#include "myview.h"
#include <QWheelEvent>
#include <QMouseEvent>
#include <QScrollBar>
#include "picscene.h"
#include <QDebug>
MyView::MyView(QWidget *parent) :
    QGraphicsView(parent)
{
    zoomRatio = 1;
    //setDragMode(QGraphicsView::ScrollHandDrag);//手型拖动
    //setAlignment(Qt::AlignLeft | Qt::AlignTop);
    //setFocusPolicy( Qt::NoFocus );
}
// static float a = 1.615;
static float a = 1.64;
void MyView::ZoomOut(void)
{
    if(zoomRatio < 6)
    {
        zoomRatio++;
//        scale(2,2);
        scale(a,a);
    }
}

void MyView::ZoomIn(void)
{
    if(zoomRatio > 2)
    {
        zoomRatio--;
        scale(1/a,1/a);
    }
}

//void MyView::wheelEvent(QWheelEvent*event)  //滚轮事件
//{
////   if(event->delta() > 0)  //如果鼠标滚轮远离使用者，则delta()返回正值
////       scale(0.5,0.5);  //视图缩放
////   else scale(2,2);
//}


//void MyView::mousePressEvent(QMouseEvent*event)
//{
////   rotate(90);  //视图旋转顺时针90度
//}

void MyView::mousePressEvent(QMouseEvent *event)
{
    if (event->button() == Qt::LeftButton) {
        m_isPressing = true;
        const QPointF scenePos = mapToScene(event->pos());
        const bool hasSelectedItem = scene() && !scene()->selectedItems().isEmpty();
        m_pressOnItem = hasSelectedItem || (scene() && scene()->itemAt(scenePos, transform()) != nullptr);
        m_lastPanPoint = event->pos();
    }

    QGraphicsView::mousePressEvent(event);
}

void MyView::mouseMoveEvent(QMouseEvent *event)
{
    if (m_isPressing && !m_pressOnItem && !m_isPanning) {
        const bool noSelectedItems = scene() && scene()->selectedItems().isEmpty();
        if (noSelectedItems) {
            QPoint delta = event->pos() - m_lastPanPoint;
            if (std::abs(delta.x()) >= MyView::PanStartDistance && std::abs(delta.x()) > std::abs(delta.y())) {
                m_isPanning = true;
                setCursor(Qt::ClosedHandCursor);
            }
        }
    }

    if (m_isPanning) {
        int deltaX = event->pos().x() - m_lastPanPoint.x();
        if (deltaX != 0) {
            horizontalScrollBar()->setValue(horizontalScrollBar()->value() - deltaX);
            m_lastPanPoint = event->pos();
        }
        event->accept();
        return;
    }

    QGraphicsView::mouseMoveEvent(event);
}

void MyView::mouseReleaseEvent(QMouseEvent *event)
{
    if (m_isPanning && event->button() == Qt::LeftButton) {
        m_isPanning = false;
        m_isPressing = false;
        setCursor(Qt::ArrowCursor);
        event->accept();
        return;
    }

    if (event->button() == Qt::LeftButton) {
        m_isPressing = false;
        m_pressOnItem = false;
    }

    QGraphicsView::mouseReleaseEvent(event);
}

void MyView::keyPressEvent(QKeyEvent *event)
{
    //event->accept();
    //parent()->event((QEvent*) event);
    if (event->key() == Qt::Key_Left || event->key() == Qt::Key_Right || event->key() == Qt::Key_Up || event->key() == Qt::Key_Down)
    {
               // 处理上下键事件
               PicScene* picScene = dynamic_cast<PicScene*>(this->scene());
               if(picScene)
               {
                    picScene->keyPressEvent(event);
               }
     }
     else
     {
               // 其他键事件交给父类处理
               QGraphicsView::keyPressEvent(event);
     }
}