(C++) Qt example 37: rounded rectangle item

Qt example 37: rounded rectangle item is a QGraphicsRectItem example that displays some QGraphicsRectItem the are movable and selectable. Additionally, the items display their coordinats.

• Download the Qt Creator project 'QtExample37' (zip)
• Download a Windows executable of 'QtExample37' (zip)

 

 

 

 

 

Technical facts

 

Application type(s)

• Desktop application

Operating system(s) or programming environment(s)

• Lubuntu 12.10 (quantal)

IDE(s):

• Qt Creator 2.5.2

Project type:

• GUI application

C++ standard:

• C++11

Compiler(s):

• G++ 4.7.2

Libraries used:

• Qt: version 4.8.3 (32 bit)
• STL: GNU ISO C++ Library, version 4.7.2

 

 

 

 

 

Qt project file: CppQtExample37.pro

 

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QT       += core gui QMAKE_CXXFLAGS += -std=c++11 -Wall -Wextra -Werror TARGET = CppQtExample37 TEMPLATE = app SOURCES += \     qtmain.cpp \     qtwidget.cpp \     qtroundedrectitem.cpp HEADERS += \     qtwidget.h \     qtroundedrectitem.h

 

 

 

 

 

qtmain.cpp

 

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#include <QApplication> #include <QDesktopWidget> #include "qtwidget.h" int main(int argc, char *argv[]) {   QApplication a(argc, argv);   QtWidget w;   {     //Resize the dialog and put it in the screen center     w.setGeometry(0,0,800,600);     const QRect screen = QApplication::desktop()->screenGeometry();     w.move( screen.center() - w.rect().center() );   }   w.show();   return a.exec(); }

 

 

 

 

 

qtroundedrectitem.h

 

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#ifndef QTRECTITEM_H #define QTRECTITEM_H #include <QGraphicsRectItem> struct QtRoundedRectItem : public QGraphicsRectItem {   QtRoundedRectItem(QGraphicsItem *parent = 0, QGraphicsScene *scene = 0);   void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);   ///Get the rounded rect corner x radius   double getRadiusX() const { return m_radius_x; }   ///Get the rounded rect corner y radius   double getRadiusY() const { return m_radius_y; }   ///Set the rounded rect corner x radius   void setRadiusX(const double radius_x) { m_radius_x = radius_x; }   ///Set the rounded rect corner y radius   void setRadiusY(const double radius_y) { m_radius_y = radius_y; }   ///Set the rounded rect   void setRoundedRect(const QRectF rect, const double radius_x, const double radius_y);   private:   ///The rounded rect corner x radius   double m_radius_x;   ///The rounded rect corner y radius   double m_radius_y; }; #endif // QTRECTITEM_H

 

 

 

 

 

qtroundedrectitem.cpp

 

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#ifdef _WIN32 //See http://www.richelbilderbeek.nl/CppCompileErrorSwprintfHasNotBeenDeclared.htm #undef __STRICT_ANSI__ #endif //#include own header file as first substantive line of code, from: // * John Lakos. Large-Scale C++ Software Design. 1996. ISBN: 0-201-63362-0. Section 3.2, page 110 #include "qtroundedrectitem.h" #include <cassert> #include <sstream> #include <QGraphicsScene> #include <QPainter> QtRoundedRectItem::QtRoundedRectItem(QGraphicsItem *parent, QGraphicsScene *scene) : QGraphicsRectItem(parent,scene) {   this->setFlags(       QGraphicsItem::ItemIsFocusable     | QGraphicsItem::ItemIsMovable     | QGraphicsItem::ItemIsSelectable); } void QtRoundedRectItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *, QWidget *) {   if (this->isSelected())   {     QPen pen;     pen.setStyle(Qt::DashLine);     painter->setPen(pen);   }   painter->drawRoundedRect(this->rect(),m_radius_x,m_radius_y); } void QtRoundedRectItem::setRoundedRect(const QRectF rect, const double radius_x, const double radius_y) {   this->setRect(rect);   this->setRadiusX(radius_x);   this->setRadiusY(radius_y); }

 

 

 

 

 

qtwidget.h

 

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#ifndef QTWIDGET_H #define QTWIDGET_H #include <QGraphicsView> ///The widget holding the items struct QtWidget : public QGraphicsView {   QtWidget(QWidget *parent = 0); }; #endif // QTWIDGET_H

 

 

 

 

 

qtwidget.cpp

 

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#ifdef _WIN32 //See http://www.richelbilderbeek.nl/CppCompileErrorSwprintfHasNotBeenDeclared.htm #undef __STRICT_ANSI__ #endif //#include own header file as first substantive line of code, from: // * John Lakos. Large-Scale C++ Software Design. 1996. ISBN: 0-201-63362-0. Section 3.2, page 110 #include "qtwidget.h" #include <cassert> #include <cmath> #include <iostream> #include <QGraphicsScene> #include <QKeyEvent> #include <QGraphicsSimpleTextItem> #include "qtroundedrectitem.h" QtWidget::QtWidget(QWidget *parent)   : QGraphicsView(new QGraphicsScene,parent) {   const int n_items = 16;   for (int i=0; i!=n_items; ++i)   {     const double angle = 2.0 * M_PI * (static_cast<double>(i) / static_cast<double>(n_items));     {       const double ray = 200.0;       const double x =  std::sin(angle) * ray;       const double y = -std::cos(angle) * ray;       QtRoundedRectItem * const item = new QtRoundedRectItem;       item->setPos(x,y);       item->setRoundedRect(QRectF(-32.0,-32.0,64.0,64.0),16.0,16.0);       scene()->addItem(item);     }     {       const double ray = 120.0;       const double x =  std::sin(angle) * ray;       const double y = -std::cos(angle) * ray;       QGraphicsRectItem * const item = new QGraphicsRectItem;       item->setFlags(           QGraphicsItem::ItemIsFocusable         | QGraphicsItem::ItemIsMovable         | QGraphicsItem::ItemIsSelectable);       item->setPos(x,y);       item->setRect(-16.0,-16.0,32.0,32.0);       scene()->addItem(item);     }   } }

 

 

 

 

 

crosscompiletowindows.sh

 

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#!/bin/sh #From http://richelbilderbeek.nl/CppQtCrosscompileToWindowsExample15.htm echo "Cross compiling to Windows" echo "1/2: Creating Windows makefile" i686-pc-mingw32-qmake CppQtExample37.pro echo "2/2: making makefile" make echo "Done"