Transform component's init and shutdown to signals

CMakeLists.txt

@@ -2776,10 +2776,9 @@ if(QML)
     src/qml/qmlplayerproxy.cpp
     src/qml/qmlvisibleeffectsmodel.cpp
     src/qml/qmlwaveformoverview.cpp
+    src/qml/mixxcomponentlifecycle.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

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);

src/qml/mixxcomponentlifecycle.cpp

@@ -0,0 +1,7 @@
+#include "mixxxcontroller.h"
+
+namespace mixxx {
+namespace qml {
+
+} // namespace qml
+} // namespace mixxx

src/qml/mixxcomponentlifecycle.h

@@ -0,0 +1,24 @@
+#ifndef MIXXX_MIXXXCOMPONENTLIFECYCLE_H
+#define MIXXX_MIXXXCOMPONENTLIFECYCLE_H
+
+#include <QObject>
+
+namespace mixxx {
+namespace qml {
+
+class MixxxComponentLifecycle {
+  public:
+    virtual ~MixxxComponentLifecycle() {
+    }
+  signals:
+    virtual void init() = 0;
+    virtual void shutdown() = 0;
+};
+
+} // namespace qml
+} // namespace mixxx
+
+#define MixxxComponentLifecycleIID "MixxxComponentLifecycle"
+Q_DECLARE_INTERFACE(mixxx::qml::MixxxComponentLifecycle, MixxxComponentLifecycleIID)
+
+#endif // MIXXX_MIXXXCOMPONENTLIFECYCLE_H

src/qml/mixxxcontroller.cpp

@@ -2,11 +2,29 @@
 
 namespace mixxx {
 namespace qml {
-void MixxxController::init() {
-    metaObject()->invokeMethod(this, "init");
+
+void MixxxController::componentComplete() {
+    QObject::connect(this,
+            &MixxxComponentLifecycle::init,
+            this,
+            &MixxxController::initChildrenComponents);
+    QObject::connect(this,
+            &MixxxComponentLifecycle::shutdown,
+            this,
+            &MixxxController::shutdownChildrenComponents);
 }
-void MixxxController::shutdown() {
-    metaObject()->invokeMethod(this, "shutdown");
+
+void MixxxController::initChildrenComponents() {
+    for (auto* childComponent : m_pChildComponents.toList<QList<MixxxComponentLifecycle*>>()) {
+        emit childComponent->init();
+    }
 }
+
+void MixxxController::shutdownChildrenComponents() {
+    for (auto* childComponent : m_pChildComponents.toList<QList<MixxxComponentLifecycle*>>()) {
+        emit childComponent->shutdown();
+    }
+}
+
 } // namespace qml
 } // namespace mixxx

src/qml/mixxxcontroller.h

@@ -6,27 +6,32 @@
 #include <QObject>
 #include <QtQml>
 
-#include "mixxxscreen.h"
+#include "mixxcomponentlifecycle.h"
 
 namespace mixxx {
 namespace qml {
 
-class MixxxController : public QObject {
+class MixxxController : public QObject, public MixxxComponentLifecycle, public QQmlParserStatus {
     Q_OBJECT
+    Q_INTERFACES(QQmlParserStatus MixxxComponentLifecycle)
     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<MixxxComponentLifecycle> childComponents MEMBER m_pChildComponents)
+    Q_CLASSINFO("DefaultProperty", "childComponents")
 
   public:
-    void init();
-    void shutdown();
+    void componentComplete() override;
 
   private:
     QString m_controllerId;
     bool m_debugMode;
-    QQmlListProperty<MixxxScreen> m_screens;
+    QList<MixxxComponentLifecycle*> m_childComponents;
+    QQmlListProperty<MixxxComponentLifecycle> m_pChildComponents;
+
+  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

@@ -5,17 +5,21 @@
 #ifndef MIXXX_MIXXXSCREEN_H
 #define MIXXX_MIXXXSCREEN_H
 
+#include <QtQml/qqmlregistration.h>
+
 #include <QImage>
 #include <QObject>
 #include <QSize>
-#include <QtQmlIntegration>
+
+#include "mixxcomponentlifecycle.h"
 
 namespace mixxx {
 namespace qml {
 
-class MixxxScreen : public QObject {
+class MixxxScreen : public QObject, public MixxxComponentLifecycle {
     Q_OBJECT
     QML_ELEMENT
+    Q_INTERFACES(MixxxComponentLifecycle)
     Q_PROPERTY(QString screenId MEMBER m_screenId REQUIRED)
     Q_PROPERTY(int width READ width WRITE setWidth)
     Q_PROPERTY(int height READ height WRITE setHeight)
@@ -34,24 +38,12 @@ 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);
 
   private:
     QString m_screenId;         // The screen identifier.