view.cpp

#include "view.h"

const double PI = 3.1415926536; 

View::View(QWidget *parent):QGraphicsView(parent)
{
	//pen= QPen(QBrush(Qt::red),3);
}

View::~View()
{

}

void View::drawBackground ( QPainter * painter, const QRectF & rect )
{
    if(!image.isNull()) painter->drawPixmap(0, 0, QPixmap::fromImage(image));
            //painter->drawPixmap(rect.left(), rect.top(), QPixmap(imageFile));
    QGraphicsView::drawBackground(painter,rect);

}

/**
  * Sets the current centerpoint.  Also updates the scene's center point.
  * Unlike centerOn, which has no way of getting the floating point center
  * back, SetCenter() stores the center point.  It also handles the special
  * sidebar case.  This function will claim the centerPoint to sceneRec ie.
  * the centerPoint must be within the sceneRec.
  */
//Set the current centerpoint in the
void View::SetCenter(const QPointF& centerPoint) {
    //Get the rectangle of the visible area in scene coords
    QRectF visibleArea = mapToScene(rect()).boundingRect();
 
    //Get the scene area
    QRectF sceneBounds = sceneRect();
 
    double boundX = visibleArea.width() / 2.0;
    double boundY = visibleArea.height() / 2.0;
    double boundWidth = sceneBounds.width() - 2.0 * boundX;
    double boundHeight = sceneBounds.height() - 2.0 * boundY;
 
    //The max boundary that the centerPoint can be to
    QRectF bounds(boundX, boundY, boundWidth, boundHeight);
 
    if(bounds.contains(centerPoint)) {
        //We are within the bounds
        CurrentCenterPoint = centerPoint;
    } else {
        //We need to clamp or use the center of the screen
        if(visibleArea.contains(sceneBounds)) {
            //Use the center of scene ie. we can see the whole scene
            CurrentCenterPoint = sceneBounds.center();
        } else {
 
            CurrentCenterPoint = centerPoint;
 
            //We need to clamp the center. The centerPoint is too large
            if(centerPoint.x() > bounds.x() + bounds.width()) {
                CurrentCenterPoint.setX(bounds.x() + bounds.width());
            } else if(centerPoint.x() < bounds.x()) {
                CurrentCenterPoint.setX(bounds.x());
            }
 
            if(centerPoint.y() > bounds.y() + bounds.height()) {
                CurrentCenterPoint.setY(bounds.y() + bounds.height());
            } else if(centerPoint.y() < bounds.y()) {
                CurrentCenterPoint.setY(bounds.y());
            }
 
        }
    }
 
    //Update the scrollbars
    centerOn(CurrentCenterPoint);
}
 
/**
  * Handles when the mouse button is pressed
  */
//void View::mousePressEvent(QMouseEvent* event) {
//    //For panning the view
//    LastPanPoint = event->pos();
//    setCursor(Qt::ClosedHandCursor);
//}
// 
///**
//  * Handles when the mouse button is released
//  */
//void View::mouseReleaseEvent(QMouseEvent* event) {
//    setCursor(Qt::OpenHandCursor);
//    LastPanPoint = QPoint();
//}
// 
///**
//*Handles the mouse move event
//*/
//void View::mouseMoveEvent(QMouseEvent* event) {
//    if(!LastPanPoint.isNull()) {
//        //Get how much we panned
//        QPointF delta = mapToScene(LastPanPoint) - mapToScene(event->pos());
//        LastPanPoint = event->pos();
// 
//        //Update the center ie. do the pan
//        SetCenter(GetCenter() + delta);
//    }
//}
 
/**
  * Zoom the view in and out.
  */
void View::wheelEvent(QWheelEvent* event) {
 
    //Get the position of the mouse before scaling, in scene coords
    QPointF pointBeforeScale(mapToScene(event->pos()));
 
    //Get the original screen centerpoint
    QPointF screenCenter = GetCenter(); //CurrentCenterPoint; //(visRect.center());
 
    //Scale the view ie. do the zoom
    double scaleFactor = 1.15; //How fast we zoom
    if(event->delta() > 0) {
        //Zoom in
        scale(scaleFactor, scaleFactor);
    } else {
        //Zooming out
        scale(1.0 / scaleFactor, 1.0 / scaleFactor);
    }
 
    //Get the position after scaling, in scene coords
    QPointF pointAfterScale(mapToScene(event->pos()));
 
    //Get the offset of how the screen moved
    QPointF offset = pointBeforeScale - pointAfterScale;
 
    //Adjust to the new center for correct zooming
    QPointF newCenter = screenCenter + offset;
    SetCenter(newCenter);
}
 
/**
  * Need to update the center so there is no jolt in the
  * interaction after resizing the widget.
  */
void View::resizeEvent(QResizeEvent* event) {
    //Get the rectangle of the visible area in scene coords
    QRectF visibleArea = mapToScene(rect()).boundingRect();
    SetCenter(visibleArea.center());
 
    //Call the subclass resize so the scrollbars are updated correctly
    QGraphicsView::resizeEvent(event);
}