QML Listview scrolling error when run on platform eglfs

donbychang

Hello all,

I write a simple program with Qt version 4.8.4 that can show the list
of the USB which plugged in my target board by using qml listview and folderlistmodel.
(My target board is ARM-cortex A9 freescale imx6)

The qml code looks like this:

@import QtQuick 1.0
import Qt.labs.folderlistmodel 1.0

ListView {
id: list
width: 200; height: 400

FolderListModel {
    id: folderModel
    folder: "/mnt/usb"
}

Component {
    id: fileDelegate
    Text { text: fileName; font.pixelSize: 32}
}

model: folderModel
delegate: fileDelegate

}@

(The complete cod of simple_qt4:
"simple_qt4_code":https://mega.co.nz/#!nJEyTK4Q!DKSWKwo4tEVYZJJM4lw7ackpwhjk81NSSSsUAJkZX8E
if you cannot download, please inform me.)

When I run he program with these options:

./simple_qt4 -platform eglfs -plugin tslib:/dev/input/event0

At first, the program can indeed show the list of USB,
however, when I scroll the listview, the list will show something in a mess.
like the following video:
"simple_qt4_error.mp4":https://mega.co.nz/#!6UMhEQ6D!SLHc1NSm8zVgnclU7HnoCHpFKLsTIdUzesURsUUWkU4
(if you can not see, please infom me)

It is strange that when I changed the pixel size of qml text to 10, it will not happend again.
I try some other pxiel size, 16~60 will all cause this problem.
(not all sizes have been tested, just random in this range)
There are 122 items totally in the USB, including the file with Chinese file name
I also try the platform linuxfb, just like this:

./simple_qt4 -platform linuxfb -plugin tslib:/dev/input/event0

It is amazing that this problem will not happen again.
By the way, if I change all item with English file name, it will not happen too.

Also, I try to run it by compling with Qt verison 5.0.2, and run on eglfs again:

./simple_qt5 -platform eglfs -plugin tslib:/dev/input/event

This problem will not happen too.
The following video can show normally of USB list without mess
"simple_qt5_normal.mp4":https://mega.co.nz/#!LJcmQLrb!L4IAhhalV1Fm00pvp2ua3n6pCXIQ-NCSjaTIptFJuQU

The Qt5.0.2 qml code looks like this:

@import QtQuick 2.0
import Qt.labs.folderlistmodel 2.0

ListView {
width: 200; height: 400

FolderListModel {
    id: folderModel
    folder: "/mnt/usb"
}

Component {
    id: fileDelegate
    Text { text: fileName; font.pixelSize: 32}
}

model: folderModel
delegate: fileDelegate

}@

(The complete cod of simple_qt5:
"simple_qt5_code":https://mega.co.nz/#!LMNUmazA!AdnN6Wcr8EIiAoJiMkm405z_mtY51gkL3SeuXjX5NzM
if you cannot download, please inform me.)

I think that maybe this problem is modified on Qt5, but I am not sure which part cause this problem.
Is it caused by plugin eglfs or Qt core problem or others?
Can I modified this problem on Qt4.8.4?

I search on web and here, but seem no find the same problem.
If there is a similar or the same problem, please inform me also.
Thank you all.

Best Regards