QLabel::clicked()

[sabeesh]

Hi,
I am using QT 4.2.2. I have a label in my main window. I want a "QLabel::clicked()" signal for my label, ie, i want to call a function when i click on a lable. How can I do that.

[vermarajeev]

Hi,
I am using QT 4.2.2. I have a label in my main window. I want a "QLabel::clicked()" signal for my label, ie, i want to call a function when i click on a lable. How can I do that.

There is no clicked signal in QLabel. What you can do is create your own QLabel class and override mousePressEvent to fire a clicked signal and catch it in your defined slot.

[sabeesh]

Hi,
Not clear!!!!!!!!!!!

[vermarajeev]

Hi,
Not clear!!!!!!!!!!!

myLabel::myLabel( const QString & text, QWidget * parent )
:QLabel(parent)
{
	connect( this, SIGNAL( clicked() ), this, SLOT( slotClicked() ) );
}
void myLabel::mousePressEvent ( QMouseEvent * event ) 
{
	emit clicked();
}
void myLabel::slotClicked()
{
	qDebug()<<"Clicked";
}

myLabel::myLabel( const QString & text, QWidget * parent )
:QLabel(parent)
{
	connect( this, SIGNAL( clicked() ), this, SLOT( slotClicked() ) );
}
void myLabel::mousePressEvent ( QMouseEvent * event ) 
{
	emit clicked();
}
void myLabel::slotClicked()
{
	qDebug()<<"Clicked";
}

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[sabeesh]

Hi,
When I give this code, qt display some errors. Can you give me a small discreption aout this code. because, i am a new comer in QT!!!!!

[marcel]

When I give this code, qt display some errors.

How do you "give" the code?

That is a QLabel subclass.
You have to define your own class, and add those methods to it and also the signal.

That code is no not complete. It is just a suggestion.
You will have to embed it in your application.

Regards

[vermarajeev]

Ok, here is the full code

//.h

class myLabel : public QLabel
{
	Q_OBJECT
public:
	myLabel( const QString & text, QWidget * parent = 0 );
	~myLabel(){}
 
signals:
	void clicked();
 
public slots:
	void slotClicked();	
 
protected:
	void mousePressEvent ( QMouseEvent * event ) ;
 
};
#endif

class myLabel : public QLabel
{
	Q_OBJECT
public:
	myLabel( const QString & text, QWidget * parent = 0 );
	~myLabel(){}

signals:
	void clicked();

public slots:
	void slotClicked();	

protected:
	void mousePressEvent ( QMouseEvent * event ) ;

};
#endif

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.cpp

myLabel::myLabel( const QString & text, QWidget * parent )
:QLabel(parent)
{
	connect( this, SIGNAL( clicked() ), this, SLOT( slotClicked() ) );
}
 
void myLabel::slotClicked()
{
	qDebug()<<"Clicked";
}
 
void myLabel::mousePressEvent ( QMouseEvent * event ) 
{
	emit clicked();
}

myLabel::myLabel( const QString & text, QWidget * parent )
:QLabel(parent)
{
	connect( this, SIGNAL( clicked() ), this, SLOT( slotClicked() ) );
}

void myLabel::slotClicked()
{
	qDebug()<<"Clicked";
}

void myLabel::mousePressEvent ( QMouseEvent * event ) 
{
	emit clicked();
}

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In your mainWindows.cpp in the constructor add this

MainWindow::MainWindow(QWidget* parent)
: QMainWindow(parent)
{
    myLabel* m_label = new myLabel(this); 
}

MainWindow::MainWindow(QWidget* parent)
: QMainWindow(parent)
{
    myLabel* m_label = new myLabel(this); 
}

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I have not tested the code so please correct the code if you get any errors
Thanks

[jbarrena]

Hi there!!

And how is it possible for the Widget to catch the clicked signal from the label???

Thanks for the help!!!

Best regards!

[gun4boy]

code of vermarajeev works well for me

[Sven]

Hi there!!

And how is it possible for the Widget to catch the clicked signal from the label???

Thanks for the help!!!

Best regards!

MainWindow::MainWindow(QWidget* parent)
: QMainWindow(parent)
{
myLabel* m_label = new myLabel(this);
}

If you use this example you can catch it like this:

MainWindow::MainWindow(QWidget* parent)
: QMainWindow(parent)
{
myLabel* m_label = new myLabel(this);
connect(myLabel, SIGNAL(clicked()), SLOT(myActionWhenMyLabelHasBeenClicked()));
}

[lotek]

Hi,

only one remark:

The "real click" will be better simulated if you will use the
mouseReleaseEvent(QMouseEvent *e) instead of mousePressEvent(QMouseEvent *e)


regards

me

[dogbear]

I agree with Lotek.
A mouse "click" is traditionally a full press-then-release event series.
Interpreting a click on a mouse press disallows the user from canceling the click when they drag the mouse away from the item, amongst other things.
Just my two-cents.
doggy