图形编辑“点线”联动

1、Visual C+图形编辑“点-线”联动 摘 要 以统筹图绘制程序的编制为例，详细给出了应用Visual C+开发工具及MFC实现图形编辑中的节点-箭线联动方法。该方法对于实现GIS应用、标图应用和统筹图应用中的类似功能有较好的参考价值。关键词 节点；箭线；编辑联动1 引言很多的图形应用如统筹图应用、GIS应用、标图应用中都存在着编辑联动的问题。所谓编辑联动，是指在对一个图元编辑修改包括位置的变动后，其他图元由于与这个图元有某种关系，而能自动同步被修改。按图元类型，可将图形联动划分为点-点、点-线、点-面、线-线、线-面、面-面等6种。文中以统筹图为例，讨论节点-箭线联动编辑问题。节

2、点与箭线图元的实现以VC自带面向对象图形例程DRAWCLI基础，添加自定义类CDrawNode和CDrawArrow来实现。依据功能设计，程序的主要工作包括：(1) 基本图元的绘制。包括绘制节点和箭线。绘制的节点图形表示为圆心标有编号圆圈；箭线的两侧标注有文字说明，且文字行与箭线保持平行，箭线带有起节点和终节点。(2) 处理图元及相互位置关系。包括删除操作和移动操作。删除某一节点，与该节点相连的箭线全部删除，且调整编号在其后面的节点编号，删除箭线不影响节点。移动节点时，与之相连的箭线相应移动，其关键是准确计算箭线的位置。2 基本图元及联动21基本图元实现设在+6.0的环境下已建立了工程Draw

3、.dsp。节点类和箭线类都是以CDrawObj为基类派生。在建立这两个类之前，需要添加以下全局变量enum DrawShape,circle,arrow,;/图元类型以及相应的工具circleTool和arrowTool(arrow)、arrowlineTool211节点类CDrawNode的设计class CDrawNode : public CDrawObjpublic:CDrawNode(const CRect& position,int Radius);void SetCircleIndex(int Index) m_nIndex=Index; 设置节点编号virtual in

4、t GetObjIndex()return m_nIndex ; /获取编号public:int m_Radius; /节点半径int m_CentreX，m_CentreY;/圆心/在圆中心写上编号，要考虑编号的位数情况 virtual void Draw(CDC* pDC,CDrawView* pView);  protected:int m_nIndex;/编号CDrawNode* m_pDrawObj;friend class CCircleTool;绘制节点的工具CCircleTool在鼠标左键按下OnLButtonDown的消息处理函数中，实际分配内存，产生一个节点对象。

5、212箭线类CDrawArrow的设计class CDrawArrow: public CDrawObjpublic: CDrawRect(const CRect& position);void SetProjectName(CString name)m_ProjectName=name;void SetProjectTime(int time) m_ProjectTime=time;CString GetProjectName() return m_ProjectName;void SetProjectTime(int time) return m_ProjectTime;bool

6、m_bForeConnect;/箭线始节点标志bool m_bBackConnect;/箭线终节点标志int m_ForeConnect; /箭线连接的始节点序号int m_BackConnect; /箭线连接的终节点序号virtual int GetObjIndex() return o;/绘制时，计算平行于箭线的说明文字的角度，位置，项目名称总在线的上方virtual void Draw(CDC* pDC,CDrawView* pView);enum ArrowType none, pureArrow, openArrow,stealthArrow, diamondArrow, ovalA

7、rrow;enum Shape rectangle, roundRectangle, ellipse, line,arrow ;protected:CString m_ProjectName; /项目名称int m_ProjectTime; /时间Shape m_nShape;ArrowType m_lArrow, m_rArrow; /for arrow only int m_lArrowSize, m_rArrowSize; /for arrow onlyprivate:void DrawArrow(ArrowType arrowType, POINT p1, POINT p2, int

8、arrowSize, CDC *,int, int , int, CBrush *);friend class CArrowTool; 绘制箭线的工具CArrowTool在OnLButtonDown中实际生成箭线对象，并记录箭线所连的开始节点，箭线的终节点确定在后面说明。2. 2图元联动操作221删除节点及箭线void CDrawView:OnEditClear() CDrawDoc* pDoc=(CDrawDoc*)GetDocument();POSITION pos = m_selection.GetHeadPosition();while (pos != NULL)CDrawO

9、bj* pObj = m_selection.GetNext(pos);GetDocument()->Remove(pObj); /删除节点CDrawNode* pDrawCircle=(CDrawNode*)pObj;nIndex=pDrawCircle->GetObjIndex();/获取节点编号，若不是节点对象，返回0if(nIndex) pDoc->m_nIndex=nIndex;pos=GetDocument()->m_objects.GetHeadPosition();int i=0;int num=pDoc->m_objects.GetCount()

10、;m_num=pDoc->m_nIndex;while(i<num)/序号位于被删除节点之后的所有节点序号减1CDrawNode* pDrawCircle=(CDrawNode*)pDoc->m_objects.GetNext(pos);if(pDrawCircle->GetObjIndex()>m_num)pDrawCircle->SetCircleIndex(m_num);m_num+; i+;pos=pDoc->m_objects.GetHeadPosition(); if(pos!=NULL)i=0;num=pDoc->m_ob

11、jects.GetCount();while(i<num)/删除与接点相连的所有箭线CDrawRect* pDrawRect=(CDrawRect*)pDoc->m_objects.GetNext(pos);if(pDrawRect!=NULL)if(nIndex=pDrawRect->m_ForeConnect)pDoc->Remove(pDrawRect);pDrawRect->Remove();if(nIndex=pDrawRect->m_BackConnect)pDoc->Remove(pDrawRect);pDrawRect->Remo

12、ve();if(nIndex<pDrawRect->m_ForeConnect)pDrawRect->m_ForeConnect-;if(nIndex<pDrawRect->m_BackConnect)pDrawRect->m_BackConnect-;i+;Invalidate();pDoc->m_nIndex=m_num;pObj->Remove(); m_selection.RemoveAll();UINT nFlags;OnLButtonDown(nFlags,CPoint(0,0);OnLButtonUp(nFlags,CPo

13、int(0,0);222用鼠标移动某一节点时，同步移动与其相连接的箭线void CSelectTool:OnMouseMove(CDrawView* pView, UINT nFlags, const CPoint& point)if (pView->GetCapture() != pView)CPoint local = point;int BackConnect;pView->ClientToDoc(local);POSITION pos;if (c_drawShape = arrow) /判断鼠标移动绘制箭线过程中是否与某一节点相连/此时函数是CRectTool:On

14、MouseMove（）调用selectTool.OnMouseMove();而跳到这里CRect circlerect;CDrawNode* pForeCircle;CDrawNode* pBackCircle;pos=pView->GetDocument()->m_objects.GetHeadPosition();if(pos!=NULL)int i=0;int num=pView->GetDocument()->m_objects.GetCount();while(i<num)CDrawNode* pDrawCircle=(CDrawNode*)pView-

15、>GetDocument()->m_objects.GetNext(pos);if(pDrawCircle!=NULL) int index=pDrawCircle->GetObjIndex();if(index)/判断circlerect=pDrawCircle->m_position;pView->DocToClient(circlerect);if(circlerect.PtInRect(point)local=pDrawCircle->GetHandle(8);BackConnect=pDrawCircle->GetObjIndex(

16、);i+;CPoint delta = (CPoint)(local - lastPoint);pos = pView->m_selection.GetHeadPosition();while (pos != NULL)CDrawObj* pObj = pView->m_selection.GetNext(pos);CRect position = pObj->m_position;if (c_drawShape = arrow)/记录终节点pObj->m_BackConnect=BackConnect;pObj->m_bBackConnect=true;/以下实

17、现移动节点，使所有的箭线跟随节点同步移动if (selectMode = move) if(pView->m_selection.GetCount()=1)CDrawNode* pDrawCircle=(CDrawNode*)pObj;int Index=pDrawCircle->GetObjIndex();if(Index) /移动节点POSITION Rectpos=pView->GetDocument()->m_objects.GetHeadPosition();if(Rectpos!=NULL)int i=0; int num=pView->Ge

18、tDocument()->m_objects.GetCount();while(i<num)/所有与之相连箭线同步移动CDrawRect* pDrawObj=(CDrawRect*)pView->GetDocument()->m_objects.GetNext(Rectpos);if(pDrawObj!=NULL)if(Index=pDrawObj->m_ForeConnect)/节点是箭线始节点CRect deltarect=pDrawObj->m_position;deltarect.BottomRight()+=delta;int length=del

19、tarect.top-deltarect.bottom;int width=deltarect.left-deltarect.right;/节点移动，箭线与节点的连接点改变，计算连接点位置if(abs(length)<abs(width)&&width<0)deltarect.BottomRight()=pDrawCircle->GetHandle(8);if(abs(length)<abs(width)&&width>0)deltarect.BottomRight()=pDrawCircle->GetHandle(4);if

20、(abs(length)>abs(width)&&width>0&&length<0)|(abs(length)>abs(width)&&width<0&&length<0)deltarect.BottomRight()=pDrawCircle->GetHandle(2);if(abs(length)>abs(width)&&length>0&&width>0)|(abs(length)>abs(width)&&len

21、gth>0&&width<0)deltarect.BottomRight()=pDrawCircle->GetHandle(6);int nIndex=pDrawObj->m_BackConnect;POSITIONcirclepos=pView->GetDocument()->m_objects.GetHeadPosition();if(circlepos!=NULL)int i=0;int num=pView->GetDocument()->m_objects.GetCount();while(i<num) C

22、DrawNode* pDrawNode=(CDrawNode*)pView->GetDocument()->m_objects.GetNext(circlepos);if(pDrawNode!=NULL)if(nIndex=pDrawNode->GetObjIndex()/计算箭线的新位置if(abs(length)<abs(width)&&width<0)deltarect.TopLeft()=pDrawNode->GetHandle(4);if(abs(length)<abs(width)&&width>0)d

23、eltarect.TopLeft()=pDrawNode->GetHandle(8);if(abs(length)>abs(width)&&width>0&&length<0)|(abs(length)>abs(width)&&width<0&&length<0)deltarect.TopLeft()=pDrawNode->GetHandle(6);if(abs(length)>abs(width)&&length>0&&width>

24、0)|(abs(length)>abs(width)&&length>0&&width<0)deltarect.TopLeft()=pDrawNode->GetHandle(2);i+;pDrawObj->MoveTo(deltarect,pView);if(Index=pDrawObj->m_BackConnect)/节点是箭线终节点CRect deltarect=pDrawObj->m_position;deltarect.TopLeft()+=delta;int length=deltarect.top-delta

25、rect.bottom;int width=deltarect.left-deltarect.right;if(abs(length)<abs(width)&&width<0)deltarect.TopLeft()=pDrawCircle->GetHandle(4);if(abs(length)<abs(width)&&width>0)deltarect.TopLeft()=pDrawCircle->GetHandle(8);if(abs(length)>abs(width)&&width>0&am

26、p;&length<0)|(abs(length)>abs(width)&&width<0&&length<0)deltarect.TopLeft()=pDrawCircle->GetHandle(6);if(abs(length)>abs(width)&&length>0&&width>0)|(abs(length)>abs(width)&&length>0&&width<0)deltarect.TopLeft()=pDra

27、wCircle->GetHandle(2);int nIndex=pDrawObj->m_ForeConnect;  POSITION circlepos=pView->GetDocument()->m_objects.GetHeadPosition();if(pos!=NULL)int i=0;int num=pView->GetDocument()->m_objects.GetCount(); while(i<num)CDrawNode* pDrawNode=(CDrawNode*)pView->GetDocument()->

28、m_objects.GetNext(circlepos);if(pDrawNode!=NULL)if(nIndex=pDrawNode->GetObjIndex()if(abs(length)<abs(width)&&width<0)deltarect.BottomRight()=pDrawNode->GetHandle(8);if(abs(length)<abs(width)&&width>0)deltarect.BottomRight()=pDrawNode->GetHandle(4);if(abs(length)&

29、gt;abs(width)&&width>0&&length<0)|(abs(length)>abs(width)&&width<0&&length<0)deltarect.BottomRight()=pDrawNode->GetHandle(2);if(abs(length)>abs(width)&&length>0&&width>0)|(abs(length)>abs(width)&&length>0&&width<0)deltarect.Bo