(12)一步一步开发一个简单CAD之观察者模式

模型数据的变化会引起视图的变化,这个可以用观察者模式实现,而多视图之间的关系可以用

组合模式实现

class CSubject//观察者模式
{
public:
 CSubject(tagCArray *solid, tagCArray *select){m_solid = solid, m_select = select;}
 virtual ~CSubject(){}
 void SetObserver(CMcadView *view){m_view = view;}//设置观察者
 void Notify()
 {
  if (m_view)
  {
  m_view->UpdateView();
  }
 }

 void DrawSolid(CDC *pDC, int DrawMode);//重画实体和选择集,双存
 

private:
 CMcadView *m_view;

 tagCArray *m_solid;
 tagCArray *m_select;

void CSubject::DrawSolid(CDC *pDC, int DrawMode)
{

 
    for (int i = 0; i < m_solid->GetSize(); i++)
    {
  (*m_solid)[i]->DrawSolid(pDC, DrawMode);
 
    }

 for (int m = 0; m < m_select->GetSize(); m++)
  {
   (*m_select)[m]->DrawSolid(pDC, Select);
  }

 

}