Qt编写自定义控件45-柱状标尺控件 - QTCN开发网

#ifndef RULERBAR_H
#define RULERBAR_H

/**
* 柱状标尺控件作者:feiyangqingyun(QQ:517216493) 2016-10-28
* 本控件来源于网络(原作者:kimtaikee(http://www.qtcn.org/bbs/read-htm-tid-33693-ds-1.html#tpc))
* 1:可设置精确度(小数点后几位)和间距
* 2:可设置背景色/柱状颜色/线条颜色
* 3:可设置长线条步长及短线条步长
* 4:可启用动画及设置动画步长
* 5:可设置范围值
* 6:支持负数刻度值
*/

#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 RulerBar : public QWidget
#else
class RulerBar : public QWidget
#endif

{
    Q_OBJECT
    Q_PROPERTY(double minValue READ getMinValue WRITE setMinValue)
    Q_PROPERTY(double maxValue READ getMaxValue WRITE setMaxValue)
    Q_PROPERTY(double value READ getValue WRITE setValue)
    Q_PROPERTY(int precision READ getPrecision WRITE setPrecision)

    Q_PROPERTY(int longStep READ getLongStep WRITE setLongStep)
    Q_PROPERTY(int shortStep READ getShortStep WRITE setShortStep)
    Q_PROPERTY(int space READ getSpace WRITE setSpace)

    Q_PROPERTY(bool animation READ getAnimation WRITE setAnimation)
    Q_PROPERTY(double animationStep READ getAnimationStep WRITE setAnimationStep)

    Q_PROPERTY(QColor bgColorStart READ getBgColorStart WRITE setBgColorStart)
    Q_PROPERTY(QColor bgColorEnd READ getBgColorEnd WRITE setBgColorEnd)
    Q_PROPERTY(QColor lineColor READ getLineColor WRITE setLineColor)
    Q_PROPERTY(QColor barBgColor READ getBarBgColor WRITE setBarBgColor)
    Q_PROPERTY(QColor barColor READ getBarColor WRITE setBarColor)

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

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

private:
    double minValue;                //最小值
    double maxValue;                //最大值
    double value;                   //目标值
    int precision;                  //精确度,小数点后几位

    int longStep;                   //长线条等分步长
    int shortStep;                  //短线条等分步长
    int space;                      //间距

    bool animation;                 //是否启用动画显示
    double animationStep;           //动画显示时步长

    QColor bgColorStart;            //背景渐变开始颜色
    QColor bgColorEnd;              //背景渐变结束颜色
    QColor lineColor;               //线条颜色
    QColor barBgColor;              //柱状背景色
    QColor barColor;                //柱状颜色

    bool reverse;                   //是否倒退
    double currentValue;            //当前值
    QTimer *timer;                  //定时器绘制动画
    QRectF barRect;                 //柱状图区域

private slots:
    void updateValue();

public:
    double getMinValue()            const;
    double getMaxValue()            const;
    double getValue()               const;
    int getPrecision()              const;

    int getLongStep()               const;
    int getShortStep()              const;
    int getSpace()                  const;

    bool getAnimation()             const;
    double getAnimationStep()       const;

    QColor getBgColorStart()        const;
    QColor getBgColorEnd()          const;
    QColor getLineColor()           const;
    QColor getBarBgColor()          const;
    QColor getBarColor()            const;

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

public Q_SLOTS:
    //设置最大最小值-范围值
    void setRange(double minValue, double maxValue);
    void setRange(int minValue, int maxValue);

    //设置最大最小值
    void setMinValue(double minValue);
    void setMaxValue(double maxValue);

    //设置目标值
    void setValue(double value);
    void setValue(int value);

    //设置精确度
    void setPrecision(int precision);
    //设置线条等分步长
    void setLongStep(int longStep);
    void setShortStep(int shortStep);
    //设置间距
    void setSpace(int space);

    //设置是否启用动画显示
    void setAnimation(bool animation);
    //设置动画显示的步长
    void setAnimationStep(double animationStep);

    //设置背景颜色
    void setBgColorStart(const QColor &bgColorStart);
    void setBgColorEnd(const QColor &bgColorEnd);
    //设置线条颜色
    void setLineColor(const QColor &lineColor);
    //设置柱状颜色
    void setBarBgColor(const QColor &barBgColor);
    void setBarColor(const QColor &barColor);

Q_SIGNALS:
    void valueChanged(double value);
};

#endif // RULERBAR_H

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

    //绘制背景
    drawBg(&painter);
    //绘制标尺
    drawRuler(&painter);
    //绘制柱状背景
    drawBarBg(&painter);
    //绘制柱状
    drawBar(&painter);
}

void RulerBar::drawBg(QPainter *painter)
{
    painter->save();
    painter->setPen(Qt::NoPen);
    QLinearGradient bgGradient(QPointF(0, 0), QPointF(0, height()));
    bgGradient.setColorAt(0.0, bgColorStart);
    bgGradient.setColorAt(1.0, bgColorEnd);
    painter->setBrush(bgGradient);
    painter->drawRect(rect());
    painter->restore();
}

void RulerBar::drawRuler(QPainter *painter)
{
    painter->save();
    painter->setPen(lineColor);

    //绘制纵向标尺线 20的长度为刻度尺文字的宽度
    double initX = space + 20;
    double initY = space;
    QPointF topPot(initX, initY);
    QPointF bottomPot(initX, height() - space);
    painter->drawLine(topPot, bottomPot);

    //绘制纵向标尺刻度
    double length = height() - 2 * space;
    //计算每一格移动多少
    double increment = length / (maxValue - minValue);
    //长线条短线条长度
    int longLineLen = 10;
    int shortLineLen = 7;

    //根据范围值绘制刻度值及刻度值
    for (int i = maxValue; i >= minValue; i = i - shortStep) {
        if (i % longStep == 0) {
            QPointF leftPot(initX + longLineLen, initY);
            QPointF rightPot(initX, initY);
            painter->drawLine(leftPot, rightPot);

            QString strValue = QString("%1").arg((double)i, 0, 'f', precision);
            double fontWidth = painter->fontMetrics().width(strValue);
            double fontHeight = painter->fontMetrics().height();
            QPointF textPot(initX - fontWidth - 5, initY + fontHeight / 3);
            painter->drawText(textPot, strValue);
        } else {
            if (i % (longStep / 2) == 0) {
                shortLineLen = 7;
            } else {
                shortLineLen = 4;
            }

            QPointF leftPot(initX + shortLineLen, initY);
            QPointF rightPot(initX, initY);
            painter->drawLine(leftPot, rightPot);
        }

        initY += increment * shortStep;
    }

    painter->restore();
}

void RulerBar::drawBarBg(QPainter *painter)
{
    painter->save();
    painter->setPen(Qt::NoPen);

    //20的长度为刻度尺文字的宽度 15为刻度尺到柱状图的宽度
    double initX = space + 20 + 15;
    QPointF topLeftPot(initX, space);
    QPointF bottomRightPot(width() - space , height() - space);
    barRect = QRectF(topLeftPot, bottomRightPot);

    painter->setBrush(barBgColor);
    painter->drawRect(barRect);
    painter->restore();
}

void RulerBar::drawBar(QPainter *painter)
{
    painter->save();
    painter->setPen(Qt::NoPen);

    double barHeight = barRect.height();
    double increment = (double)barHeight / (maxValue - minValue);
    double initY = (currentValue - minValue) * increment;

    QPointF topLeftPot(barRect.topLeft().x(), barRect.bottomLeft().y() - initY);
    QPointF bottomRightPot(barRect.bottomRight());
    QRectF currentRect(topLeftPot, bottomRightPot);

    painter->setBrush(barColor);
    painter->drawRect(currentRect);
    painter->restore();
}