2020.02.27

想要代码,留邮箱吧。或者到https://download.csdn.net/download/XuePiaoFei1/12195991下载,或者https://files-cdn.cnblogs.com/files/warmlight/NewProject.rar

近来Qt开发时可能遇到这样的需求:两个(或多个)矩形,要用直线将它们连接起来,之后还要把它们保存到xml中,并且能够还原。

类似于下图:

首先想到的就是Qt自带的demo:diagramscene。因为demo中有箭头方向,开始节点和结束节点,连坐标都已经有了,保存还原都可以完成。但是,demo的直线不是竖直或水平的,所以肯定要对demo进行修改。(扯淡了,demo肯定不会符合个人的需求的,无论如何都要修改的。)

刚用Qt不久,网络上也搜不到类似的问题,也许是自己找不到,只能寄希望于Qt的demo,限制了自己的思想。可是目前没有更好的办法。

我的工程有几个要点,要能够保存和还原,箭头的首尾节点肯定要确定,或者说首尾节点的坐标一定要知道。

demo中的基本元素够了,我想只对arrow类作修改,希望能达到目标。

我先把我改造后的arrow类贴出来,然后再试图分析一下。

头文件:

 /****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** BSD License Usage
** Alternatively, you may use this file under the terms of the BSD license
** as follows:
**
** "Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
** * Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** * Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in
** the documentation and/or other materials provided with the
** distribution.
** * Neither the name of The Qt Company Ltd nor the names of its
** contributors may be used to endorse or promote products derived
** from this software without specific prior written permission.
**
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
**
** $QT_END_LICENSE$
**
****************************************************************************/ #ifndef ARROW_H
#define ARROW_H #include <QGraphicsLineItem> #include "diagramitem.h" QT_BEGIN_NAMESPACE
class QGraphicsPolygonItem;
class QGraphicsLineItem;
class QGraphicsScene;
class QRectF;
class QGraphicsSceneMouseEvent;
class QPainterPath;
QT_END_NAMESPACE enum LineType {
lineType1 = , //横竖
lineType2, //竖横
lineType3, //横竖横
lineType4 //竖横竖
}; //! [0]
class Arrow : public QGraphicsLineItem
{
public:
enum { Type = UserType + }; Arrow(DiagramItem *startItem, DiagramItem *endItem,
QGraphicsItem *parent = );
~Arrow() {m_bDeleteFlag = true;} int type() const override { return Type; }
QRectF boundingRect() const override;
QPainterPath shape() const override;
void setColor(const QColor &color) { myColor = color; }
DiagramItem *startItem() const { return myStartItem; }
DiagramItem *endItem() const { return myEndItem; } void setItemId(QString startItemId ,QString startEndId);
void updatePosition(); QString getStartId(){return startId;}
QString getEndId(){return endId;} void setStartItem(DiagramItem *startItem){ myStartItem = startItem; }
void setEndItem(DiagramItem *endItem){ myEndItem = endItem; } void setArrowFlag(bool IsArrow){bisArrow = IsArrow;}
bool getArrowFlag(){return bisArrow;}
bool getDeleteFlage() {return m_bDeleteFlag;}
void DrawArrow(QPainter *painter, QPointF startPt, QPointF endPt, bool bArrow);
void ThreeLine(QPainter *painter, QPointF startPt, QPointF endPt);//三段线
void TwoLine(QPainter *painter, QPointF startPt, QPointF endPt); //两段线
//void SetLineStyle(bool bVhvLine);//线段的折线风格
//void SetLineType(int nLineType);//线段的数量
void SetLineType(LineType lineType);
int GetLineType() {return m_lineType;}
void DrawLine(QPainter *painter, QPointF startPt, QPointF endPt);
protected:
void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = ) override; private:
DiagramItem *myStartItem;
DiagramItem *myEndItem;
QColor myColor;
QPolygonF arrowHead;
QString startId;
QString endId;
bool bisArrow;
bool m_bDeleteFlag;//
LineType m_lineType;
//bool m_bVhvLine;//true三段线,竖横竖; false三段线 横竖横
//bool m_bVhLine;// true两段线 竖横; false 两段线 横竖
//int m_nLineType;//2-2段线,3-3段线
}; inline void Arrow::setItemId(QString startItemId ,QString startEndId){
startId = startItemId;
endId = startEndId;
}
//! [0] #endif // ARROW_H

cpp文件:

 /****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** BSD License Usage
** Alternatively, you may use this file under the terms of the BSD license
** as follows:
**
** "Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
** * Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** * Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in
** the documentation and/or other materials provided with the
** distribution.
** * Neither the name of The Qt Company Ltd nor the names of its
** contributors may be used to endorse or promote products derived
** from this software without specific prior written permission.
**
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "arrow.h"
#include <qmath.h>
#include <QPen>
#include <QPainter>
#include <QDebug> //! [0]
Arrow::Arrow(DiagramItem *startItem, DiagramItem *endItem, QGraphicsItem *parent)
: QGraphicsLineItem(parent)
{
m_bDeleteFlag = false;//20191121 sdl
myStartItem = startItem;
myEndItem = endItem;
setFlag(QGraphicsItem::ItemIsSelectable, true);
myColor = Qt::black;
setPen(QPen(myColor, , Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
bisArrow = true;
if(myStartItem){startId = myStartItem->getItemId();}
if(myEndItem){endId = myEndItem->getItemId();}
m_lineType = LineType::lineType1;
}
//! [0] //! [1]
QRectF Arrow::boundingRect() const
{
qreal extra = (pen().width() + ) / 2.0; return QRectF(line().p1(), QSizeF(line().p2().x() - line().p1().x(),
line().p2().y() - line().p1().y()))
.normalized()
.adjusted(-extra, -extra, extra, extra);
}
//! [1] //! [2]
QPainterPath Arrow::shape() const
{
QPainterPath path = QGraphicsLineItem::shape();
path.addPolygon(arrowHead);
return path;
}
//! [2] //! [3]
void Arrow::updatePosition()
{
QPointF endPt = mapFromItem(myEndItem, , );
QLineF line(mapFromItem(myStartItem, , ), endPt);
setLine(line);
} //! [3] //! [4]
void Arrow::paint(QPainter *painter, const QStyleOptionGraphicsItem *,
QWidget *)
{
if(myStartItem == NULL || myEndItem == NULL) return;
if(myStartItem->GetDeleteFlag() || myEndItem->GetDeleteFlag()) return;
if (myStartItem->collidesWithItem(myEndItem))
return; QPointF start = myStartItem->pos();
QPointF end = myEndItem->pos();
if(qFuzzyCompare(start.x(), end.x())){ //如果在同一竖直或水平线时,直接连接两节点中心点
DrawArrow(painter, start, end, true);
return;
}
if (qFuzzyCompare(start.y(), end.y())) {
DrawArrow(painter, start, end, true);
return;
} DrawLine(painter, start, end);
// if(m_nLineType == 2){
// TwoLine(painter, start, end);
// }
// else if (m_nLineType == 3) {
// ThreeLine(painter, start, end);
// }
}
//! [7] void Arrow::DrawArrow(QPainter *painter, QPointF startPt, QPointF endPt, bool bArrow)
{
if(endPt == QPointF(, )){
return;
}
QPen myPen = pen();
myPen.setColor(myColor);
qreal arrowSize = ;
painter->setPen(myPen);
painter->setBrush(myColor);
//! [4] //! [5] QLineF centerLine(startPt, endPt); QPolygonF endPolygon;
endPolygon = myEndItem->polygon();
QPointF p1 = endPolygon.first() + endPt;
QPointF p2;
QPointF intersectPoint;
QLineF polyLine;
for (int i = ; i < endPolygon.count(); ++i) {
p2 = endPolygon.at(i) + endPt;
polyLine = QLineF(p1, p2);
QLineF::IntersectType intersectType =
polyLine.intersect(centerLine, &intersectPoint);
if (intersectType == QLineF::BoundedIntersection)
break;
p1 = p2;
} setLine(QLineF(endPt, startPt/*myStartItem->pos()*/)); //! [5] //! [6]
if (bArrow){
setLine(QLineF(intersectPoint, startPt/*myStartItem->pos()*/));//如果是箭头所在的线
}
double angle = std::atan2(-line().dy(), line().dx()); QPointF arrowP1 = line().p1() + QPointF(sin(angle + M_PI / ) * arrowSize,
cos(angle + M_PI / ) * arrowSize);
QPointF arrowP2 = line().p1() + QPointF(sin(angle + M_PI - M_PI / ) * arrowSize,
cos(angle + M_PI - M_PI / ) * arrowSize); arrowHead.clear();
arrowHead << line().p1() << arrowP1 << arrowP2;
//! [6] //! [7]
painter->drawLine(line());
//是否画箭头
if(bArrow){
painter->drawPolygon(arrowHead);
}
if (isSelected()) {
painter->setPen(QPen(myColor, , Qt::DashLine));
QLineF myLine = line();
myLine.translate(, 4.0);
painter->drawLine(myLine);
myLine.translate(,-8.0);
painter->drawLine(myLine);
}
} void Arrow::ThreeLine(QPainter *painter, QPointF start, QPointF end)
{
if(m_lineType == LineType::lineType4){
qreal midY = (start.y() + end.y()) / ;
QPointF startPt = myStartItem->pos();
QPointF endPt = myEndItem->pos(); endPt.setX(startPt.x());
endPt.setY(midY);
DrawArrow(painter, startPt, endPt, false); startPt = endPt;
endPt.setX(myEndItem->pos().x());
endPt.setY(startPt.y());
DrawArrow(painter, startPt, endPt, false); startPt = endPt;
endPt = myEndItem->pos(); DrawArrow(painter, startPt, endPt, true);
}
else if(m_lineType == LineType::lineType3){
qreal midX = (start.x() + end.x()) / ;
QPointF startPt = myStartItem->pos();
QPointF endPt = myEndItem->pos(); endPt.setX(midX);
endPt.setY(startPt.y());
DrawArrow(painter, startPt, endPt, false); startPt = endPt;
endPt.setX(startPt.x());
endPt.setY(myEndItem->pos().y());
DrawArrow(painter, startPt, endPt, false); startPt = endPt;
endPt = myEndItem->pos();
DrawArrow(painter, startPt, endPt, true);
}
} void Arrow::TwoLine(QPainter *painter, QPointF startPt, QPointF endPt)
{
if(m_lineType == LineType::lineType2){
endPt.setX(startPt.x());
endPt.setY(endPt.y());
DrawArrow(painter, startPt, endPt, false); startPt = endPt;
endPt = myEndItem->pos();
DrawArrow(painter, startPt, endPt, true);
}
else if(m_lineType == LineType::lineType1){
endPt.setY(startPt.y());
DrawArrow(painter, startPt, endPt, false); startPt = endPt;
endPt = myEndItem->pos();
DrawArrow(painter, startPt, endPt, true);
}
} //void Arrow::SetLineStyle(bool bVhvLine)
//{
// m_bVhvLine = bVhvLine;
//} void Arrow::SetLineType(LineType lineType)
{
if(lineType > lineType4 || lineType < lineType1)
m_lineType = lineType1;
else{
m_lineType = lineType;
}
} void Arrow::DrawLine(QPainter *painter, QPointF start, QPointF end)
{
if(m_lineType == LineType::lineType4){
qreal midY = (start.y() + end.y()) / ;
QPointF startPt = myStartItem->pos();
QPointF endPt = myEndItem->pos(); endPt.setX(startPt.x());
endPt.setY(midY);
DrawArrow(painter, startPt, endPt, false); startPt = endPt;
endPt.setX(myEndItem->pos().x());
endPt.setY(startPt.y());
DrawArrow(painter, startPt, endPt, false); startPt = endPt;
endPt = myEndItem->pos(); DrawArrow(painter, startPt, endPt, true);
}
else if(m_lineType == LineType::lineType3){
qreal midX = (start.x() + end.x()) / ;
QPointF startPt = myStartItem->pos();
QPointF endPt = myEndItem->pos(); endPt.setX(midX);
endPt.setY(startPt.y());
DrawArrow(painter, startPt, endPt, false); startPt = endPt;
endPt.setX(startPt.x());
endPt.setY(myEndItem->pos().y());
DrawArrow(painter, startPt, endPt, false); startPt = endPt;
endPt = myEndItem->pos();
DrawArrow(painter, startPt, endPt, true);
}
else if(m_lineType == LineType::lineType2){
end.setX(start.x());
end.setY(end.y());
DrawArrow(painter, start, end, false); start = end;
end = myEndItem->pos();
DrawArrow(painter, start, end, true);
}
else if(m_lineType == LineType::lineType1){
end.setY(start.y());
DrawArrow(painter, start, end, false); start = end;
end = myEndItem->pos();
DrawArrow(painter, start, end, true);
}
else {//默认是linetype1
m_lineType = LineType::lineType1;
end.setY(start.y());
DrawArrow(painter, start, end, false); start = end;
end = myEndItem->pos();
DrawArrow(painter, start, end, true);
}
}

这个类中,有一些代码冗余。

我在这里分了四类画线方式,即头文件中的LineType。在横竖横和竖横竖的类型中,中间线段取的是中点画线。箭头首尾的节点都有了,保存也可以的。也可以根据个人情况修改箭头类。

操作:编辑图形时,基本图形时拖拽到场景中的。连线不是拖拽,是单击选中一种类型,在场景中连接两个基本图形即可。选中一个画线方式,再次拖拽基本图形或右键鼠标后,需要再次选择画线方式,才能再次画线。右键鼠标会出现右键菜单,打开、保存、删除。保存,保存场景中图形为xml;打开,打开保存的xml文件;删除,可删除基本图形或者箭头。注意:删除基本图形时,如果基本图形有连线,连线也会被删除。

还有一些功能待完善,如修改基本图形的名称等。

结果图:

稍后把代码传到csdn。如果博客园能上传代码就好了。

qt 带箭头的直线 (类似viso)的更多相关文章

  1. MFC中如何画带实心箭头的直线

    工作中遇到话流程图的项目,需要画带箭头的直线,经过摸索,解决:思路如下: (1) 两个点(p1,p2)确定一个直线,以直线的一个端点(假设p2)为原点,设定一个角度 (2)以P2为原点得到向量P2P1 ...

  2. Leaflet 带箭头轨迹以及沿轨迹带方向的动态marker

    前面写了篇文章,mapboxgl实现带箭头轨迹线,介绍了如何基于mapboxgl实现类似高德地图导航轨迹效果. 下图是我基于leaflet实现的效果. 接下来分享一下在我基于leaflet实现该效果时 ...

  3. 不得不吐槽的Android PopupWindow的几个痛点(实现带箭头的上下文菜单遇到的坑)

    说到PopupWindow,我个人感觉是又爱又恨,没有深入使用之前总觉得这个东西应该很简单,很好用,但是真正使用PopupWindow实现一些效果的时候总会遇到一些问题,但是即便是人家的api有问题, ...

  4. 使用纯CSS实现带箭头的提示框

    爱编程爱分享,原创文章,转载请注明出处,谢谢!http://www.cnblogs.com/fozero/p/6187323.html 1.全部代码 <!DOCTYPE html> < ...

  5. popover带箭头弹框

    我们先来看一下效果吧: 分析:这个带箭头的弹框其实是一个控制器,通过Modal方式展现,但跟传统模态方式效果不一样,我们一眼就能看出. Xib方式实现popover: 1.segue的时候选择Pres ...

  6. css实现带箭头选项卡

    这阵子在做一个web端项目中遇到一个问题,需要实现带箭头的选项卡点击可切换.起初没想太多,直接切一个向上的小箭头图片,外层div设置相同颜色的边框,再用相对定位和绝对定位.这种方法是可行的,但是因为手 ...

  7. div+css实现圆形div以及带箭头提示框效果

    .img{ width:90px; height:90px; border-radius:45px; margin:0 40%; border:solid rgb(100,100,100) 1px;& ...

  8. iOS 新浪微博-2.0 搜索框/标题带箭头/下拉菜单

    不管是搜索框还是下拉菜单,我们都需要对背景的图片进行拉伸.定义一个Category分类对图片进行操作. UIImage+Effect.h #import <UIKit/UIKit.h> @ ...

  9. iOS 带箭头菜单选项弹窗LFPopupMenu

    一.效果图 由于是模拟器缩得比较小,一些细线可能显示不出来,不是bug哈. 二.用法 LFPopupMenuItem *item1 = [LFPopupMenuItem createWithTitle ...

随机推荐

  1. c++IO对象不可复制

    IO类型的3个独立的头文件: iostream定义读写控制窗口的类型, fstream 定义读写已命名文件的类型,             (包含fstream类) sstream定义读写存储在内存中 ...

  2. Java面向对象XMind

    Java面向对象的思维导图

  3. 使用Apache服务器实现Nginx反向代理

    实验环境:centos7 注:因为本次实验在同一台服务器上,Apache与Nginx同为80端口,所以改Apache端口为60 1 配置Nginx服务器: 编辑Nginx配置文件,写入以下内容 loc ...

  4. BZOJ 1046 [HAOI2007]上升序列(LIS + 贪心)

    题意: m次询问,问下标最小字典序的长度为x的LIS是什么 n<=10000, m<=1000 思路: 先nlogn求出f[i]为以a[i]开头的LIS长度 然后贪心即可,复杂度nm 我们 ...

  5. 如何查看MySql的sql语句性能

    原文链接:https://blog.csdn.net/jwq101666/article/details/78561022Explain命令在解决数据库性能上是第一推荐使用命令,大部分的性能问题可以通 ...

  6. 《C# GDI+ 破境之道》:第一境 GDI+基础 —— 第二节:画矩形

    有了上一节画线的基础,画矩形的各种边线就特别好理解了,所以,本节在矩形边线上,就不做过多的讲解了,关注一下画“随机矩形”的具体实现就好.与画线相比较,画矩形稍微复杂的一点就是在于它多了很多填充的样式. ...

  7. Python实现IOC控制反转

    思路: 用一个字典存储beanName和资源 初始化时先将beanName和资源注册到字典中 然后用一个Dscriptor类根据beanName动态请求资源,从而实现控制反转 # -*- coding ...

  8. Thingsboard源码安装部署

    交流QQ群 如果安装有其他问题,可以到QQ群求助 环境安装 开发环境要求:Jdk 1.8版本Postgresql 9以上Node.jsNpmMaven 3.6以上Git工具Idea开发工具 JDK 下 ...

  9. 【大白话系统】MySQL 学习总结 之 缓冲池(Buffer Pool) 如何支撑高并发和动态调整

    如果大家对我的 [大白话系列]MySQL 学习总结系列 感兴趣的话,可以点击关注一波. 一.上节回顾 在上节< 缓冲池(Buffer Pool) 的设计原理和管理机制>中,介绍了缓冲池整体 ...

  10. 数据算法 --hadoop/spark数据处理技巧 --(1.二次排序问题 2. TopN问题)

    一.二次排序问题. MR/hadoop两种方案: 1.让reducer读取和缓存给个定键的所有值(例如,缓存到一个数组数据结构中,)然后对这些值完成一个reducer中排序.这种方法不具有可伸缩性,因 ...