Thanks, mrjj!
That's it!

Merry christmas

@mrjj
Thanks for the welcoming :-)

Indeed, the QStyledItemDelegate works fine, but only when I use a QTableWidget. So a first solution was to create a QTableWidget with 1 row and 1 column, and insert my delegate inside. The problem with this technique is that it's hard to perfectly mimic a QLineEdit (behavior, style, etc). For instance, with a QTableWidget, there is no simple click on items to enter in edit mode (this is a double click, at least), as far as I know. It's still possible to redefine the behavior, I guess, but it's not worth it. I don't like the whole thing.

That's why I came up with another idea. This time, I keep my QLineEdit as is, and I add/remove the input mask when having/losing focus. Thanks to that, I'm now able to see the "true" text (without mask format) when I'm not editing it (QLineEdit does not have the focus), while I can see the text (with mask format) when I'm editing it (has focus). I know it's not totally elegant, but I don't think there is an elegant solution at all for this "problem".

For those interested, a quick example on how to achieve this:
(1) install an event filter (installEventFilter()) on the QLineEdit
(2) filter on focus in/out
(2.1) focus in: add the mask (setInputMask())
(2.1) focus out: remove the mask and set the text to the value before the mask was removed (because removing the mask erases the text inside the QLineEdit)

Hi
Yes calling the function directly is actually a better solution in this case.
Its worth mentioning that the so called slots are 100% normal c++ member functions
and can be called without any Qt involvement/use of.

void MainWindow::on_pushButton_clicked() { int value=ui->lineEdit->text().toInt(); // get value Dialog dialog1; dialog1.sendIntData(value); dialog1.exec(); }

Thanks for posting your solution.

Happy coding.

Hi,

for an integer input between 0 and 100 set the mask to "009". Thats all.

But why use QLineEdit if you are only manipulating numbers ? That makes the code uselessly complicated.

QRegularExpression rx("[A-Za-z0-9]*"); QRegularExpressionalidator *v = new QRegularExpressionValidator(rx, this); ui->LE_ObjectName->setValidator(v);

There are a number of sites providing this service, most of them commercially.
http://verify-email.org/ has a free API limited to 5 checks an hour. https://emailhunter.co/ limits to 150 a month

So if you use as mentioned earlier in same post , you can use the below code to restrict special characters.

QRegularExpression regex("^[a-zA-Z0-9_]*$");
QValidator *validator = new QRegularExpressionValidator(regex, this);
m_lineEdit->setValidator(validator);

If you want to change the colour with respect to characters entered you can go for the below code.
Then dont use validator
connect(m_lineEdit,SIGNAL(textChanged(QString)),this,SLOT(getLineEditValue(QString)),Qt::UniqueConnection);

use connection statement to get values when you type in QLineEdit.

And Below Slot can be used to observe the changes done while typing in QLineEdit, with respect to characters, when u enter special characters Color changes to Red, and Color changes to Green when entering the digits or letters.

void LineEditProgram::getLineEditValue(QString stringValue)
{
qDebug () << "value changed" << stringValue;

QString temp = m_lineEdit->text(); QRegExp regexp("^[0-9A-Za-z_]*$"); if (!regexp.exactMatch(temp)) { qDebug () << "colour changed to red" << stringValue; m_lineEdit->setStyleSheet("border: 5px solid red"); m_label->setText(stringValue); } else { qDebug () << "colour changed to green" << stringValue; m_lineEdit->setStyleSheet("border: 5px solid green"); m_label->setText(stringValue); }

}

@Tirolel
If you want t do it that way you shouldn't you cast the widget to find out what type it is before you actually use it?

if(qobject_cast<QLineEdit*>(pLine->widget()) != 0)
...

Test for which type it is then use the correct type cast to use the actual member functions...

Hi and welcome to devnet,

Looks like the keyboard layout of your Pi doesn't match the keyboard layout of your desktop computer.

Which are both ?

@mrjj Thanks Mrjj :) it went perfect, you're awesome haha ;)

Thank you it worked.

@shavera Did you tried to call QWidget::Update() after modifing your whileEditing property ?

Dear @SGaist, Thanks for the reply. Actually i do not want user to change the cursor position. I got one work around. I have connected the cursor position changed signal to one slot which automatically sets the cursor position to the end. The slot first calculate the text length and then moves the cursor to the last position. So in this case even if user tries to change the cursor location, cursor automatically comes at the end and whatever the user types is appended to the end.

Regards
Sid

Hi,

Since those are only numbers, why not use QSpinBox ?

How small are we talking about ?

Note that if you mix that keyboard with Qt's input framework, you're probably going to have another problem when the keyboard's line edit gets the focus.

Dear @peniwize, I am not aware of direct entry of special symbols in QLineEdit in MAC but in WINDOWS OS we can do with the help of ALT key and the symbol code. Basically go to Character Map and select the special symbol then you will be able to see the corresponding Key code to that special character. Just hold ALT symbol and enter the code from num pad by enabling NUM LOCK. Then release the ALT key. That special symbol will automatically appear in the QLineEdit in Windows. May be something similar you can try in MAC OS too.
Good luck!!

@vinothrajendran4
that said, i did find some code on the new that uses a trick.
please see this sample
https://www.dropbox.com/s/m6slequi83tbqg2/linedit.zip?dl=0

You need to accept the event so the parent knows that the event has been handled. Otherwise the event will go all children until someone accepts it or if none do, it will be ignored.
so keyEv->accept() should do the trick.

From the documentation for placeholderText : QString:
"This property holds the line edit's placeholder text.
Setting this property makes the line edit display a grayed-out placeholder text as long as the line edit is empty."
So, setting the text means the place holder text isn't shown any more.
You can check whether the value is empty before you use it. If it is empty you use your default value.

Hi @Yatshan, and welcome to the Qt Dev Net!

Sorry I don't have any experience with Scintilla, so I don't know how to solve your problem. Have you tried asking the person who created QsciScintilla?

Hi,

Just a wild guess but you might be resizing it to 0

@SGaist Thanks for your quick answer. And sorry for the delayed reply.

Overriding QLineEdit was in my mind. Wanted to know if there are any straight forward way to get it done.

But now am sure about that!

Thank you!

Solved! It is working now!

I had set:

lineedit->setMaxLength(10);

before.

This has been limiting:

...,'g', 10));

After I have removed it, it works!

@Chris-Kawa thanks for the other post, but

'g', 10

works fine now! Thanks anyway!

@SteveMBay Just for clarification, did you fix the wrong behaviours or do you need more help about this issue?

AFAIK, stylesheets where introduced in Qt 4.2 so how can they use stylesheets if they use 4.1 ?

@mrdebug
If you are using only uppercase letters in QRegExp you should be fine. E.g. "[IO]{1,1}" shall match only an uppercase 'I' or an uppercase 'O'.

@Endar
I hope this will help you
QRegExpValidator* validator = new QRegExpValidator(QRegExp("[A-a-Z-z][A-a-Z-z]\\d{0,2}\\d[A-a-Z-z][A-a-Z-z]"));
ui->lineEdit->setValidator(validator);

For the moment I have made the GraphicsView 1 pixel shorter than the screen layout (i.e. 1920x1079) which makes everything work perfectly. I'm using an QGLWidget as the viewport for the GraphicsView. When I try to use the new QOpenGLWidget instead the (normal) widgets that are added on top of the graphics view are rendered correctly, however anything drawn using OpenGL flickers as soon as any part of the widget normal needs to be redrawn. E.g. when adding a QLineEdit and the cursor blinks or when text is inputted into the widget the parts drawn with OpenGL (in the graphicsview) flickers. Which makes it (QOpenGLWidget as a viewport) impossible to use in our case.

You can create the QLineEdits dynamically

Hi, this is old now but in case someone else finds this:
I managed to solve this problem by using
setSizeConstraint(QtWidgets.QLayout.SetNoConstraint)
for a layout holding the QLineEdit widget. Actually it wasn't the layout holding the widget, but the layout holding that layout, so you may need to experiment to find out where you need to make this update (or just use SetNoConstraint for all your layouts)
I hope this helps someone!