Qt编写自定义控件37-发光按钮（会呼吸的痛） - QTCN开发网

#ifndef LIGHTPOINT_H
#define LIGHTPOINT_H

/**
* 呼吸点控件作者:feiyangqingyun(QQ:517216493) 2017-11-27
* 1:可设置呼吸间隔
* 2:可设置颜色透明渐变步长
* 3:可设置背景颜色
*/

#include <QWidget>

#ifdef quc
#if (QT_VERSION < QT_VERSION_CHECK(5,7,0))
#include <QtDesigner/QDesignerExportWidget>
#else
#include <QtUiPlugin/QDesignerExportWidget>
#endif

class QDESIGNER_WIDGET_EXPORT LightPoint : public QWidget
#else
class LightPoint : public QWidget
#endif

{
    Q_OBJECT
    Q_PROPERTY(int step READ getStep WRITE setStep)
    Q_PROPERTY(int interval READ getInterval WRITE setInterval)
    Q_PROPERTY(QColor bgColor READ getBgColor WRITE setBgColor)

public:
    explicit LightPoint(QWidget *parent = 0);
    ~LightPoint();

protected:
    void paintEvent(QPaintEvent *);
    void drawBg(QPainter *painter);

private:
    int step;                       //颜色透明渐变步长
    int interval;                   //定时器间隔
    QColor bgColor;                 //背景颜色

    QTimer *timer;                  //绘制定时器
    int offset;                     //偏移量
    bool add;                       //是否增加

public:
    int getStep()                   const;
    int getInterval()               const;
    QColor getBgColor()             const;

    QSize sizeHint()                const;
    QSize minimumSizeHint()         const;

public slots:
    //设置颜色透明渐变步长
    void setStep(int step);

    //设置定时器间隔
    void setInterval(int interval);

    //设置背景颜色
    void setBgColor(const QColor &bgColor);

};

#endif // LIGHTPOINT_H

#pragma execution_character_set("utf-8")

#include "lightpoint.h"
#include "qpainter.h"
#include "qevent.h"
#include "qtimer.h"
#include "qdebug.h"

LightPoint::LightPoint(QWidget *parent) : QWidget(parent)
{
    step = 10;
    interval = 100;
    bgColor = QColor(255, 0, 0);

    timer = new QTimer(this);
    connect(timer, SIGNAL(timeout()), this, SLOT(update()));
    timer->start(100);

    offset = 0;
    add = true;
}

LightPoint::~LightPoint()
{
    if (timer->isActive()) {
        timer->stop();
    }
}

void LightPoint::paintEvent(QPaintEvent *)
{
    int width = this->width();
    int height = this->height();
    int side = qMin(width, height);

    //绘制准备工作,启用反锯齿,平移坐标轴中心,等比例缩放
    QPainter painter(this);
    painter.setRenderHints(QPainter::Antialiasing | QPainter::TextAntialiasing);
    painter.translate(width / 2, height / 2);
    painter.scale(side / 200.0, side / 200.0);

    //绘制背景
    drawBg(&painter);
}

void LightPoint::drawBg(QPainter *painter)
{
    int radius = 99;
    painter->save();

    QRadialGradient g(QPoint(0, 0), radius);

    (offset < 70 && add) ? (offset += step) : (add = false);
    (offset > 0 && !add) ? (offset -= step) : (add = true);

    bgColor.setAlpha(255);
    g.setColorAt(0.1, bgColor);
    bgColor.setAlpha(100 + offset);
    g.setColorAt(0.3, bgColor);
    bgColor.setAlpha(50 + offset);
    g.setColorAt(0.6, bgColor);
    bgColor.setAlpha(0);
    g.setColorAt(1.0, bgColor);

    painter->setPen(Qt::NoPen);
    painter->setBrush(g);
    painter->drawEllipse(-radius, -radius, radius * 2, radius * 2);

    painter->restore();
}

int LightPoint::getStep() const
{
    return this->step;
}

int LightPoint::getInterval() const
{
    return this->interval;
}

QColor LightPoint::getBgColor() const
{
    return this->bgColor;
}

QSize LightPoint::sizeHint() const
{
    return QSize(100, 100);
}

QSize LightPoint::minimumSizeHint() const
{
    return QSize(5, 5);
}

void LightPoint::setStep(int step)
{
    if (this->step != step) {
        this->step = step;
        update();
    }
}

void LightPoint::setInterval(int interval)
{
    if (this->interval != interval) {
        this->interval = interval;
        timer->setInterval(interval);
        update();
    }
}

void LightPoint::setBgColor(const QColor &bgColor)
{
    if (this->bgColor != bgColor) {
        this->bgColor = bgColor;
        update();
    }
}