Connecting QPushButton to QListWidget

walle19

Hi All,

Platform: Linux Kubuntu 14
QT version: 4.7.1

I have a QListWidget and want to perform the following:
After pressing (single click) on an element on the list (it will be highlighted) I want to press on a QPushButton that is connected to it via signal slot mechanism, and the slot will perform a specific task on the selected element.

I tried achieving this with the following:

connect(open_element_button, SIGNAL(clicked(QModelIndex)),this,SLOT(onOpenElementButtonPushed(QModelIndex)));

Where open_element_button is QPushButton
but it didn't work.
I'm pretty sure the SIGNAL(clicked(QModelIndex)) part isn't accurate.

Any suggestions ?
Thanks!

JonB

@walle19 said in Connecting QPushButton to QListWidget:

Any suggestions ?

Yes: start by changing over to new style signals & slots before you do anything else.

SGaist

Hi,

Clicked has no such parameter so you can stop that. Retrieve the selected item in the slot connected to the clicked signal.

Other suggestion: urgently update your distribution and Qt version. Qt 4.7.1 is way more than outdated. If you are stuck to Qt 4 then at least update to the last release of the series (which has also reached end of life a long time ago).

walle19

@SGaist Thanks for the reply.
After retrieving the selected item, is there a way to emit a signal that it has been double clicked ?
My goal is to provide a QPushButton that will perform the functionality of double clicking an item in the QListWidget.

SGaist

Well, you should rather have a slot connected to the QListWidget::itemDoubleClicked signal and then call the same function from the slot connect to your QPushButton::clicked signal.

walle19

@SGaist Yes that was what I was going for.
Now consider I am using QAbstractItemView::doubleClicked(const QModelIndex & index).
I looked for a way to get the QModelIndex in my QPushButton SLOT().
So initially I thought I will call QListWidget::currentItem() and then QListWidget::indexFromItem(QListWidgetItem * item).
This would be ideal but that last method is protected and I cannot call it.

Any idea ?

Christian Ehrlicher

@walle19 said in Connecting QPushButton to QListWidget:

Any idea ?

QListWidget has a signal QListWidget::itemDoubleClicked(QListWidgetItem*).

walle19

@Christian-Ehrlicher Thanks for your reply. This method is good,
But Is there a way to retrieve the QModelIndex of the QListWidgetItem ?

eyllanesc

@walle19 Use indexFromItem() method: QModelIndex index = listwidget->indexFromItem(item);

walle19

@eyllanesc isn't this a protected method ?
I am getting a compile error when compiling it.

......./Qt-4.7.1/include/QtGui/qlistwidget.h:287:17: error: ‘QModelIndex QListWidget::indexFromItem(QListWidgetItem*) const’ is protected
     QModelIndex indexFromItem(QListWidgetItem *item) const

Christian Ehrlicher

Why do you need the index at all? Either use a QListWidget and work only with QListWidgetItems or use a QListView and use an own model but do not mix both.
Also why are you using Qt4?

walle19

@Christian-Ehrlicher Hi,
Using QT4 is a constraint.
I need to use index as the chosen row number for a already defined SLOT() that gets a QModelIndex as argument when doubleClicked(QModelIndex) SIGNAL() is sent.
For now I use a workaround - In the QPushButton SLOT() I pass the QAbstractItem::doubleClicked(QModelIndex) SLOT() a non valid QModelIndex.
I check the validity - if valid I use index.row(), if not I call QListWidget::currentRow().

Thanks for all the help

Christian Ehrlicher

Then use the other signal from the QListWidget which gives you a QListWidgetItem. As I said - mixing them is cumbersome - either use the convenience model or an own but don't mix it.