(C++) QtExample36

 

 

Qt example 36: arrows with multiple midpoints is a Qt example elaborates on Qt example 34: moveable, selectable and editable arrows, but has arrows with an angle in them instead.

Technical facts

 

Application type(s)

• Desktop application

Operating system(s) or programming environment(s)

• Lubuntu 15.04 (vivid)

IDE(s):

• Qt Creator 3.1.1

Project type:

• GUI application

C++ standard:

• C++98

Compiler(s):

• G++ 4.9.2

Libraries used:

• Qt: version 5.4.1 (32 bit)
• STL: GNU ISO C++ Library, version 4.9.2

 

 

 

 

 

Qt project file: ./CppQtExample36/CppQtExample36.pro

 

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QT       += core gui greaterThan(QT_MAJOR_VERSION, 4): QT += widgets TEMPLATE = app SOURCES += main.cpp \     gamewidget.cpp HEADERS  += \     gamewidget.h FORMS    += RESOURCES += \     CppQtExample36.qrc

 

 

 

 

 

./CppQtExample36/gamewidget.h

 

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#ifndef GAMEWIDGET_H #define GAMEWIDGET_H #include <QWidget> class GameWidget : public QWidget {   Q_OBJECT   public:   GameWidget();   void paintEvent(QPaintEvent *);   private:   int m_x;   int m_y;   private slots:   ///Responds to internal QTimer   void OnTimer(); }; #endif // GAMEWIDGET_H

 

 

 

 

 

./CppQtExample36/gamewidget.cpp

 

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#include "gamewidget.h" #include <QBrush> #include <QColor> #include <QDialog> #include <QPainter> #include <QTimer> GameWidget::GameWidget() : m_x(0), m_y(0) {   ///Create the heartbeat of the program   QTimer * const timer = new QTimer(this);   QObject::connect(timer,SIGNAL(timeout()),this,SLOT(OnTimer()));   timer->setInterval(20);   timer->start(); } void GameWidget::OnTimer() {   ++m_x;   ++m_y;   this->repaint();   if (m_x > 256) { m_x = 0; m_y = 0; } } void GameWidget::paintEvent(QPaintEvent *) {   QPainter painter(this);   QPixmap pixmap(":/PicBeer.png");   painter.drawPixmap(this->rect(),pixmap);   painter.drawPixmap(100-m_x    ,100+m_y    ,120,120,pixmap);   painter.drawPixmap(100-m_x+100,100-m_y    ,120,120,pixmap);   painter.drawPixmap(100+m_x    ,100+m_y+100,120,120,pixmap);   painter.drawPixmap(100+m_x+100,100-m_y+100,120,120,pixmap); }

 

 

 

 

 

./CppQtExample36/main.cpp

 

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