Catch a Key, like designer

[aekilic]

Dear All

I started a thread yesterday, but I dont know why and how, it has been moved to newbei

What I would like to do is, like in designer, I would like to create a line, and when a press a line it should write on the line what I have pressed.

Is the a example code for this, or where could I find the codes for the designer.

[spirit]

I started a thread yesterday, but I dont know why and how, it has been moved to newbei

because it's newbie question, just install event filter to your line edit and process QKeyEvent.

[wagmare]

can u give more information about ur need ..

[aekilic]

What I need is

I would like to know which key has been pressed for a qline

[spirit]

here is an example, is it hard to write it by youself?


...
lineEdit = new QLineEdit();
lineEdit->installEventFilter(this);
...
bool MyWidget::eventFilter(QObject *o, QEvent *e)
{
if (o == lineEdit && e->type() == QEvent::KeyPress) {
const QKeyEvent *ke = static_cast<QKeyEvent *>(e);
const QKeySequence ks(ke->modifiers() + ke->key());
lineEdit->setText(ks.toString());
}
return QWidget::eventFilter(o, e);
}

nothing special, right?
that's why you question is newbie. ;)

[wagmare]

use keypressEvent and check with the respected key ... QKeyEvent has a function
bool operator== ( QKeyEvent * e, QKeySequence::StandardKey key ) where standard keys will help u ..

[aekilic]

Dear spirit

Thank you very much for your reply yes you right it was easy but the problem is, we wrote a program which is open source there is a company who is selling a similar program whoes owner is treatening us everyday that we made a program like this. So I am not really thinking 100% sorry

[aekilic]

I got another problem for this, the code you have sent is working fine spirit for CTRL

When I press shift + r , it writes to the line SHIFT+RR or for ALT it writes ALT+Rr

Can any ona tell me the reason?

[spirit]

try this


lineEdit->setText(ks.toString(QKeySequence::NativeText));

[aekilic]

no I still get

Shift+HH when I press shift+h

[spirit]

what system do you use?
under Windows this code works fine.

[wagmare]

in linus also the same problem arise .. if i press key "a" it shows "Aa" ...

[spirit]

from Qt Assistant


QKeySequence::NativeText 0 The key sequence as a platform specific string. This means that it will be shown translated and on the Mac it will resemble a key sequence from the menu bar. This enum is best used when you want to display the string to the user.
QKeySequence::PortableText 1 The key sequence is given in a "portable" format, suitable for reading and writing to a file. In many cases, it will look similar to the native text on Windows and X11.

[aekilic]

I use vista Qt4.5.0

[spirit]

take a look implementation of QtKeySequenceEdit in QTDIR\tools\shared\qtpropertybrowser\qttreepropert ybrowser.cpp.

[aekilic]

I accidentaly use this code


if (o == lineDeNo && e->type() == QEvent::KeyPress) {
const QKeyEvent *ke = static_cast<QKeyEvent *>(e);
const QKeySequence ks(ke->modifiers() + ke->key());
lineDeNo->setText(ks.toString(QKeySequence::NativeText));
}
if (o == lineMa && e->type() == QEvent::KeyPress) {
const QKeyEvent *ke = static_cast<QKeyEvent *>(e);
const QKeySequence ks(ke->modifiers() + ke->key());
lineMa->setText(ks.toString());
lineDeNo->setText(ks.toString(QKeySequence::PortableText));
}

When editting lineDoNo it doesnt work but When I edit lineMa, lineDeNo works fine,

I try

if (o == lineDeNo && e->type() == QEvent::KeyPress) {
const QKeyEvent *ke = static_cast<QKeyEvent *>(e);
const QKeySequence ks(ke->modifiers() + ke->key());
lineDeNo->setText(ks.toString(QKeySequence::PortableText));
}

but it doesnt work...

[spirit]

do you install event filters for both lineedits?

[aekilic]

yes, I do install for both lines

[spirit]

ok, can you attach compilable example which contains this bug?

[aekilic]

do you mean the code for this area?

[spirit]

minimal compilable example which reproduce your problem.

[aekilic]

lineDeNo->installEventFilter(this);
lineMa->installEventFilter(this);




bool formAyarlar::eventFilter(QObject *o, QEvent *e)
{
if (o == lineDeNo && e->type() == QEvent::KeyPress) {
const QKeyEvent *ke = static_cast<QKeyEvent *>(e);
const QKeySequence ks(ke->modifiers() + ke->key());
lineDeNo->setText(ks.toString(QKeySequence::NativeText));
}else if (o == lineMa && e->type() == QEvent::KeyPress) {
const QKeyEvent *ke = static_cast<QKeyEvent *>(e);
const QKeySequence ks(ke->modifiers() + ke->key());
// lineMa->setText(ks.toString());
lineMa->setText(ks.toString(QKeySequence::PortableText));
}
}

[wysota]

This is not compilable :) A compilable example is something that includes a main() and the piece of code you want tested so that if one writes qmake && make it will compile.

And please don't start multiple threads on the same subject. Moving to newbie (again).

[spirit]

this how should look like "minimal compilable example"


#include <QtGui>

class TestWidget: public QWidget
{
Q_OBJECT

public:
TestWidget(QWidget *parent = 0)
: QWidget(parent)
{
QVBoxLayout *vbl = new QVBoxLayout(this);
m_lineEditNativeText = new QLineEdit();
m_lineEditPortableText = new QLineEdit();

m_lineEditNativeText->installEventFilter(this);
m_lineEditPortableText->installEventFilter(this);

vbl->addWidget(m_lineEditNativeText);
vbl->addWidget(m_lineEditPortableText);
}

protected:
bool eventFilter(QObject *o, QEvent *e)
{
if (e->type() == QEvent::KeyPress) {
const QKeyEvent *ke = static_cast<QKeyEvent *>(e);
const QKeySequence ks(ke->modifiers() + ke->key());
if (o == m_lineEditNativeText)
m_lineEditNativeText->setText(ks.toString(QKeySequence::NativeText));
else if (o == m_lineEditPortableText)
m_lineEditPortableText->setText(ks.toString());
}
return QWidget::eventFilter(o, e);
}

private:
QLineEdit *m_lineEditNativeText;
QLineEdit *m_lineEditPortableText;
};

int main(int argc, char **argv)
{
QApplication app(argc, argv);

TestWidget tw;
tw.show();

return app.exec();
}

#include "main.moc"

works fine, but symbol duplicated.

[spirit]

intresting thing, if modify my code in this way


if (o == m_lineEditNativeText) {
m_lineEditNativeText->setText(ks.toString(QKeySequence::NativeText));
m_lineEditPortableText->setText(ks.toString());
}// else if (o == m_lineEditPortableText)
// m_lineEditPortableText->setText(ks.toString());

then a string in m_lineEditPortableText contains text without duplicating letter.

[spirit]

crap, it's my mistake, eventFilter should look like


bool eventFilter(QObject *o, QEvent *e)
{
if (e->type() == QEvent::KeyPress) {
const QKeyEvent *ke = static_cast<QKeyEvent *>(e);
const QKeySequence ks(ke->modifiers() + ke->key());
if (o == m_lineEditNativeText) {
m_lineEditNativeText->setText(ks.toString(QKeySequence::NativeText));
return true;
} else if (o == m_lineEditPortableText) {
m_lineEditPortableText->setText(ks.toString());
return true;
}
}
return QWidget::eventFilter(o, e);
}

:o

[aekilic]

Let me try

[aekilic]

yes works perfect thank you very much spirit you are my life saver!