(C++) How to implement a clickable QWidget?

 

FAQ for if you want to use QWidget to display clickable images.

 

The trick is to override 'mousePressEvent' and use the QWidget's geometry() member function:

 

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void Dialog::mousePressEvent(QMouseEvent * event) {   if (ui->widget->geometry().contains(     event->x(), event->y()))   {     //Do something   } }

 

The full code can be viewed and downloaded below.

 

The sprites used in this example are from a game of mine, called Maziak.

 

 

 

 

 

Project and source code

 

Operating system: Ubuntu 10.04 LTS Lucid Lynx

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)

 

• View a screenshot of 'CppQtClickableQWidget' (png)
• Download the C++ Qt Creator project 'CppQtClickableQWidget' (zip)

 

 

 

 

 

CppQtClickableQWidget.pro

 

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#------------------------------------------------- # # Project created by QtCreator 2010-07-31T12:04:49 # #------------------------------------------------- QT += core gui TARGET = CppQtClickableQWidget TEMPLATE = app SOURCES += main.cpp\ dialog.cpp HEADERS += dialog.h FORMS += dialog.ui RESOURCES += \ resources.qrc

 

 

 

 

 

dialog.h

 

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#ifndef DIALOG_H #define DIALOG_H #include <QDialog> struct QMouseEvent; 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;     void mousePressEvent(QMouseEvent* event);     void paintEvent(QPaintEvent * event);     bool m_show_1st; }; #endif // DIALOG_H

 

 

 

 

 

dialog.cpp

 

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#include <QMouseEvent> #include <QPainter> #include "dialog.h" #include "ui_dialog.h" Dialog::Dialog(QWidget *parent) :     QDialog(parent),     ui(new Ui::Dialog),     m_show_1st(true) {   ui->setupUi(this); } 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::paintEvent(QPaintEvent*) {   QPainter painter(this);   QPixmap pixmap(m_show_1st     ? ":/images/PlayerWon1.png"     : ":/images/PlayerScared.png");   painter.drawPixmap(ui->widget->geometry(),pixmap); } void Dialog::mousePressEvent(QMouseEvent * event) {   if (ui->widget->geometry().contains(     event->x(), event->y()))   {     m_show_1st = !m_show_1st;     repaint();   } }

 

 

 

 

 

main.cpp

 

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#include <QtGui/QApplication> #include "dialog.h" int main(int argc, char *argv[]) {   QApplication a(argc, argv);   Dialog w;   w.show();   return a.exec(); }