QGraphicsPixmapItem example 1: basic is a QGraphicsPixmapItem example. This example shows how to put multiple movable QGraphicsPixmapItems on screen. Note that the pixmaps are transparent, because the images supplied were transparent.

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++11

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: ./CppQGraphicsPixmapItemExample1/CppQGraphicsPixmapItemExample1.pro


exists (../../DesktopApplication.pri) {

  include(../../DesktopApplication.pri)

}

!exists (../../DesktopApplication.pri) {

  QT += core printsupport

  QT += gui

  greaterThan(QT_MAJOR_VERSION, 4): QT += widgets svg

  CONFIG   += console

  CONFIG   -= app_bundle

  TEMPLATE = app

  CONFIG(release, debug|release) {

    DEFINES += NDEBUG NTRACE_BILDERBIKKEL

  }

  QMAKE_CXXFLAGS += -std=c++11 -Wall -Wextra -Weffc++

  unix {

    QMAKE_CXXFLAGS += -Werror

  }

}



exists(../../Libraries/Boost.pri) {

  include(../../Libraries/Boost.pri)

}

!exists(../../Libraries/Boost.pri) {

  win32 {

    INCLUDEPATH += \

      ../../Libraries/boost_1_55_0

  }

}



SOURCES += \

    qtmain.cpp \

    qtwidget.cpp \

    qtitem.cpp



HEADERS += \

    qtwidget.h \

    qtitem.h



RESOURCES += \

    CppQGraphicsPixmapItemExample1.qrc

./CppQGraphicsPixmapItemExample1/qtitem.h


#ifndef QTITEM_H

#define QTITEM_H



#pragma GCC diagnostic push

#pragma GCC diagnostic ignored "-Weffc++"

#pragma GCC diagnostic ignored "-Wunused-local-typedefs"

#pragma GCC diagnostic ignored "-Wunused-but-set-parameter"

#include <QGraphicsPixmapItem>

#pragma GCC diagnostic pop



///A QGraphicsPixmapItem that loads its pixmap from resources

struct QtItem : public QGraphicsPixmapItem

{

  QtItem(QGraphicsItem *parent = 0);

};



#endif // QTITEM_H

./CppQGraphicsPixmapItemExample1/qtitem.cpp


#pragma GCC diagnostic push

#pragma GCC diagnostic ignored "-Weffc++"

#pragma GCC diagnostic ignored "-Wunused-local-typedefs"

#pragma GCC diagnostic ignored "-Wunused-but-set-parameter"

#include <cassert>

#include <QPainter>

#include "qtitem.h"

#pragma GCC diagnostic pop



QtItem::QtItem(QGraphicsItem *parent)

  : QGraphicsPixmapItem(parent)

{

  assert(this->pixmap().isNull()

    && "Assume no pixmap loaded yet");



  //Load the pixmap from resources

  this->setPixmap(QPixmap(":/images/PicR.png"));



  assert(!this->pixmap().isNull()

    && "Assume pixmap is loaded successfully");



  this->setFlags(QGraphicsItem::ItemIsMovable);

}

./CppQGraphicsPixmapItemExample1/qtmain.cpp


#pragma GCC diagnostic push

#pragma GCC diagnostic ignored "-Weffc++"

#pragma GCC diagnostic ignored "-Wunused-local-typedefs"

#pragma GCC diagnostic ignored "-Wunused-but-set-parameter"

#include <QApplication>

#include "qtwidget.h"

#pragma GCC diagnostic pop



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

{

  QApplication a(argc, argv);

  QtWidget w;

  w.setGeometry(100,100,400,400);

  w.show();

  return a.exec();

}

./CppQGraphicsPixmapItemExample1/qtwidget.h


#ifndef QTWIDGET_H

#define QTWIDGET_H



#pragma GCC diagnostic push

#pragma GCC diagnostic ignored "-Weffc++"

#pragma GCC diagnostic ignored "-Wunused-local-typedefs"

#pragma GCC diagnostic ignored "-Wunused-but-set-parameter"

#include <QGraphicsView>

#pragma GCC diagnostic pop



struct QtWidget : public QGraphicsView

{

  QtWidget();

};



#endif // QTWIDGET_H

./CppQGraphicsPixmapItemExample1/qtwidget.cpp


#pragma GCC diagnostic push

#pragma GCC diagnostic ignored "-Weffc++"

#pragma GCC diagnostic ignored "-Wunused-local-typedefs"

#pragma GCC diagnostic ignored "-Wunused-but-set-parameter"

#include <cassert>

#include <QGraphicsScene>

#include <QGraphicsPixmapItem>

#include "qtitem.h"

#include "qtwidget.h"

#pragma GCC diagnostic pop



QtWidget::QtWidget()

{

  QGraphicsScene * const scene = new QGraphicsScene(this);

  this->setScene(scene);



  const int n_items = 64;

  for (int i=0; i!=n_items; ++i)

  {

    QtItem * const item = new QtItem;

    //Scatter those items around a bit

    item->setPos(

      - 128 + (std::rand() % 256),

      - 128 + (std::rand() % 256));



    scene->addItem(item);

  }

}

Go back to Richel Bilderbeek's C++ page.

Go back to Richel Bilderbeek's homepage.

This page has been created by the tool CodeToHtml

(C++) QGraphicsPixmapItemExample1