QLineEdit cursor not vissible or blocked

[Alundra]

Hi all,
I have a custom Line editor who act as SliderLineEdit (like a spinbox horizontal without button).
All works fine but on the double click event I change ReadOnly to false to allow to edit value by hand and here comes the problem.
The problem is the text cursor is not visible until I use an arrow key (left or right) or I put a value by key.
Here the code of the double click event :

void CDoubleSliderLineEdit::mouseDoubleClickEvent( QMouseEvent* event )
{
  // Check if we are in read-only mode.
  if( isReadOnly() )
  {
    // Change states.
    setReadOnly( false );
    m_SliderMode = false;
 
    // Restore override cursor.
    QApplication::restoreOverrideCursor();
  }
  else
  {
    // Base class.
    QLineEdit::mouseDoubleClickEvent( event );
  }
}

void CDoubleSliderLineEdit::mouseDoubleClickEvent( QMouseEvent* event )
{
  // Check if we are in read-only mode.
  if( isReadOnly() )
  {
    // Change states.
    setReadOnly( false );
    m_SliderMode = false;

    // Restore override cursor.
    QApplication::restoreOverrideCursor();
  }
  else
  {
    // Base class.
    QLineEdit::mouseDoubleClickEvent( event );
  }
}

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I have to add m_SliderMode = false;, without it it's blocked like one mouse pressed but never released.
Thanks for the help

[anda_skoa]

You probably have to set the focus, see QWidget::setFocus()

Cheers,
_

[Alundra]

I have tried to add setFocus() at the end of mouseDoubleClickEvent, the result is the same.

[anda_skoa]

Hmm, no idea. Can you post or attach the code of your slider?

Cheers,
_

[Alundra]

Here a minimal code who reproduce the issue and can be compiled easy.
The code contains a QVBoxLayout to switch because when the CustomLineEdit lost focus he changes his state.
By default the CustomLineEdit is on read-only and waits a double click to change value.

#include <QApplication>
#include <QMainWindow>
#include <QLineEdit>
#include <QVBoxLayout>
 
class CustomLineEdit : public QLineEdit
{
public:
 
    CustomLineEdit(QWidget* parent = 0) :
    QLineEdit(parent)
    {
        setReadOnly(true);
        setText("0.00");
    }
 
protected:
 
    virtual void focusOutEvent(QFocusEvent* event)
    {
        QLineEdit::focusOutEvent(event);
        setReadOnly(true);
        deselect();
    }
 
    virtual void mouseDoubleClickEvent(QMouseEvent* event)
    {
        if(isReadOnly())
            setReadOnly(false);
        else
            QLineEdit::mouseDoubleClickEvent(event);
    }
};
 
class MainWindow : public QMainWindow
{
public:
 
    MainWindow(QWidget* parent = 0) :
    QMainWindow(parent)
    {
        QVBoxLayout* Layout = new QVBoxLayout;
        Layout->addWidget(new QLineEdit);
        Layout->addWidget(new CustomLineEdit);
        QWidget* Widget = new QWidget(this);
        Widget->setLayout(Layout);
        setCentralWidget(Widget);
    }
};
 
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();
    return a.exec();
}

#include <QApplication>
#include <QMainWindow>
#include <QLineEdit>
#include <QVBoxLayout>

class CustomLineEdit : public QLineEdit
{
public:

    CustomLineEdit(QWidget* parent = 0) :
    QLineEdit(parent)
    {
        setReadOnly(true);
        setText("0.00");
    }

protected:

    virtual void focusOutEvent(QFocusEvent* event)
    {
        QLineEdit::focusOutEvent(event);
        setReadOnly(true);
        deselect();
    }

    virtual void mouseDoubleClickEvent(QMouseEvent* event)
    {
        if(isReadOnly())
            setReadOnly(false);
        else
            QLineEdit::mouseDoubleClickEvent(event);
    }
};

class MainWindow : public QMainWindow
{
public:

    MainWindow(QWidget* parent = 0) :
    QMainWindow(parent)
    {
        QVBoxLayout* Layout = new QVBoxLayout;
        Layout->addWidget(new QLineEdit);
        Layout->addWidget(new CustomLineEdit);
        QWidget* Widget = new QWidget(this);
        Widget->setLayout(Layout);
        setCentralWidget(Widget);
    }
};

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();
    return a.exec();
}

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[anda_skoa]

Indeed, very strange.

Interestingly it works with Qt4.

Cheers,
_

[Alundra]

Is it possible to have a fix for QT 5.3 ?
Thanks

[anda_skoa]

If someone finds the issue and submits a fix via the qt-project.org workflow then yes, it can be in 5.3

Cheers,
_

[Alundra]

If someone finds the issue and submits a fix via the qt-project.org workflow then yes, it can be in 5.3

Cheers,
_

Ok that mean no fix will be there for a long time I think.

[anda_skoa]

How can you tell?

Did you get a reponse in that direction on your bug report?
Have you reported the issue or checked if someone else already has?

Cheers,
_

[Alundra]

it's called experience

[anda_skoa]

Your experience tells you that unreported bugs take a long to get fixed?

Cheers,
_

[Alundra]

i'm not the only one to say that, but it's not very important on this case because this one is not a BIG bug.

[fabrizio.benedetti]

I found this bug still exists in Qt 5.6.3 and I came up with a workaround. Here it is, in case anyone needs it:

//--------------------------------------------------------
void QActivatableLineEdit::mousePressEvent(QMouseEvent* e)
{
  if (isReadOnly() == false)
  {
    QLineEdit::mousePressEvent(e);
    return;
  }
 
  QLineEdit::setReadOnly(false);
  QLineEdit::mousePressEvent(e);
 
   // Qt5 bug! The cursor is not shown!
  int cp = cursorPositionAt(e->pos());
  QApplication::postEvent(this, new QKeyEvent(QEvent::KeyPress, Qt::Key_Right, Qt::NoModifier));
  QApplication::postEvent(this, new QKeyEvent(QEvent::KeyRelease, Qt::Key_Right, Qt::NoModifier));
  QApplication::processEvents();
  setCursorPosition(cp);
}

//--------------------------------------------------------
void QActivatableLineEdit::mousePressEvent(QMouseEvent* e)
{
  if (isReadOnly() == false)
  {
    QLineEdit::mousePressEvent(e);
    return;
  }

  QLineEdit::setReadOnly(false);
  QLineEdit::mousePressEvent(e);

   // Qt5 bug! The cursor is not shown!
  int cp = cursorPositionAt(e->pos());
  QApplication::postEvent(this, new QKeyEvent(QEvent::KeyPress, Qt::Key_Right, Qt::NoModifier));
  QApplication::postEvent(this, new QKeyEvent(QEvent::KeyRelease, Qt::Key_Right, Qt::NoModifier));
  QApplication::processEvents();
  setCursorPosition(cp);
}

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[geekowl]

As a trick:

if(isReadOnly()){
            setReadOnly(false);
            setSelection(text().length(), text().length() + 1); 
}

if(isReadOnly()){
            setReadOnly(false);
            setSelection(text().length(), text().length() + 1); 
}

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