samples/html/virtual/virtual.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        virtua;.cpp
   3 // Purpose:     wxHtml testing example
   4 //              demonstrates virtual file systems feature
   5 /////////////////////////////////////////////////////////////////////////////
   6
   7 // For compilers that support precompilation, includes "wx/wx.h".
   8 #include "wx/wxprec.h"
   9
  10 #ifdef __BORLANDC__
  11     #pragma hdrstop
  12 #endif
  13
  14 // for all others, include the necessary headers (this file is usually all you
  15 // need because it includes almost all "standard" wxWidgets headers
  16 #ifndef WX_PRECOMP
  17     #include "wx/wx.h"
  18 #endif
  19
  20
  21 #include "wx/html/htmlwin.h"
  22
  23
  24 // new handler class:
  25
  26 #include "wx/wfstream.h"
  27 #include "wx/mstream.h"
  28
  29
  30
  31 class MyVFS : public wxFileSystemHandler
  32 {
  33 public:
  34     MyVFS() : wxFileSystemHandler() {}
  35
  36     wxFSFile* OpenFile(wxFileSystem& fs, const wxString& location);
  37     bool CanOpen(const wxString& location);
  38 };
  39
  40
  41 bool MyVFS::CanOpen(const wxString& location)
  42 {
  43     return (GetProtocol(location) == wxT("myVFS"));
  44 }
  45
  46
  47
  48 wxFSFile* MyVFS::OpenFile(wxFileSystem& WXUNUSED(fs), const wxString& location)
  49 {
  50     wxFSFile *f;
  51     wxInputStream *str;
  52     static char buf[1024];
  53     const wxWX2MBbuf loc = location.ToAscii();
  54
  55     sprintf(buf, "<html><body><h2><i>You're in Node <u>%s</u></i></h2><p>"
  56                  "Where do you want to go?<br><blockquote>"
  57                  "<a href=\"%s-1\">sub-1</a><br>"
  58                  "<a href=\"%s-2\">sub-2</a><br>"
  59                  "<a href=\"%s-3\">sub-3</a><br>"
  60                  "</blockquote></body></html>",
  61                  (const char*)loc, (const char*)loc, (const char*)loc,
  62                  (const char*)loc);
  63
  64     // NB: There's a terrible hack involved: we fill 'buf' with new data every
  65     //     time this method is called and return new wxMemoryInputStream pointing to it.
  66     //     This won't work as soon as there are 2+ myVFS files opened. Fortunately,
  67     //     this won't happen because wxHTML keeps only one "page" file opened at the
  68     //     time.
  69     str = new wxMemoryInputStream(buf, strlen(buf));
  70     f = new wxFSFile(str, location, wxT("text/html"), wxEmptyString, wxDateTime::Today());
  71
  72     return f;
  73 }
  74
  75
  76
  77 // ----------------------------------------------------------------------------
  78 // private classes
  79 // ----------------------------------------------------------------------------
  80
  81 // Define a new application type, each program should derive a class from wxApp
  82    class MyApp : public wxApp
  83    {
  84    public:
  85     // override base class virtuals
  86     // ----------------------------
  87
  88     // this one is called on application startup and is a good place for the app
  89     // initialization (doing it here and not in the ctor allows to have an error
  90     // return: if OnInit() returns false, the application terminates)
  91       virtual bool OnInit();
  92    };
  93
  94 // Define a new frame type: this is going to be our main frame
  95    class MyFrame : public wxFrame
  96    {
  97    public:
  98     // ctor(s)
  99       MyFrame(const wxString& title, const wxPoint& pos, const wxSize& size);
 100
 101     // event handlers (these functions should _not_ be virtual)
 102       void OnQuit(wxCommandEvent& event);
 103       void OnBack(wxCommandEvent& event);
 104       void OnForward(wxCommandEvent& event);
 105
 106    private:
 107     // any class wishing to process wxWidgets events must use this macro
 108     DECLARE_EVENT_TABLE()
 109    };
 110
 111 // ----------------------------------------------------------------------------
 112 // constants
 113 // ----------------------------------------------------------------------------
 114
 115 // IDs for the controls and the menu commands
 116    enum
 117    {
 118     // menu items
 119    Minimal_Quit = 1,
 120    Minimal_Back,
 121    Minimal_Forward,
 122
 123     // controls start here (the numbers are, of course, arbitrary)
 124    Minimal_Text = 1000
 125    };
 126
 127 // ----------------------------------------------------------------------------
 128 // event tables and other macros for wxWidgets
 129 // ----------------------------------------------------------------------------
 130
 131 // the event tables connect the wxWidgets events with the functions (event
 132 // handlers) which process them. It can be also done at run-time, but for the
 133 // simple menu events like this the static method is much simpler.
 134    BEGIN_EVENT_TABLE(MyFrame, wxFrame)
 135    EVT_MENU(Minimal_Quit,  MyFrame::OnQuit)
 136    EVT_MENU(Minimal_Back, MyFrame::OnBack)
 137    EVT_MENU(Minimal_Forward, MyFrame::OnForward)
 138    END_EVENT_TABLE()
 139
 140    // Create a new application object: this macro will allow wxWidgets to create
 141    // the application object during program execution (it's better than using a
 142    // static object for many reasons) and also declares the accessor function
 143    // wxGetApp() which will return the reference of the right type (i.e. MyApp and
 144    // not wxApp)
 145    IMPLEMENT_APP(MyApp)
 146
 147    // ============================================================================
 148    // implementation
 149    // ============================================================================
 150
 151    // ----------------------------------------------------------------------------
 152    // the application class
 153    // ----------------------------------------------------------------------------
 154
 155    // `Main program' equivalent: the program execution "starts" here
 156    bool MyApp::OnInit()
 157    {
 158      if ( !wxApp::OnInit() )
 159          return false;
 160
 161     // Create the main application window
 162       MyFrame *frame = new MyFrame(_("wxHtmlWindow testing application"),
 163          wxDefaultPosition, wxSize(640, 480));
 164
 165     // Show it and tell the application that it's our main window
 166     // @@@ what does it do exactly, in fact? is it necessary here?
 167       frame->Show(true);
 168       SetTopWindow(frame);
 169       wxFileSystem::AddHandler(new MyVFS);
 170
 171     // success: wxApp::OnRun() will be called which will enter the main message
 172     // loop and the application will run. If we returned false here, the
 173     // application would exit immediately.
 174       return true;
 175    }
 176
 177 // ----------------------------------------------------------------------------
 178 // main frame
 179 // ----------------------------------------------------------------------------
 180
 181 wxHtmlWindow *html;
 182
 183 // frame constructor
 184    MyFrame::MyFrame(const wxString& title, const wxPoint& pos, const wxSize& size)
 185    : wxFrame((wxFrame *)NULL, wxID_ANY, title, pos, size)
 186    {
 187     // create a menu bar
 188       wxMenu *menuFile = new wxMenu;
 189       wxMenu *menuNav = new wxMenu;
 190
 191       menuFile->Append(Minimal_Quit, _("E&xit"));
 192       menuNav->Append(Minimal_Back, _("Go &BACK"));
 193       menuNav->Append(Minimal_Forward, _("Go &FORWARD"));
 194
 195     // now append the freshly created menu to the menu bar...
 196       wxMenuBar *menuBar = new wxMenuBar;
 197       menuBar->Append(menuFile, _("&File"));
 198       menuBar->Append(menuNav, _("&Navigate"));
 199
 200     // ... and attach this menu bar to the frame
 201       SetMenuBar(menuBar);
 202
 203 #if wxUSE_STATUSBAR
 204       CreateStatusBar(2);
 205 #endif // wxUSE_STATUSBAR
 206
 207       html = new wxHtmlWindow(this);
 208       html -> SetRelatedFrame(this, _("VFS Demo: '%s'"));
 209 #if wxUSE_STATUSBAR
 210       html -> SetRelatedStatusBar(1);
 211 #endif // wxUSE_STATUSBAR
 212       html -> LoadPage(wxT("start.htm"));
 213    }
 214
 215
 216 // event handlers
 217
 218    void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event))
 219    {
 220     // true is to force the frame to close
 221       Close(true);
 222    }
 223
 224    void MyFrame::OnBack(wxCommandEvent& WXUNUSED(event))
 225    {
 226    if (!html -> HistoryBack()) wxMessageBox(_("You reached prehistory era!"));
 227    }
 228
 229
 230    void MyFrame::OnForward(wxCommandEvent& WXUNUSED(event))
 231    {
 232    if (!html -> HistoryForward()) wxMessageBox(_("No more items in history!"));
 233    }