QLineEdit -- how to enter single value -- with no spaces

Question

I have made an editor in which i have to enter a Hex or decimal value in each field. Here the field i am using is QLineEdit.

Now requirement is that each Qlineedit box accept only one value without spaces. Then i can read this text value & convert it directly from string to decimal.

Is it possible to make QlineEdit to accept only one value without spaces ? Boxes in below figure are QLineEdit.

I do not want to use combo box here.

enter image description here

Can't you just remove the spaces before converting or how does an example of a problematic input look like? — user2672165, Sep 29 '13 at 12:06

score 2 · Answer 1 · answered Sep 29 '13 at 10:34

If the answer was just decimal, I'd suggest you use a QSpinBox instead. I did find a thread on how to implement a Hexidecimal SpinBox, but unfortunately the link to the third-party widget is dead. However it does say you could:

subclass QSpinBox and reimplement textFromValue() and valueFromText() to show hexadecimal values.

With the right Decimal-to-Hexidecimal function (you don't mention what language you are using) this would be a suitable solution.

The other alternative, is to use the QLineEdit.setValidator function with a custom subclass of QValidator to provide a validation method. For this, just re-implement the QValidator.validate function to check what a "valid" value.

BTW that link to qxt was old here is the current link:http://libqxt.bitbucket.org/doc/0.6/qxtbasespinbox.html — drescherjm, Sep 29 '13 at 13:43

Abhishek Bansal · Accepted Answer · 2013-09-29T16:35:45.890

1

To build on Lego Stormtroopr's answer, I think QValidator is a good and simple option. For example

dialog->lineedit1->setValidator(new QRegExpValidator( QRegExp("[0-9]{1,20}"), this ));

Here, the QRegExp denotes that you shall only accept digits from 0 to 9 and no other key-presses (spaces or letters) and you shall accept atleast 1 and maximum 20 characters (digits). You then set your lineedit's validator to this value. For more information, you can visit http://qt-project.org/doc/qt-5.0/qtcore/qregexp.html

or for a double,

QDoubleValidator *myDblVal = new QDoubleValidator( 0.0, MAX_VALUE, 1, this);
myDblVal->setNotation( QDoubleValidator::StandardNotation );
dialog->lineedit1->setValidator( myDblVal );

Here you simply use the inbuilt Qt functionality for double validation. You shall only accept a decimal between 0 and MAX_VALUE.

edited Sep 29 '13 at 16:35

answered Sep 29 '13 at 12:39

Abhishek Bansal

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what exactly are you trying to do here ..? – Katoch Sep 29 '13 at 16:25
thanks ... i will try this... can you also write one statement for ... accepting Hex value ... – Katoch Sep 30 '13 at 01:12
What format of hex value do you plan to enter. If it is a simple hex number then [0-9A-Fa-f] would suffice. For any other format following link may give you some idea. http://stackoverflow.com/questions/2760206/qvalidator-for-hex-input – Abhishek Bansal Sep 30 '13 at 05:33

QLineEdit -- how to enter single value -- with no spaces

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