zwx_helper， 让wxWidgets界面开发变轻松。

通过重载c++operator，实现一种轻松的wxWidgets界面编程风格，如html编写页面一样直观容易。

举一例，一个界面页有四块区，如果是开发html的话，是从头到脚一气书写

<div id='0'>
    <div id='1'>
        <input type="button" onclick="handler()">
    </div>
    <div id='2'>
        <input type="button" onclick="handler()">
    </div>
    <div id='3'>
        <input type="button" onclick="handler()">
    </div>
    <div id='4'>
        <input type="button" onclick="handler()">
    </div>
</div>

我的目标是，让c++开发的代码书写也一气呵成

Frame* frame = new Frame;
layout::begin(new layout)
    (layout::begin(new layout)
        (new button) [ onclick = [] (event&) {} ]
        (layout::end)
    )
    (layout::begin(new layout)
        (new button) [ onclick = [] (event&) {} ]
        (layout::end)
    )
    (layout::begin(new layout)
        (new button) [ onclick = [] (event&) {} ]
        (layout::end)
    )
    (layout::begin(new layout)
        (new button) [ onclick = [] (event&) {} ]
        (layout::end)
    )
    (layout::end, [=] (layout& layout) {
                                frame->SetLayout(layout);
                            });

菜单布局编写直观自然，处理器函数绑定同时到位

Frame* frame = new Frame;
menu::begin(new MenuBar)
    ("File", 
         menu::begin(new Menu)
　　　　　　　　　　　　(ID_OPEN, "open",   [=] (event&) {  })
                    (ID_NEW,   "new",    [=] (event&) {  })
                    (menu::end)
     )
     ("About",
          menu::begin(new Menu)
　　　　　　　　　　　　　(ID_HELP,   "help",    [=] (event&)  {   })
                     (menu::end)
     )
     (menu::end,   [=] (MenuBar* mb) {
                                      frame->SetMenuBar(mb);
                                });

理想总是美好的，现在回到现实中的界面开发，让人眼痛的c++代码，

1 必须在多处代码操作，步骤烦多，分散在多处代码。

2 布局编写不符合人的思维-将整体拆分再拆分，而是从枝节末端创建一层一层往上添加挂钩。

MFC，WTL与wxWidgets的开发步骤类似，这里只关注wxWidgets，

1 在头文件中，自定义窗口类声明事件（窗口消息）分派函数；

2 在源文件中，添加事件（窗口消息）分派函数的实现宏；

3 添加一个事件（窗口消息）处理器函数，

3-1 在头文件中，声明为自定义窗口类的成员函数

3-2 在源文件中，实现该函数

3-3 在源文件中，在那个TABLE宏里添加事件id，处理器函数

4 在某个窗口容器的初始化回调中，创建事件id对应的子窗口／控件，设置相关的id

5 过了一段时间后，维护某个控件的处理器函数

5-1 在布局代码中找到这个控件，看到它相关的id

5-2 在源代码找到分派事件的窗口类，在它的TABLE宏里众多条目中找出对应项

5-3 最后才定位到目标处理器函数

做一样事情，却要在多处代码文件中跳转切换，只要漏了一步又会浪费时间调试一翻，实在烦人烦心。

// MyFrame.h

enum
{
    ID_SOME
};

class MyFrame : public wxFrame
{
public:
     void hanlde_some_event(wxEvent&);
private:
     wxDECLARE_EVENT_TABLE()      
}

// MyFrame.cpp

wxBEGIN_EVENT_TABLE(MyFrame,  wxFrame)
     EVT_XXXX(ID_SOME,    &MyFrame::handle_some_event)
wxEND_EVENT_TABLE()


void MyFrame::handle_some_event(wxEvent&)
{
    // todo
}


MyFrame::MyFrame()
{
     // ....
     this->Add(new wxSomeWindow(this, ID_SOME, ...);
     // ....
}

下面是用zwx_helper重写官方layout sample布局的代码的对比

先是官方代码

layout.h https://github.com/wxWidgets/wxWidgets/blob/master/samples/layout/layout.h

layout.cpp https://github.com/wxWidgets/wxWidgets/blob/master/samples/layout/layout.cpp

// ----------------------------------------------------------------------------
// MyFrame
// ----------------------------------------------------------------------------

wxBEGIN_EVENT_TABLE(MyFrame, wxFrame)
  EVT_MENU(LAYOUT_ABOUT, MyFrame::OnAbout)
  EVT_MENU(LAYOUT_QUIT, MyFrame::OnQuit)

  EVT_MENU(LAYOUT_TEST_PROPORTIONS, MyFrame::TestProportions)
  EVT_MENU(LAYOUT_TEST_SIZER, MyFrame::TestFlexSizers)
  EVT_MENU(LAYOUT_TEST_NB_SIZER, MyFrame::TestNotebookSizers)
  EVT_MENU(LAYOUT_TEST_GB_SIZER, MyFrame::TestGridBagSizer)
  EVT_MENU(LAYOUT_TEST_SET_MINIMAL, MyFrame::TestSetMinimal)
  EVT_MENU(LAYOUT_TEST_NESTED, MyFrame::TestNested)
  EVT_MENU(LAYOUT_TEST_WRAP, MyFrame::TestWrap)
wxEND_EVENT_TABLE()

// Define my frame constructor
MyFrame::MyFrame()
       : wxFrame(NULL, wxID_ANY, "wxWidgets Layout Demo")
{
    SetIcon(wxICON(sample));

    // Make a menubar
    wxMenu *file_menu = new wxMenu;

    file_menu->Append(LAYOUT_TEST_PROPORTIONS, "&Proportions demo...	F1");
    file_menu->Append(LAYOUT_TEST_SIZER, "Test wx&FlexSizer...	F2");
    file_menu->Append(LAYOUT_TEST_NB_SIZER, "Test &notebook sizers...	F3");
    file_menu->Append(LAYOUT_TEST_GB_SIZER, "Test &gridbag sizer...	F4");
    file_menu->Append(LAYOUT_TEST_SET_MINIMAL, "Test Set&ItemMinSize...	F5");
    file_menu->Append(LAYOUT_TEST_NESTED, "Test nested sizer in a wxPanel...	F6");
    file_menu->Append(LAYOUT_TEST_WRAP, "Test wrap sizers...	F7");

    file_menu->AppendSeparator();
    file_menu->Append(LAYOUT_QUIT, "E&xit", "Quit program");

    wxMenu *help_menu = new wxMenu;
    help_menu->Append(LAYOUT_ABOUT, "&About", "About layout demo...");

    wxMenuBar *menu_bar = new wxMenuBar;

    menu_bar->Append(file_menu, "&File");
    menu_bar->Append(help_menu, "&Help");

    // Associate the menu bar with the frame
    SetMenuBar(menu_bar);

#if wxUSE_STATUSBAR
    CreateStatusBar(2);
    SetStatusText("wxWidgets layout demo");
#endif // wxUSE_STATUSBAR

    wxPanel* p = new wxPanel(this, wxID_ANY);

    // we want to get a dialog that is stretchable because it
    // has a text ctrl in the middle. at the bottom, we have
    // two buttons which.

    wxBoxSizer *topsizer = new wxBoxSizer( wxVERTICAL );

    // 1) top: create wxStaticText with minimum size equal to its default size
    topsizer->Add(
        new wxStaticText( p, wxID_ANY, "An explanation (wxALIGN_RIGHT)." ),
        wxSizerFlags().Align(wxALIGN_RIGHT).Border(wxALL & ~wxBOTTOM, 5));
    topsizer->Add(
        new wxStaticText( p, wxID_ANY, "An explanation (wxALIGN_LEFT)." ),
        wxSizerFlags().Align(wxALIGN_LEFT).Border(wxALL & ~wxBOTTOM, 5));
    topsizer->Add(
        new wxStaticText( p, wxID_ANY, "An explanation (wxALIGN_CENTRE_HORIZONTAL)." ),
        wxSizerFlags().Align(wxALIGN_CENTRE_HORIZONTAL).Border(wxALL & ~wxBOTTOM, 5));

    // 2) top: create wxTextCtrl with minimum size (100x60)
    topsizer->Add(
        new wxTextCtrl( p, wxID_ANY, "My text (wxEXPAND).", wxDefaultPosition, wxSize(100,60), wxTE_MULTILINE),
        wxSizerFlags(1).Expand().Border(wxALL, 5));

    // 2.5) Gratuitous test of wxStaticBoxSizers
    wxBoxSizer *statsizer = new wxStaticBoxSizer(
        new wxStaticBox(p, wxID_ANY, "A wxStaticBoxSizer"), wxVERTICAL );
    statsizer->Add(
        new wxStaticText(p, wxID_ANY, "And some TEXT inside it"),
        wxSizerFlags().Border(wxALL, 30));
    topsizer->Add(
        statsizer,
        wxSizerFlags(1).Expand().Border(wxALL, 10));

    // 2.7) And a test of wxGridSizer
    wxGridSizer *gridsizer = new wxGridSizer(2, 5, 5);
    gridsizer->Add(new wxStaticText(p, wxID_ANY, "Label"),
                wxSizerFlags().Align(wxALIGN_RIGHT | wxALIGN_CENTER_VERTICAL));
    gridsizer->Add(new wxTextCtrl(p, wxID_ANY, "Grid sizer demo"),
                wxSizerFlags(1).Align(wxGROW | wxALIGN_CENTER_VERTICAL));
    gridsizer->Add(new wxStaticText(p, wxID_ANY, "Another label"),
                wxSizerFlags().Align(wxALIGN_RIGHT | wxALIGN_CENTER_VERTICAL));
    gridsizer->Add(new wxTextCtrl(p, wxID_ANY, "More text"),
                wxSizerFlags(1).Align(wxGROW | wxALIGN_CENTER_VERTICAL));
    gridsizer->Add(new wxStaticText(p, wxID_ANY, "Final label"),
                wxSizerFlags().Align(wxALIGN_RIGHT | wxALIGN_CENTER_VERTICAL));
    gridsizer->Add(new wxTextCtrl(p, wxID_ANY, "And yet more text"),
                wxSizerFlags().Align(wxGROW | wxALIGN_CENTER_VERTICAL));
    topsizer->Add(
        gridsizer,
        wxSizerFlags().Proportion(1).Expand().Border(wxALL, 10));


#if wxUSE_STATLINE
    // 3) middle: create wxStaticLine with minimum size (3x3)
    topsizer->Add(
        new wxStaticLine( p, wxID_ANY, wxDefaultPosition, wxSize(3,3), wxHORIZONTAL),
        wxSizerFlags().Expand());
#endif // wxUSE_STATLINE


    // 4) bottom: create two centred wxButtons
    wxBoxSizer *button_box = new wxBoxSizer( wxHORIZONTAL );
    button_box->Add(
        new wxButton( p, wxID_ANY, "Two buttons in a box" ),
        wxSizerFlags().Border(wxALL, 7));
    button_box->Add(
        new wxButton( p, wxID_ANY, "(wxCENTER)" ),
        wxSizerFlags().Border(wxALL, 7));

    topsizer->Add(button_box, wxSizerFlags().Center());

    p->SetSizer( topsizer );

    // don't allow frame to get smaller than what the sizers tell it and also set
    // the initial size as calculated by the sizers
    topsizer->SetSizeHints( this );
}

最后是我的代码

std::shared_ptr<MyFrameDelegate> sptr_delegate;

bool MyApp::OnInit()
{
    if (!wxApp::OnInit())
        return false;
    
    MyFrame* frame = new MyFrame;
    sptr_delegate = std::shared_ptr<MyFrameDelegate>(new MyFrameDelegate(frame));
    MyFrameDelegate* delegate = sptr_delegate.get();
    wxPanel* p = new wxPanel((wxWindow*)frame, wxID_ANY);
    wxMenuBar* mb = 
    menu::begin(new wxMenuBar)
                ("&File",
                 menu::begin(new wxMenu)
                    (LAYOUT_TEST_PROPORTIONS, "&Proportions demo...	F1", &MyFrame::TestMenuCommand, frame)
                    (LAYOUT_TEST_SIZER, "Test wx&FlexSizer...	F2", &MyFrame::TestMenuCommand, frame)
                    (LAYOUT_TEST_NB_SIZER, "Test &notebook sizers...	F3", &MyFrame::TestMenuCommand, frame)
                    (LAYOUT_TEST_GB_SIZER, "Test &gridbag sizer...	F4", frame, [=](wxCommandEvent& event) { frame->TestMenuCommand(event); })
                    (LAYOUT_TEST_SET_MINIMAL, "Test Set&ItemMinSize...	F5")
                    (LAYOUT_TEST_NESTED, "Test nested sizer in a wxPanel...	F6", frame, [=](wxCommandEvent& event) { sptr_delegate->TestMenuCommand(event); })(LAYOUT_TEST_WRAP, "Test wrap sizers...	F7")
                    (menu::end))
                ("&Help",
                 menu::begin(new wxMenu)
                    (LAYOUT_ABOUT, "&About", "About layout demo...")
                    (menu::end))
                ("level-tree",
                 menu::begin(new wxMenu)
                    (wxID_ANY, "level-1.1", 
                        menu::begin(new wxMenu)
                                (wxID_ANY, "level-1.1-level-2.1")
                                (wxID_ANY, "level-1.1-level-2.2")
                                (menu::end))
                    (wxID_ANY, "level-1.2", 
                        menu::begin(new wxMenu)
                                (wxID_ANY, "level-1.2-level-2.1")
                                (wxID_ANY, "level-1.2-level-2.2")
                                (menu::end))
                    (menu::end))
                (menu::end, 
                    [=](wxMenuBar* mb) {
                        frame->SetMenuBar(mb);
                    });
    
    layout::begin(new wxBoxSizer(wxVERTICAL))
    // 1) top: create wxStaticText with minimum size equal to its default size
        (new wxStaticText( p, wxID_ANY, "An explanation (wxALIGN_RIGHT)." ),
        wxSizerFlags().Align(wxALIGN_RIGHT).Border(wxALL & ~wxBOTTOM, 5))
        (new wxStaticText( p, wxID_ANY, "An explanation (wxALIGN_LEFT)." ),
        wxSizerFlags().Align(wxALIGN_LEFT).Border(wxALL & ~wxBOTTOM, 5))
        (new wxStaticText( p, wxID_ANY, "An explanation (wxALIGN_CENTRE_HORIZONTAL)." ),
        wxSizerFlags().Align(wxALIGN_CENTRE_HORIZONTAL).Border(wxALL & ~wxBOTTOM, 5))

    // 2) top: create wxTextCtrl with minimum size (100x60)
        (new wxTextCtrl( p, wxID_ANY, "My text (wxEXPAND).", wxDefaultPosition, wxSize(100,60), wxTE_MULTILINE),
        wxSizerFlags(1).Expand().Border(wxALL, 5))

    // 2.5) Gratuitous test of wxStaticBoxSizers
        (layout::begin(new wxStaticBoxSizer(new wxStaticBox(p, wxID_ANY, "A wxStaticBoxSizer"), wxVERTICAL))
            (new wxStaticText(p, wxID_ANY, "And some TEXT inside it"), wxSizerFlags().Border(wxALL, 30))
            (layout::end), wxSizerFlags(1).Expand().Border(wxALL, 10))

    // 2.7) And a test of wxGridSizer
        (layout::begin(new wxGridSizer(2, 5, 5))
                (new wxStaticText(p, wxID_ANY, "Label"),
                wxSizerFlags().Align(wxALIGN_RIGHT | wxALIGN_CENTER_VERTICAL))
                (new wxTextCtrl(p, wxID_ANY, "Grid sizer demo"),
                wxSizerFlags(1).Align(wxGROW | wxALIGN_CENTER_VERTICAL))
                (new wxStaticText(p, wxID_ANY, "Another label"),
                wxSizerFlags().Align(wxALIGN_RIGHT | wxALIGN_CENTER_VERTICAL))
                (new wxTextCtrl(p, wxID_ANY, "More text"),
                wxSizerFlags(1).Align(wxGROW | wxALIGN_CENTER_VERTICAL))
                (new wxStaticText(p, wxID_ANY, "Final label"),
                wxSizerFlags().Align(wxALIGN_RIGHT | wxALIGN_CENTER_VERTICAL))
                (new wxTextCtrl(p, wxID_ANY, "And yet more text"),
                wxSizerFlags().Align(wxGROW | wxALIGN_CENTER_VERTICAL))
                (layout::end), wxSizerFlags().Proportion(1).Expand().Border(wxALL, 10))


#if wxUSE_STATLINE
    // 3) middle: create wxStaticLine with minimum size (3x3)
        (new wxStaticLine( p, wxID_ANY, wxDefaultPosition, wxSize(3,3), wxHORIZONTAL),
            wxSizerFlags().Expand())
#endif // wxUSE_STATLINE


    // 4) bottom: create two centred wxButtons
        (layout::begin(new wxBoxSizer( wxHORIZONTAL ))
            (new wxButton( p, wxID_ANY, "Two buttons in a box" ),
            wxSizerFlags().Border(wxALL, 7))[onclick = [=](wxCommandEvent& e) { delegate->OnClick(e); } ]
            (new wxButton( p, wxID_ANY, "(wxCENTER)" ),
            wxSizerFlags().Border(wxALL, 7))
            (layout::end), wxSizerFlags().Center())
        (layout::end, 
            [=](wxSizer* s) { 
                p->SetSizer(s); 
                s->SetSizeHints(frame); 
            });
    
    frame->Show(true);
    return true;
}

zwx_helper将会在https://github.com/bbqz007/zhelper-wxWidgets/发布。