Transform component's init and shutdown to signals

CMakeLists.txt

@@ -2777,9 +2777,7 @@ if(QML)
     src/qml/qmlvisibleeffectsmodel.cpp
     src/qml/qmlwaveformoverview.cpp
     src/qml/mixxxcontroller.cpp
-    src/qml/mixxxcontroller.h
     src/qml/mixxxscreen.cpp
-    src/qml/mixxxscreen.h
     # The following sources need to be in this target to get QML_ELEMENT properly interpreted
     src/control/controlmodel.cpp
     src/control/controlsortfiltermodel.cpp

res/controllers/Denon-DN-S3700.midi.xml

@@ -7,9 +7,7 @@
     </info>
     <controller id="DN-S3700">
         <scriptfiles>
-            <file filename="Denon-DN-S3700.qml" functionprefix=""/>
+            <file filename="Denon-DN-S3700.qml" />
         </scriptfiles>
-        <controls />
-        <outputs/>
     </controller>
 </MixxxControllerPreset>

res/controllers/Denon-DN-S3700.qml

@@ -5,16 +5,12 @@ import "Mixxx"
 MixxxController {
     id: controller
 
-    function init() {
-        console.error(controller.controllerId, controller.debugMode);
-    }
-    function shutdown() {
-        console.error(`Shutting down ${controller.controllerId} with debug mode ${controller.debugMode}`);
-    }
+    onInit: console.error(`Starting controller ${controller.controllerId} with debug mode ${controller.debugMode}`)
+    onShutdown: console.error(`Shutting down ${controller.controllerId} with debug mode ${controller.debugMode}`)
 
     MixxxScreen {
         screenId: "screen 7"
         splashOff: 5000
-        Component.onCompleted: console.error(`MixxxScreen.identifier=${screenId} ${splashOff}`)
+        onInit: console.error(`MixxxScreen.screenId=${screenId}, MixxxScreen.splashOff=${splashOff}`)
     }
 }

src/controllers/scripting/legacy/controllerscriptenginelegacy.cpp

@@ -129,7 +129,7 @@ bool ControllerScriptEngineLegacy::callShutdownFunction() {
 
 #ifdef MIXXX_USE_QML
     for (const auto& controller : m_mixxxController) {
-        controller->shutdown();
+        emit controller->shutdown();
     }
 
     if (!m_bQmlMode) {
@@ -207,7 +207,7 @@ bool ControllerScriptEngineLegacy::callInitFunction() {
         }
 
         for (const auto& controller : m_mixxxController) {
-            controller->init();
+            emit controller->init();
         }
 
         QHashIterator<QString, std::shared_ptr<QQuickItem>> i(m_rootItems);
@@ -261,48 +261,7 @@ bool ControllerScriptEngineLegacy::callInitFunction() {
             // ControllerScriptEngineBase::handleQMLErrors
         }
 
-        QListIterator<std::shared_ptr<mixxx::qml::MixxxController>> controllers(m_mixxxController);
-        bool controllersSuccess = true;
-        while (controllers.hasNext()) {
-            const QMetaObject* metaObject = controllers.next()->metaObject();
-
-            VERIFY_OR_DEBUG_ASSERT(metaObject) {
-                qCWarning(m_logger) << "Invalid meta object for controller";
-                continue;
-            }
-
-            QMetaMethod initFunction;
-            bool typed = false;
-            int methodIdx = metaObject->indexOfMethod(kQmlComponentInitFunctionUntypedSignature);
-
-            if (methodIdx == -1 || !metaObject->method(methodIdx).isValid()) {
-                qCDebug(m_logger) << "QML controller has no valid untyped init method.";
-                methodIdx = metaObject->indexOfMethod(kQmlComponentFunctionTypedSignature);
-                typed = true;
-            }
-
-            initFunction = metaObject->method(methodIdx);
-
-            if (!initFunction.isValid()) {
-                qCDebug(m_logger) << "QML controller has no valid untyped init method; Skipping.";
-                continue;
-            }
-
-            qCDebug(m_logger) << "Executing init on QML controller";
-            if (typed) {
-                success &= initFunction.invoke(i.value().get(),
-                        Qt::DirectConnection,
-                        Q_ARG(QString, controllerName),
-                        Q_ARG(bool, m_logger().isDebugEnabled()));
-            } else {
-                success &= initFunction.invoke(i.value().get(),
-                        Qt::DirectConnection,
-                        Q_ARG(QVariant, controllerName),
-                        Q_ARG(QVariant, m_logger().isDebugEnabled()));
-            }
-        }
-
-        return success && controllersSuccess;
+        return success;
     }
 #endif
 }

src/qml/mixxxcontroller.cpp

@@ -2,11 +2,38 @@
 
 namespace mixxx {
 namespace qml {
-void MixxxController::init() {
-    metaObject()->invokeMethod(this, "init");
+
+MixxxController::MixxxController(QObject* parent)
+        : QObject(parent), m_pChildren(this, &m_children) {
 }
-void MixxxController::shutdown() {
-    metaObject()->invokeMethod(this, "shutdown");
+
+void MixxxController::classBegin() {
 }
+
+void MixxxController::componentComplete() {
+    QObject::connect(this,
+            &MixxxController::init,
+            this,
+            &MixxxController::initChildrenComponents);
+    QObject::connect(this,
+            &MixxxController::shutdown,
+            this,
+            &MixxxController::shutdownChildrenComponents);
+}
+
+void MixxxController::initChildrenComponents() {
+    for (auto* childComponent : m_children) {
+        // Try emit init signal
+        QMetaObject::invokeMethod(childComponent, "init", Qt::DirectConnection);
+    }
+}
+
+void MixxxController::shutdownChildrenComponents() {
+    for (auto* childComponent : m_children) {
+        // Try emit shutdown signal
+        QMetaObject::invokeMethod(childComponent, "shutdown", Qt::DirectConnection);
+    }
+}
+
 } // namespace qml
 } // namespace mixxx

src/qml/mixxxcontroller.h

@@ -6,27 +6,36 @@
 #include <QObject>
 #include <QtQml>
 
-#include "mixxxscreen.h"
-
 namespace mixxx {
 namespace qml {
 
-class MixxxController : public QObject {
+class MixxxController : public QObject, public QQmlParserStatus {
     Q_OBJECT
+    Q_INTERFACES(QQmlParserStatus)
     QML_ELEMENT
     Q_PROPERTY(QString controllerId MEMBER m_controllerId)
     Q_PROPERTY(bool debugMode MEMBER m_debugMode)
-    Q_PROPERTY(QQmlListProperty<MixxxScreen> screens MEMBER m_screens)
-    Q_CLASSINFO("DefaultProperty", "screens")
+    Q_PROPERTY(QQmlListProperty<QObject> childComponents MEMBER m_pChildren)
+    Q_CLASSINFO("DefaultProperty", "childComponents")
 
   public:
+    explicit MixxxController(QObject* parent = nullptr);
+    void classBegin() override;
+    void componentComplete() override;
+
+  signals:
     void init();
     void shutdown();
 
   private:
     QString m_controllerId;
     bool m_debugMode;
-    QQmlListProperty<MixxxScreen> m_screens;
+    QList<QObject*> m_children;
+    QQmlListProperty<QObject> m_pChildren;
+
+  private slots:
+    void initChildrenComponents();
+    void shutdownChildrenComponents();
 };
 
 } // namespace qml

src/qml/mixxxscreen.cpp

@@ -2,5 +2,30 @@
 
 namespace mixxx {
 namespace qml {
+
+int MixxxScreen::width() {
+    return m_size.width();
+}
+
+void MixxxScreen::setWidth(int value) {
+    m_size = QSize(value, m_size.height());
+}
+
+int MixxxScreen::height() {
+    return m_size.width();
+}
+
+void MixxxScreen::setHeight(int value) {
+    m_size = QSize(m_size.width(), value);
+}
+
+uint MixxxScreen::splashOff() {
+    return m_splashOff.count();
+}
+
+void MixxxScreen::setSplashOff(uint value) {
+    m_splashOff = std::chrono::milliseconds(value);
+}
+
 } // namespace qml
 } // namespace mixxx

src/qml/mixxxscreen.h

@@ -5,10 +5,11 @@
 #ifndef MIXXX_MIXXXSCREEN_H
 #define MIXXX_MIXXXSCREEN_H
 
+#include <QtQml/qqmlregistration.h>
+
 #include <QImage>
 #include <QObject>
 #include <QSize>
-#include <QtQmlIntegration>
 
 namespace mixxx {
 namespace qml {
@@ -34,24 +35,16 @@ class MixxxScreen : public QObject {
     };
     Q_ENUM(ColorEndian)
 
-    int width() {
-        return m_size.width();
-    }
-    void setWidth(int value) {
-        m_size = QSize(value, m_size.height());
-    }
-    int height() {
-        return m_size.width();
-    }
-    void setHeight(int value) {
-        m_size = QSize(m_size.width(), value);
-    }
-    uint splashOff() {
-        return m_splashOff.count();
-    }
-    void setSplashOff(uint value) {
-        m_splashOff = std::chrono::milliseconds(value);
-    }
+    int width();
+    void setWidth(int value);
+    int height();
+    void setHeight(int value);
+    uint splashOff();
+    void setSplashOff(uint value);
+
+  signals:
+    void init();
+    void shutdown();
 
   private:
     QString m_screenId;         // The screen identifier.