Qt 5.8 QML Image async long delay

franzi

Hi,

after I updated Qt 5.7 to Qt 5.8, I noticed loading of images over HTTP became very slow. I'm running the application on RPi, but the same thing happens on Linux Ubuntu. Reverting to Qt 5.7 the problem is solved. Consider this QML snippet:

main.qml

import QtQuick 2.0
import QtQuick.Controls 1.0

ApplicationWindow {
    visible: true
    width: 1350
    height: 800
    title: qsTr("Qt Quick Controls 1.0")

    GridView {
        id: grid
        width: parent.width
        height: cellHeight

        cellWidth: 225
        cellHeight: 320

        focus: true

        model: 20
        delegate: Card {
            pic: (index > 5) ? "http://www.planwallpaper.com/static/images/nasas-images-of-most-remarkable-events-you-cant-miss.jpg" : "https://d36tnp772eyphs.cloudfront.net/blogs/1/2015/04/lion-photo.jpg"

        }

        Keys.onReturnPressed: time.running = false;
    }

    Timer {
        id: time
        interval: 1
        running: true
        repeat: true
        property double count: 0.0
        property double time0: 0.0
        onTriggered: {
            if(time0 == 0.0) time0 = Date.now();
            txt.text = "elapsed time (ms): " + (Date.now() - time0);
            for(grid.currentIndex = 0; grid.currentIndex < 20; grid.currentIndex++)
                    count += grid.currentItem.load;
            if(count == 20.0)
                time.running = false;
            else count = 0.0
        }
    }

    Text {
        id: txt
        anchors.bottom: parent.bottom
        anchors.right: parent.right
        font.pixelSize: 30
    }
}

Card.qml

import QtQuick 2.0

Item {
    id: cardItem
    width: 235
    height: 320
    property string pic
    property double load: cardImage.progress

    Image {
        id: cardImage
        anchors.fill: cardItem
        source: pic
    }
}

What I noticed too, if I set asynchronous: true on images loaded over qrc, the same thing happens - those have a big delay too. My first guess is that something has changed in how Qt handles async image loading, but I can't find anything in the changelogs.

Any help is appreciated. Thanks.

SGaist

Hi and welcome to devnet,

Looks like a regression. You should take a look at the bug report system to see if it's something known. If not please consider opening a new report providing a minimal compilable example.