QListWidget: double click item -> multiple itemDoubleClicked signals

[jiveaxe]

Hi, I've a strange problem with a QListWidget; have defined this connection:

connect(ui->listWidget, SIGNAL(itemDoubleClicked(QListWidgetItem*)), this, SLOT(doSomething(QListWidgetItem*)));

connect(ui->listWidget, SIGNAL(itemDoubleClicked(QListWidgetItem*)), this, SLOT(doSomething(QListWidgetItem*)));

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doSomething() contains a simple qDebug(), just for testing. Now, when I double click an item, in the application output I got multiple time the same qDebug() message.

I'm doing anything wrong?

[Lykurg]

Do you connect the signal multiple times to the slot? For clarifying use Qt::UniqueConnection. Can you make an example?

[jiveaxe]

Here a sample:

#include "mainwindow.h"
#include "ui_mainwindow.h"
 
#include <QDir>
 
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
 
    QDir shortcutsFolder(QDir::homePath() + QDir::separator() + m_currentDir);
    QFileInfoList shortcuts(shortcutsFolder.entryInfoList(QDir::Files, QDir::Name | QDir::IgnoreCase));
 
    foreach (QFileInfo fi, shortcuts){
        QListWidgetItem *item = new QListWidgetItem(fi.fileName());
        connect(ui->listWidget, SIGNAL(itemDoubleClicked(QListWidgetItem*)), this, SLOT(doSomething(QListWidgetItem*)));
        ui->listWidget->addItem(item);
    }
}
 
MainWindow::~MainWindow()
{
    delete ui;
}
 
void MainWindow::doSomething(QListWidgetItem *item)
{
    qDebug() << item->text();
}

#include "mainwindow.h"
#include "ui_mainwindow.h"

#include <QDir>

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    QDir shortcutsFolder(QDir::homePath() + QDir::separator() + m_currentDir);
    QFileInfoList shortcuts(shortcutsFolder.entryInfoList(QDir::Files, QDir::Name | QDir::IgnoreCase));

    foreach (QFileInfo fi, shortcuts){
        QListWidgetItem *item = new QListWidgetItem(fi.fileName());
        connect(ui->listWidget, SIGNAL(itemDoubleClicked(QListWidgetItem*)), this, SLOT(doSomething(QListWidgetItem*)));
        ui->listWidget->addItem(item);
    }
}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWindow::doSomething(QListWidgetItem *item)
{
    qDebug() << item->text();
}

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Adding Qt::UniqueConnection to connect line fixes the behaviour.

[Spitfire]

move

connect(ui->listWidget, SIGNAL(itemDoubleClicked(QListWidgetItem*)), this, SLOT(doSomething(QListWidgetItem*)));

connect(ui->listWidget, SIGNAL(itemDoubleClicked(QListWidgetItem*)), this, SLOT(doSomething(QListWidgetItem*)));

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from foreach() loop.
You're not connecting "item" in there so you need to call it only once.

[jiveaxe]

You're absolutely right. Thanks