Qt编写自定义控件60-声音波形图

#ifndef WAVEDATA_H
#define WAVEDATA_H

/**
 * 音量采样值波形控件 作者:feiyangqingyun(QQ:517216493) 2017-9-10
 * 1:可设置采样深度
 * 2:可设置当前位置线条宽度/线条颜色
 * 3:可设置前景色/背景色
 * 4:可设置数据展示样式,线条样式/柱状样式/平滑样式
 */

#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 WaveData : public QWidget
#else
class WaveData : public QWidget
#endif

{
    Q_OBJECT
    Q_ENUMS(WaveStyle)
    Q_PROPERTY(double deep READ getDeep WRITE setDeep)
    Q_PROPERTY(bool showLine READ getShowLine WRITE setShowLine)
    Q_PROPERTY(int lineWidth READ getLineWidth WRITE setLineWidth)
    Q_PROPERTY(QColor lineColor READ getLineColor WRITE setLineColor)
    Q_PROPERTY(QColor foreground READ getForeground WRITE setForeground)
    Q_PROPERTY(QColor background READ getBackground WRITE setBackground)
    Q_PROPERTY(WaveStyle waveStyle READ getWaveStyle WRITE setWaveStyle)

public:
    enum WaveStyle {
        WaveStyle_Line = 0,     //线条样式
        WaveStyle_Smooth = 1,   //平滑样式
        WaveStyle_Bar = 2       //柱状样式
    };

    explicit WaveData(QWidget *parent = 0);

protected:
    void mousePressEvent(QMouseEvent *);
    void paintEvent(QPaintEvent *);
    void drawBg(QPainter *painter);
    void drawData(QPainter *painter);
    void drawLine(QPainter *painter);

private:    
    double deep;                //采集深度
    bool showLine;              //显示线条
    int lineWidth;              //线条宽度
    QColor lineColor;           //线条颜色
    QColor foreground;          //前景色
    QColor background;          //背景色
    WaveStyle waveStyle;        //数据样式

    int length;                 //采样点长度
    int position;               //当前位置
    QVector<float> data;        //采样点数据

public:    
    double getDeep()            const;
    bool getShowLine()          const;
    int getLineWidth()          const;
    QColor getLineColor()       const;
    QColor getForeground()      const;
    QColor getBackground()      const;
    WaveStyle getWaveStyle()    const;

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

public slots:
    //设置深度
    void setDeep(double deep);

    //设置是否显示线条
    void setShowLine(bool showLine);
    //设置线条宽度
    void setLineWidth(int lineWidth);
    //设置线条颜色
    void setLineColor(const QColor &lineColor);

    //设置前景色
    void setForeground(const QColor &foreground);
    //设置背景色
    void setBackground(const QColor &background);

    //设置数据样式
    void setWaveStyle(const WaveStyle &waveStyle);

    //设置总长度
    void setLength(int length);
    //设置当前位置
    void setPosition(int position);

    //设置当前数据
    void setData(const QVector<float> &data);
    //清空数据
    void clearData();

signals:
    void positionChanged(int position);
};

#endif // WAVEDATA_H

void WaveData::paintEvent(QPaintEvent *)
{
    //绘制准备工作,启用反锯齿
    QPainter painter(this);
    painter.setRenderHints(QPainter::Antialiasing);

    //绘制背景
    drawBg(&painter);
    //绘制数据
    drawData(&painter);
    //绘制当前位置线条
    drawLine(&painter);
}

void WaveData::drawBg(QPainter *painter)
{
    painter->save();
    painter->fillRect(this->rect(), background);
    painter->restore();
}

void WaveData::drawData(QPainter *painter)
{
    if (data.count() == 0) {
        return;
    }

    painter->save();

    //获取最大值最小值
    float max = data.at(0);
    float min = data.at(0);
    int count = data.count();

    for (int i = 1; i < count; i++) {
        if (max < data.at(i)) {
            max = data.at(i);
        }

        if (min > data.at(i)) {
            min = data.at(i);
        }
    }

    //转化成当前屏幕的内的坐标大小
    max += deep;
    min -= deep;

    //自动转换数据到屏幕坐标位置
    QVector<QPointF> points;
    for (int i = 0; i < count; i++) {
        double x = i * width() / count;
        double y = height() - (((data.at(i) - min) / (max - min)) * height());
        points.append(QPointF(x, y));
    }

    //绘制不同的风格
    if (waveStyle == WaveStyle_Line) {
        painter->setPen(foreground);
        for (int i = 0; i < count - 1; i++) {
            painter->drawLine(points.at(i), points.at(i + 1));
        }
    } else if (waveStyle == WaveStyle_Smooth) {
        painter->setPen(foreground);
        QPainterPath path = SmoothCurveCreator::createSmoothCurve(points);
        painter->drawPath(path);
    } else if (waveStyle == WaveStyle_Bar) {
        double penWidth = width() / (count * 1.6);
        QPen pen;
        pen.setColor(foreground);
        pen.setWidthF(penWidth);
        pen.setCapStyle(Qt::RoundCap);
        painter->setPen(pen);

        for (int i = 0; i < count; i++) {
            QPointF point = points.at(i);
            double x = point.x() + penWidth / 1.2;
            painter->drawLine(QPointF(x, point.y()), QPointF(x, height()));
        }
    }

    painter->restore();
}

void WaveData::drawLine(QPainter *painter)
{
    if (!showLine || position > length || data.count() <= 0) {
        return;
    }

    painter->save();

    QPen pen;
    pen.setWidth(lineWidth);
    pen.setColor(lineColor);
    painter->setPen(pen);

    //计算当前位置对应的坐标
    int x = ((double)position / length) * width();
    painter->drawLine(x, 0, x, height());

    painter->restore();
}