How get signal returnPressed in QTextEdit

[Roszko]

Hello,
I am new user Qt and I have got a small problem. So, I don't know how can I resize QLineEdit (more lines) or how can I catch signal when enter has been pressed in QTextEdit?
I am writing simple chat program and I want to create message box, but QLineEdit is too small field and I don't know how can I catch pressed enter in QTextEdit.
Thanks for help.
Goodbye

[faldzip]

Hello,
I am new user Qt and I have got a small problem. So, I don't know how can I resize QLineEdit (more lines)

use QTextEdit

or how can I catch signal when enter has been pressed in QTextEdit?

Either subclass from QTextEdit and add you functionality in keyPressEvent() or install eventFilter without subclassing.

[Roszko]

Can you get me a simple example with keyPressEvent() using?

[elcuco]

void	my_class::keyPressEvent(QKeyEvent *e)
{
	QTextCursor c = textCursor();
	switch (e->key()) {
		case Qt::Key_Escape:
		// whatever
		break;
 
		case Qt::Key_Enter:
		case Qt::Key_Return:
		// whatever
		break;
  }
}

void	my_class::keyPressEvent(QKeyEvent *e)
{
	QTextCursor c = textCursor();
	switch (e->key()) {
		case Qt::Key_Escape:
		// whatever
		break;

		case Qt::Key_Enter:
		case Qt::Key_Return:
		// whatever
		break;
  }
}

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[Roszko]

ok, but must I send any connect and what signal must be supported?

[squidge]

No signal, you subclass the control and override the keyPressEvent. If you want a signal, you'll need to emit it from that method.

[Xandareva]

I have one question. How can I move cursor to begin of QTextEdit? Why do I want to move cursor? Because if I press Enter, Message will send to server and all is ok, but I have one problem, Cursor has been in second line after pressed Enter ;/ and if I send second message (press Enter), message will send with word of new line. I would cursor will be in first line after pressed enter.
Thanks for reply

[squidge]

Look at moveCursor method.

[faldzip]

I have one question. How can I move cursor to begin of QTextEdit? Why do I want to move cursor? Because if I press Enter, Message will send to server and all is ok, but I have one problem, Cursor has been in second line after pressed Enter ;/ and if I send second message (press Enter), message will send with word of new line. I would cursor will be in first line after pressed enter.
Thanks for reply

It seems that when you send a message and pass keyPressEvent further (to the default implementation) so it is then inserting new line. You must "eat" the event and not pass it further: accept it (QEvent::accept()) and not pass it to the base class implementation.

[Xandareva]

I don't know what is wrong here:

bool SimpleChatClient::eventFilter(QObject *obj, QEvent *event)
{
    if (obj == message) {
        if (event->type() == QEvent::KeyPress) {
            QKeyEvent *keyEvent = static_cast<QKeyEvent*>(event);
            switch(keyEvent->key()) {
                case Qt::Key_Enter:
                case Qt::Key_Return:
                    sendMessage();
                break;
            }
            return false;
        } else {
            return QObject::eventFilter(obj, event);
        }
    } else {
        return QObject::eventFilter(obj, event);
    }
}

bool SimpleChatClient::eventFilter(QObject *obj, QEvent *event)
{
    if (obj == message) {
        if (event->type() == QEvent::KeyPress) {
            QKeyEvent *keyEvent = static_cast<QKeyEvent*>(event);
            switch(keyEvent->key()) {
                case Qt::Key_Enter:
                case Qt::Key_Return:
                    sendMessage();
                break;
            }
            return false;
        } else {
            return QObject::eventFilter(obj, event);
        }
    } else {
        return QObject::eventFilter(obj, event);
    }
}

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And I don't know how to does it remake to work properly.

[faldzip]

I don't know what is wrong here:

bool SimpleChatClient::eventFilter(QObject *obj, QEvent *event)
{
    if (obj == message) {
        if (event->type() == QEvent::KeyPress) {
            QKeyEvent *keyEvent = static_cast<QKeyEvent*>(event);
            switch(keyEvent->key()) {
                case Qt::Key_Enter:
                case Qt::Key_Return:
                    sendMessage();
                break;
            }
            return false;
        } else {
            return QObject::eventFilter(obj, event);
        }
    } else {
        return QObject::eventFilter(obj, event);
    }
}

bool SimpleChatClient::eventFilter(QObject *obj, QEvent *event)
{
    if (obj == message) {
        if (event->type() == QEvent::KeyPress) {
            QKeyEvent *keyEvent = static_cast<QKeyEvent*>(event);
            switch(keyEvent->key()) {
                case Qt::Key_Enter:
                case Qt::Key_Return:
                    sendMessage();
                break;
            }
            return false;
        } else {
            return QObject::eventFilter(obj, event);
        }
    } else {
        return QObject::eventFilter(obj, event);
    }
}

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And I don't know how to does it remake to work properly.

If you want to "eat" the key you must return true.

P.S. This is explained in Qt docs (QObject::eventFilter()):

In your reimplementation of this function, if you want to filter the event out, i.e. stop it being handled further, return true; otherwise return false.

[Xandareva]

but now I can't write in this box.

[faldzip]

return true in line 10. Only in case you call sendMessage(). In other places you can return QObject::eventFilter(obj, event);

[Xandareva]

thx! It works.