Kind of solved. If I set sizeAdjustPolicy to AdjustToContents and sizePolicy to Maximum, the list widget size will adjust to accomodate items plus small margins around them. I'm quite happy with the result, it would be even better if I could make items equally distribute across available space, but even now it looks good enough.

@VRonin Yeah you are right. Usually my custom widget has another widgets (like another label for text, button for submit etc.) so I used setItemWidget. But your way better for only images.

@learnist said in How to edit a QListwidgetItem by using custom context menu ? need some corrections:

but for point 3 ,which edit trigger should i use ??
can you please elaborate

If you don't want double clicking or any key pressing to trigger the editing, just set it to QAbstractItemView::NoEditTriggers.

By the way, how are your buttons connected ?
You might want to rather call the dialog's accept slot from on_buttonBox_accepted rather than connecting it directly to your button.

Hi
10.000 items take some time to create and add.

Print_Descendants_key must not touch/access the ListWidget from the other thread. that will not be good.

To make the UI less hanged while adding such a number of items, you can do 3 things.

1: use a View + custom model instead.
If you already have all the data in a list/vector, a custom model on top of that would be super fast.
2:
Use a thread to send data to main. Make sure the thread is not hammering the
main gui as that would lag too. You can also use a QTimer and simply slow down the adding.
3:
Do the ugly trick of calling QApplication::processEvents() (in the loop that adds the items)
to allow the main GUI to be more responsive.

@Mr-Workalot said in is there a way to minimize/hide and show the QListWidget in my UI:

i guess this can be done when i select 2 widgets atleas

Yes.
Select the your list widget and the left layout, then you can layout them using splitter...

Hi
The downside of having 22 dialogs is all the .cpp and .h you get and also adding new features, say you want to have an image of the
dish at some later point you would have to add this 22 places.

For your use case, it sounds like data driver would be much better.
Meaning you have just one dialog and then based on the data structure where you keep the information about
the recipes, you add the needed EditLines at runtime.

SO as @JonB asks, are they that special each of the dishes that you cant handle them very much the same?

Good then please mark the thread as solved using the "Topic Tools" button so that other forum users may know a solution has been found.

@mrjj Thanks so much , really helped me understand.

@VRonin

Doing a few (rather simple) tests, I found the following (which confirms your suspicion)

Works: (but no check box) - this is expected to work

// create item QListWidgetItem* item = new QListWidgetItem(name, ui->listDriveInfo); // item->setText(name); // item->setFlags(item->flags() | Qt::ItemIsUserCheckable); // item->setCheckState(enabled ? Qt::Checked : Qt::Unchecked); // add item to list ui->listDriveInfo->addItem(item);

this crashes on setFlags() call

// create item QListWidgetItem* item = new QListWidgetItem(name, ui->listDriveInfo); // item->setText(name); //set checkable and state Qt::ItemFlags localFlags = item->flags(); item->setFlags(localFlags | Qt::ItemIsUserCheckable); item->setCheckState(enabled ? Qt::Checked : Qt::Unchecked); // add item to list ui->listDriveInfo->addItem(item);

but these 2 both work (without setting owning QListWidget)

// create item QListWidgetItem* item = new QListWidgetItem(name); // item->setText(name); //set checkable and state Qt::ItemFlags localFlags = item->flags(); item->setFlags(localFlags | Qt::ItemIsUserCheckable); item->setCheckState(enabled ? Qt::Checked : Qt::Unchecked); // add item to list ui->listDriveInfo->addItem(item);

and

// create item QListWidgetItem* item = new QListWidgetItem(); // item->setText(name); //set checkable and state Qt::ItemFlags localFlags = item->flags(); item->setFlags(localFlags | Qt::ItemIsUserCheckable); item->setCheckState(enabled ? Qt::Checked : Qt::Unchecked); // add item to list ui->listDriveInfo->addItem(item);

Testing:

I create a new application, did exactly the same (add a string and a checkbox) and that work 100%. Create a form, throw on a
QListWidget and run it with this code.

QListWidgetItem* item = new QListWidgetItem("New", ui->listWidget); item->setFlags(item->flags() | Qt::ItemIsUserCheckable); item->setCheckState(Qt::Unchecked); QListWidgetItem* item1 = new QListWidgetItem("New 1", ui->listWidget); item1->setFlags(item->flags() | Qt::ItemIsUserCheckable); item1->setCheckState(Qt::Unchecked); QListWidgetItem* item2 = new QListWidgetItem("New 2", ui->listWidget); item2->setFlags(item->flags() | Qt::ItemIsUserCheckable); item2->setCheckState(Qt::Unchecked); ui->listWidget->addItem(item); ui->listWidget->addItem(item1); ui->listWidget->addItem(item2); connect(ui->listWidget, &QListWidget::itemClicked, this, [this](QListWidgetItem * i) { // Get drive info from driveList int pos = ui->listWidget->row(i); // check state & set state bool active = i->checkState() == Qt::Checked; qDebug() << (active ? "enabled" : "disabled"); });

So my question is, bug (on whose side) or some setting on my side? Thoughts on what to look for?

@mrjj

I see, thank you. I'm going for that route then

Drag'n'Drop from a QListWidget to another QListWidget should work out-of-the-box if dragEnabled/acceptDrops is active - see documentation

@Ratzz Sorry i can not check your answer as solved answer, Qt forum has a bug about that. I solved my problem, i've already read the topic that you linked here but after you posted it then a read again and i solved my problem thank you, but even so trying to give more explanatory answers is a good way because i like this forum and i want to see answers from another angles, another perspectives. When i get experienced at Qt i want to give good answers too. :)

And thank you so much Mr. @dheerendra . I think approach with row is a better way but i was need to a quick way so that stackoverflow link helped me about that.

@nebulaekg It wasn't wrong, it was just the easy method. With easy comes very little customization. Now that you want to change it's behavior it becomes much harder. For simple lists you can definitely use the widget but for anything more you want a view/model and then delegates to control display.

Check into it I'm sure you'll find it's not that much harder than the widget and will give you the control you want. :)

@J.Hilk
It works ! THANKS :-)

@philm001
the stylesheet declaration should rather look like this i guess:

w->setStyleSheet(QString("QListView::item { background: rgba(255, 0, 0, %1)}").arg(value.toInt())

setItemWidget should come with a huge warning about it being the wrong solution in 90% of the cases.

What you need is a QStyledItemDelegate.
use QListWidgetItem::setData to store your text, image and color in 3 different roles (Qt::EditRole, Qt::DecorationRole and Qt::UserRole appear to be the most natural choices)

then subclass QStyledItemDelegate and reimplement paint (you can find Qt's implementation here to use as a starting point)

finally just call QListWidget::setItemDelegate to assign the delegate to the view

@raven-worx

my bad, Thanks for the link it helped a lot.

@brucezcg said in QListWidget: How to disable when mouse hover ,the items change background color?:

I don't want to change background color when hover,
I just want to disable hover, when hover, the items stay the background color, may be different colors, so I couldn't set
hover to certain color.

Well in that post I linked you on stackoverflow, it shows:

QListWidget::item:hover, QListWidget::item:disabled:hover, QListWidget::item:hover:!active, {background: transparent;}

That means it just hides the hover, doesn't set it to a certain color. It should do exactly what you need.

You can of course make a custom delegate too. That's more work that setting a quick css though.

Hi,

Can you show your .pro file ?