《QT实用小工具·五十二》文本或窗口炫酷有趣的滚动条—

《QT实用小工具·五十二》文本或窗口炫酷有趣的滚动条——果冻条

1、概述
源码放在文章末尾

该项目实现了文本或窗口纤细的滚动条——果冻条
一个可以像弓弦一样拉出来，并且来回弹动的普通滚动条。

思路为此，但发现实际效果更像条状果冻，并且略有谐音，

故，称之为——“果冻条”！

项目demo演示如下所示：
在这里插入图片描述

项目部分代码如下所示：

#ifndef SLIMSCROLLBAR_H
#define SLIMSCROLLBAR_H#include <QObject>
#include <QScrollBar>
#include <QMouseEvent>
#include <QResizeEvent>
#include <QPainter>
#include <QPainterPath>
#include <QTimer>
#include <QDebug>
#include <QDateTime>
#include <QtMath>
#include "slimscrollbarpopup.h"#define DEB_EVENT if (0) qDebug()class SlimScrollBar : public QScrollBar
{Q_OBJECT
public:SlimScrollBar(QWidget* parent = nullptr);/*** 鼠标松开时抖动动画* 松开的时候计算每一次抖动距离+时间，放入队列中* 定时调整抖动的队列实体索引*/struct Jitter{Jitter(QPoint p, qint64 t) : point(p), timestamp(t) {}QPoint point;     // 要运动到的目标坐标qint64 timestamp; // 运动到目标坐标应该的时间戳，结束后删除本次抖动路径对象};/*** 鼠标按下/弹起水波纹动画* 鼠标按下时动画速度慢（压住），松开后动画速度骤然加快* 同样用队列记录所有的水波纹动画实体*/struct Water{Water(QPoint p, qint64 t) : point(p), press_timestamp(t),release_timestamp(0), finish_timestamp(0), finished(false) {}QPoint point;qint64 press_timestamp;   // 鼠标按下时间戳qint64 release_timestamp; // 鼠标松开时间戳。与按下时间戳、现行时间戳一起成为水波纹进度计算参数qint64 finish_timestamp;  // 结束时间戳。与当前时间戳相减则为渐变消失经过的时间戳bool finished;            // 是否结束。结束后改为渐变消失};void enable();void disable();void setBgColors(QColor normal, QColor hover, QColor press);void setFgColors(QColor normal, QColor hover, QColor press);void setRoundCap(bool round);protected:void enterEvent(QEvent* e) override;void leaveEvent(QEvent* e) override;void mousePressEvent(QMouseEvent *e) override;void mouseMoveEvent(QMouseEvent *e) override;void mouseReleaseEvent(QMouseEvent *e) override;void wheelEvent(QWheelEvent *e) override;void paintEvent(QPaintEvent *e) override;void sliderChange(SliderChange change) override;void contextMenuEvent(QContextMenuEvent *e) override;void hideEvent(QHideEvent *e) override;void resizeEvent(QResizeEvent *e) override;private:void paintPixmap();void activeTimer();void setOffsetPoss();int quick_sqrt(long X) const;void calcPixmapSize();void startPopup();void repaintPopup();void setJitter();qint64 getTimestamp();inline QPen getPen(QColor color, int width);signals:public slots:private slots:void eventTimer();private:QPixmap pixmap;QTimer* event_timer;QColor bg_normal_color = QColor(0xF0, 0xF0, 0xF0, 64);QColor bg_hover_color = QColor(0xF0, 0xF0, 0xF0, 128);QColor bg_press_color = QColor(0xF0, 0xF0, 0xF0, 192);QColor fg_normal_color = QColor(0xCC, 0xCC, 0xCC, 64);QColor fg_hover_color = QColor(0xCC, 0xCC, 0xCC, 128);QColor fg_press_color = QColor(0xCC, 0xCC, 0xCC, 192);bool round_cap = false;bool enabling = true;bool hovering = false;bool pressing = false;int hover_prop = 0;int press_prop = 0;QPoint press_pos;  // 按下位置QPoint mouse_pos;  // 鼠标位置QPoint target_pos; // 实时随队鼠标的目标点（相对竖直中心）QPoint anchor_pos; // 逐步靠近目标点的锚点QPoint effect_pos; // 偏差（相对于左上角），逐步靠近锚点根号位置bool popuping = false;SlimScrollBarPopup* popup = nullptr;QPoint popup_offset; // 弹窗和自己的左上角的绝对位置差double elastic_coefficient; // 弹性系数QList<Jitter> jitters;int jitter_duration;QList<Water> waters;int water_press_duration, water_release_duration, water_finish_duration;int water_radius;
};#endif // SLIMSCROLLBAR_H