Key Press Event Handling

[kosasker]

I know, there is more thread about that in this forum. I looked all of them, but still i cant work it.

Vista Business
Qt SDK 2010.05
Qt Creator 2.0.1

I'm just trying to get which key is pressed.

mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
 
#include "ui_mainwindow.h"
 
class MainWindow : public QMainWindow, private Ui::MainWindow
{
    Q_OBJECT
private:
    Ui::MainWindow *gui;
 
public:
    explicit MainWindow(QWidget *parent = 0);
 
protected:
    bool keypres(QKeyEvent *keyevent);
 
};
 
#endif // MAINWINDOW_H

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include "ui_mainwindow.h"

class MainWindow : public QMainWindow, private Ui::MainWindow
{
    Q_OBJECT
private:
    Ui::MainWindow *gui;

public:
    explicit MainWindow(QWidget *parent = 0);

protected:
    bool keypres(QKeyEvent *keyevent);

};

#endif // MAINWINDOW_H

To copy to clipboard, switch view to plain text mode 

mainwindow.cpp

#include "mainwindow.h"
#include <QKeyEvent>
#include <QDebug>
 
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),gui(new Ui::MainWindow){
    gui->setupUi(this);
 
    gui->textEdit->installEventFilter(this);
 
}
 
bool MainWindow::keypres(QKeyEvent *keyevent)
{
    if (keyevent->key()==Qt::Key_W)
        {
            qDebug() << "hi";
        }
}

#include "mainwindow.h"
#include <QKeyEvent>
#include <QDebug>

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

    gui->textEdit->installEventFilter(this);

}

bool MainWindow::keypres(QKeyEvent *keyevent)
{
    if (keyevent->key()==Qt::Key_W)
        {
            qDebug() << "hi";
        }
}

To copy to clipboard, switch view to plain text mode 

main.cpp

#include <QtGui/QApplication>
#include "mainwindow.h"
 
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();
 
    return a.exec();
}

#include <QtGui/QApplication>
#include "mainwindow.h"

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();

    return a.exec();
}

To copy to clipboard, switch view to plain text mode 

I just want to control keys and key events.
Regards.

[Gokulnathvc]

http://developer.qt.nokia.com/forums/viewthread/1243

http://stackoverflow.com/questions/3...qt-qmainwindow

I think this may help you

[pan]

You need to set a focusPolicy

[high_flyer]

Your event handler signature is wrong.
The documentation for QObject::installEventFilter() has an example exactly for key press events.
Why not start there?
http://doc.qt.nokia.com/latest/qobje...allEventFilter

[kosasker]

Well then.
@pan : i added focus policy
and done somethings but thats have no effect.

i made it with QDialog base class. But with QMainWindows its not working. I'm tired.
I just open Qt Creator and create gui application, which is using QMainWindow base class.

mainwindows.cpp

#include "mainwindow.h"
#include <QDebug>
 
MainWindow::MainWindow(QWidget *parent) :
        QMainWindow(parent), ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    this->setWindowFlags(Qt::Dialog);
    this->setFocusPolicy(Qt::NoFocus);
    ui->textEdit->setFocusPolicy(Qt::StrongFocus);
    ui->textEdit->installEventFilter(this);
}
 
bool MainWindow::catch_event(QObject *obj, QEvent *event)
{
    if (obj == ui->textEdit && event->type()==QEvent::KeyPress)
        {
            QKeyEvent *keyevent = static_cast<QKeyEvent*>(event);
            qDebug() << "key event";
            return QObject::eventFilter(obj,event);
        }
    return QObject::eventFilter(obj,event);
}

#include "mainwindow.h"
#include <QDebug>

MainWindow::MainWindow(QWidget *parent) :
        QMainWindow(parent), ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    this->setWindowFlags(Qt::Dialog);
    this->setFocusPolicy(Qt::NoFocus);
    ui->textEdit->setFocusPolicy(Qt::StrongFocus);
    ui->textEdit->installEventFilter(this);
}

bool MainWindow::catch_event(QObject *obj, QEvent *event)
{
    if (obj == ui->textEdit && event->type()==QEvent::KeyPress)
        {
            QKeyEvent *keyevent = static_cast<QKeyEvent*>(event);
            qDebug() << "key event";
            return QObject::eventFilter(obj,event);
        }
    return QObject::eventFilter(obj,event);
}

To copy to clipboard, switch view to plain text mode 

Problem is not solved but i'm tired about 2 days. I will do with QDialog class.

Thanks all...

[high_flyer]

Problem is not solved but i'm tired about 2 days.

I told you what the problem is!
And I gave a link to almost exactly the code you need, you only need to copy paste and introduce the changes in the handler to do the filtering based on the rules you need it.
So what is the problem?


heh... you really should read your own signature and apply some though on it...

[kosasker]

Ok. Punch me
Bro its really not working. You think, i make joke ?
Try if you didnt believe ok.
Thanks so.

I'm missing something' s.. But i cant find it yet.

[high_flyer]

The event filter filterObj receives events via its eventFilter() function.

not 'catch_event'.

all you had to do is COPY PASTE the example!!

//change the class name to your
bool KeyPressEater::eventFilter(QObject *obj, QEvent *event)
 {
     if (event->type() == QEvent::KeyPress) {
         //and here put your own logic!!
         QKeyEvent *keyEvent = static_cast<QKeyEvent *>(event);
         qDebug("Ate key press %d", keyEvent->key());
         return true;
     } else {
         // standard event processing
         return QObject::eventFilter(obj, event);
     }
 }

//change the class name to your
bool KeyPressEater::eventFilter(QObject *obj, QEvent *event)
 {
     if (event->type() == QEvent::KeyPress) {
         //and here put your own logic!!
         QKeyEvent *keyEvent = static_cast<QKeyEvent *>(event);
         qDebug("Ate key press %d", keyEvent->key());
         return true;
     } else {
         // standard event processing
         return QObject::eventFilter(obj, event);
     }
 }

To copy to clipboard, switch view to plain text mode 

[kosasker]

Well, show me a corner. I will cry at there...

this->textEdit->installEventFilter(this);

this->textEdit->installEventFilter(this);

To copy to clipboard, switch view to plain text mode 

I find where i missed up.
My goal is make a terminal program like putty.
Thanks.