第11章 GUI Page411~420 步骤五支持其他图形

本文主要是介绍第11章 GUI Page411~420 步骤五支持其他图形，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

运行效果：

源代码

//item_i.hpp 抽象“图形元素”接口定义
#ifndef ITEM_I_HPP_INCLUDED
#define ITEM_I_HPP_INCLUDED#include <wx/gdicmn.h>
#include <wx/dc.h>class IItem
{
public://作为接口，记得要有虚析构virtual ~IItem(){}//使用DC画出自己//注意：“画”的方法不应该修改对象的数据virtual void Draw(wxDC& dc) const = 0; //纯虚函数//开始在某一点上绘图virtual void OnDrawStart(wxPoint const& point) = 0; //纯虚函数//结束在某一点virtual void OnDrawEnd(wxPoint const& point) = 0; //纯虚函数
};#endif // ITEM_I_HPP_INCLUDED

//item_line.hpp 修改现有的LineItem类，实现IItem接口#ifndef ITEM_LINE_HPP_INCLUDED
#define ITEM_LINE_HPP_INCLUDED#include "item_i.hpp"class LineItem : public IItem
{
public:LineItem(): _startPosition(0, 0), _endPosition(0, 0){}virtual void Draw(wxDC& dc) const;//    virtual void OnDrawStart(wxPoint const& point) //书上写法void OnDrawStart(wxPoint const& point) override //C++11{_startPosition = point;}virtual void OnDrawEnd(wxPoint const& point) //写不写virtual不影响{_endPosition = point;}private://不写Logic后缀，但仍然是存储逻辑坐标wxPoint _startPosition, _endPosition;
};#endif // ITEM_LINE_HPP_INCLUDED

//item_line.cpp
#include "item_line.hpp"void LineItem::Draw(wxDC& dc) const
{dc.DrawLine(_startPosition, _endPosition);//就这一行，画直线
}

/**************************************************************** Name:      wxMyPainterApp.h* Purpose:   Defines Application Class* Author:    yanzhenxi (3065598272@qq.com)* Created:   2023-12-21* Copyright: yanzhenxi ()* License:**************************************************************/#ifndef WXMYPAINTERAPP_H
#define WXMYPAINTERAPP_H#include <wx/app.h>class wxMyPainterApp : public wxApp
{public:virtual bool OnInit();
};#endif // WXMYPAINTERAPP_H

/**************************************************************** Name:      wxMyPainterApp.cpp* Purpose:   Code for Application Class* Author:    yanzhenxi (3065598272@qq.com)* Created:   2023-12-21* Copyright: yanzhenxi ()* License:**************************************************************/#include "wxMyPainterApp.h"//(*AppHeaders
#include "wxMyPainterMain.h"
#include <wx/image.h>
//*)IMPLEMENT_APP(wxMyPainterApp);bool wxMyPainterApp::OnInit()
{//(*AppInitializebool wxsOK = true;wxInitAllImageHandlers();if ( wxsOK ){wxMyPainterFrame* Frame = new wxMyPainterFrame(0);Frame->Show();SetTopWindow(Frame);}//*)return wxsOK;}

/**************************************************************** Name:      wxMyPainterMain.h* Purpose:   Defines Application Frame* Author:    yanzhenxi (3065598272@qq.com)* Created:   2023-12-21* Copyright: yanzhenxi ()* License:**************************************************************/#ifndef WXMYPAINTERMAIN_H
#define WXMYPAINTERMAIN_H
#include <list>
#include "item_i.hpp"//(*Headers(wxMyPainterFrame)
#include <wx/scrolwin.h>
#include <wx/sizer.h>
#include <wx/menu.h>
#include <wx/listbox.h>
#include <wx/frame.h>
#include <wx/statusbr.h>
//*)class wxMyPainterFrame: public wxFrame
{public:wxMyPainterFrame(wxWindow* parent,wxWindowID id = -1);virtual ~wxMyPainterFrame();private://(*Handlers(wxMyPainterFrame)void OnQuit(wxCommandEvent& event);void OnAbout(wxCommandEvent& event);void OnScrolledWindow1LeftDown(wxMouseEvent& event);void OnScrolledWindow1MouseMove(wxMouseEvent& event);void OnScrolledWindow1LeftUp(wxMouseEvent& event);void OnScrolledWindow1Paint(wxPaintEvent& event);//*)//(*Identifiers(wxMyPainterFrame)static const long ID_LISTBOX1;static const long ID_SCROLLEDWINDOW1;static const long idMenuQuit;static const long idMenuNone;static const long idMenuLine;static const long idMenuRectangle;static const long idMenuCircle;static const long idMenuText;static const long idMenuAbout;static const long ID_STATUSBAR1;//*)//(*Declarations(wxMyPainterFrame)wxMenuItem* MenuItemLine;wxMenuItem* MenuItemNone;wxScrolledWindow* ScrolledWindow1;wxMenu* Menu3;wxMenuItem* MenuItemText;wxStatusBar* StatusBar1;wxMenuItem* MenuItemRectangle;wxMenuItem* MenuItemCircle;wxListBox* ListBox1;//*)private:void RemoveAllItems();IItem* CreateNewItem();/*每当用户鼠标按下，就创建一个新的_newItem,等画完之后（鼠标抬起），就将它加入“_items”列表中。这也解释了为什么不需要“_drawing”这个标志，因为当“_newItem”不为空，就说明用户正在画新的线。OnPaint事件的思路配套调整为：每次都画出“_items”中的所有元素；然后如果“_newItem”不为空，则把用户正在拖拽的线也画出来。*/IItem* _newItem;std::list <IItem*> _items;DECLARE_EVENT_TABLE()
};#endif // WXMYPAINTERMAIN_H

/**************************************************************** Name:      wxMyPainterMain.cpp* Purpose:   Code for Application Frame* Author:    yanzhenxi (3065598272@qq.com)* Created:   2023-12-21* Copyright: yanzhenxi ()* License:**************************************************************/#include "wxMyPainterMain.h"
#include <wx/msgdlg.h>
#include <wx/dcclient.h>
#include "item_line.hpp"//(*InternalHeaders(wxMyPainterFrame)
#include <wx/settings.h>
#include <wx/intl.h>
#include <wx/string.h>
//*)//helper functions
enum wxbuildinfoformat {short_f, long_f };wxString wxbuildinfo(wxbuildinfoformat format)
{wxString wxbuild(wxVERSION_STRING);if (format == long_f ){
#if defined(__WXMSW__)wxbuild << _T("-Windows");
#elif defined(__UNIX__)wxbuild << _T("-Linux");
#endif#if wxUSE_UNICODEwxbuild << _T("-Unicode build");
#elsewxbuild << _T("-ANSI build");
#endif // wxUSE_UNICODE}return wxbuild;
}//(*IdInit(wxMyPainterFrame)
const long wxMyPainterFrame::ID_LISTBOX1 = wxNewId();
const long wxMyPainterFrame::ID_SCROLLEDWINDOW1 = wxNewId();
const long wxMyPainterFrame::idMenuQuit = wxNewId();
const long wxMyPainterFrame::idMenuNone = wxNewId();
const long wxMyPainterFrame::idMenuLine = wxNewId();
const long wxMyPainterFrame::idMenuRectangle = wxNewId();
const long wxMyPainterFrame::idMenuCircle = wxNewId();
const long wxMyPainterFrame::idMenuText = wxNewId();
const long wxMyPainterFrame::idMenuAbout = wxNewId();
const long wxMyPainterFrame::ID_STATUSBAR1 = wxNewId();
//*)BEGIN_EVENT_TABLE(wxMyPainterFrame,wxFrame)//(*EventTable(wxMyPainterFrame)//*)
END_EVENT_TABLE()wxMyPainterFrame::wxMyPainterFrame(wxWindow* parent,wxWindowID id): _newItem(nullptr)
{//(*Initialize(wxMyPainterFrame)wxMenuItem* MenuItemAbout;wxMenu* Menu1;wxMenuItem* MenuItemQuit;wxBoxSizer* BoxSizer1;wxMenuBar* MenuBar1;wxMenu* Menu2;Create(parent, id, wxEmptyString, wxDefaultPosition, wxDefaultSize, wxDEFAULT_FRAME_STYLE, _T("id"));SetClientSize(wxSize(208,94));BoxSizer1 = new wxBoxSizer(wxHORIZONTAL);ListBox1 = new wxListBox(this, ID_LISTBOX1, wxDefaultPosition, wxSize(168,68), 0, 0, 0, wxDefaultValidator, _T("ID_LISTBOX1"));BoxSizer1->Add(ListBox1, 0, wxALL|wxEXPAND, 5);ScrolledWindow1 = new wxScrolledWindow(this, ID_SCROLLEDWINDOW1, wxDefaultPosition, wxDefaultSize, wxVSCROLL|wxHSCROLL, _T("ID_SCROLLEDWINDOW1"));ScrolledWindow1->SetBackgroundColour(wxSystemSettings::GetColour(wxSYS_COLOUR_WINDOW));BoxSizer1->Add(ScrolledWindow1, 1, wxALL|wxEXPAND, 5);SetSizer(BoxSizer1);MenuBar1 = new wxMenuBar();Menu1 = new wxMenu();MenuItemQuit = new wxMenuItem(Menu1, idMenuQuit, _("退出\tAlt-F4"), _("Quit the application"), wxITEM_NORMAL);Menu1->Append(MenuItemQuit);MenuBar1->Append(Menu1, _("文件[&F]"));Menu3 = new wxMenu();MenuItemNone = new wxMenuItem(Menu3, idMenuNone, _("无"), wxEmptyString, wxITEM_RADIO);Menu3->Append(MenuItemNone);MenuItemLine = new wxMenuItem(Menu3, idMenuLine, _("直线"), wxEmptyString, wxITEM_RADIO);Menu3->Append(MenuItemLine);MenuItemRectangle = new wxMenuItem(Menu3, idMenuRectangle, _("矩形"), wxEmptyString, wxITEM_RADIO);Menu3->Append(MenuItemRectangle);MenuItemCircle = new wxMenuItem(Menu3, idMenuCircle, _("圆形"), wxEmptyString, wxITEM_RADIO);Menu3->Append(MenuItemCircle);MenuItemText = new wxMenuItem(Menu3, idMenuText, _("文字"), wxEmptyString, wxITEM_RADIO);Menu3->Append(MenuItemText);MenuBar1->Append(Menu3, _("组件[&I]"));Menu2 = new wxMenu();MenuItemAbout = new wxMenuItem(Menu2, idMenuAbout, _("关于\tF1"), _("Show info about this application"), wxITEM_NORMAL);Menu2->Append(MenuItemAbout);MenuBar1->Append(Menu2, _("帮助[&H]"));SetMenuBar(MenuBar1);StatusBar1 = new wxStatusBar(this, ID_STATUSBAR1, 0, _T("ID_STATUSBAR1"));int __wxStatusBarWidths_1[1] = { -1 };int __wxStatusBarStyles_1[1] = { wxSB_NORMAL };StatusBar1->SetFieldsCount(1,__wxStatusBarWidths_1);StatusBar1->SetStatusStyles(1,__wxStatusBarStyles_1);SetStatusBar(StatusBar1);SetSizer(BoxSizer1);Layout();ScrolledWindow1->Connect(wxEVT_PAINT,(wxObjectEventFunction)&wxMyPainterFrame::OnScrolledWindow1Paint,0,this);ScrolledWindow1->Connect(wxEVT_LEFT_DOWN,(wxObjectEventFunction)&wxMyPainterFrame::OnScrolledWindow1LeftDown,0,this);ScrolledWindow1->Connect(wxEVT_LEFT_UP,(wxObjectEventFunction)&wxMyPainterFrame::OnScrolledWindow1LeftUp,0,this);ScrolledWindow1->Connect(wxEVT_MOTION,(wxObjectEventFunction)&wxMyPainterFrame::OnScrolledWindow1MouseMove,0,this);Connect(idMenuQuit,wxEVT_COMMAND_MENU_SELECTED,(wxObjectEventFunction)&wxMyPainterFrame::OnQuit);Connect(idMenuAbout,wxEVT_COMMAND_MENU_SELECTED,(wxObjectEventFunction)&wxMyPainterFrame::OnAbout);//*)//设置滚动选项ScrolledWindow1->SetScrollRate(10, 10);ScrolledWindow1->SetVirtualSize(500, 480);
}wxMyPainterFrame::~wxMyPainterFrame()
{RemoveAllItems();//(*Destroy(wxMyPainterFrame)//*)
}void wxMyPainterFrame::OnQuit(wxCommandEvent& event)
{Close();
}void wxMyPainterFrame::OnAbout(wxCommandEvent& event)
{wxString msg = wxbuildinfo(long_f);wxMessageBox(msg, _("Welcome to..."));
}IItem* wxMyPainterFrame::CreateNewItem()
{if(this->MenuItemLine->IsChecked())//小心，别写成IsCheckable(){return new LineItem();}return nullptr;
}void wxMyPainterFrame::RemoveAllItems()
{for(std::list<IItem*>::iterator it = _items.begin(); it != _items.end(); ++it){delete *it; //释放每个_newItem占据的内存}_items.clear(); //释放_items中元素(指向_newItem的指针)占据的内存
}void wxMyPainterFrame::OnScrolledWindow1LeftDown(wxMouseEvent& event)
{if(_newItem) return; //正在划线，返回_newItem = this->CreateNewItem();if(!_newItem) return;_newItem->OnDrawStart(ScrolledWindow1->CalcUnscrolledPosition(event.GetPosition()));
}void wxMyPainterFrame::OnScrolledWindow1MouseMove(wxMouseEvent& event)
{if(!_newItem) //不在绘画状态{return;//直接退出}_newItem->OnDrawEnd(//物理坐标转为逻辑坐标ScrolledWindow1->CalcUnscrolledPosition(event.GetPosition()));ScrolledWindow1->Refresh();
}void wxMyPainterFrame::OnScrolledWindow1LeftUp(wxMouseEvent& event)
{if(!_newItem) //不在绘画状态？{return;//直接退出}_newItem->OnDrawEnd(//物理坐标转为逻辑坐标ScrolledWindow1->CalcUnscrolledPosition(event.GetPosition()));_items.push_back(_newItem); //记录到列表中_newItem = nullptr; //结束绘画状态ScrolledWindow1->Refresh();
}
//将_items中的所有线都画出来
void wxMyPainterFrame::OnScrolledWindow1Paint(wxPaintEvent& event)
{wxPaintDC dc(ScrolledWindow1);//DoPrepareDC会自行调校ScrolledWindow1->DoPrepareDC(dc);//先画出list中的每一项for(std::list <IItem*> :: const_iterator it = _items.begin(); it != _items.end(); ++it){IItem const* item = *it;item->Draw(dc);}//如果刚巧用户正在画新项，把它也显示出来//否则用户只能“盲画”了if(_newItem){_newItem->Draw(dc);}
}