VZ: I have reformatted it to correspond to our style conventions (tab stop =

4, no hard tabs, no function(void), ...) and added a couple of comments to
make it (hopefully!) more understandable.


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@744 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

samples/minimal/minimal.cpp

@@ -6,112 +6,185 @@
 // Created:     04/01/98
 // RCS-ID:      $Id$
 // Copyright:   (c) Julian Smart and Markus Holzem
-// Licence:   	wxWindows license
+// Licence:     wxWindows license
 /////////////////////////////////////////////////////////////////////////////
 
+// ============================================================================
+// declarations
+// ============================================================================
+
+// ----------------------------------------------------------------------------
+// headers
+// ----------------------------------------------------------------------------
 #ifdef __GNUG__
-#pragma implementation "minimal.cpp"
+    #pragma implementation "minimal.cpp"
-#pragma interface "minimal.cpp"
+    #pragma interface "minimal.cpp"
 #endif
 
 // For compilers that support precompilation, includes "wx/wx.h".
 #include "wx/wxprec.h"
 
 #ifdef __BORLANDC__
-#pragma hdrstop
+    #pragma hdrstop
 #endif
 
+// for all others, include the necessary headers (this file is usually all you
+// need because it includes almost all "standard" wxWindows headers
 #ifndef WX_PRECOMP
-#include "wx/wx.h"
+    #include "wx/wx.h"
 #endif
 
+// ----------------------------------------------------------------------------
+// ressources
+// ----------------------------------------------------------------------------
+// the application icon
 #ifdef __WXGTK__
-#include "mondrian.xpm"
+    #include "mondrian.xpm"
 #endif
 
-// Define a new application type
+// ----------------------------------------------------------------------------
-class MyApp: public wxApp
+// private classes
-{ public:
+// ----------------------------------------------------------------------------
-    bool OnInit(void);
+
+// Define a new application type, each program should derive a class from wxApp
+class MyApp : public wxApp
+{
+public:
+    // override base class virtuals
+    // ----------------------------
+
+    // this one is called on application startup and is a good place for the app
+    // initialization (doing it here and not in the ctor allows to have an error
+    // return: if OnInit() returns false, the application terminates)
+    virtual bool OnInit();
 };
 
-// Define a new frame type
+// Define a new frame type: this is going to be our main frame
-class MyFrame: public wxFrame
+class MyFrame : public wxFrame
-{ public:
+{
-    MyFrame(wxFrame *parent, const wxString& title,
+public:
-       const wxPoint& pos, const wxSize& size);
+    // ctor(s)
-    
+    MyFrame(const wxString& title, const wxPoint& pos, const wxSize& size);
- public:
+
+    // event handlers (these functions should _not_ be virtual)
     void OnQuit(wxCommandEvent& event);
     void OnAbout(wxCommandEvent& event);
-	bool OnClose(void) { return TRUE; }
 
-   DECLARE_EVENT_TABLE()
+private:
-    
+    // any class wishing to process wxWindows events must use this macro
+    DECLARE_EVENT_TABLE()
 };
 
-// ID for the menu commands
+// ----------------------------------------------------------------------------
-#define MINIMAL_QUIT 	1
+// constants
-#define MINIMAL_TEXT 	101
+// ----------------------------------------------------------------------------
-#define MINIMAL_ABOUT 	102
 
+// IDs for the controls and the menu commands
+enum
+{
+    // menu items
+    Minimal_Quit = 1,
+    Minimal_About,
+
+    // controls start here (the numbers are, of course, arbitrary)
+    Minimal_Text = 1000,
+};
+
+// ----------------------------------------------------------------------------
+// event tables and other macros for wxWindows
+// ----------------------------------------------------------------------------
+
+// the event tables connect the wxWindows events with the functions (event
+// handlers) which process them. It can be also done at run-time, but for the
+// simple menu events like this the static method is much simpler.
 BEGIN_EVENT_TABLE(MyFrame, wxFrame)
-	EVT_MENU(MINIMAL_QUIT, MyFrame::OnQuit)
+    EVT_MENU(Minimal_Quit,  MyFrame::OnQuit)
-	EVT_MENU(MINIMAL_ABOUT, MyFrame::OnAbout)
+    EVT_MENU(Minimal_About, MyFrame::OnAbout)
 END_EVENT_TABLE()
 
-// Create a new application object
+// Create a new application object: this macro will allow wxWindows to create
-IMPLEMENT_APP	(MyApp)
+// the application object during program execution (it's better than using a
+// static object for many reasons) and also declares the accessor function
+// wxGetApp() which will return the reference of the right type (i.e. MyApp and
+// not wxApp)
+IMPLEMENT_APP(MyApp)
 
-// `Main program' equivalent
+// ============================================================================
-bool MyApp::OnInit(void)
+// implementation
+// ============================================================================
+
+// ----------------------------------------------------------------------------
+// the application class
+// ----------------------------------------------------------------------------
+
+// `Main program' equivalent: the program execution "starts" here
+bool MyApp::OnInit()
 {
-  // Create the main frame window
+    // Create the main application window
-  MyFrame *frame = new MyFrame((wxFrame *) NULL, "Minimal wxWindows App",
+    MyFrame *frame = new MyFrame("Minimal wxWindows App",
-      wxPoint(50, 50), wxSize(450, 340));
+                                 wxPoint(50, 50), wxSize(450, 340));
 
-  // Give it an icon
+    // Show it and tell the application that it's our main window
-  frame->SetIcon(wxICON(mondrian));
+    // @@@ what does it do exactly, in fact? is it necessary here?
+    frame->Show(TRUE);
+    SetTopWindow(frame);
 
-  // Make a menubar
+    // success: wxApp::OnRun() will be called which will enter the main message
-  wxMenu *file_menu = new wxMenu;
+    // loop and the application will run. If we returned FALSE here, the
-
+    // application would exit immediately.
-  file_menu->Append(MINIMAL_ABOUT, "&About");
+    return TRUE;
-  file_menu->Append(MINIMAL_QUIT, "E&xit");
-  wxMenuBar *menu_bar = new wxMenuBar;
-  menu_bar->Append(file_menu, "&File");
-  frame->SetMenuBar(menu_bar);
-
-  // Make a panel with a message
-  wxPanel *panel = new wxPanel(frame, -1, wxPoint(0, 0), wxSize(400, 200), wxTAB_TRAVERSAL);
-
-  (void)new wxStaticText(panel, 311, "Hello!", wxPoint(10, 10), wxSize(-1, -1), 0);
-
-  // Show the frame
-  frame->Show(TRUE);
-  
-  SetTopWindow(frame);
-
-  return TRUE;
 }
 
-// My frame constructor
+// ----------------------------------------------------------------------------
-MyFrame::MyFrame(wxFrame *parent, const wxString& title,
+// main frame
-       const wxPoint& pos, const wxSize& size):
+// ----------------------------------------------------------------------------
-  wxFrame(parent, -1, title, pos, size)
-{}
 
-void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event) )
+// frame constructor
+MyFrame::MyFrame(const wxString& title, const wxPoint& pos, const wxSize& size)
+       : wxFrame((wxFrame *)NULL, -1, title, pos, size)
 {
-  Close(TRUE);
+    // set the frame icon
-}
+    SetIcon(wxICON(mondrian));
 
-void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event) )
+    // create a menu bar
-{
+    wxMenu *menuFile = new wxMenu;
-  wxMessageDialog dialog(this, "This is a minimal sample\nA second line in the message box",
-  	"About Minimal", wxYES_NO|wxCANCEL);
 
-  dialog.ShowModal();
+    menuFile->Append(Minimal_About, "&About...");
+    menuFile->AppendSeparator();
+    menuFile->Append(Minimal_Quit, "E&xit");
+
+    // now append the freshly created menu to the menu bar...
+    wxMenuBar *menuBar = new wxMenuBar;
+    menuBar->Append(menuFile, "&File");
+
+    // ... and attach this menu bar to the frame
+    SetMenuBar(menuBar);
+
+    // create a status bar just for fun (by default with 1 pane only)
+    CreateStatusBar();
+    SetStatusText("Welcome to wxWindows!");
+
+    // now create some controls
+
+    // a panel first - if there were several controls, it would allow us to
+    // navigate between them from the keyboard
+    wxPanel *panel = new wxPanel(this, -1, wxPoint(0, 0), wxSize(400, 200));
+
+    // and a static control whose parent is the panel
+    (void)new wxStaticText(panel, -1, "Hello, world!", wxPoint(10, 10));
 }
 
 
+// event handlers
+
+void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event))
+{
+    // TRUE is to force the frame to close
+    Close(TRUE);
+}
+
+void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event))
+{
+    wxMessageBox("This is a minimal sample\nA second line in the message box",
+                 "About Minimal", wxOK | wxICON_INFORMATION, this);
+}