(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); }