canvas.cpp

QT 开发环境里面一个很重要的文件

}

void Main::init()
{
    clear();

    static int r=24;
    qsrand(++r);

    mainCount++;
    butterflyimg = 0;
    logoimg = 0;

    int i;
    for ( i=0; i < int(canvas.width()) / 56; i++) {
	addButterfly();
    }
    for ( i=0; i < int(canvas.width()) / 85; i++) {
	addHexagon();
    }
    for ( i=0; i < int(canvas.width()) / 128; i++) {
	addLogo();
    }
}

Main::~Main()
{
    delete printer;
    if ( !--mainCount ) {
	delete[] butterflyimg;
	butterflyimg = 0;
	delete[] logoimg;
	logoimg = 0;
    }
}

void Main::newView()
{
    // Open a new view... have it delete when closed.
    Main *m = new Main(canvas, 0, 0, Qt::WDestructiveClose);
    m->show();
}

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 ALT-S for some sprites."
		"<li> Press ALT-C for some circles."
		"<li> Press ALT-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::enlarge()
{
    canvas.setSceneRect(0, 0, canvas.width()*4/3, canvas.height()*4/3);
}

void Main::shrink()
{
    canvas.setSceneRect(0, 0, canvas.width()*3/4, canvas.height()*3/4);
}

void Main::rotateClockwise()
{
    editor->rotate( 22.5 );
}

void Main::rotateCounterClockwise()
{
    editor->rotate( -22.5 );
}

void Main::zoomIn()
{
    editor->scale( 2.0, 2.0 );
}

void Main::zoomOut()
{
    editor->scale( 0.5, 0.5 );
}

void Main::mirror()
{
    editor->scale( -1, 1 );
}

void Main::moveL()
{
    editor->translate( -16, 0 );
}

void Main::moveR()
{
    editor->translate( +16, 0 );
}

void Main::moveU()
{
    editor->translate( 0, -16 );
}

void Main::moveD()
{
    editor->translate( 0, +16 );
}

void Main::print()
{
    if ( !printer ) printer = new QPrinter;
    if ( printer->setup(this) ) {
	QPainter pp(printer);
        canvas.render(&pp);
    }
}


void Main::addSprite()
{
    BouncyLogo* i = new BouncyLogo;
    canvas.addItem(i);
    i->initPos();
    i->setZValue(qrand()%256);
}

QString butterfly_fn;
QString logo_fn;


void Main::addButterfly()
{
    if ( butterfly_fn.isEmpty() )
	return;
    if ( !butterflyimg ) {
	butterflyimg = new QImage[4];
	butterflyimg[0].load( butterfly_fn );
	butterflyimg[1] = butterflyimg[0].smoothScale( int(butterflyimg[0].width()*0.75),
		int(butterflyimg[0].height()*0.75) );
	butterflyimg[2] = butterflyimg[0].smoothScale( int(butterflyimg[0].width()*0.5),
		int(butterflyimg[0].height()*0.5) );
	butterflyimg[3] = butterflyimg[0].smoothScale( int(butterflyimg[0].width()*0.25),
		int(butterflyimg[0].height()*0.25) );
    }
    QAbstractGraphicsShapeItem* i = new ImageItem(butterflyimg[qrand()%4]);
    canvas.addItem(i);
    i->setPos(qrand()%int(canvas.width()-butterflyimg->width()),
	    qrand()%int(canvas.height()-butterflyimg->height()));
    i->setZValue(qrand()%256+250);
}

void Main::addLogo()
{
    if ( logo_fn.isEmpty() )
	return;
    if ( !logoimg ) {
	logoimg = new QImage[4];
	logoimg[0].load( logo_fn );
	logoimg[1] = logoimg[0].smoothScale( int(logoimg[0].width()*0.75),
		int(logoimg[0].height()*0.75) );
	logoimg[2] = logoimg[0].smoothScale( int(logoimg[0].width()*0.5),
		int(logoimg[0].height()*0.5) );
	logoimg[3] = logoimg[0].smoothScale( int(logoimg[0].width()*0.25),
		int(logoimg[0].height()*0.25) );
    }
    QAbstractGraphicsShapeItem* i = new ImageItem(logoimg[qrand()%4]);
    canvas.addItem(i);
    i->setPos(qrand()%int(canvas.width()-logoimg->width()),
	    qrand()%int(canvas.height()-logoimg->width()));
    i->setZValue(qrand()%256+256);
}



void Main::addCircle()
{
    QAbstractGraphicsShapeItem* i = canvas.addEllipse(QRectF(0,0,50,50));
    i->setFlag(QGraphicsItem::ItemIsMovable);
    i->setPen(Qt::NoPen);
    i->setBrush( QColor(qrand()%32*8,qrand()%32*8,qrand()%32*8) );
    i->setPos(qrand()%int(canvas.width()),qrand()%int(canvas.height()));
    i->setZValue(qrand()%256);
}

void Main::addHexagon()
{
    const int size = int(canvas.width() / 25);
    Q3PointArray 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);
    QGraphicsPolygonItem* i = canvas.addPolygon(pa);
    i->setFlag(QGraphicsItem::ItemIsMovable);
    i->setPen(Qt::NoPen);
    i->setBrush( QColor(qrand()%32*8,qrand()%32*8,qrand()%32*8) );
    i->setPos(qrand()%int(canvas.width()),qrand()%int(canvas.height()));
    i->setZValue(qrand()%256);
}

void Main::addPolygon()
{
    const int size = int(canvas.width()/2);
    Q3PointArray 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);
    QGraphicsPolygonItem* i = canvas.addPolygon(pa);
    i->setFlag(QGraphicsItem::ItemIsMovable);
    i->setPen(Qt::NoPen);
    i->setBrush( QColor(qrand()%32*8,qrand()%32*8,qrand()%32*8) );
    i->setPos(qrand()%int(canvas.width()),qrand()%int(canvas.height()));
    i->setZValue(qrand()%256);
}

void Main::addSpline()
{
    const int size = int(canvas.width()/6);

    Q3PointArray pa(12);
    pa[0] = QPoint(0,0);
    pa[1] = QPoint(size/2,0);
    pa[2] = QPoint(size,size/2);
    pa[3] = QPoint(size,size);
    pa[4] = QPoint(size,size*3/2);
    pa[5] = QPoint(size/2,size*2);
    pa[6] = QPoint(0,size*2);
    pa[7] = QPoint(-size/2,size*2);
    pa[8] = QPoint(size/4,size*3/2);
    pa[9] = QPoint(0,size);
    pa[10]= QPoint(-size/4,size/2);
    pa[11]= QPoint(-size/2,0);

    QPainterPath path;
    path.moveTo(pa[0]);
    for (int i = 1; i < pa.size(); i += 3)
        path.cubicTo(pa[i], pa[(i + 1) % pa.size()], pa[(i + 2) % pa.size()]);

    QGraphicsPathItem* item = canvas.addPath(path);
    item->setFlag(QGraphicsItem::ItemIsMovable);
    item->setPen(Qt::NoPen);
    item->setBrush( QColor(qrand()%32*8,qrand()%32*8,qrand()%32*8) );
    item->setPos(qrand()%int(canvas.width()),qrand()%int(canvas.height()));
    item->setZValue(qrand()%256);
}

void Main::addText()
{
    QGraphicsTextItem* i = canvas.addText("QCanvasText");
    i->setFlag(QGraphicsItem::ItemIsMovable);
    i->setPos(qrand()%int(canvas.width()),qrand()%int(canvas.height()));
    i->setZValue(qrand()%256);
}

void Main::addLine()
{
    QGraphicsLineItem* i = canvas.addLine(QLineF( qrand()%int(canvas.width()), qrand()%int(canvas.height()),
                                                  qrand()%int(canvas.width()), qrand()%int(canvas.height()) ));
    i->setFlag(QGraphicsItem::ItemIsMovable);
    i->setPen( QPen(QColor(qrand()%32*8,qrand()%32*8,qrand()%32*8), 6) );
    i->setZValue(qrand()%256);
}

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 = int(canvas.width());
    int h = int(canvas.height());

    const int dist = 30;
    int rows = h / dist;
    int cols = w / dist;

#ifndef QT_NO_PROGRESSDIALOG
    Q3ProgressDialog progress( "Creating mesh...", "Abort", rows,
			      this, "progress", TRUE );
#endif

    Q3MemArray<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.addItem(el);
	    nodecount++;
	    int r = qrand();
	    int xrand = r %20;
	    int yrand = (r/20) %20;
	    el->setPos( xrand + x0 + i*dist + (j%2 ? dist/2 : 0 ),
                        yrand + y0 + j*dist );

	    if ( j > 0 ) {
		if ( i < cols-1 )
		    canvas.addItem(new EdgeItem( lastRow[i], el));
		if ( j%2 )
		    canvas.addItem(new EdgeItem( lastRow[i+1], el));
		else if ( i > 0 )
		    canvas.addItem(new EdgeItem( lastRow[i-1], el));
	    }
	    if ( prev ) {
		canvas.addItem(new EdgeItem( prev, el));
	    }
	    if ( i > 0 ) lastRow[i-1] = prev;
	    prev = el;
	}
	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()
{
    QAbstractGraphicsShapeItem *i = canvas.addRect( QRectF(qrand()%int(canvas.width()),
                                                          qrand()%int(canvas.height()),
                                                          canvas.width()/5,
                                                          canvas.width()/5) );
    i->setFlag(QGraphicsItem::ItemIsMovable);
    int z = qrand()%256;
    i->setBrush( QColor(z,z,z) );
    i->setPen( QPen(QColor(qrand()%32*8,qrand()%32*8,qrand()%32*8), 6) );
    i->setZValue(z);
}