(C++ Qt) How to make a clickable QLabel?

How to make a clickable QLabel? is a QT FAQ with multiple answers:

A) You cannot
B) You can, if you use QLabel to display text, if you replace the QLabel by a (disguised) QPushButton
C) You can, if you use QLabel to display an image, see Qt example 17: clickable QLabels showing an image

Answer B source code

You can disguise a QPushButton to look like a QLabel, by settings its Flat property to true. This looks like this (png).

Download the Qt Creator project 'CppQtClickableLabel' (zip)

Operating system: Ubuntu

IDE: Qt Creator 2.0.0

Project type: Qt4 GUI Application

Compiler: G++ 4.4.1

Libraries used:

Qt: version 4.7.0 (32 bit)

main.cpp


#include <QtGui/QApplication>

#include "dialog.h"



int main(int argc, char *argv[])

{

  QApplication a(argc, argv);

  Dialog w;

  w.show();

  return a.exec();

}

dialog.h


#ifndef DIALOG_H

#define DIALOG_H



#include <QDialog>



namespace Ui {

  class Dialog;

}



class Dialog : public QDialog

{

  Q_OBJECT

  

public:

  explicit Dialog(QWidget *parent = 0);

  ~Dialog();

  

protected:

  void changeEvent(QEvent *e);

  

private:

  Ui::Dialog *ui;

private slots:

  void onClick();

  

};



#endif // DIALOG_H

dialog.cpp


#include <cstdlib>



#include "dialog.h"

#include "ui_dialog.h"



Dialog::Dialog(QWidget *parent) :

    QDialog(parent),

    ui(new Ui::Dialog)

{

  ui->setupUi(this);

  this->setWindowTitle("CppQtClickableLabel");

  //A QLabel does not emit a clicked signal

  QObject::connect(ui->label_text,SIGNAL(clicked()),this,SLOT(onClick()));

  //But a QPushButton does!

  QObject::connect(ui->button,SIGNAL(clicked()),this,SLOT(onClick()));

}



Dialog::~Dialog()

{

  delete ui;

}



void Dialog::changeEvent(QEvent *e)

{

  QDialog::changeEvent(e);

  switch (e->type()) {

  case QEvent::LanguageChange:

    ui->retranslateUi(this);

    break;

  default:

    break;

  }

}



void Dialog::onClick()

{

  QString s; s.setNum(std::rand());

  this->setWindowTitle(s);

}

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