Is it possible to dynamically populate a ListView within a GridView ?

[andrioli.n]

We could safe some time if you tell me how often I should repeat the question on whether the property getter is being called before you deem it worthy to be answered, then I can just do that in a single posting.

Unless of course you don't want to narrow down the problem?

Cheers,
_

I should read more carefully, my bad...

You're right, the getters of my OverviewEntry are well called but none of the ChannelEntry's one. (by the way, the ChannelEntry object is used elsewhere in the code and qml and worked well in a usual usage)

[anda_skoa]

Ok, so OverviewEntry::channel() is called for all instances of OverViewEntry?
And each call returned a non-empty list?

Cheers,
_

[andrioli.n]

Ok, so OverviewEntry::channel() is called for all instances of OverViewEntry?
And each call returned a non-empty list?

Cheers,
_

Exactly, that's why I suspect I misunderstood the way Qt is working behind the scene.

[anda_skoa]

Ok, so lets summarize:

- Your OverviewEntry QML instances are created
- They display the value of the name property
- They call the channels() getter when assigning to the ListView's model property
- The channels() getters return a correct, non-empty QList<ChannelEntry*>
- The ListView counts are 0

What kind of output do you get when you put this into the ListViews

onModelChanged: console.log("model for " + modelData.name + " is " + model);

onModelChanged: console.log("model for " + modelData.name + " is " + model);

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Cheers,
_

[andrioli.n]

Ok, so lets summarize:

- Your OverviewEntry QML instances are created
- They display the value of the name property
- They call the channels() getter when assigning to the ListView's model property
- The channels() getters return a correct, non-empty QList<ChannelEntry*>
- The ListView counts are 0

What kind of output do you get when you put this into the ListViews

onModelChanged: console.log("model for " + modelData.name + " is " + model);

onModelChanged: console.log("model for " + modelData.name + " is " + model);

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Cheers,
_

I just made the test and this is the output :

• qml: model for OverviewEntry 1 is QVariant(QList<ChannelEntry*>)
• qml: model for OverviewEntry 2 is QVariant(QList<ChannelEntry*>)
• qml: model for OverviewEntry 3 is QVariant(QList<ChannelEntry*>)
• qml: model for OverviewEntry 4 is QVariant(QList<ChannelEntry*>)
• qml: model for OverviewEntry 5 is QVariant(QList<ChannelEntry*>)
• qml: model for OverviewEntry 6 is QVariant(QList<ChannelEntry*>)

[anda_skoa]

Hmm.
You also have

Q_DECLARE_METATYPE(QList<ChannelEntry*>);

Q_DECLARE_METATYPE(QList<ChannelEntry*>);

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have you tried adding

Q_DECLARE_METATYPE(ChannelEntry*);

Q_DECLARE_METATYPE(ChannelEntry*);

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Cheers,
_

[andrioli.n]

Hmm.
You also have

Q_DECLARE_METATYPE(QList<ChannelEntry*>);

Q_DECLARE_METATYPE(QList<ChannelEntry*>);

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have you tried adding

Q_DECLARE_METATYPE(ChannelEntry*);

Q_DECLARE_METATYPE(ChannelEntry*);

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Cheers,
_

I tried but it doesn't change anything. Even with these two Q_DECLARE_METATYPE commented, it works same way.

But if I comment :

//Main.cpp
...
qmlRegisterType<ChannelEntry>("ChannelEntry", 1, 0, "ChannelEntry");
...

//Main.cpp
...
qmlRegisterType<ChannelEntry>("ChannelEntry", 1, 0, "ChannelEntry");
...

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The app crashed...

[anda_skoa]

Probably because you are now using the same name for the registered type and the QML element type.
Change the second string argument here and maybe also use qmlRegisterUncreatableType()

Cheers,
_

[andrioli.n]

Probably because you are now using the same name for the registered type and the QML element type.
Change the second string argument here and maybe also use qmlRegisterUncreatableType()

Cheers,
_

I tried by refactoring my C++ type ChannelEntry into QChannelEntry and setting :

//Main.cpp
...
qmlRegisterType<QChannelEntry>("ChannelEntry", 1, 0, "QChannelEntry");
qmlRegisterUncreatableType<QChannelEntry>("ChannelEntry", 1, 0, "QChannelEntry","");
...

//Main.cpp
...
qmlRegisterType<QChannelEntry>("ChannelEntry", 1, 0, "QChannelEntry");
qmlRegisterUncreatableType<QChannelEntry>("ChannelEntry", 1, 0, "QChannelEntry","");
...

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And the only change is the result of your debug output :

• qml: model for OverviewEntry 1 is QVariant(QList<QChannelEntry*>)
• qml: model for OverviewEntry 2 is QVariant(QList<QChannelEntry*>)
• qml: model for OverviewEntry 3 is QVariant(QList<QChannelEntry*>)
• qml: model for OverviewEntry 4 is QVariant(QList<QChannelEntry*>)
• qml: model for OverviewEntry 5 is QVariant(QList<QChannelEntry*>)
• qml: model for OverviewEntry 6 is QVariant(QList<QChannelEntry*>)

Remark : I also tried by commenting qmlRegisterType or qmlRegisterUncreatableType but with no success

[anda_skoa]

Ok, strange.

Can you try to create a minimal example that can be built and run and shows the problem?

Cheers,
_

[andrioli.n]

Sorry for the late reply but I haven't got the time until now.

I made this little example which build and run but with the same problem.

ListViewExample.zip

I hope it helps to understand the issue.

[anda_skoa]

Ok, this is more complicated than I thought

I found two things that work:
- make the channels property a QList<QObject*>
- Use a QAbstractListModel derived class to provide the channel data

Some other observations:
- main.cpp cannot compile because there is no MainWindow.h, it is mainwindow.h
- this can be written much shorter. Instead of

QString::fromStdString("channel " + QString::number(i).toStdString()).toStdString().c_str())

QString::fromStdString("channel " + QString::number(i).toStdString()).toStdString().c_str())

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write this

QString("channel %1").arg(i);

QString("channel %1").arg(i);

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Cheers,
_