@Chris-Kawa said in Weird connection between QComboBox, QBasicTimer and static object initialization.:

In general singleton pattern doesn't go too well with QObjects.

... and is not needed in most cases - this one here is one of the most cases where a singleton is not needed

@JonB
I am new with qt.
I am not able to implement this, any working sample code will be helpful for me.

Thanks in advance for help.

Thanks,
Mahesh

Windows 10.0.19045, Qt 5.15, I think. At least Qt 5, that's for sure.

@jaivardhanf said in How to change QTableView data based on selection in QComboBox.:

So below is my code.

Something seems to have gone wrong with the code tags, making it hard to read and potentially missing code.

Qt::ItemFlags LineModel::flags(const QModelIndex& index) const
{
return Qt::ItemIsEditable | QAbstractTableModel::flags(index);
}

Adding the ItemIsEditable flag doesn't matter if the goal isn't to edit the item through the view.

This is how I connect the signal and slot

connect(ui->lineClass, &QComboBox::currentTextChanged, this, &GetOptionsClass::TextChanged);

Verify that the slot is called when it should be, and that the arguments are as expected.

@SGaist If forcing fusion style, it'll show the full list. But the style itself is very different. Fusion style has tick boxes and shows everything with no scrollbar I think.

@Dariusz said in Called object is not of the correct type (class destructor may have already run) - what is it? o.o:

Hey
Yeah thats a crazy one overload, looking at data years old so uhh my bad!
Fixing it sadly did not help, another signal/slots screams here >
This crash > connect(addItem, &QAction::triggered, this, &icCGraphicsScene::addItemPoint);
This works > connect(addItem, &QAction::triggered, this, this { this->addItemPoint(); });
Yes I know the "works" one is not good, but I simply cant connect normal signals on M1 mac. Maybe its ARM issue ?

DISCLAIMER: I have never developed Qt application for Mac (or used a Mac).

My guess is that you have an issue on instance class life cycle.
When creating a lambda function, the captured variables are copied.

But this is just a fealling...

Can you provide a minimal complete script to reproduce this behaviour ?

@JonB Yes ! and my problem is solved thank you @posktomten

@CJha
So it's obviously internal. Ignore it, and no you won't be able to alter what qApp->topLevelWidgets() returns, just remove any QComboBoxPrivateContainers.

The problem arises from the usage of the method m_model.setStringList(). The latter always clear the previous data, hence the index always reset upon its call.

Solution:

Use m_model.setStringList() only in the constructor to init the model.

After that manually insert the row on the model and set the data for the respective row. This can be achieved with a simple modification in the slot method.

MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent) , ui(new Ui::MainWindow) { ui->setupUi(this); m_model.setStringList({"1","2"}); ui->comboBox->setModel(&model); } void MainWindow::on_pushButton_clicked() { m_model.insertRow(model.rowCount()); m_model.setData(model.index(model.rowCount()-1), "3"); }

In the example above, "3" is appended to the list model without changing the current index from the QComboBox.

@Proton-Phoenix Thank you!

@mrjj said in QComboBox foregroun color not displayed in main widget:

Hi
That sets the colors when drawn.
It sounds like you want to also change the selection color ?

https://forum.qt.io/topic/108718/change-qcombobox-popup-highlighted-item-background-color/12

So in a "human" test it works, if I set it, it works properly. But when I try to load my settings and set it "programmatically", even tho it says it sets pallets (btw I had to use ButtonText). Then it does not work... sigh. Its bananas. Will try to make simple examples.

@artwaw
I'm not sure, but in addition to @SGaist you may also find you want to use https://doc.qt.io/qt-5/qabstractitemview.html#openPersistentEditor ?

@Pl45m4 I'll try this...changing it's position

@SGaist

Thanks I got it working, I don't know why it works but I'll take it. I updated the first post for future reference.

@learnist
Np :)
However, for a real app, you should also consider the use case where users spell the new name
wrong and want to delete it/edit it later to correct it.

@mikael-larsson
Hi
You could try an event filter on the Combobox and call the code for hover effect but
if your effect is purely stylesheet based then i think you then must send it fake hover event to trigger it or something like that.

You might also be able to subclass the combo and rig the paintEvent with
if (someflag)
option.state |= QStyle::State_MouseOver;

to trigger hover on command from the event filter/ or combo hover or how you plan to trigger it.

I think I have found a solution that is not necessarily complete (e.g. drive the combbox with keyboard).

I add a boolean (e.g. mSkipToogle=false) at the same place than mSkipHide.

I rewrite eventFilter (QObject* object, QEvent* event).

bool CFilterCountryComboBox::eventFilter (QObject* object, QEvent* event) { QEvent::Type type = event->type (); if (object == view ()->viewport ()) { switch (type) { case QEvent::MouseButtonRelease : case QEvent::MouseButtonPress : mSkipHide = true; mSkipToogle = false; break; case QEvent::Hide : case QEvent::Show : mSkipToogle = true; break; default : break; } } if (type == QEvent::MouseButtonRelease && static_cast<QMouseEvent*>(event)->button () == Qt::RightButton) { return true; } return QComboBox::eventFilter (object, event); } Now rewrite toggleItemCheckState (int index) void CFilterCountryComboBox::toggleItemCheckState (int index) { if (!mSkipToogle) { QVariant value = itemData (index, Qt::CheckStateRole); Qt::CheckState state = static_cast<Qt::CheckState>(value.toInt ()); setItemData (index, (state == Qt::Unchecked ? Qt::Checked : Qt::Unchecked), Qt::CheckStateRole); } else { mSkipToogle = false; } }

It seems to work on Windows with Qt 5.12.7.
Good luck

@hobbyProgrammer
You cannot have a combo which is both bound to a model and has some extra row inserted into it --- it's one or the other.

There are several possible approaches:

Make your SQL query return a UNION ALL which includes a literal <select> as an extra row. Not really nice, because it makes the <select> be an extra row from the query.

Copy the result set from the query into another model (you probably only need a list, perhaps a QStringList) where you insert the extra <select> as an item and use that as the combo's model. If you don't get a better example, this is the most obvious to code.

Interpose a QIdentityProxyModel between the query model and the combo, and add the extra row there. I suspect this is the way it's supposed to be done(?).