#include "myview.h"


#define VIEW_CENTER viewport()->rect().center()
const double PI = 3.1415926535898;

MyView::MyView(QWidget *parent) :
     QGraphicsView(parent),
    beishu(1.00000)
{
    setDragMode(QGraphicsView::ScrollHandDrag);
}

void MyView::mousePressEvent(QMouseEvent *event)
{
    bottonstatus = true;
    QGraphicsView::mousePressEvent(event);
}
void MyView::mouseMoveEvent(QMouseEvent *event)
{
    QGraphicsView::mouseMoveEvent(event);
}
void MyView::mouseReleaseEvent(QMouseEvent *event)
{
    bottonstatus = false;
    QGraphicsView::mouseReleaseEvent(event);
}

// 放大/缩小
void MyView::wheelEvent(QWheelEvent *event)
{
    // 滚轮的滚动量
    QPoint scrollAmount = event->angleDelta();
    // 正值表示滚轮远离使用者（放大），负值表示朝向使用者（缩小）
    scrollAmount.y() > 0 ? zoomIn() : zoomOut();
}

// 放大
void MyView::zoomIn()
{
    scale(1.1, 1.1);
    beishu *= 1.1;
    centerOn(450, 700 - (200 / beishu));
}

// 缩小
void MyView::zoomOut()
{
    scale(1 / 1.1, 1 / 1.1);
    beishu /= 1.1;
    centerOn(450, 700 - (200 / beishu));
}