MousePressEvent for QTextEdit

[anju123]

I have used a QTextEdit on my main widget, Now the problem is that it is not recognizing the MousePress event when I click on the QTextEdit area. I have read similar posts on this problem, but nothing is working. Another strange thing is that the QTextEdit is responding to "Doubleclick" event perfectly but not for "MousePress" event. I am not able to understand this behaviour.
Any kind of help is more than welcome.

[rajesh]

Hi Anju,
have you used installEventFilter() for QTextEdit?

[rajesh]

you subdrive QTextEdit and write
void MyTextEdit::mousePressEvent(QMouseEvent *event)
{
//event->ignore();
}

OR

you can use installEventFilter
see the example:

class MyMainClass   
{
 Q_OBJECT
 
 
protected:
 bool eventFilter(QObject *target, QEvent *event);
private:
   QTextEdit * m_pTextEdit;
};
 
in constructor:
m_pTextEdit->installEventFilter(this);
 
bool MyMainClass::eventFilter(QObject *target, QEvent *event)
{
 if (target == m_pTextEdit) 
 {
    if (event->type() == QEvent::MouseButtonPress)
   {
        // you can write your code here, like this:
   }
    if (event->type() == QEvent::KeyPress)
    {
        QKeyEvent *keyEvent = static_cast<QKeyEvent *>(event);
        std::string str = keyEvent->text().toStdString();
        char ch = str[0];
        if (!((ch <= '9' && ch >= '0') | (ch <= 'F' && ch >= 'A') | 
        (ch <= 'f' && ch >= 'a')))
        {
                          if (ch != 9) return true;
                           else
                          return QWidget::eventFilter(target, event);
         }
 
      }
   }
   else
   return QWidget::eventFilter(target, event);
}

class MyMainClass   
{
 Q_OBJECT
 
 
protected:
 bool eventFilter(QObject *target, QEvent *event);
private:
   QTextEdit * m_pTextEdit;
};
 
in constructor:
m_pTextEdit->installEventFilter(this);
 
bool MyMainClass::eventFilter(QObject *target, QEvent *event)
{
 if (target == m_pTextEdit) 
 {
    if (event->type() == QEvent::MouseButtonPress)
   {
        // you can write your code here, like this:
   }
    if (event->type() == QEvent::KeyPress)
    {
        QKeyEvent *keyEvent = static_cast<QKeyEvent *>(event);
        std::string str = keyEvent->text().toStdString();
        char ch = str[0];
        if (!((ch <= '9' && ch >= '0') | (ch <= 'F' && ch >= 'A') | 
        (ch <= 'f' && ch >= 'a')))
        {
                          if (ch != 9) return true;
                           else
                          return QWidget::eventFilter(target, event);
         }
 
      }
   }
   else
   return QWidget::eventFilter(target, event);
}

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[anju123]

I have tried the installeventFilter as well, I am now pasting the code as I think it might be the problem with my code.
Here is my class:

SelectableItem_C::SelectableItem_C(QWidget* parent) 
{
    	 _label_textedit = new QTextEdit(this);
    _label_textedit->setFont(font);
    _label_textedit->setAlignment(Qt::AlignCenter);
    _label_textedit->setPaletteBackgroundColor(dark_background);
    _label_textedit->setAutoFillBackground(true);
	_label_textedit->setFrameShape(QFrame::NoFrame);
	_label_textedit->setWordWrapMode(QTextOption::WrapAtWordBoundaryOrAnywhere);
	_label_textedit->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
    _label_textedit->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
	_label_textedit->setTextInteractionFlags(Qt::NoTextInteraction);
 
 
	QSizePolicy sizePolicy(static_cast<QSizePolicy::Policy>(5), static_cast<QSizePolicy::Policy>(5));
    sizePolicy.setHorizontalStretch(0);
    sizePolicy.setVerticalStretch(0);
    sizePolicy.setHeightForWidth(_label_textedit->sizePolicy().hasHeightForWidth());
    _label_textedit->setSizePolicy(sizePolicy);
 
	_label_textedit->viewport()->setCursor(Qt::ArrowCursor);
	_label_textedit->installEventFilter(this);
	_label_textedit->viewport()->setMouseTracking(true);
 
}

SelectableItem_C::SelectableItem_C(QWidget* parent) 
{
    	 _label_textedit = new QTextEdit(this);
    _label_textedit->setFont(font);
    _label_textedit->setAlignment(Qt::AlignCenter);
    _label_textedit->setPaletteBackgroundColor(dark_background);
    _label_textedit->setAutoFillBackground(true);
	_label_textedit->setFrameShape(QFrame::NoFrame);
	_label_textedit->setWordWrapMode(QTextOption::WrapAtWordBoundaryOrAnywhere);
	_label_textedit->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
    _label_textedit->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
	_label_textedit->setTextInteractionFlags(Qt::NoTextInteraction);


	QSizePolicy sizePolicy(static_cast<QSizePolicy::Policy>(5), static_cast<QSizePolicy::Policy>(5));
    sizePolicy.setHorizontalStretch(0);
    sizePolicy.setVerticalStretch(0);
    sizePolicy.setHeightForWidth(_label_textedit->sizePolicy().hasHeightForWidth());
    _label_textedit->setSizePolicy(sizePolicy);

	_label_textedit->viewport()->setCursor(Qt::ArrowCursor);
	_label_textedit->installEventFilter(this);
	_label_textedit->viewport()->setMouseTracking(true);

}

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and here is the event filter function in this class

bool SelectableItem_C::eventFilter( QObject *obj, QEvent *ev )
 {    
	 //printf("got in\n");    
	 if ( obj == _label_textedit )     
	 {    
		if ( ev->type() == QEvent::MouseButtonPress )    
		{        
			emit MousePressed_Signal(this);      
			return TRUE;    
		}     
	 }     
	 else     
	 {    
		 //printf("af: %d,%d\n",e->x(),e->y());        
		 // pass the event on to the parent class    
		 return QWidget::eventFilter( obj, ev );    
	 }
	 return TRUE;  
 }

bool SelectableItem_C::eventFilter( QObject *obj, QEvent *ev )
 {    
	 //printf("got in\n");    
	 if ( obj == _label_textedit )     
	 {    
		if ( ev->type() == QEvent::MouseButtonPress )    
		{        
			emit MousePressed_Signal(this);      
			return TRUE;    
		}     
	 }     
	 else     
	 {    
		 //printf("af: %d,%d\n",e->x(),e->y());        
		 // pass the event on to the parent class    
		 return QWidget::eventFilter( obj, ev );    
	 }
	 return TRUE;  
 }

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I have defined a "MousePressed_Signal" which is doing the desired work.
I could not even come in to the "If condition" with my debugging.
One more thing is that I have overridden the functions "mousePressEvent" and "mouseDoubleClickEvent" for my class. I can see that control goes to the function "mouseDoubleClickEvent" when I double click on the QTextEdit control, but not when I just do a single click on the same QTextEdit ?

[rajesh]

Anju,
which version of Qt you are using?
I doesn't find setPaletteBackgroundColor() in Qt 4.3

in my code mousePressEvent(QMouseEvent *event) working fine.
anyway I will test your code and write you back.

[rajesh]

Anju,
I tested your code in my application and mousePressEvent(QMouseEvent *event) working fine. even eventFilter() not required.
I have Qt4.3.1 on windows xp.

[elcuco]

Try attaching the event filter into the viewport (look into the documentation of QAbstractScrollArea.

[anju123]

Ok..
So it could be the problem of QT versiosn as well. I am using Qt 4.2.2 on windows Xp

[jpn]

It's not a problem of any specific Qt version. Read QObject::eventFilter() docs:

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.

[anju123]

Thanks to everybody,
I need to use _label_textedit->viewport()->installEventFilter(this); to get the control for required mousepress event