110 lines
3.5 KiB
C++
110 lines
3.5 KiB
C++
#include "QImageWidget.h"
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#include <QDebug>
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#include <QGraphicsSceneMouseEvent>
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#include <QPointF>
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#include <QGraphicsSceneDragDropEvent>
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#include <QDrag>
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#include <math.h>
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QImageWidget::QImageWidget(QPixmap* pixmap)
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{
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m_pix = *pixmap;
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setAcceptDrops(true);//If enabled is true, this item will accept hover events; otherwise, it will ignore them. By default, items do not accept hover events.
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m_scaleValue = 0;
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m_scaleDafault = 0;
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m_isMove = false;
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}
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QRectF QImageWidget::boundingRect() const
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{
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return QRectF(-m_pix.width() / 2, -m_pix.height() / 2,
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m_pix.width(), m_pix.height());
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}
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void QImageWidget::paint(QPainter* painter, const QStyleOptionGraphicsItem*,
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QWidget*)
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{
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painter->drawPixmap(-m_pix.width() / 2, -m_pix.height() / 2, m_pix);
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}
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void QImageWidget::mousePressEvent(QGraphicsSceneMouseEvent* event)
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{
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if (event->button() == Qt::LeftButton)
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{
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m_startPos = event->pos();//鼠标左击时，获取当前鼠标在图片中的坐标，
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m_isMove = true;//标记鼠标左键被按下
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}
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else if (event->button() == Qt::RightButton)
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{
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ResetItemPos();//右击鼠标重置大小
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}
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}
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void QImageWidget::mouseMoveEvent(QGraphicsSceneMouseEvent* event)
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{
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if (m_isMove)
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{
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QPointF point = (event->pos() - m_startPos) * m_scaleValue;
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moveBy(point.x(), point.y());
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}
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}
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void QImageWidget::mouseReleaseEvent(QGraphicsSceneMouseEvent*)
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{
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m_isMove = false;//标记鼠标左键已经抬起
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}
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void QImageWidget::wheelEvent(QGraphicsSceneWheelEvent* event)//鼠标滚轮事件
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{
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if ((event->delta() > 0) && (m_scaleValue >= 50))//最大放大到原始图像的50倍
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{
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return;
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}
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else if ((event->delta() < 0) && (m_scaleValue <= m_scaleDafault))//图像缩小到自适应大小之后就不继续缩小
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{
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ResetItemPos();//重置图片大小和位置，使之自适应控件窗口大小
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}
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else
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{
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qreal qrealOriginScale = m_scaleValue;
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if (event->delta() > 0)//鼠标滚轮向前滚动
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{
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m_scaleValue *= 1.1;//每次放大10%
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}
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else
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{
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m_scaleValue *= 0.9;//每次缩小10%
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}
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setScale(m_scaleValue);
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if (event->delta() > 0)
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{
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moveBy(-event->pos().x() * qrealOriginScale * 0.1, -event->pos().y() * qrealOriginScale * 0.1);//使图片缩放的效果看起来像是以鼠标所在点为中心进行缩放的
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}
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else
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{
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moveBy(event->pos().x() * qrealOriginScale * 0.1, event->pos().y() * qrealOriginScale * 0.1);//使图片缩放的效果看起来像是以鼠标所在点为中心进行缩放的
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}
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}
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}
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//将主界面的控件QGraphicsView的width和height传进本类中，并根据图像的长宽和控件的长宽的比例来使图片缩放到适合控件的大小
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void QImageWidget::setQGraphicsViewWH(int nwidth, int nheight)
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{
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int nImgWidth = m_pix.width();
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int nImgHeight = m_pix.height();
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qreal temp1 = nwidth * 1.0 / nImgWidth;
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qreal temp2 = nheight * 1.0 / nImgHeight;
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if (temp1 > temp2)
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{
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m_scaleDafault = temp2;
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}
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else
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{
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m_scaleDafault = temp1;
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}
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setScale(m_scaleDafault);
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m_scaleValue = m_scaleDafault;
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}
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//重置图片位置
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void QImageWidget::ResetItemPos()
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{
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m_scaleValue = m_scaleDafault;//缩放比例回到一开始的自适应比例
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setScale(m_scaleDafault);//缩放到一开始的自适应大小
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setPos(0, 0);
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}
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qreal QImageWidget::getScaleValue() const
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{
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return m_scaleValue;
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} |