start to delay a bit objects creation.

use a component incubator to create objects whuile the event loop is running

load applets ui only when they get a view

it will have to be cleaned out a lot, by moving the loading logic into AppletInterface

src/scriptengines/qml/declarative/qmlobject.cpp

@@ -34,7 +34,6 @@
 //#include "private/declarative/dataenginebindings_p.h"
 
 
-
 class QmlObjectPrivate
 {
 public:
@@ -66,6 +65,7 @@ public:
 
     QString qmlPath;
     QQmlEngine* engine;
+    QQmlIncubator incubator;
     QQmlComponent* component;
     QObject *root;
     bool delay : 1;
@@ -127,6 +127,7 @@ QmlObject::QmlObject(QObject *parent)
       d(new QmlObjectPrivate(this))
 {
     d->engine = new QQmlEngine(this);
+    d->engine->setIncubationController(new QmlObjectIncubationController(0));
     //d->engine->setNetworkAccessManagerFactory(new PackageAccessManagerFactory());
 }
 
@@ -185,14 +186,14 @@ void QmlObject::completeInitialization()
         return;
     }
 
-    QQmlIncubator incubator;
-    d->component->create(incubator);
+    d->component->create(d->incubator);
 
-    while (!incubator.isReady() && incubator.status() != QQmlIncubator::Error) {
+    while (!d->incubator.isReady() && d->incubator.status() != QQmlIncubator::Error) {
         QCoreApplication::processEvents(QEventLoop::AllEvents, 50);
     }
 
-    d->root = incubator.object();
+    d->root = d->incubator.object();
+    //d->root = d->component->create();
 
     if (!d->root) {
         d->errorPrint();

src/scriptengines/qml/declarative/qmlobject.h

@@ -21,7 +21,12 @@
 #define QMLOBJECT_H
 
 #include <QObject>
+#include <QQmlIncubationController>
 
+#include <QWindow>
+#include <QAnimationDriver>
+#include <QGuiApplication>
+#include <QScreen>
 
 class QQmlEngine;
 class QQmlComponent;
@@ -29,6 +34,53 @@ class QQmlComponent;
 
 class QmlObjectPrivate;
 
+class QmlObjectIncubationController : public QObject, public QQmlIncubationController
+{
+    Q_OBJECT
+
+public:
+    QmlObjectIncubationController(QObject *parent)
+        : QQmlIncubationController(),
+          QObject(parent)
+    {
+        // Allow incubation for 1/3 of a frame.
+        m_incubation_time = qMax(1, int(1000 / QGuiApplication::primaryScreen()->refreshRate()) / 3);
+    }
+
+protected:
+    virtual bool event(QEvent *e)
+    {
+        if (e->type() == QEvent::User) {
+            incubate();
+            return true;
+        }
+        return QObject::event(e);
+    }
+
+public slots:
+    void incubate()
+    {
+        if (incubatingObjectCount()) {
+            incubateFor(m_incubation_time * 2);
+            if (incubatingObjectCount()) {
+                QCoreApplication::postEvent(this, new QEvent(QEvent::User));
+            }
+        }
+    }
+
+    void animationStopped() { incubate(); }
+
+protected:
+    virtual void incubatingObjectCountChanged(int count)
+    {
+        if (count) {
+            QCoreApplication::postEvent(this, new QEvent(QEvent::User));
+        }
+    }
+private:
+    int m_incubation_time;
+};
+
 /**
  * @class QmlObject plasma/declarativewidget.h <Plasma/QmlObject>
  *

src/scriptengines/qml/plasmoid/appletinterface.cpp

@@ -68,6 +68,10 @@ AppletInterface::AppletInterface(DeclarativeAppletScript *script, QQuickItem *pa
             this, SIGNAL(locationChanged()));
     connect(m_appletScriptEngine, SIGNAL(contextChanged()),
             this, SIGNAL(contextChanged()));
+    
+    m_creationTimer = new QTimer(this);
+    m_creationTimer->setSingleShot(true);
+    connect(m_creationTimer, &QTimer::timeout, m_appletScriptEngine, &DeclarativeAppletScript::delayedInit);
 }
 
 AppletInterface::~AppletInterface()
@@ -89,6 +93,9 @@ void AppletInterface::setUiObject(QObject *object)
     QQmlExpression expr(m_appletScriptEngine->engine()->rootContext(), object, "parent");
     QQmlProperty prop(object, "anchors.fill");
     prop.write(expr.evaluate());
+
+    geometryChanged(QRectF(), QRectF(x(), y(), width(), height()));
+    emit busyChanged();
 }
 
 QObject *AppletInterface::uiObject() const
@@ -138,7 +145,7 @@ void AppletInterface::setTitle(const QString &title)
 
 bool AppletInterface::isBusy() const
 {
-    return m_busy;
+    return !m_uiObject || m_busy;
 }
 
 void AppletInterface::setBusy(bool busy)
@@ -505,4 +512,22 @@ void AppletInterface::geometryChanged(const QRectF &newGeometry, const QRectF &o
     }
 }
 
+void AppletInterface::itemChange(ItemChange change, const ItemChangeData &value)
+{
+    if (change == QQuickItem::ItemSceneChange) {
+        //we have a window: create the 
+        if (value.window && !m_uiObject && !m_creationTimer->isActive()) {
+            m_appletScriptEngine->delayedInit();
+
+            /*Experiment on even more delayed, doesn't seem to be good
+            QTime time = QTime::currentTime();
+            qsrand((uint)time.msec());
+            const int interval = qrand() % ((1000 + 1) - 50) + 50;
+            //QTimer::singleShot(interval, m_appletScriptEngine, SLOT(delayedInit()));
+            m_creationTimer->start(interval);*/
+        }
+    }
+    QQuickItem::itemChange(change, value);
+}
+
 #include "moc_appletinterface.cpp"

src/scriptengines/qml/plasmoid/appletinterface.h

@@ -228,6 +228,7 @@ Q_SIGNALS:
 
 protected:
     void geometryChanged(const QRectF &newGeometry, const QRectF &oldGeometry);
+    void itemChange(ItemChange change, const ItemChangeData &value);
 
     DeclarativeAppletScript *m_appletScriptEngine;
 
@@ -244,6 +245,8 @@ private:
     QWeakPointer<QObject> m_uiObject;
     QWeakPointer<QObject> m_compactUiObject;
 
+    QTimer *m_creationTimer;
+
     Plasma::BackgroundHints m_backgroundHints;
     bool m_busy : 1;
     bool m_expanded : 1;

src/scriptengines/qml/plasmoid/declarativeappletscript.cpp

@@ -98,7 +98,15 @@ bool DeclarativeAppletScript::init()
     connect(applet(), SIGNAL(activate()),
             this, SLOT(activate()));
 
+    //FIXME: everything should be delayed
+    if (pc) {
+        delayedInit();
+    }
+    return true;
+}
 
+bool DeclarativeAppletScript::delayedInit()
+{
     m_qmlObject = new QmlObject(applet());
     m_qmlObject->setInitializationDelayed(true);
     //FIXME: what replaced this?
@@ -146,9 +154,10 @@ bool DeclarativeAppletScript::init()
 
     m_interface->setUiObject(m_qmlObject->rootObject());
 
-    qDebug() << "Graphic object created:" << a << a->property("graphicObject");
+    qDebug() << "Graphic object created:" << applet() << applet()->property("graphicObject");
 
     //Create the ToolBox
+    Plasma::Containment *pc = qobject_cast<Plasma::Containment *>(applet());
     if (pc) {
         Plasma::Package pkg = Plasma::PluginLoader::self()->loadPackage("Plasma/Generic");
         pkg.setPath("org.kde.toolbox");
@@ -175,7 +184,7 @@ bool DeclarativeAppletScript::init()
         }
     }
 
-    return !a->failedToLaunch();
+    return !applet()->failedToLaunch();
 }
 
 QString DeclarativeAppletScript::filePath(const QString &type, const QString &file) const

src/scriptengines/qml/plasmoid/declarativeappletscript.h

@@ -56,6 +56,7 @@ public Q_SLOTS:
     void executeAction(const QString &name);
     void activate();
     void configChanged();
+    bool delayedInit();
 
 protected:
     bool init();

src/shell/containments/testpanel/contents/ui/main.qml

@@ -21,7 +21,8 @@ import QtQuick 2.0
 import org.kde.plasma.core 0.1 as PlasmaCore
 import org.kde.plasma.components 0.1 as PlasmaComponents
 
-Row {
+
+Item {
     id: root
     width: 640
     height: 48
@@ -31,13 +32,13 @@ Row {
     Connections {
         target: plasmoid
         onAppletAdded: {
-            var container = appletContainerComponent.createObject(root)
-            container.visible = true
+            var container = appletContainerComponent.createObject(row)
             print("Applet added in test panel: " + applet)
             applet.parent = container
             container.applet = applet
-            applet.anchors.fill= applet.parent
+            applet.anchors.fill = applet.parent
             applet.visible = true
+            container.visible = true
         }
     }
 
@@ -45,12 +46,13 @@ Row {
         id: appletContainerComponent
         Item {
             id: container
+            visible: false
 
             anchors {
                 top: parent.top
                 bottom: parent.bottom
             }
-            width: height
+            width:  height
 
             property Item applet
 
@@ -64,8 +66,16 @@ Row {
         }
     }
 
+    Row {
+        id: row
+        anchors {
+            top: parent.top
+            bottom: parent.bottom
+        }
+    }
+
     Component.onCompleted: {
         print("Test Panel loaded")
         print(plasmoid)
     }
-}
+}