Qt利用tablewidget模拟手指实现滑动
作者：诺谦
这篇文章主要为大家详细介绍了Qt如何利用tablewidget模拟手指实现滑动效果，文中的示例代码讲解详细，对我们学习Qt有一定的帮助，需要的可以参考一下
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_HCustomScroll.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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