Clickable QLabel: Difference between revisions

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(Cleanup)
(Added includes, changed constructor)
Line 7: Line 7:


<code>
<code>
class ClickableLabel : public QLabel
#ifndef CLICKABLELABEL_H
{
#define CLICKABLELABEL_H
Q_OBJECT
 
#include <QLabel>
#include <QWidget>
#include <Qt>
 
class ClickableLabel : public QLabel {  
    Q_OBJECT  
 
public:
public:
     explicit ClickableLabel( const QString& text="", QWidget* parent=0 );
     explicit ClickableLabel(QWidget* parent = Q_NULLPTR, Qt::WindowFlags f = Qt::WindowFlags());
     ~ClickableLabel();
     ~ClickableLabel();
signals:
signals:
     void clicked();
     void clicked();
protected:
protected:
     void mousePressEvent(QMouseEvent* event);
     void mousePressEvent(QMouseEvent* event);
};
};
#endif // CLICKABLELABEL_H
</code>
</code>


Line 23: Line 36:


<code>
<code>
ClickableLabel::ClickableLabel(const QString& text, QWidget* parent)
#include "clickablelabel.h"
     : QLabel(parent)
 
{
ClickableLabel::ClickableLabel(QWidget* parent, Qt::WindowFlags f)
     setText(text);
     : QLabel(parent) {
      
}
}


ClickableLabel::~ClickableLabel()
ClickableLabel::~ClickableLabel() {}
{
}


void ClickableLabel::mousePressEvent(QMouseEvent* event)
void ClickableLabel::mousePressEvent(QMouseEvent* event) {
{
     emit clicked();
     emit clicked();
}
}
</code>
</code>



Revision as of 07:13, 18 May 2017

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A "clicked" signal may sometimes be required from a label, but there is no "clicked" signal emitted by QLabel. You can work around this easily by making a QPushButton like a label by setting the 'flat' property.

However, if there are other properties of a QLabel object that you need, here is a code snippet for a custom QLabel which can emit a signal: 'clicked'. In other words, a Clickable QLabel!

Header

#ifndef CLICKABLELABEL_H
#define CLICKABLELABEL_H

#include <QLabel>
#include <QWidget>
#include <Qt>

class ClickableLabel : public QLabel { 
    Q_OBJECT 

public:
    explicit ClickableLabel(QWidget* parent = Q_NULLPTR, Qt::WindowFlags f = Qt::WindowFlags());
    ~ClickableLabel();

signals:
    void clicked();

protected:
    void mousePressEvent(QMouseEvent* event);

};

#endif // CLICKABLELABEL_H

Source

#include "clickablelabel.h"

ClickableLabel::ClickableLabel(QWidget* parent, Qt::WindowFlags f)
    : QLabel(parent) {
    
}

ClickableLabel::~ClickableLabel() {}

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

What we do here is simple: Catch the mouse press event on the label. Then emit 'clicked' signal. We could as well make the signal be emitted when mouse gets released. This is let to be a decision of the developer.