Qt5 Coordinate System

This time, there was basically no major error .. Based on the down-Down Function of the buttons, the up-down function is implemented, and the rotate () function is rotated.

Myitem. h

# Ifndef myitem_h # define myitem_h # include <qgraphicsitem> class myitem: Public qgraphicsitem {public: myitem (); qrectf boundingrect () const; void paint (qpainter * painter, const alert * option, qwidget * widget); void setcolor (const qcolor & color) {brushcolor = color;} void keypressevent (qkeyevent * event); void mousepressevent (qgraphicsscenemouseevent * event ); // press the mouse button to respond to void hoverenterevent (qgraphicsscenehoverevent * event); // void contextmenuevent (callback * event); Private: qcolor brushcolor ;};# endif // myitem_h

Myview. h

#ifndef MYVIEW_H#define MYVIEW_H#include <QGraphicsView>class MyView : public QGraphicsView{    Q_OBJECTpublic:    explicit MyView(QWidget *parent = 0);protected:    void keyPressEvent(QKeyEvent *event);signals:public slots:};#endif // MYVIEW_H

Main. cpp

# Include <qapplication> # include "myitem. H "# include" myview. H "# include" myitem. CPP "# include" myview. CPP "# include <qtime> int main (INT argc, char * argv []) {qapplication app (argc, argv); qsrand (qtime (0, 0, 0 ). secsto (qtime: currenttime (); qgraphicsscene scene; scene. setscenerect (-200,-150,400,300); For (INT I = 0; I <= 5; ++ I) {myitem * Item = new myitem; item-> setcolor (qcolor (qrand () % 256, qrand () % 256, qrand () % 256 )); // randomly generate the color item-> setpos (I * 50-90,-50); scene. additem (item);} myview view; view. setscene (& scene); view. setbackgroundbrush (qpixmap (".. /myview/11.jpg"); view. show (); Return app.exe C ();}

Myitem. cpp

# Include "myitem. H "# include <qpainter> # include <qcursor> # include <qkeyevent> # include <qgraphicsscenehoverevent> # include <qgraphicsscenecontextmenuevent> # include <qmenu> myitem: myitem () {brushcolor = QT: red; setflag (qgraphicsitem: itemisfocusable); setflag (Expiration: itemismovable); setaccepthoverevents (true);} qrectf myitem: boundingrect () const {qreal adjust = 0.5; return qrectf (-10-adjust,-10-adjust, 20 + adjust, 20 + adjust);} void myitem: paint (qpainter * painter, const qstyleoptiongraphicsitem * option, qwidget * widget) {If (hasfocus () {painter-> setpen (qpen (qcolor (255,255,255,200 )));} else {painter-> setpen (qpen (qcolor (100,100,100,100);} painter-> setbrush (brushcolor); painter-> drawrect (-10,-, 20 );} void myitem: mousepressevent (qgraphicsscenemouseevent * event) {setfocus (); setcursor (QT: closedhandcursor);} void myitem: keypressevent (qkeyevent * event) {If (Event-> key () = QT: key_down) // X, Y moves {moveBy ();} else if (Event-> key () = QT: key_up) {moveBy (0,-10) ;}} void myitem: hoverenterevent (qgraphicsscenehoverevent * event) {setcursor (QT: openhandcursor ); settooltip ("I am item");} void myitem: contextmenuevent (qgraphicsscenecontextmenuevent * event) {qmenu menu; qaction * moveaction = menu. addaction ("Move Back"); // right-click the menu to display qaction * selectedaction = menu.exe C (Event-> screenpos (); If (selectedaction = moveaction) // return to (0, 0) point {setpos (0, 0 );}}

Myview. cpp

# Include "myview. H "# include <qkeyevent> myview: myview (qwidget * parent): qgraphicsview (parent) {} void myview: keypressevent (qkeyevent * event) {Switch (Event-> key () {Case QT: key_plus: // + scale (1.2, 1.2); break; Case QT: key_minus: //-scale (1/1. 2, 1/1.2); break; Case QT: key_right: Rotate (30); break; Case QT: key_left: Rotate (-30); break;} qgraphicsview :: keypressevent (event );}