Qt利用tablewidget模拟手指实现滑动

目录

• 1.介绍
• 2.CustomScroll类

1.介绍

嵌入式由于需要支持手指滑动,所以先写个demo,来试验.

每次按下的时候,获取一次按下的pos以及按下的时间,然后释放的时候获取一次释放pos,从而计算出,每秒移动的像素点,其中计算代码如下所示:

int ms= QDateTime::currentDateTime().toMSecsSinceEpoch()-pressMSec;
int Pixel_per_second=qAbs(releasePoint_y - pressPoint_y)*1000/ms;       //计算每秒移动像素点

获取到每秒移动像素点后,再结合ms(持续时间),进行判断,从而实现手指离开后,是否需要再滑动一下.具体代码如下所示:

 if(ms > 1000)      //滑动的时间太长
{
     m_dragFlag = MOUSE_RELEASE;
     if(!m_scrollTimer.isActive())
         m_scrollTimer.start(1000);  //1S后取消滑动条显示
     return true;
}

if(releasePoint_y - pressPoint_y > 0)     //向下滑动
{
    moveValue = m_scrollBar->value() - Pixel_per_second*0.2*(300/ms);//滑动时间越长,moveValue值越小,因为不是快速滑动
    if(moveValue < scrollV_min)
    {
        moveValue = scrollV_min;
    }
}
else
{
    moveValue = m_scrollBar->value() + Pixel_per_second*0.2*(300/ms);
    if(moveValue > scrollV_max)
    {
        moveValue = scrollV_max;
    }
}

最后再调用QPropertyAnimation类来实现动画滑动:

animation->setDuration(2000-ms);
animation->setEndValue(moveValue);
animation->setEasingCurve(QEasingCurve::OutQuart);

界面如下图所示:

2.CustomScroll类

CustomScroll:自定义滑动,该类包含了一个显示滑动条.逻辑如下所示:

• 当用户只是单击item时,则不显示.
• 如果用户点击item进行滑动时,则显示.
• 如果用户滑动后释放鼠标(离开手指),则1s后取消显示

效果如下所示:

CustomScroll.h如下所示:

#ifndef CustomScroll_H
#define CustomScroll_H

#include <QObject>
#include <QWidget>
#include <QTimer>
#include <QTableView>
#include <QPropertyAnimation>
#include <QDateTime>
class CustomScroll : public QWidget
{
    Q_OBJECT

    typedef enum tagLuiScrollMouseDragInfo {
        MOUSE_RELEASE = 0,                       //鼠标离开
        MOUSE_PRESS = 1,                         //按下
        MOUSE_PRESS_MOVE = 2,                   //按下移动
        MOUSE_RELEASE_MOVE = 3                   //鼠标离开并滑动
    }LUI_Scroll_Mouse_Drag_INFO_E;

    LUI_Scroll_Mouse_Drag_INFO_E m_dragFlag = MOUSE_RELEASE;

    QTimer m_scrollTimer;
    QTimer m_selectTimer;
    QTableView *m_table;
    QScrollBar *m_scrollBar;

    QPropertyAnimation *animation;
    int  m_selectRow;
    int  m_srcollH;

    void paintEvent(QPaintEvent *);

    bool eventFilter(QObject *obj, QEvent *evt);

public:
    explicit CustomScroll(QTableView* table,QWidget *parent = nullptr);

signals:

public slots:
    void scrollTimeOut();
    void selectTimeOut();
};

#endif // CustomScroll_H

CustomScroll.cpp如下所示:

#include "customscroll.h"
#include <QMouseEvent>
#include <QDebug>
#include <QApplication>
#include <QPainter>
#include <QTableWidget>
#include <QHeaderView>
#include <QScrollBar>
#include <QAbstractAnimation>

CustomScroll::CustomScroll(QTableView* table,QWidget *parent) : QWidget(parent)
{
#define  SRCOLL_HEIGHT  22

    setAttribute(Qt::WA_TranslucentBackground);

    m_table = table;

    m_scrollBar = table->verticalScrollBar();

    m_table->viewport()->installEventFilter(this);

    m_table->setVerticalScrollMode(QAbstractItemView::ScrollPerPixel);

    animation =  new QPropertyAnimation(m_scrollBar,"value",this);

    connect(&m_scrollTimer,SIGNAL(timeout()),this,SLOT(scrollTimeOut()));

    connect(&m_selectTimer,SIGNAL(timeout()),this,SLOT(selectTimeOut()));

    this->setMinimumSize(10, table->height());
    this->setMaximumSize(10, table->height());
    this->move(table->width()-10,0);            //将滑动条移至最右侧
    this->raise();

    m_srcollH  = table->height()* SRCOLL_HEIGHT/100.0;

}

void CustomScroll::selectTimeOut()
{
    m_table->selectRow(m_selectRow);
    m_selectTimer.stop();
    this->update();
}

void CustomScroll::scrollTimeOut()
{

    if(m_dragFlag == MOUSE_RELEASE_MOVE && animation->state()==QAbstractAnimation::Stopped) //停下来了
    {
        this->update();
        m_dragFlag = MOUSE_RELEASE;
        m_scrollTimer.setInterval(1000);
    }
    else
    {
        this->update();
        if(m_scrollTimer.interval()==1000)
            m_scrollTimer.stop();
    }

}

bool CustomScroll::eventFilter(QObject *obj, QEvent *evt)
{
    static int pressPoint_y   = 0;
    static int dragPoint_y    = -1;
    static qint64 pressMSec ;
    QMouseEvent *mouse =  dynamic_cast<QMouseEvent *>(evt);

    int scrollV_max = m_scrollBar->maximum ();
    int scrollV_min = m_scrollBar->minimum ();

     //根据鼠标的动作——按下、放开、拖动，执行相应的操作
    if(mouse)
    {
        if( mouse->type() ==QEvent::MouseButtonPress)    //首次按下
        {
            pressMSec = QDateTime::currentDateTime().toMSecsSinceEpoch();     //记录按下的时间
            dragPoint_y  = mouse->pos().y();               //当前坐标
            pressPoint_y = dragPoint_y;                      //按下的位置

            animation->stop();
            m_selectRow =  m_table->indexAt(mouse->pos() ).row();    //选择当前行
            qDebug()<<mouse->pos()<<m_selectRow;
            m_selectTimer.start(100);
            m_dragFlag = MOUSE_PRESS;
            return true;
        }
        else if(mouse->type() == QEvent::MouseButtonRelease && m_dragFlag == MOUSE_PRESS)   //未移动
        {
            m_dragFlag = MOUSE_RELEASE;
            if(!m_scrollTimer.isActive())
                m_scrollTimer.start(1000);  //1S后取消滑动条显示
            return true;
        }
        else if(mouse->type() == QEvent::MouseButtonRelease && m_dragFlag == MOUSE_PRESS_MOVE)
        {
            dragPoint_y = -1;
            int releasePoint_y = mouse->pos().y();

            int ms= QDateTime::currentDateTime().toMSecsSinceEpoch()-pressMSec;
            int Pixel_per_second=qAbs(releasePoint_y - pressPoint_y)*1000/ms;       //计算每秒像素点

            if(Pixel_per_second<300 || qAbs(releasePoint_y - pressPoint_y) < 45)
            {
                m_dragFlag = MOUSE_RELEASE;
                if(!m_scrollTimer.isActive())
                    m_scrollTimer.start(1000);  //1S后取消滑动条显示
                return true;
            }
            else
            {

                int moveValue ;

                 if(ms > 1000)      //滑动的时间太长
                {
                     m_dragFlag = MOUSE_RELEASE;
                     if(!m_scrollTimer.isActive())
                         m_scrollTimer.start(1000);  //1S后取消滑动条显示
                     return true;
                }

                if(releasePoint_y - pressPoint_y > 0)     //向下滑动
                {
                    moveValue = m_scrollBar->value() - Pixel_per_second*0.2*(300/ms);//滑动时间越长,moveValue值越小,因为不是快速滑动
                    if(moveValue < scrollV_min)
                    {
                        moveValue = scrollV_min;
                    }
                }
                else
                {

                    moveValue = m_scrollBar->value() + Pixel_per_second*0.2*(300/ms);
                    if(moveValue > scrollV_max)
                    {
                        moveValue = scrollV_max;
                    }
                }

                animation->setDuration(2000-ms);
                animation->setEndValue(moveValue);
                animation->setEasingCurve(QEasingCurve::OutQuart);

                if(!m_scrollTimer.isActive())
                    m_scrollTimer.start(50);  //定时刷新滑动条显示

                animation->start();
                m_dragFlag = MOUSE_RELEASE_MOVE;

            }
             return true;
        }
        else if(mouse->type() == QEvent::MouseMove && (m_dragFlag!= MOUSE_RELEASE) )
        {
            if(  m_dragFlag == MOUSE_PRESS)     //开始移动
            {
                if(qAbs(dragPoint_y - mouse->pos().y()) < 4)      //判断移动阀值,避免误操作
                    return true;
                else
                {
                   m_dragFlag = MOUSE_PRESS_MOVE;
                   if(m_selectTimer.isActive())                         //已经移动了,所以取消选择
                       m_selectTimer.stop();
                   m_table->clearSelection();
                   dragPoint_y = mouse->pos().y();                      //获取当前坐标
                   update();
                   return true;
                }
            }

            int moveValue = ( dragPoint_y-mouse->pos().y())+m_scrollBar->value();    //差距

            dragPoint_y = mouse->pos().y();                        //获取当前坐标

            if(scrollV_min > moveValue)
            {
                moveValue = scrollV_min;
            }
            if(moveValue > scrollV_max)
            {
                moveValue = scrollV_max;
            }
            m_scrollBar->setValue(moveValue);
            update();

            return true;
        }
    }
        return QWidget::eventFilter(obj,evt);
}

void CustomScroll::paintEvent(QPaintEvent *)
{
#define  WIDTH 6
#define  MIN_HEIGHT 6

    if(m_dragFlag== MOUSE_RELEASE||m_dragFlag== MOUSE_PRESS)
    {
        return;
    }

    int scrollV_max = m_scrollBar->maximum ();

    QPainter painter(this);

    int y = (m_table->verticalScrollBar()->value()*(m_table->height()-m_srcollH))/(float)(scrollV_max);

    painter.setPen(Qt::NoPen);
   // painter.setBrush(QColor(180,180,180,200));
   // painter.drawRoundedRect(0,0,this->width(),this->height(),3,3);

    painter.setBrush(QColor(80,80,80,140));
    painter.drawRoundedRect(0,y,WIDTH,m_srcollH,3,3);
}

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