<![CDATA[Dynamically add animation to dynamically created QML component from C++]]>I have a rectangle in rect.qml

import QtQuick 2.0
Rectangle{
    id: myRect;
   width: 100
   height: 100
   color: "red"
}

and animation in anim.qml:

import QtQuick 2.12
ScaleAnimator {
        id: rotationAnim
        target: myRect
        from: 0
        to: 1
        duration: 2000
}

I load the rectangle from c++:

QQmlComponent component(qmlEngine, QUrl::fromLocalFile("rect.qml"));
QQmlContext* rootItemContext = QQmlEngine::contextForObject(rootWindow);
QQuickItem *object = qobject_cast<QQuickItem*>(component.beginCreate(rootItemContext));
if(object != nullptr) {
    QQmlEngine::setObjectOwnership(object, QQmlEngine::CppOwnership);
    object->setParentItem(rootWindow->contentItem());
    object->setParent(qmlEngine);
    }
}

component.completeCreate();

I can load the animation the same way, but obviously, I get the error:

ReferenceError: myRect is not defined

I want to keep a rectangle and animation in different files. I have a set of animations and depending on my need I want to append selected animation to a rectangle.
Is there any way to refer to this rectangle from the animation or any way to append an animation to an existing object?

]]>https://forum.qt.io/topic/105261/dynamically-add-animation-to-dynamically-created-qml-component-from-cRSS for NodeSun, 17 May 2026 11:02:54 GMTTue, 23 Jul 2019 11:27:27 GMT60<![CDATA[Reply to Dynamically add animation to dynamically created QML component from C++ on Tue, 23 Jul 2019 14:31:49 GMT]]>@IntruderExcluder exactly what I needed. Thank you very much.

]]>https://forum.qt.io/post/542419https://forum.qt.io/post/542419Tue, 23 Jul 2019 14:31:49 GMT<![CDATA[Reply to Dynamically add animation to dynamically created QML component from C++ on Tue, 23 Jul 2019 13:01:48 GMT]]>Remove target property then and set running to false for your ScaleAnimator. Create Animator at C++ like Rectangle and do a bit magic like in example below:

    QQmlComponent rect(&engine, QUrl(QStringLiteral("qrc:/MyRect.qml")));
    QQuickItem* rectangle = qobject_cast<QQuickItem*>(rect.beginCreate(context));
    if (rectangle != nullptr) {
        auto rootItem = engine.rootObjects()[0]->property("contentItem").value<QQuickItem*>();
        rectangle->setParentItem(rootItem);
        QQmlComponent a1(&engine, QUrl(QStringLiteral("qrc:/Anim1.qml")));
        auto animation = a1.beginCreate(context);
        rect.completeCreate();
        animation->setParent(rectangle);
        animation->setProperty("target", QVariant::fromValue(rectangle));
        a1.completeCreate();
        animation->setProperty("running", true);
    }
]]>https://forum.qt.io/post/542413https://forum.qt.io/post/542413Tue, 23 Jul 2019 13:01:48 GMT<![CDATA[Reply to Dynamically add animation to dynamically created QML component from C++ on Tue, 23 Jul 2019 12:17:05 GMT]]>Of course, I can define ScaleAnimator inside the rectangle. I did not express myself clearly. I have animation and rectangle in separate files, because:

  • I have a rectangle.
  • I have a set of animations.
    I create a rectangle and sometimes I want to append animation and sometimes I don't. Sometimes I append animation 1, and other time animation 2. I want to this dynamically.
]]>https://forum.qt.io/post/542399https://forum.qt.io/post/542399Tue, 23 Jul 2019 12:17:05 GMT<![CDATA[Reply to Dynamically add animation to dynamically created QML component from C++ on Tue, 23 Jul 2019 11:38:28 GMT]]>Hi @ChrisTof , you can do like this:-

Rectangle {
    id: myRect
    width: 100
    height: 100
    color: "red"

    Anim
    {
        target: myRect
    }
}

Note:- Remove target inside ScaleAnimator in anim.qml

]]>https://forum.qt.io/post/542389https://forum.qt.io/post/542389Tue, 23 Jul 2019 11:38:28 GMT<![CDATA[Reply to Dynamically add animation to dynamically created QML component from C++ on Tue, 23 Jul 2019 11:36:58 GMT]]>You can define ScaleAnimator inside your rectacgle, like in documentation.

]]>https://forum.qt.io/post/542388https://forum.qt.io/post/542388Tue, 23 Jul 2019 11:36:58 GMT