QGraphicsView实现简易地图19『迁徙图』

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模仿echarts的迁徙图效果
用到了前2篇制作的散点(涟漪效果)和两年前的路径动画类；然尾迹效果未依附路径，有待优化。
动态演示效果

静态展示图片

核心代码

#pragma once
#include "Item/AbstractGeoItem.h"
#include "DataStruct/GeoData.h"/** 迁徙图-移动图元*/class QWHAnimationPath;class MigrationMoveItem : public AbstractGeoItem
{
public:explicit MigrationMoveItem(const GeoCoord &center, const GeoCoord &target, QGraphicsItem *parent = nullptr);~MigrationMoveItem();// 更新地理位置virtual void updateGeoPos();// 设置路径位置百分比void setPercent(qreal percent);protected:virtual QRectF boundingRect() const override;virtual void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) override;private:void updatePath();private:GeoCoord m_targetPos;QWHAnimationPath *m_animatePath;
};

#include "MigrationMoveItem.h"
#include <QPainterPath>
#include <QPainter>
#include <QtMath>
#include <QLinearGradient>
#include "Utility/QWHAnimationPath.h"MigrationMoveItem::MigrationMoveItem(const GeoCoord &center, const GeoCoord &target, QGraphicsItem *parent /*= nullptr*/): AbstractGeoItem(parent)
{setZValue(302);m_lon = center.lon;m_lat = center.lat;m_targetPos = target;m_animatePath = new QWHAnimationPath(false);m_animatePath->setType(QWHAnimationPath::SLOPE);m_animatePath->setTarget(QWHAnimationPath::ITEM);m_animatePath->setItem(this);updatePath();
}MigrationMoveItem::~MigrationMoveItem()
{}void MigrationMoveItem::updateGeoPos()
{updatePath();
}void MigrationMoveItem::setPercent(qreal percent)
{m_animatePath->setCurPercent(percent);
}QRectF MigrationMoveItem::boundingRect() const
{return QRectF(-20, -20, 40, 100);
}void MigrationMoveItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
{// 飞机QPainterPath path;path.moveTo(0, -20);path.lineTo(-4, -16);path.lineTo(-4, -4);path.lineTo(-20, 4);path.lineTo(-4, 4);path.lineTo(-4, 16);path.lineTo(-8, 20);path.lineTo(8, 20);path.lineTo(4, 16);path.lineTo(4, 4);path.lineTo(20, 4);path.lineTo(4, -4);path.lineTo(4, -16);path.closeSubpath();painter->setPen(Qt::NoPen);painter->setBrush(Qt::green);painter->drawPath(path);// 尾迹QPainterPath path2;path2.moveTo(-4, 20);path2.lineTo(0, 60);path2.lineTo(0, 60);path2.lineTo(4, 20);QLinearGradient lg(0, 20, 0, 60);lg.setColorAt(0, Qt::white);lg.setColorAt(1, Qt::transparent);painter->setBrush(lg);painter->drawPath(path2);
}void MigrationMoveItem::updatePath()
{QPainterPath path;QPointF centerPos = sceneCoordFromGeoCoord(m_lon, m_lat);QPointF targetPos = sceneCoordFromGeoCoord(m_targetPos.lon, m_targetPos.lat);QPointF pos = targetPos - centerPos;double k = qAtan2(-pos.y(), pos.x());double cx = 0.5 * (centerPos.x() + targetPos.x());double cy = 0.5 * (centerPos.y() + targetPos.y());double ctrlx = cx - qCos(M_PI / 2 - k) * 70;double ctrlY = cy - qSin(M_PI / 2 - k) * 70;path.moveTo(centerPos);path.quadTo(QPointF(ctrlx, ctrlY), targetPos);m_animatePath->setPath(path);
}

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