Missing mouse events with StackView and OpenGL

Tom_H

Hello. I'm writing an OpenGL Android app using the technique shown in the openglunderqml example. In main.qml, I used an ApplicationWindow containing MyQuickItem and everything was fine until I needed to add more UI screens.

I decided to use a StackView, so I moved the block containing MyQuickItem to MainPage.qml and set the main.stackview.initialItem to MainPage.qml.

But now my C++ code doesn't receive any mouse/touch events, which I need for rotating the object.

Is there a way for me to receive mouse events using StackView? If not, is there another solution?

Thanks.

main.qml:

ApplicationWindow {
    StackView {
        id: stackview
        width: parent.width
        initialItem: "MainPage.qml"
    }
    ...
}

MainPage.qml:

import MyQuickItem 1.0

Page {
    MyQuickItem {
        id: app
    }
    ...
}

main.qml that works:

ApplicationWindow {
    MyQuickItem {
        id: app
    }
    ...
}

Diracsbracket

Hi @Tom_H
This seems to have nothing to do with whether you are using a StackedView or not.

I tried with the Simple Pie Chart example from:
http://doc.qt.io/qt-5/qtqml-tutorials-extending-qml-example.html
as my custom QQuickItem and added the mousePressEvent() and hoverMoveEvent() handlers to it. (Since you are targetting touch devices it seems, that last one won't be of interest to you, but I added it to test those events as well.)

    void mousePressEvent(QMouseEvent* event)
    {
        QQuickItem::mousePressEvent(event);
        qDebug() << "Pressed: " <<  event->pos();
    }

    void hoverMoveEvent(QHoverEvent* event) {
        QQuickItem::hoverMoveEvent(event);
        qDebug() << "Moved: " << event->pos();
    }

Then, I wrapped the whole thing exactly as you do, in its own QML file, since a Page, and then use it as that as the initialItem of the StackView. Yet, I still get all the mouse events: clicking and hovering works?

Tom_H

Thank you for investigating, but your example doesn't use OpenGL. This problem seems to be unique to this method of OpenGL and StackView. I have found two solutions, one using an invisible StackView, and the other using a Popup.

Solution 1:

ApplicationWindow {
    MyQuickItem {
        id: app
    }

    StackView {
        id: stack
        anchors.fill: parent
        visible: false
        // Setting opacity to 0 doesn't work, it still hides mouse events.
    }

    function showpage(page) {
        stack.visible = true
        stack.push(page)
    }

    function closepage() {
        stack.pop()
        stack.visible = false
    }
}

Solution 2:

ApplicationWindow {
    MyQuickItem {
        id: app
    }

    // Define a Popup for each page
    Popup {
        id: page2
        anchors.fill: parent
        Page2 {}
    }

    function showpage2() {
        page2.open()
    }
}