() const
+{
+    return m_objectType;
+}
+
+void GeneratedPDFObject::setObjectType(ObjectType objectType)
+{
+    m_objectType = objectType;
+
+    if (!canHaveSubitems())
+    {
+        clearItems();
+    }
+}
+
+QString GeneratedPDFObject::getDictionaryItemName() const
+{
+    return m_dictionaryItemName;
+}
+
+void GeneratedPDFObject::setDictionaryItemName(const QString& dictionaryItemName)
+{
+    m_dictionaryItemName = dictionaryItemName;
+}
+
+GeneratedParameter::GeneratedParameter(QObject* parent) :
+    BaseClass(parent)
+{
+
+}
+
+bool GeneratedParameter::hasField(GeneratedBase::FieldType fieldType) const
+{
+    switch (fieldType)
+    {
+        case FieldType::Name:
+        case FieldType::DataType:
+        case FieldType::Description:
+            return true;
+
+        default:
+            break;
+    }
+
+    return false;
+}
+
+QVariant GeneratedParameter::readField(GeneratedBase::FieldType fieldType) const
+{
+    switch (fieldType)
+    {
+        case FieldType::Name:
+            return m_parameterName;
+        case FieldType::DataType:
+            return m_parameterDataType;
+        case FieldType::Description:
+            return m_parameterDescription;
+
+        default:
+            break;
+    }
+
+    return QVariant();
+}
+
+void GeneratedParameter::writeField(GeneratedBase::FieldType fieldType, QVariant value)
+{
+    switch (fieldType)
+    {
+        case FieldType::Name:
+            m_parameterName = value.toString();
+            break;
+        case FieldType::DataType:
+            m_parameterDataType = static_cast<DataType>(value.toInt());
+            break;
+        case FieldType::Description:
+            m_parameterDescription = value.toString();
+            break;
+
+        default:
+            break;
+    }
+}
+
+void GeneratedParameter::fillComboBox(QComboBox* comboBox, GeneratedBase::FieldType fieldType)
+{
+    switch (fieldType)
+    {
+        case FieldType::DataType:
+            Serializer::fillComboBox(comboBox, m_parameterDataType);
+            break;
+
+        default:
+            break;
+    }
+}
+
+bool GeneratedParameter::canHaveSubitems() const
+{
+    return false;
+}
+
+QString GeneratedParameter::getParameterName() const
+{
+    return m_parameterName;
+}
+
+void GeneratedParameter::setParameterName(const QString& parameterName)
+{
+    m_parameterName = parameterName;
+}
+
+GeneratedParameter::DataType GeneratedParameter::getParameterDataType() const
+{
+    return m_parameterDataType;
+}
+
+void GeneratedParameter::setParameterDataType(const DataType& parameterDataType)
+{
+    m_parameterDataType = parameterDataType;
+}
+
+QString GeneratedParameter::getParameterDescription() const
+{
+    return m_parameterDescription;
+}
+
+void GeneratedParameter::setParameterDescription(const QString& parameterDescription)
+{
+    m_parameterDescription = parameterDescription;
+}
+
 }
diff --git a/CodeGenerator/codegenerator.h b/CodeGenerator/codegenerator.h
index 26dd907..e0e6602 100644
--- a/CodeGenerator/codegenerator.h
+++ b/CodeGenerator/codegenerator.h
@@ -24,6 +24,7 @@
 #include <QDomDocument>
 #include <QDomElement>
 #include <QObjectList>
+#include <QComboBox>
 
 namespace codegen
 {
@@ -33,6 +34,7 @@ class Serializer
 public:
     static QObject* load(const QDomElement& element, QObject* parent);
     static void store(QObject* object, QDomElement& element);
+    static QObject* clone(QObject* object, QObject* parent);
 
     template<typename T>
     static inline QString convertEnumToString(T enumValue)
@@ -55,6 +57,23 @@ public:
             value = T();
         }
     }
+
+    template<typename T>
+    static inline void fillComboBox(QComboBox* comboBox, T value)
+    {
+        QMetaEnum metaEnum = QMetaEnum::fromType<T>();
+        Q_ASSERT(metaEnum.isValid());
+
+        const int keyCount = metaEnum.keyCount();
+        comboBox->setUpdatesEnabled(false);
+        comboBox->clear();
+        for (int i = 0; i < keyCount; ++i)
+        {
+            comboBox->addItem(metaEnum.key(i), metaEnum.value(i));
+        }
+        comboBox->setCurrentIndex(comboBox->findData(int(value)));
+        comboBox->setUpdatesEnabled(true);
+    }
 };
 
 class GeneratedFunction;
@@ -75,18 +94,200 @@ public:
     void setFunctions(const QObjectList& functions);
 
     GeneratedFunction* addFunction(const QString& name);
+    GeneratedFunction* addFunction(GeneratedFunction* function);
+    void removeFunction(GeneratedFunction* function);
 
 private:
     QObjectList m_functions;
 };
 
-class GeneratedFunction : public QObject
+class GeneratedBase : public QObject
 {
     Q_OBJECT
 
 private:
     using BaseClass = QObject;
 
+public:
+    using BaseClass::BaseClass;
+
+    enum class FieldType
+    {
+        Name,
+        ItemType,
+        DataType,
+        Value,
+        Description
+    };
+
+    enum DataType
+    {
+        _void,
+        _PDFNull,
+        _bool,
+        _PDFInteger,
+        _PDFReal,
+        _PDFObjectReference,
+        _QString,
+        _QPointF,
+        _QRectF,
+        _QVariant
+    };
+    Q_ENUM(DataType)
+
+    Q_PROPERTY(QObjectList items READ getItems WRITE setItems)
+
+    virtual bool hasField(FieldType fieldType) const = 0;
+    virtual QVariant readField(FieldType fieldType) const = 0;
+    virtual void writeField(FieldType fieldType, QVariant value) = 0;
+    virtual void fillComboBox(QComboBox* comboBox, FieldType fieldType) = 0;
+    virtual bool canHaveSubitems() const = 0;
+
+    QObjectList getItems() const;
+    void setItems(const QObjectList& items);
+    void addItem(QObject* object);
+    void removeItem(QObject* object);
+    void clearItems();
+
+private:
+    QObjectList m_items;
+};
+
+class GeneratedParameter : public GeneratedBase
+{
+    Q_OBJECT
+
+private:
+    using BaseClass = GeneratedBase;
+
+public:
+    Q_INVOKABLE GeneratedParameter(QObject* parent);
+    Q_PROPERTY(QString parameterName READ getParameterName WRITE setParameterName)
+    Q_PROPERTY(DataType parameterType READ getParameterDataType WRITE setParameterDataType)
+    Q_PROPERTY(QString parameterDescription READ getParameterDescription WRITE setParameterDescription)
+
+    virtual bool hasField(FieldType fieldType) const override;
+    virtual QVariant readField(FieldType fieldType) const override;
+    virtual void writeField(FieldType fieldType, QVariant value) override;
+    virtual void fillComboBox(QComboBox* comboBox, FieldType fieldType) override;
+    virtual bool canHaveSubitems() const override;
+
+    QString getParameterName() const;
+    void setParameterName(const QString& parameterName);
+
+    DataType getParameterDataType() const;
+    void setParameterDataType(const DataType& parameterDataType);
+
+    QString getParameterDescription() const;
+    void setParameterDescription(const QString& parameterDescription);
+
+private:
+    QString m_parameterName;
+    DataType m_parameterDataType = _void;
+    QString m_parameterDescription;
+};
+
+class GeneratedPDFObject : public GeneratedBase
+{
+    Q_OBJECT
+
+private:
+    using BaseClass = GeneratedBase;
+
+public:
+
+    enum ObjectType
+    {
+        Object,
+        ArraySimple,
+        ArrayComplex,
+        Dictionary,
+        DictionaryItemSimple,
+        DictionaryItemComplex
+    };
+    Q_ENUM(ObjectType)
+
+    Q_INVOKABLE GeneratedPDFObject(QObject* parent);
+    Q_PROPERTY(QString dictionaryItemName READ getDictionaryItemName WRITE setDictionaryItemName)
+    Q_PROPERTY(ObjectType objectType READ getObjectType WRITE setObjectType)
+    Q_PROPERTY(QString value READ getValue WRITE setValue)
+
+    virtual bool hasField(FieldType fieldType) const override;
+    virtual QVariant readField(FieldType fieldType) const override;
+    virtual void writeField(FieldType fieldType, QVariant value) override;
+    virtual void fillComboBox(QComboBox* comboBox, FieldType fieldType) override;
+    virtual bool canHaveSubitems() const override;
+
+    QString getValue() const;
+    void setValue(const QString& value);
+
+    ObjectType getObjectType() const;
+    void setObjectType(ObjectType objectType);
+
+    QString getDictionaryItemName() const;
+    void setDictionaryItemName(const QString& dictionaryItemName);
+
+private:
+    QString m_dictionaryItemName;
+    ObjectType m_objectType = Object;
+    QString m_value;
+};
+
+class GeneratedAction : public GeneratedBase
+{
+    Q_OBJECT
+
+private:
+    using BaseClass = GeneratedBase;
+
+public:
+
+    enum ActionType
+    {
+        Parameters,
+        CreateObject,
+        Code
+    };
+    Q_ENUM(ActionType)
+
+    Q_INVOKABLE GeneratedAction(QObject* parent);
+    Q_PROPERTY(ActionType actionType READ getActionType WRITE setActionType)
+    Q_PROPERTY(QString variableName READ getVariableName WRITE setVariableName)
+    Q_PROPERTY(DataType variableType READ getVariableType WRITE setVariableType)
+    Q_PROPERTY(QString code READ getCode WRITE setCode)
+
+    virtual bool hasField(FieldType fieldType) const override;
+    virtual QVariant readField(FieldType fieldType) const override;
+    virtual void writeField(FieldType fieldType, QVariant value) override;
+    virtual void fillComboBox(QComboBox* comboBox, FieldType fieldType) override;
+    virtual bool canHaveSubitems() const override;
+
+    ActionType getActionType() const;
+    void setActionType(ActionType actionType);
+
+    QString getVariableName() const;
+    void setVariableName(const QString& variableName);
+
+    DataType getVariableType() const;
+    void setVariableType(DataType variableType);
+
+    QString getCode() const;
+    void setCode(const QString& code);
+
+private:
+    ActionType m_actionType;
+    QString m_variableName;
+    DataType m_variableType = _void;
+    QString m_code;
+};
+
+class GeneratedFunction : public GeneratedBase
+{
+    Q_OBJECT
+
+private:
+    using BaseClass = GeneratedBase;
+
 public:
 
     enum FunctionType
@@ -99,9 +300,16 @@ public:
 
     Q_INVOKABLE GeneratedFunction(QObject* parent);
 
-    Q_PROPERTY(QString functionType READ getFunctionTypeString WRITE setFunctionTypeString)
+    Q_PROPERTY(FunctionType functionType READ getFunctionType WRITE setFunctionType)
     Q_PROPERTY(QString functionName READ getFunctionName WRITE setFunctionName)
     Q_PROPERTY(QString functionDescription READ getFunctionDescription WRITE setFunctionDescription)
+    Q_PROPERTY(DataType returnType READ getReturnType WRITE setReturnType)
+
+    virtual bool hasField(FieldType fieldType) const override;
+    virtual QVariant readField(FieldType fieldType) const override;
+    virtual void writeField(FieldType fieldType, QVariant value) override;
+    virtual void fillComboBox(QComboBox* comboBox, FieldType fieldType) override;
+    virtual bool canHaveSubitems() const override;
 
     QString getFunctionTypeString() const;
     void setFunctionTypeString(const QString& string);
@@ -115,10 +323,17 @@ public:
     QString getFunctionDescription() const;
     void setFunctionDescription(const QString& functionDescription);
 
+    DataType getReturnType() const;
+    void setReturnType(DataType returnType);
+
+    /// Create a clone of this function
+    GeneratedFunction* clone(QObject* parent);
+
 private:
     FunctionType m_functionType = FunctionType::Annotations;
     QString m_functionName;
     QString m_functionDescription;
+    DataType m_returnType = _void;
 };
 
 class CodeGenerator : public QObject
@@ -133,7 +348,10 @@ public:
 
     void initialize();
 
+    QObjectList getFunctions() const { return m_storage->getFunctions(); }
     GeneratedFunction* addFunction(const QString& name) { return m_storage->addFunction(name); }
+    GeneratedFunction* addFunction(GeneratedFunction* function) { return m_storage->addFunction(function); }
+    void removeFunction(GeneratedFunction* function) { m_storage->removeFunction(function); }
 
     void load(const QDomDocument& document);
     void store(QDomDocument& document);
diff --git a/CodeGenerator/generatormainwindow.cpp b/CodeGenerator/generatormainwindow.cpp
index f3c6672..ec25bbd 100644
--- a/CodeGenerator/generatormainwindow.cpp
+++ b/CodeGenerator/generatormainwindow.cpp
@@ -25,11 +25,14 @@
 #include <QTextStream>
 #include <QFileDialog>
 #include <QFileInfo>
+#include <QInputDialog>
 
 GeneratorMainWindow::GeneratorMainWindow(QWidget *parent) :
     QMainWindow(parent),
     ui(new Ui::GeneratorMainWindow),
-    m_generator(new codegen::CodeGenerator(this))
+    m_generator(new codegen::CodeGenerator(this)),
+    m_currentFunction(nullptr),
+    m_isLoadingData(false)
 {
     ui->setupUi(this);
 
@@ -41,10 +44,10 @@ GeneratorMainWindow::GeneratorMainWindow(QWidget *parent) :
     {
         load(m_defaultFileName);
     }
+    connect(ui->generatedFunctionsTreeWidget, &QTreeWidget::currentItemChanged, this, &GeneratorMainWindow::onCurrentItemChanged);
 
-    // Temporary - to delete:
-    m_generator->addFunction("createAnnotationWatermark");
-    m_generator->addFunction("createAnnotationFreeText");
+    setWindowState(Qt::WindowMaximized);
+    updateFunctionListUI();
 }
 
 GeneratorMainWindow::~GeneratorMainWindow()
@@ -73,6 +76,84 @@ void GeneratorMainWindow::saveSettings()
     settings.setValue("fileName", m_defaultFileName);
 }
 
+void GeneratorMainWindow::updateFunctionListUI()
+{
+    BoolGuard guard(m_isLoadingData);
+
+    ui->generatedFunctionsTreeWidget->setUpdatesEnabled(false);
+    ui->generatedFunctionsTreeWidget->clear();
+    m_mapFunctionToWidgetItem.clear();
+
+    // First, create roots
+    std::map<codegen::GeneratedFunction::FunctionType, QTreeWidgetItem*> mapFunctionTypeToRoot;
+    for (QObject* functionObject : m_generator->getFunctions())
+    {
+        codegen::GeneratedFunction* function = qobject_cast<codegen::GeneratedFunction*>(functionObject);
+        Q_ASSERT(function);
+
+        if (!mapFunctionTypeToRoot.count(function->getFunctionType()))
+        {
+            QTreeWidgetItem* subroot = new QTreeWidgetItem(ui->generatedFunctionsTreeWidget, QStringList(function->getFunctionTypeString()));
+            subroot->setFlags(Qt::ItemIsEnabled);
+            mapFunctionTypeToRoot[function->getFunctionType()] = subroot;
+        }
+    }
+    ui->generatedFunctionsTreeWidget->sortByColumn(0, Qt::AscendingOrder);
+
+    for (QObject* functionObject : m_generator->getFunctions())
+    {
+        codegen::GeneratedFunction* function = qobject_cast<codegen::GeneratedFunction*>(functionObject);
+        Q_ASSERT(function);
+
+        QTreeWidgetItem* functionItem = new QTreeWidgetItem(mapFunctionTypeToRoot[function->getFunctionType()], QStringList(function->getFunctionName()));
+        functionItem->setFlags(Qt::ItemIsEnabled | Qt::ItemIsSelectable);
+        functionItem->setData(0, Qt::UserRole, QVariant::fromValue(function));
+        m_mapFunctionToWidgetItem[function] = functionItem;
+    }
+
+    ui->generatedFunctionsTreeWidget->expandAll();
+    ui->generatedFunctionsTreeWidget->setUpdatesEnabled(true);
+
+    // Select current function
+    auto it = m_mapFunctionToWidgetItem.find(m_currentFunction);
+    if (it != m_mapFunctionToWidgetItem.cend())
+    {
+        ui->generatedFunctionsTreeWidget->setCurrentItem(it->second, 0, QItemSelectionModel::SelectCurrent);
+    }
+
+    m_isLoadingData = false;
+}
+
+void GeneratorMainWindow::setCurrentFunction(codegen::GeneratedFunction* currentFunction)
+{
+    BoolGuard guard(m_isLoadingData);
+
+    if (m_currentFunction != currentFunction)
+    {
+        m_currentFunction = currentFunction;
+
+        // Select current function
+        auto it = m_mapFunctionToWidgetItem.find(m_currentFunction);
+        if (it != m_mapFunctionToWidgetItem.cend())
+        {
+            ui->generatedFunctionsTreeWidget->setCurrentItem(it->second, 0, QItemSelectionModel::SelectCurrent);
+        }
+    }
+}
+
+void GeneratorMainWindow::onCurrentItemChanged(QTreeWidgetItem* current, QTreeWidgetItem* previous)
+{
+    Q_UNUSED(previous);
+
+    if (m_isLoadingData)
+    {
+        return;
+    }
+
+    codegen::GeneratedFunction* function = current->data(0, Qt::UserRole).value<codegen::GeneratedFunction*>();
+    setCurrentFunction(function);
+}
+
 void GeneratorMainWindow::loadSettings()
 {
     QSettings settings("MelkaJ");
@@ -132,3 +213,35 @@ void GeneratorMainWindow::on_actionSave_triggered()
         on_actionSaveAs_triggered();
     }
 }
+
+void GeneratorMainWindow::on_newFunctionButton_clicked()
+{
+    QString functionName = QInputDialog::getText(this, tr("Create function"), tr("Enter function name"));
+    if (!functionName.isEmpty())
+    {
+        codegen::GeneratedFunction* generatedFunction = m_generator->addFunction(functionName);
+        updateFunctionListUI();
+        setCurrentFunction(generatedFunction);
+    }
+}
+
+void GeneratorMainWindow::on_cloneFunctionButton_clicked()
+{
+    if (m_currentFunction)
+    {
+        codegen::GeneratedFunction* generatedFunction = m_generator->addFunction(m_currentFunction->clone(nullptr));
+        updateFunctionListUI();
+        setCurrentFunction(generatedFunction);
+    }
+}
+
+void GeneratorMainWindow::on_removeFunctionButton_clicked()
+{
+    if (m_currentFunction)
+    {
+        codegen::GeneratedFunction* functionToDelete = m_currentFunction;
+        setCurrentFunction(nullptr);
+        m_generator->removeFunction(functionToDelete);
+        updateFunctionListUI();
+    }
+}
diff --git a/CodeGenerator/generatormainwindow.h b/CodeGenerator/generatormainwindow.h
index 6ac705d..1484f5a 100644
--- a/CodeGenerator/generatormainwindow.h
+++ b/CodeGenerator/generatormainwindow.h
@@ -20,9 +20,12 @@
 
 #include <QMainWindow>
 
+class QTreeWidgetItem;
+
 namespace codegen
 {
 class CodeGenerator;
+class GeneratedFunction;
 }
 
 namespace Ui
@@ -30,6 +33,26 @@ namespace Ui
 class GeneratorMainWindow;
 }
 
+class BoolGuard
+{
+public:
+    explicit inline BoolGuard(bool& value) :
+        m_oldValue(value),
+        m_value(&value)
+    {
+        *m_value = true;
+    }
+
+    inline ~BoolGuard()
+    {
+        *m_value = m_oldValue;
+    }
+
+private:
+    bool m_oldValue;
+    bool* m_value;
+};
+
 class GeneratorMainWindow : public QMainWindow
 {
     Q_OBJECT
@@ -44,16 +67,25 @@ public:
 private slots:
     void on_actionLoad_triggered();
     void on_actionSaveAs_triggered();
-
     void on_actionSave_triggered();
+    void on_newFunctionButton_clicked();
+    void on_cloneFunctionButton_clicked();
+    void on_removeFunctionButton_clicked();
 
 private:
     void loadSettings();
     void saveSettings();
 
+    void updateFunctionListUI();
+    void setCurrentFunction(codegen::GeneratedFunction* currentFunction);
+    void onCurrentItemChanged(QTreeWidgetItem* current, QTreeWidgetItem* previous);
+
     Ui::GeneratorMainWindow* ui;
     codegen::CodeGenerator* m_generator;
+    codegen::GeneratedFunction* m_currentFunction;
     QString m_defaultFileName;
+    std::map<codegen::GeneratedFunction*, QTreeWidgetItem*> m_mapFunctionToWidgetItem;
+    bool m_isLoadingData;
 };
 
 #endif // GENERATORMAINWINDOW_H
diff --git a/CodeGenerator/generatormainwindow.ui b/CodeGenerator/generatormainwindow.ui
index d902060..5fbaf35 100644
--- a/CodeGenerator/generatormainwindow.ui
+++ b/CodeGenerator/generatormainwindow.ui
@@ -19,6 +19,12 @@
      <layout class="QVBoxLayout" name="generatedFunctionsVerticalLayout">
       <item>
        <widget class="QTreeWidget" name="generatedFunctionsTreeWidget">
+        <property name="uniformRowHeights">
+         <bool>true</bool>
+        </property>
+        <attribute name="headerVisible">
+         <bool>false</bool>
+        </attribute>
         <column>
          <property name="text">
           <string notr="true">1</string>
@@ -26,37 +32,6 @@
         </column>
        </widget>
       </item>
-      <item>
-       <layout class="QHBoxLayout" name="generatedFunctionsMoveButtonsSpacer">
-        <item>
-         <spacer name="horizontalSpacer">
-          <property name="orientation">
-           <enum>Qt::Horizontal</enum>
-          </property>
-          <property name="sizeHint" stdset="0">
-           <size>
-            <width>40</width>
-            <height>20</height>
-           </size>
-          </property>
-         </spacer>
-        </item>
-        <item>
-         <widget class="QPushButton" name="functionMoveUpButton">
-          <property name="text">
-           <string>Up</string>
-          </property>
-         </widget>
-        </item>
-        <item>
-         <widget class="QPushButton" name="functionMoveDownButton">
-          <property name="text">
-           <string>Down</string>
-          </property>
-         </widget>
-        </item>
-       </layout>
-      </item>
       <item>
        <layout class="QHBoxLayout" name="horizontalLayout">
         <item>
@@ -104,10 +79,72 @@
         <property name="title">
          <string>Parameters</string>
         </property>
+        <layout class="QGridLayout" name="parametersGroupBoxLayout" columnstretch="0,0,0,0">
+         <item row="3" column="0">
+          <widget class="QLabel" name="parameterDataTypeLabel">
+           <property name="text">
+            <string>Data type</string>
+           </property>
+          </widget>
+         </item>
+         <item row="4" column="1">
+          <widget class="QLineEdit" name="parameterValueEdit"/>
+         </item>
+         <item row="2" column="1">
+          <widget class="QComboBox" name="parameterItemTypeCombo"/>
+         </item>
+         <item row="1" column="1">
+          <widget class="QLineEdit" name="parameterNameEdit"/>
+         </item>
+         <item row="1" column="3" rowspan="4">
+          <widget class="QTextBrowser" name="descriptionEdit">
+           <property name="acceptRichText">
+            <bool>false</bool>
+           </property>
+          </widget>
+         </item>
+         <item row="4" column="0">
+          <widget class="QLabel" name="parameterValueLabel">
+           <property name="text">
+            <string>Value</string>
+           </property>
+          </widget>
+         </item>
+         <item row="2" column="0">
+          <widget class="QLabel" name="parameterItemTypeLabel">
+           <property name="text">
+            <string>Item type</string>
+           </property>
+          </widget>
+         </item>
+         <item row="1" column="0">
+          <widget class="QLabel" name="parameterNameLabel">
+           <property name="text">
+            <string>Name</string>
+           </property>
+          </widget>
+         </item>
+         <item row="0" column="3">
+          <widget class="QLabel" name="descriptionLabel">
+           <property name="text">
+            <string>Text description</string>
+           </property>
+          </widget>
+         </item>
+         <item row="3" column="1">
+          <widget class="QComboBox" name="parameterDataTypeCombo"/>
+         </item>
+        </layout>
        </widget>
       </item>
       <item>
-       <widget class="QTreeView" name="treeView"/>
+       <widget class="QTreeWidget" name="parameterTreeWidget">
+        <column>
+         <property name="text">
+          <string notr="true">1</string>
+         </property>
+        </column>
+       </widget>
       </item>
       <item>
        <layout class="QHBoxLayout" name="horizontalLayout_2">
@@ -125,30 +162,37 @@
          </spacer>
         </item>
         <item>
-         <widget class="QPushButton" name="pushButton_6">
+         <widget class="QPushButton" name="itemDeleteButton">
           <property name="text">
-           <string>PushButton</string>
+           <string>Delete</string>
           </property>
          </widget>
         </item>
         <item>
-         <widget class="QPushButton" name="pushButton_5">
+         <widget class="QPushButton" name="itemUpButton">
           <property name="text">
-           <string>PushButton</string>
+           <string>Up</string>
           </property>
          </widget>
         </item>
         <item>
-         <widget class="QPushButton" name="pushButton_8">
+         <widget class="QPushButton" name="itemDownButton">
           <property name="text">
-           <string>PushButton</string>
+           <string>Down</string>
           </property>
          </widget>
         </item>
         <item>
-         <widget class="QPushButton" name="pushButton_7">
+         <widget class="QPushButton" name="itemNewChildButton">
           <property name="text">
-           <string>PushButton</string>
+           <string>New Child</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QPushButton" name="itemNewSiblingButton">
+          <property name="text">
+           <string>New Sibling</string>
           </property>
          </widget>
         </item>