eventFilter run many times

[sonichy]

https://github.com/sonichy/HTYFileManager
I am writing a file manager, and I want to capture enter to open file.
The lineEditLocation, listView and tableView will emit enter press event.
Use eventFilter, every object run 3 times !
When I open a image file in QListView, it will open 3 windows of the image.

lineEditLocation->installEventFilter(this);
ui->listView->installEventFilter(this);
ui->tableView->installEventFilter(this);

bool MainWindow::eventFilter(QObject *obj, QEvent *event)
{
    QKeyEvent *KE = static_cast<QKeyEvent*>(event);
    if (KE->key() == Qt::Key_Return || KE->key() == Qt::Key_Enter) {
        qDebug() << "eventFilter" << obj;
        if (obj == lineEditLocation) {
            openL();
        } else if (obj == ui->listView) {
            if(ui->listView->selectionModel()->selectedIndexes().size() != 0)
                open(ui->listView->selectionModel()->selectedIndexes().at(0));            
        } else if (obj == ui->tableView) {
            if(ui->tableView->selectionModel()->selectedIndexes().size() != 0)
                open(ui->tableView->selectionModel()->selectedIndexes().at(0));            
        }
    }
    return QObject::eventFilter(obj, event);
}

[Gojir4]

Hello,

You have to return true when the event has been "consumed". I think the event is propagated three times as you have installed three event filters and you don't stop event propagation.

lineEditLocation->installEventFilter(this);
ui->listView->installEventFilter(this);
ui->tableView->installEventFilter(this);

bool MainWindow::eventFilter(QObject *obj, QEvent *event)
{
    QKeyEvent *KE = static_cast<QKeyEvent*>(event);
    if (KE->key() == Qt::Key_Return || KE->key() == Qt::Key_Enter) {
        qDebug() << "eventFilter" << obj;
        if (obj == lineEditLocation) {
            openL();
        } else if (obj == ui->listView) {
            if(ui->listView->selectionModel()->selectedIndexes().size() != 0)
                open(ui->listView->selectionModel()->selectedIndexes().at(0));            
        } else if (obj == ui->tableView) {
            if(ui->tableView->selectionModel()->selectedIndexes().size() != 0)
                open(ui->tableView->selectionModel()->selectedIndexes().at(0));            
        } else return QObject::eventFilter(obj, event);
        return true;  //return TRUE, stopping event propagation
    }
    return QObject::eventFilter(obj, event);
}

This could be the issue.
From the doc: "The eventFilter() function must return true if the event should be filtered, (i.e. stopped); otherwise it must return false."

[sonichy]

@Gojir4 Thank you !

[garycho]

Pressing any key within a child widget will return in 3 events

QEvent::ShortcutOverride
QEvent::KeyPress
QEvent::KeyRelease

We would handle the event of interest only if condition below is met

if ( keyEvent->type() == QEvent::KeyPress)
{

}