Russian Qt Forum

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);

    paintWidget widget;
    widget.show();

    return app.exec();
}

mainWidget::mainWidget(QWidget *parent) : QWidget(parent)
{
    paintWidget *map = new paintWidget();
    scrollArea = new QScrollArea(this);
    scrollArea->setWidget(map);
}

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);

    mainWidget widget;
    widget.show();

    return app.exec();
}

mainWidget::mainWidget(QWidget *parent) : QWidget(parent)
{
    QTextEdit *map = new QTextEdit();
    scrollArea = new QScrollArea(this);
    scrollArea->setWidget(map);	
}

class paintWidget : public QWidget
{
public:
    paintWidget(QWidget *parent = 0);
    
protected:
    void paintEvent(QPaintEvent *e);
    void mousePressEvent(QMouseEvent *e);
    void mouseMoveEvent(QMouseEvent *e);
    bool isInside(int ix, int iy, int a, int n);
    
private:
    QPixmap mapImage;
    QPoint curLine[2];
    QPoint point[MAX_VERTEX_NUMBER];
    int vert_num;
    
    QPoint area[MAX_AREA_NUMBER][MAX_VERTEX_NUMBER];
    int area_num;
    int a_vert_num[MAX_AREA_NUMBER];
    
    int activeArea;
    
    bool bDrawing;
    
    double x1lon, x2lon;  // ??????? - x
    double y1lat, y2lat;  // ?????? - y
    int width, height;
    double stepx, stepy;
    double curlon, curlat;
};

paintWidget::paintWidget(QWidget *parent) : QWidget(parent)
{
    setMouseTracking(true);
    
    vert_num = 0;
    area_num = 0;
    activeArea = -1;
    
    mapImage = QPixmap("e:\\map.bmp");
    width = mapImage.width();
    height = mapImage.height();
    
    x1lon = 30.146484;
    x2lon = 30.585938;
    y1lat = 59.800634;
    y2lat = 60.108670;
    
    stepx = (x2lon - x1lon) / width;
    stepy = (y2lat - y1lat) / height;
    
    bDrawing = false;
}

void paintWidget::paintEvent(QPaintEvent *e)
{
    QPainter painter(this);
    QPen pen;
    QBrush brush;
    
    painter.drawPixmap(0,0,mapImage);
    
    pen.setColor(QColor(0,200,0));
    pen.setWidth(2);
    painter.setPen(pen);
    brush.setStyle(Qt::SolidPattern);
    brush.setColor(QColor(0,255,0,10));
    painter.setBrush(brush);
    for(int a=0; a<area_num; a++)
    {
        for(int i=1; i<a_vert_num[a]; i++)
        {
            painter.drawPolygon(area[a],a_vert_num[a]-1);
        }
    }
    
    
    pen.setColor(QColor(Qt::black));
    painter.setPen(pen);
    painter.setFont(QFont("Lucida Console",14));
    painter.drawText(QRect(15,10,200,200),QString("%1\n%2").arg(curlat).arg(curlon));
    
    pen.setColor(QColor(255,128,0));
    pen.setWidth(2);
    painter.setPen(pen);
    if(bDrawing)
    {
        for(int i=1; i<vert_num; i++)
            painter.drawLine(point[i-1],point[i]);
        painter.drawLine(curLine[0],curLine[1]);
    }
    if(activeArea >= 0)
    {
        painter.drawPolygon(area[activeArea],a_vert_num[activeArea]-1);
    }
    
}

void paintWidget::mousePressEvent(QMouseEvent *e)
{
     if(e->button() == Qt::LeftButton)
     {
         if(bDrawing)
         {
             point[vert_num++] = curLine[1];
             curLine[0] = curLine[1];
         }else{
             point[0] = e->pos();
             vert_num = 1;
             curLine[0] = curLine[1] = e->pos();
             bDrawing = true;
         }
     }
     
     if(e->button() == Qt::RightButton)
     {
         if(bDrawing)
         {
             point[vert_num++] = point[0];
             bDrawing = false;
             
             // ??????????? ?????????? ??????? ? ????????
             int l = sizeof(point) / sizeof(point[0]);
             for(int i=0; i<l; i++)
             {
                 area[area_num][i] = point[i];
             }
             a_vert_num[area_num++] = vert_num;
         }
     }
     
     update();
}

void paintWidget::mouseMoveEvent(QMouseEvent *e)
{
    if(bDrawing)
    {
        // ???????? ? ???????????
        QPoint mouse;
        QPoint point;
        QPoint temp;
        int m = 999;
        int tempm;
        mouse = e->pos();
        for(int a=0; a<area_num; a++)
        {
            for(int i=1; i<a_vert_num[a]; i++)
            {
                temp = mouse-area[a][i];
                tempm = temp.manhattanLength();
                if(tempm < m)
                {
                    point = area[a][i];
                    m = tempm;                    
                }
            }
        }
        if(m<20)
        {
            curLine[1] = point;
        }else{
            curLine[1] = e->pos();
        }
        update();
    }else{
        activeArea = -1;
        for(int i=0; i<area_num; i++)
            if(isInside(e->x(),e->y(),i,a_vert_num[i]))
                activeArea = i;
        update();
    }
    
    curlon = x1lon + e->x()*stepx;
    curlat = y2lat - e->y()*stepy;
}

bool paintWidget::isInside(int ix, int iy, int a, int n)
{
    // mine
    double sx = (double)ix;
    double sy = (double)iy;
    
    int poly[n*2];
    for(int i=0; i<n; i++)
    {
        poly[i*2] = area[a][i].x();
        poly[i*2+1] = area[a][i].y();
    }
    // end of mine
    
  int x[50], y[50];
  n--;
  for(int i=0; i<n; i++)
  {
    x[i] = poly[i*2];
    y[i] = poly[i*2+1];
  }
	int pj, pk=0;
	double wrkx, yu, yl;
	for (pj=0; pj<n; pj++)
	{
		yu = y[pj]>y[(pj+1)%n]?y[pj]:y[(pj+1)%n];
		yl = y[pj]<y[(pj+1)%n]?y[pj]:y[(pj+1)%n];
		if (y[(pj+1)%n] - y[pj])
			wrkx = x[pj] + (x[(pj+1)%n] - x[pj])*(sy - y[pj])/(y[(pj+1)%n] - y[pj]);
		else
			wrkx = x[pj];
		if (yu >= sy) 
			if (yl < sy)
			{
				if (sx > wrkx)
						pk++;
				if (fabs(sx - wrkx) < 0.00001) return true;
			}
		if ((fabs(sy - yl) < 0.00001) && (fabs(yu - yl) < 0.00001) && (fabs(fabs(wrkx - x[pj]) + fabs(wrkx - x[(pj+1)%n]) - fabs(x[pj] - x[(pj+1)%n])) < 0.0001))
			return true;
	}
	if (pk%2) 
		return true;
	else
		return false;
}

paintWidget::paintWidget(QWidget *parent) : QWidget(parent)
{	
    setMouseTracking(true);
    
    vert_num = 0;
    area_num = 0;
    activeArea = -1;
    
	mapImage = QPixmap("e:/map.bmp");
    width = mapImage.width();
    height = mapImage.height();

    resize(width, height);
....

mainWidget::mainWidget(QWidget *parent) : QWidget(parent)
{
    paintWidget *map = new paintWidget();
    scrollArea = new QScrollArea(this);
    scrollArea->setWidget(map);
}

void mainWidget::resizeEvent(QResizeEvent * event)
{
    m_pScrollArea->resize(event->size());
}

#include <QApplication>
#include <QPushButton>
#include <QPainter>
#include <QImage>
#include <QRgb>
#include <QMainWindow>
#include <QScrollArea>

//#define USE_SET_MIN_SIZE 1
//#define USE_MIN_HINT     1

class paintWidget : public QWidget
{
public:
    paintWidget(QWidget *parent = 0);
    
#ifdef USE_MIN_HINT
    virtual QSize sizeHint() const;
#endif
protected:
    void paintEvent(QPaintEvent *e);
    
private:

    QSize m_size;
    QImage m_img;
};

paintWidget::paintWidget(QWidget *parent) : QWidget(parent)
{
    m_size = QSize(256, 256);
    m_img = QImage(m_size, QImage::Format_RGB32);
#ifdef USE_SET_MIN_SIZE
    setMinimumSize(m_size);
#endif
}
#ifdef USE_MIN_HINT
QSize paintWidget::sizeHint() const
{
    return m_size;
}
#endif
void paintWidget::paintEvent(QPaintEvent *e)
{
    QPainter painter(this);
    QPen pen;
    QBrush brush;

    for(int y=0; y<m_size.height(); y++)
    {
        QRgb* prgb = (QRgb*)m_img.scanLine(y);
        for(int x=0; x<m_size.width(); x++)
        {
            *prgb++ = qRgb(x, y, x+y);
        }
    
    }

    painter.drawImage(QRect(0, 0, width(), height()), m_img, QRect(0, 0, 256, 256));
}

int main( int argc, char **argv )
{
    QApplication a( argc, argv );

    paintWidget pw1;
    pw1.show();

    QMainWindow mw;
    mw.show();

    QScrollArea* psa = new QScrollArea(&mw);
    mw.setCentralWidget(psa);
    paintWidget* ppw2 = new paintWidget(psa);
    psa->setWidget(ppw2);

    return a.exec();
}

//#define USE_SET_MIN_SIZE 1
//#define USE_MIN_HINT     1