#include "pixitem.h"
#include <QDebug>
#include <QGraphicsSceneMouseEvent>
#include <QPointF>
#include <QGraphicsSceneDragDropEvent>
#include <QDrag>
#include <math.h>
//构造函数初始化了变量pix
PixItem::PixItem(QPixmap *pixmap)
{
pix = *pixmap;
setAcceptDrops(true); //设置可拖拽
m_scaleValue = 0;
m_isMove = false;
}
//实现自己的图元边界函数
QRectF PixItem::boundingRect() const
{
return QRectF(-pix.width() / 2, -pix.height() / 2,
pix.width(), pix.height());
}
//只需QPainter的drawPixmap()函数将图元图片绘出即可
void PixItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *,
QWidget *)
{
painter->drawPixmap(-pix.width() / 2, -pix.height() / 2, pix);
}
//鼠标点击事件 局部缩放
void PixItem::mousePressEvent(QGraphicsSceneMouseEvent *event)
{
m_startPos = event->pos();
m_isMove = true;
int scaleValue = m_scaleValue;
if(m_zoomState == ZOOM_IN) //局部放大
{
scaleValue++;
}
else if(m_zoomState == ZOOM_OUT) //局部缩小
{
scaleValue--;
}
if (scaleValue > ZOOM_IN_TIMES || scaleValue < ZOOM_OUT_TIMES)
return;
if (m_scaleValue != scaleValue)
{
setTransformOriginPoint(event->pos().x(), event->pos().y());
}
m_scaleValue = scaleValue;
qreal s;
//实现局部缩放
if(m_scaleValue > 0)
{
s = pow(1.1, m_scaleValue); //放大 计算x的y方次 参数都是double类型
}else
{
s = pow(1 / 1.1, -m_scaleValue); //缩小
}
setScale(s);
}
void PixItem::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
{
if(m_isMove)
{
QPointF point = event->pos() - m_startPos;
moveBy(point.x(), point.y());
}
}
void PixItem::mouseReleaseEvent(QGraphicsSceneMouseEvent *)
{
m_isMove = false;
}
//使用滚轮整体缩放
void PixItem::wheelEvent(QGraphicsSceneWheelEvent *event)
{
setZoomState(NO_STATE);
int scaleValue = m_scaleValue;
if(event->delta() > 0) //delta（）为正，滚轮向上滚
{
scaleValue++;
}
else
{
scaleValue--;
}
if (scaleValue > ZOOM_IN_TIMES || scaleValue < ZOOM_OUT_TIMES)
return;
m_scaleValue = scaleValue;
qreal s;
if(m_scaleValue > 0)
{
s = pow(1.1, m_scaleValue); //放大 计算x的y方次 参数都是double类型
}
else
{
s = pow(1 / 1.1, -m_scaleValue); //缩小
}
setScale(s);
setTransformOriginPoint(event->pos().x(), event->pos().y());
}
//从widget获取的缩放值，用于同步滚轮和按键
void PixItem::setScaleValue(const int &scaleValue)
{
if (scaleValue > ZOOM_IN_TIMES || scaleValue < ZOOM_OUT_TIMES)
return;
m_scaleValue = scaleValue;
qreal s;
if(m_scaleValue > 0)
{
s = pow(1.1, m_scaleValue); //放大 计算x的y方次 参数都是double类型
}
else
{
s = pow(1 / 1.1, -m_scaleValue); //缩小
}
setScale(s);
}
void PixItem::setZoomState(const int &zoomState)
{
m_zoomState = zoomState;
if (m_zoomState == RESET)
{
m_scaleValue = 0;
setScale(1);
setTransformOriginPoint(0, 0);
}
}
int PixItem::getScaleValue() const
{
return m_scaleValue;
}
