QT 一个widget设置多个tooltips

学习自《Foundations of Qt Development》

针对一个widget设置多个不同的​

​tooltips​

​​，当鼠标移动到不同的区域能得到不同的提示。

自定义​​

​tooltip​

​​事件: 因为没有现成的​

​tooltipEvent​

​​，所以需要自己来处理鼠标在不同位置的情况，使用​

​QWidget::event()​

​​

调用​​

​QWidget::paintEvent()​

​​来绘画四个矩形。

细节如下：

#ifndef TIPZONE_H
#define

#include <QWidget>
#include <QPainter>
#include <QRect>
#include <QEvent>

class tipZone : public QWidget
{
    Q_OBJECT
    QRect redRec, blueRec, blackRec, whiteRec;
    int width, height;

public:
    explicit tipZone(QWidget *parent = 0);

signals:

public slots:

protected:
    bool event(QEvent * e);
    void paintEvent(QPaintEvent * event);

};

#endif      

#include "tipzone.h"
#include <QHelpEvent>

tipZone::tipZone(QWidget *parent) :
    QWidget(parent)
{
    QRect geo = this->geometry();
    width = geo.width();            // don't use this->width
    height = geo.height();          // don't use this->height
    redRec = QRect(0,0,width/2,height/2);
    blueRec = QRect(width/2,0,width/2,height/2);
    blackRec = QRect(0,height/2,width/2,height/2);
    whiteRec = QRect(width/2,height/2,width/2,height/2);
}

bool tipZone::event(QEvent *e)
{
    if(e->type() == QEvent::ToolTip){
        QHelpEvent *helpEvent = static_cast<QHelpEvent *>(e);
        if(redRec.contains(helpEvent->pos()))
            setToolTip(QObject::tr("red"));
        else if(blueRec.contains(helpEvent->pos()))
            setToolTip(QObject::tr("blue"));
        else if(blackRec.contains(helpEvent->pos()))
            setToolTip(QObject::tr("black"));
        else if(whiteRec.contains(helpEvent->pos()))
            setToolTip(QObject::tr("white"));
    }
    return QWidget::event(e);
}

void tipZone::paintEvent(QPaintEvent *event)
{
    QPainter *painter = new QPainter(this);
    painter->fillRect(redRec,Qt::red);
    painter->fillRect(blueRec,Qt::blue);
    painter->fillRect(blackRec,Qt::black);
    painter->fillRect(whiteRec,Qt::white);
}