📄 canvas.cpp
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#include <qdatetime.h>#include <qmainwindow.h>#include <qstatusbar.h>#include <qmessagebox.h>#include <qmenubar.h>#include <qapplication.h>#include <qkeycode.h>#include <qpainter.h>#include <qlabel.h>#include <qimage.h>#include <qprogressdialog.h>#include "canvas.h"#include <stdlib.h>// We use a global variable to save memory - all the brushes and pens in// the mesh are shared.static QBrush *tb = 0;static QPen *tp = 0;class EdgeItem;class NodeItem;class EdgeItem: public QCanvasLine{public: EdgeItem( NodeItem*, NodeItem*, QCanvas *canvas ); void setFromPoint( int x, int y ) ; void setToPoint( int x, int y ); static int count() { return c; } void moveBy(double dx, double dy);private: static int c;};static const int imageRTTI = 984376;class ImageItem: public QCanvasRectangle{public: ImageItem( QImage img, QCanvas *canvas ); int rtti () const { return imageRTTI; } bool hit( const QPoint&) const;protected: void drawShape( QPainter & );private: QImage image; QPixmap pixmap;};ImageItem::ImageItem( QImage img, QCanvas *canvas ) : QCanvasRectangle( canvas ), image(img){ setSize( image.width(), image.height() );#ifndef _WS_QWS_ pixmap.convertFromImage(image, OrderedAlphaDither);#endif}void ImageItem::drawShape( QPainter &p ){// On Qt/Embedded, we can paint a QImage as fast as a QPixmap,// but on other platforms, we need to use a QPixmap.#ifdef _WS_QWS_ p.drawImage( int(x()), int(y()), image, 0, 0, -1, -1, OrderedAlphaDither );#else p.drawPixmap( int(x()), int(y()), pixmap );#endif}bool ImageItem::hit( const QPoint &p ) const{ int ix = p.x()-int(x()); int iy = p.y()-int(y()); if ( !image.valid( ix , iy ) ) return FALSE; QRgb pixel = image.pixel( ix, iy ); return qAlpha( pixel ) != 0;}class NodeItem: public QCanvasEllipse{public: NodeItem( QCanvas *canvas ); ~NodeItem() {} void addInEdge( EdgeItem *edge ) { inList.append( edge ); } void addOutEdge( EdgeItem *edge ) { outList.append( edge ); } void moveBy(double dx, double dy); // QPoint center() { return boundingRect().center(); }private: QList<EdgeItem> inList; QList<EdgeItem> outList;};int EdgeItem::c = 0;void EdgeItem::moveBy(double, double){ //nothing}EdgeItem::EdgeItem( NodeItem *from, NodeItem *to, QCanvas *canvas ) : QCanvasLine( canvas ){ c++; setPen( *tp ); setBrush( *tb ); from->addOutEdge( this ); to->addInEdge( this ); setPoints( int(from->x()), int(from->y()), int(to->x()), int(to->y()) ); setZ( 127 );}void EdgeItem::setFromPoint( int x, int y ){ setPoints( x,y, endPoint().x(), endPoint().y() );}void EdgeItem::setToPoint( int x, int y ){ setPoints( startPoint().x(), startPoint().y(), x, y );}void NodeItem::moveBy(double dx, double dy){ QCanvasEllipse::moveBy( dx, dy ); QListIterator<EdgeItem> it1( inList ); EdgeItem *edge; while (( edge = it1.current() )) { ++it1; edge->setToPoint( int(x()), int(y()) ); } QListIterator<EdgeItem> it2( outList ); while (( edge = it2.current() )) { ++it2; edge->setFromPoint( int(x()), int(y()) ); }}NodeItem::NodeItem( QCanvas *canvas ) : QCanvasEllipse( 6, 6, canvas ){ setPen( *tp ); setBrush( *tb ); setZ( 128 );}FigureEditor::FigureEditor( QCanvas& c, QWidget* parent, const char* name, WFlags f) : QCanvasView(&c,parent,name,f){}void FigureEditor::contentsMousePressEvent(QMouseEvent* e){ QCanvasItemList l=canvas()->collisions(e->pos()); for (QCanvasItemList::Iterator it=l.begin(); it!=l.end(); ++it) { if ( (*it)->rtti() == imageRTTI ) { ImageItem *item= (ImageItem*)(*it); if ( !item->hit( e->pos() ) ) continue; } moving = *it; moving_start = e->pos(); return; } moving = 0;}void FigureEditor::clear(){ QCanvasItemList list = canvas()->allItems(); QCanvasItemList::Iterator it = list.begin(); for (; it != list.end(); ++it) { if ( *it ) delete *it; }}void Main::init(){ clear(); static int r=24; srand(++r); int i; for ( i=0; i<canvas.width() / 56; i++) { addButterfly(); } for ( i=0; i<canvas.width() / 85; i++) { addHexagon(); } for ( i=0; i<canvas.width() / 128; i++) { addLogo(); }}void FigureEditor::contentsMouseMoveEvent(QMouseEvent* e){ if ( moving ) { moving->moveBy(e->pos().x() - moving_start.x(), e->pos().y() - moving_start.y()); moving_start = e->pos(); canvas()->update(); }}BouncyLogo::BouncyLogo(QCanvas* canvas) : QCanvasSprite(0,canvas){ static QCanvasPixmapArray logo("qt-trans.xpm"); setSequence(&logo); setAnimated(TRUE); initPos();}const int logo_rtti = 1234;int BouncyLogo::rtti() const{ return logo_rtti;}void BouncyLogo::initPos(){ initSpeed(); int trial=1000; do { move(rand()%canvas()->width(),rand()%canvas()->height()); advance(0); } while (trial-- && xVelocity()==0.0 && yVelocity()==0.0);}void BouncyLogo::initSpeed(){ const double speed = 4.0; double d = (double)(rand()%1024) / 1024.0; setVelocity( d*speed*2-speed, (1-d)*speed*2-speed );}void BouncyLogo::advance(int stage){ switch ( stage ) { case 0: { double vx = xVelocity(); double vy = yVelocity(); if ( vx == 0.0 && vy == 0.0 ) { // stopped last turn initSpeed(); vx = xVelocity(); vy = yVelocity(); } double nx = x() + vx; double ny = y() + vy; if ( nx < 0 || nx >= canvas()->width() ) vx = -vy; if ( ny < 0 || ny >= canvas()->height() ) vy = -vy; for (int bounce=0; bounce<4; bounce++) { QCanvasItemList l=collisions(FALSE); for (QCanvasItemList::Iterator it=l.begin(); it!=l.end(); ++it) { QCanvasItem *hit = *it; if ( hit->rtti()==logo_rtti && hit->collidesWith(this) ) { switch ( bounce ) { case 0: vx = -vx; break; case 1: vy = -vy; vx = -vx; break; case 2: vx = -vx; break; case 3: // Stop for this turn vx = 0; vy = 0; break; } setVelocity(vx,vy); break; } } } if ( x()+vx < 0 || x()+vx >= canvas()->width() ) vx = 0; if ( y()+vy < 0 || y()+vy >= canvas()->height() ) vy = 0; setVelocity(vx,vy); } break; case 1: QCanvasItem::advance(stage); break; }}Main::Main(QCanvas& c, QWidget* parent, const char* name, WFlags f) : QMainWindow(parent,name,f), canvas(c){ editor = new FigureEditor(canvas,this); QMenuBar* menu = menuBar(); QPopupMenu* file = new QPopupMenu; file->insertItem("&Fill canvas", this, SLOT(init()), CTRL+Key_F); file->insertItem("&Erase canvas", this, SLOT(clear()), CTRL+Key_E); file->insertItem("&New view", this, SLOT(newView()), CTRL+Key_N); file->insertSeparator(); file->insertItem("E&xit", qApp, SLOT(quit()), CTRL+Key_Q); menu->insertItem("&File", file); QPopupMenu* edit = new QPopupMenu; edit->insertItem("Add &Circle", this, SLOT(addCircle()), CTRL+Key_C); edit->insertItem("Add &Hexagon", this, SLOT(addHexagon()), CTRL+Key_H); edit->insertItem("Add &Polygon", this, SLOT(addPolygon()), CTRL+Key_P); edit->insertItem("Add &Text", this, SLOT(addText()), CTRL+Key_T); edit->insertItem("Add &Line", this, SLOT(addLine()), CTRL+Key_L); edit->insertItem("Add &Rectangle", this, SLOT(addRectangle()), CTRL+Key_R); edit->insertItem("Add &Sprite", this, SLOT(addSprite()), CTRL+Key_S); edit->insertItem("Create &Mesh", this, SLOT(addMesh()) ); edit->insertItem("Add &Alpha-blended image", this, SLOT(addButterfly()), CTRL+Key_A); edit->insertSeparator(); edit->insertItem("&Enlarge", this, SLOT(enlarge()), CTRL+Key_Plus); edit->insertItem("Shr&ink", this, SLOT(shrink()), CTRL+Key_Minus); menu->insertItem("&Edit", edit); options = new QPopupMenu; dbf_id = options->insertItem("Double buffer", this, SLOT(toggleDoubleBuffer())); options->setItemChecked(dbf_id, TRUE); menu->insertItem("&Options",options); menu->insertSeparator(); QPopupMenu* help = new QPopupMenu; help->insertItem("&About", this, SLOT(help()), Key_F1); help->setItemChecked(dbf_id, TRUE); menu->insertItem("&Help",help); statusBar(); setCentralWidget(editor); init();}void Main::newView(){ // Open a new view... have it delete when closed. Main *m = new Main(canvas, 0, 0, WDestructiveClose); qApp->setMainWidget(m); m->show(); qApp->setMainWidget(0);}void Main::clear(){ editor->clear();}void Main::help(){ static QMessageBox* about = new QMessageBox( "Qt Canvas Example", "<h3>The QCanvas classes example</h3>" "<ul>" "<li> Press CTRL-S for some sprites." "<li> Press CTRL-C for some circles." "<li> Press CTRL-L for some lines." "<li> Drag the objects around." "<li> Read the code!" "</ul>", QMessageBox::Information, 1, 0, 0, this, 0, FALSE ); about->setButtonText( 1, "Dismiss" ); about->show();}void Main::aboutQt(){ QMessageBox::aboutQt( this, "Qt Canvas Example" );}void Main::toggleDoubleBuffer(){ bool s = !options->isItemChecked(dbf_id); options->setItemChecked(dbf_id,s); canvas.setDoubleBuffering(s);}void Main::enlarge(){ canvas.resize(canvas.width()*4/3, canvas.height()*4/3);}void Main::shrink(){ canvas.resize(canvas.width()*3/4, canvas.height()*3/4);}void Main::addSprite(){ QCanvasItem* i = new BouncyLogo(&canvas); i->setZ(rand()%256); i->show();}QString butterfly_fn;QString logo_fn;void Main::addButterfly(){ if ( butterfly_fn.isEmpty() ) return; static QImage *img; if ( !img ) { img = new QImage[4]; img[0].load( butterfly_fn ); img[1] = img[0].smoothScale( int(img[0].width()*0.75), int(img[0].height()*0.75) ); img[2] = img[0].smoothScale( int(img[0].width()*0.5), int(img[0].height()*0.5) ); img[3] = img[0].smoothScale( int(img[0].width()*0.25), int(img[0].height()*0.25) ); } QCanvasPolygonalItem* i = new ImageItem(img[rand()%4],&canvas); i->move(rand()%(canvas.width()-img->width()), rand()%(canvas.height()-img->height())); i->setZ(rand()%256+250); i->show();}void Main::addLogo(){ if ( logo_fn.isEmpty() ) return; static QImage *img; if ( !img ) { img = new QImage[4]; img[0].load( logo_fn ); img[1] = img[0].smoothScale( int(img[0].width()*0.75), int(img[0].height()*0.75) ); img[2] = img[0].smoothScale( int(img[0].width()*0.5), int(img[0].height()*0.5) ); img[3] = img[0].smoothScale( int(img[0].width()*0.25), int(img[0].height()*0.25) ); } QCanvasPolygonalItem* i = new ImageItem(img[rand()%4],&canvas); i->move(rand()%(canvas.width()-img->width()), rand()%(canvas.height()-img->width())); i->setZ(rand()%256+256); i->show();}void Main::addCircle(){ QCanvasPolygonalItem* i = new QCanvasEllipse(50,50,&canvas); i->setBrush( QColor(rand()%32*8,rand()%32*8,rand()%32*8) ); i->move(rand()%canvas.width(),rand()%canvas.height()); i->setZ(rand()%256); i->show();}void Main::addHexagon(){ QCanvasPolygon* i = new QCanvasPolygon(&canvas); const int size = canvas.width() / 25; QPointArray pa(6); pa[0] = QPoint(2*size,0); pa[1] = QPoint(size,-size*173/100); pa[2] = QPoint(-size,-size*173/100); pa[3] = QPoint(-2*size,0); pa[4] = QPoint(-size,size*173/100); pa[5] = QPoint(size,size*173/100); i->setPoints(pa); i->setBrush( QColor(rand()%32*8,rand()%32*8,rand()%32*8) ); i->move(rand()%canvas.width(),rand()%canvas.height()); i->setZ(rand()%256); i->show();}void Main::addPolygon(){ QCanvasPolygon* i = new QCanvasPolygon(&canvas); const int size = canvas.width()/2; QPointArray pa(6); pa[0] = QPoint(0,0); pa[1] = QPoint(size,size/5); pa[2] = QPoint(size*4/5,size); pa[3] = QPoint(size/6,size*5/4); pa[4] = QPoint(size*3/4,size*3/4); pa[5] = QPoint(size*3/4,size/4); i->setPoints(pa); i->setBrush( QColor(rand()%32*8,rand()%32*8,rand()%32*8) ); i->move(rand()%canvas.width(),rand()%canvas.height()); i->setZ(rand()%256); i->show();}void Main::addText(){ QCanvasText* i = new QCanvasText(&canvas); i->setText("QCanvasText"); i->move(rand()%canvas.width(),rand()%canvas.height()); i->setZ(rand()%256); i->setFont(QFont("helvetica",24)); i->show();}void Main::addLine(){ QCanvasLine* i = new QCanvasLine(&canvas); i->setPoints( rand()%canvas.width(), rand()%canvas.height(), rand()%canvas.width(), rand()%canvas.height() ); i->setPen( QPen(QColor(rand()%32*8,rand()%32*8,rand()%32*8), 6) ); i->setZ(rand()%256); i->show();}void Main::addMesh(){ int x0 = 0; int y0 = 0; if ( !tb ) tb = new QBrush( Qt::red ); if ( !tp ) tp = new QPen( Qt::black ); int nodecount = 0; int w = canvas.width(); int h = canvas.height(); const int dist = 30; int rows = h / dist; int cols = w / dist;#ifndef QT_NO_PROGRESSDIALOG QProgressDialog progress( "Creating mesh...", "Abort", rows, this, "progress", TRUE );#endif QArray<NodeItem*> lastRow(cols); for ( int j = 0; j < rows; j++ ) { int n = j%2 ? cols-1 : cols; NodeItem *prev = 0; for ( int i = 0; i < n; i++ ) { NodeItem *el = new NodeItem( &canvas ); nodecount++; int r = rand(); int xrand = r %20; int yrand = (r/20) %20; el->move( xrand + x0 + i*dist + (j%2 ? dist/2 : 0 ), yrand + y0 + j*dist ); if ( j > 0 ) { if ( i < cols-1 ) (new EdgeItem( lastRow[i], el, &canvas ))->show(); if ( j%2 ) (new EdgeItem( lastRow[i+1], el, &canvas ))->show(); else if ( i > 0 ) (new EdgeItem( lastRow[i-1], el, &canvas ))->show(); } if ( prev ) { (new EdgeItem( prev, el, &canvas ))->show(); } if ( i > 0 ) lastRow[i-1] = prev; prev = el; el->show(); } lastRow[n-1]=prev;#ifndef QT_NO_PROGRESSDIALOG progress.setProgress( j ); if ( progress.wasCancelled() ) break;#endif }#ifndef QT_NO_PROGRESSDIALOG progress.setProgress( rows );#endif // qDebug( "%d nodes, %d edges", nodecount, EdgeItem::count() );}void Main::addRectangle(){ QCanvasPolygonalItem *i = new QCanvasRectangle( rand()%canvas.width(),rand()%canvas.height(), canvas.width()/5,canvas.width()/5,&canvas); int z = rand()%256; i->setBrush( QColor(z,z,z) ); i->setPen( QPen(QColor(rand()%32*8,rand()%32*8,rand()%32*8), 6) ); i->setZ(z); i->show();}
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