QLineEdit set min max range?

[whitefurrows]

Hi,

sorry i don't have get a notification. That's right, but the user can put wrong values to the QLineEdit.

What can i do?

Greetings,

Whitefurrows

[jacek]

That's right, but the user can put wrong values to the QLineEdit.

The problem is that line edit can loose focus when it contains an intermediate value. IMO you should ask the Trolls whether this is a correct behavior.

[whitefurrows]

Hi,

thank's to you. You know a way how can i set focus to a QLineEdit as long as contains an intermediate value?

Greetings

Whitefurrows

[jpn]

There are many ways to do that. You could override line edit's focusOutEvent(), use an event filter, or install an event filter even on the application. In all cases, you'll just have to ask the validator for it's state and then set the focus back on the line edit when appropriate.

[whitefurrows]

Hi,

can you help me to do that, please?

I try that:

protected:
	QLineEdit focusOutEvent(QFocusEvent* event) const;

protected:
	QLineEdit focusOutEvent(QFocusEvent* event) const;

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QLineEdit MyWidget::focusOutEvent(QFocusEvent* event) const{
	const QObject* ob=QObject::sender();
	int i =0;
	while (ob!=lineEditList[i] && i<lineEditList.size())
		i++;
 
	if(LineEdit Validator state == intermediate) //How can i do that?
                            leList[i]->setEditFocus(true);
}

QLineEdit MyWidget::focusOutEvent(QFocusEvent* event) const{
	const QObject* ob=QObject::sender();
	int i =0;
	while (ob!=lineEditList[i] && i<lineEditList.size())
		i++;

	if(LineEdit Validator state == intermediate) //How can i do that?
                            leList[i]->setEditFocus(true);
}

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Thanks in advance,

Whitefurrows

[jpn]

The focus out event could look for example something like this:

void MyLineEdit::focusOutEvent(QFocusEvent* event)
{
	// check validator state
	int pos = 0;
	QValidator::State state = validator()->validate(text(), pos);
 
	if (state == QValidator::Intermediate)
	{
		// keep focus if intermediate
		setFocus();
	}
	else
	{
		// otherwise call base class implementation and let it
		// handle focus out actions (so cursor stops blinking etc.)
		QLineEdit::focusOutEvent(event);
	}
}

void MyLineEdit::focusOutEvent(QFocusEvent* event)
{
	// check validator state
	int pos = 0;
	QValidator::State state = validator()->validate(text(), pos);

	if (state == QValidator::Intermediate)
	{
		// keep focus if intermediate
		setFocus();
	}
	else
	{
		// otherwise call base class implementation and let it
		// handle focus out actions (so cursor stops blinking etc.)
		QLineEdit::focusOutEvent(event);
	}
}

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If you have difficulties in subclassing QLineEdit, I suggest you to switch back to your favourite C++ book and learn the secrects of inheritance..

[whitefurrows]

Hi,

the problem is i can't subclassing QLineEdit. I use the designer and the designer use the QLineEdit and not MyLineEdit.

Sorry my stupid question i'm a beginner and learn. Please help me one more time.

Greetings,

Whitefurrows

[jpn]

You can use the subclassed line edit widget by promoting it as custom widget in the designer. See the context menu of the line edit.

[whitefurrows]

Hi,

thank you that's work, but i have one more problem MyLineEdit keep focus if intermediate but if i press button "Save" can i save the data(that's wrong) and MyLineEdit keep focus.

Is that OK? What can i do?

Greetings,

Whitefurrows

[jpn]

Sorry, what's the problem? You'll have to explain a bit more clearly. "Can I save the data" is quite an abstract concept..

[whitefurrows]

Sorry, ok i try it. I have many QLineEdit's on a QWidget and a Button. When the user push the butten, then store the programm the values from the QlineEdit's to the database. The user can store the data always, but that is wrong. I wont the user can save the data only if all QlineEdit's contain right values?

You know what i mean?

[jpn]

You could check the validator states whenever QLineEdit::textChanged() signal is emitted. Or you could emit signals (sending state as a parameter) from the validators whenever they are asked to validate. There are many possibilities... But anyway, you have to somehow keep track of the validator states and enable/disable the button when appropriate.

Edit: just a side note.. have you looked the possibility of using for example QSqlTableModel + QTableView and a custom delegate to provide suitable editor..?