Set focus to another qLineEdit by pressing the enter-key or by using arrow-keys

[phil63]

Hi,

I am using several QLineEdit.
And I would like to set the focus to the next QLineEdit when the down-arrow is pressed or when the Enter-key is pressed. And set the focus to the previous QLineEdit when the up-arrow is pressed.

Could you help me to do so.

Thank you in advance.

@this->NumDonne1 = new QLineEdit(this);
NumDonne1->setGeometry(210,53,45,26);
//------------------------------
this->NumDonne2 = new QLineEdit(this);
NumDonne2->setGeometry(210,153,45,26);
//------------------------------
this->NumDonne3 = new QLineEdit(this);
NumDonne3->setGeometry(210,253,45,26);
//------------------------------
this->NumDonne4 = new QLineEdit(this);
NumDonne4->setGeometry(210, 353,45,26);
//------------------------------

NumDonne1->setFocus();@

[qxoz]

Hi.
For your goals you need
@eventFilter(QObject *, QEvent *)@

for conveniency create a line edit list:
@QList<QObject*> leCollection;
...
leCollection.append(NumDonne1);
...
leCollection.append(NumDonneN);
@

first of all you need install event filter for each line edit:
@
foreach(QWidget *wdg, leCollection)
{
wdg - > installEventFilter(this)
}@

in eventFilter body:
@bool MainWindow::eventFilter(QObject *obj, QEvent *pe)
{
if(pe->type() == QEvent::KeyPress)
{
int LeIndex = leCollection.indexOf(obj);
QKeyEvent keyEvent = static_cast<QKeyEvent >(pe);
if(keyEvent->key() == Qt::Key_Return || keyEvent->key() == Qt::Key_Enter ||keyEvent->key() == Qt::Key_Down)
{
if(LeIndex>0)(static_cast<QWidget>(leCollection.at(LeIndex-1)))->setFocus();
}
if(keyEvent->key() == Qt::Key_Up)
{
if(LeIndex<leCollection.count()-1) (static_cast<QWidget>(leCollection.at(LeIndex+1)))->setFocus();
}
}
return QMainWindow::eventFilter(obj, pe);
}@

something like that.

[phil63]

Hi, Thank you for your answer and valuable help.

I followed your advises but I didn't succeed in adapting your code to my program.
Please I still need your help.

error message :
fenetre.cpp:34: error: invalid conversion from QObject* const' to QWidget*'

By changing :

@foreach(QWidget *wdg, leCollection)@

into

@foreach(QObject *wdg, leCollection)@
There is no error anymore , the program runs but no window shows up.

Thank you
@

//fenetre.cpp
//--------------------
#include "fenetre.h"
#include<QtGui>
#include <QLineEdit>

fenetre::fenetre()
{

this->NumDonne1 = new QLineEdit(this);
// NumDonne1->setGeometry(210,53,45,26);
//------------------------------
this->NumDonne2 = new QLineEdit(this);
NumDonne2->setGeometry(210,153,45,26);
//------------------------------
this->NumDonne3 = new QLineEdit(this);
NumDonne3->setGeometry(210,253,45,26);
//------------------------------
this->NumDonne4 = new QLineEdit(this);
NumDonne4->setGeometry(210, 353,45,26);
//------------------------------

// line->setFocus(Qt::keypressed()==Entrer);
NumDonne3->setFocus();

//QList<QObject*> leCollection;

leCollection.append(NumDonne1);
leCollection.append(NumDonne2);
leCollection.append(NumDonne3);
leCollection.append(NumDonne4);

foreach(QWidget *wdg, leCollection)
{
wdg->installEventFilter(this);
}

//----------------------------
}
//---------------------------------------
fenetre::~fenetre(){}
//---------------------------------

bool fenetre::eventFilter(QObject *obj, QEvent *pe)
{
if(pe->type() == QEvent::KeyPress)
{
int LeIndex = leCollection.indexOf(obj);
QKeyEvent keyEvent = static_cast<QKeyEvent >(pe);
if(keyEvent->key() == Qt::Key_Return || keyEvent->key() == Qt::Key_Enter
||keyEvent->key() == Qt::Key_Down)
{
if(LeIndex>0)(static_cast<QWidget>(leCollection.at(LeIndex-1)))->setFocus
();
}
if(keyEvent->key() == Qt::Key_Up)
{
if(LeIndex<leCollection.count()-1)
(static_cast<QWidget>(leCollection.at(LeIndex+1)))->setFocus();
}
}
return fenetre::eventFilter(obj, pe);

}

@

@
//fenetre.h
//--------------

#ifndef FENETRE_H
#define FENETRE_H
#include <QtGui/QMainWindow>

include <QLineEdit>

#include <QLineEdit>

class fenetre : public QWidget
{
Q_OBJECT
public:

fenetre();
~fenetre();

QLineEdit *NumDonne1 ;
QLineEdit *NumDonne2 ;
QLineEdit *NumDonne3 ;
QLineEdit *NumDonne4 ;

QList<QObject*> leCollection;

bool eventFilter(QObject *obj, QEvent *pe);

public slots:

};

#endif // FENETRE_H

@

@
//main.cpp
//------------

int main(int argc, char *argv[])
{
QApplication a(argc, argv);

fenetre h;
 h.setGeometry(100,100,300,300);

h.show();
return a.exec();

}
@

[Sam]

You can also check "focusNextChild()":http://qt-project.org/doc/qt-5.1/qtwidgets/qwidget.html#focusNextChild function. In this case you don't have to keep a list of widgets.