[wxperl-users] Virtual FS sample

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Hi,

Can anybody help translate the wx/samples/html/virtual/virtual.cpp
sample to wxPerl?
It's not a lot, but understanding it is a challenge :-)

Take a look at the sample app, it's very cool. It creates HTML
on-the-fly, like CGI. The author of wxHTML pointed me to the sample,
which is unfortunately in C++.

First the C++ code, followed by my Perl attempt:

class MyVFS : public wxFileSystemHandler
{
public:
    MyVFS() : wxFileSystemHandler() {}

    wxFSFile* OpenFile(wxFileSystem& fs, const wxString& location);
    bool CanOpen(const wxString& location);
};
------------------------------------

I did this as:

package MyVFS;

use strict;
use vars qw(@ISA);

@ISA=qw(wxFileSystemHandler);

use Wx qw(wxID_OK wxID_CANCEL);
use Wx::FS;

sub new {
    my( $class ) = shift;
    my( $this ) = $class->SUPER::new( @_ );

    # No idea where the $fs and $location values would come from.

    $this->OpenFile( $fs, $location );

    $this->CanOpen($location);

    # WDR: handler declarations for MyVFS

        $this;
}

# WDR: methods for MyVFS

MyVFS::CanOpen($location)
{
    return (GetProtocol(location) == "myVFS");
}

# WDR: handler implementations for MyVFS

---------------------------------------

I don't know if that was correct because I can't try it out yet.
However, now I'm stuck. Especially with the wxFSFile bit below, not to
mention the stuff about memory leaks in the comments.

bool MyVFS::CanOpen(const wxString& location)
{
    return (GetProtocol(location) == "myVFS");
}

wxFSFile* MyVFS::OpenFile(wxFileSystem& fs, const wxString& location)
{
    wxFSFile *f;
    wxInputStream *str;
    char *buf = (char*)malloc(1024);

    sprintf(buf, "<html><body><h2><i>You're in Node
<u>%s</u></i></h2><p>"
                 "Where do you want to go?<br><blockquote>"
                 "<a href=\"%s-1\">sub-1</a><br>"
                 "<a href=\"%s-2\">sub-2</a><br>"
                 "<a href=\"%s-3\">sub-3</a><br>"
                 "</blockquote></body></html>",
                 location.GetData(), location.GetData(),
location.GetData(), location.GetData());

    // WARNING: wxMemoryInputStream will not free buf.
    // There is a memory leak here.
    str = new wxMemoryInputStream(buf, strlen(buf));
    f = new wxFSFile(str, location, "text/html", wxEmptyString,
wxDateTime::Today());
    return f;
}
---------------------------------------

Otherwise, I think only the handler needs adding to OnInit, which
should be:

wxFileSystem::AddHandler(MyVFS->new);
------------------------------------

I've included the entire C++ file below, in case you don't have it
handy (X:\wx\samples\html\virtual\virtual.cpp).

Many Thanks,

Marcus

Here is the entire C++ file:

////////////////////////////////////////////////////////////////////////
/////
// Name:        virtua;.cpp
// Purpose:     wxHtml testing example
//              demonstrates virtual file systems feature
////////////////////////////////////////////////////////////////////////
/////

#ifdef __GNUG__
    #pragma implementation "test.cpp"
    #pragma interface "test.cpp"
#endif

// For compilers that support precompilation, includes "wx/wx.h".
#include <wx/wxprec.h>

#ifdef __BORLANDC__
    #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>
#endif

#include <wx/html/htmlwin.h>

// new handler class:

#include <wx/wfstream.h>
#include <wx/mstream.h>

class MyVFS : public wxFileSystemHandler
{
public:
    MyVFS() : wxFileSystemHandler() {}

    wxFSFile* OpenFile(wxFileSystem& fs, const wxString& location);
    bool CanOpen(const wxString& location);
};

bool MyVFS::CanOpen(const wxString& location)
{
    return (GetProtocol(location) == "myVFS");
}

wxFSFile* MyVFS::OpenFile(wxFileSystem& fs, const wxString& location)
{
    wxFSFile *f;
    wxInputStream *str;
    char *buf = (char*)malloc(1024);

    sprintf(buf, "<html><body><h2><i>You're in Node
<u>%s</u></i></h2><p>"
                 "Where do you want to go?<br><blockquote>"
                 "<a href=\"%s-1\">sub-1</a><br>"
                 "<a href=\"%s-2\">sub-2</a><br>"
                 "<a href=\"%s-3\">sub-3</a><br>"
                 "</blockquote></body></html>",
                 location.GetData(), location.GetData(),
location.GetData(), location.GetData());

    // WARNING: wxMemoryInputStream will not free buf.
    // There is a memory leak here.
    str = new wxMemoryInputStream(buf, strlen(buf));
    f = new wxFSFile(str, location, "text/html", wxEmptyString,
wxDateTime::Today());
    return f;
}

//
------------------------------------------------------------------------
----
// private classes
//
------------------------------------------------------------------------
----

// 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: this is going to be our main frame
   class MyFrame : public wxFrame
   {
   public:
    // ctor(s)
      MyFrame(const wxString& title, const wxPoint& pos, const wxSize&
size);

    // event handlers (these functions should _not_ be virtual)
      void OnQuit(wxCommandEvent& event);
      void OnAbout(wxCommandEvent& event);
      void OnBack(wxCommandEvent& event);
      void OnForward(wxCommandEvent& event);

   private:
    // any class wishing to process wxWindows events must use this
macro
    DECLARE_EVENT_TABLE()
   };

//
------------------------------------------------------------------------
----
// constants
//
------------------------------------------------------------------------
----

// IDs for the controls and the menu commands
   enum
   {
    // menu items
   Minimal_Quit = 1,
   Minimal_About,
   Minimal_Back,
   Minimal_Forward,

    // 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_About, MyFrame::OnAbout)
   EVT_MENU(Minimal_Back, MyFrame::OnBack)
   EVT_MENU(Minimal_Forward, MyFrame::OnForward)
   END_EVENT_TABLE()

   // Create a new application object: this macro will allow wxWindows
to create
   // 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)

   //
========================================================================
====
   // implementation
   //
========================================================================
====

   //
------------------------------------------------------------------------
----
   // the application class
   //
------------------------------------------------------------------------
----

   // `Main program' equivalent: the program execution "starts" here
   bool MyApp::OnInit()
   {
    // Create the main application window
      MyFrame *frame = new MyFrame("wxHtmlWindow testing application",
         wxPoint(50, 50), wxSize(640, 480));

    // Show it and tell the application that it's our main window
    // @@@ what does it do exactly, in fact? is it necessary here?
      frame->Show(TRUE);
      SetTopWindow(frame);
      wxFileSystem::AddHandler(new MyVFS);

    // success: wxApp::OnRun() will be called which will enter the main
message
    // loop and the application will run. If we returned FALSE here,
the
    // application would exit immediately.
      return TRUE;
   }

//
------------------------------------------------------------------------
----
// main frame
//
------------------------------------------------------------------------
----

wxHtmlWindow *html;

// frame constructor
   MyFrame::MyFrame(const wxString& title, const wxPoint& pos, const
wxSize& size)
   : wxFrame((wxFrame *)NULL, -1, title, pos, size)
   {
    // create a menu bar
      wxMenu *menuFile = new wxMenu;
      wxMenu *menuNav = new wxMenu;

      menuFile->Append(Minimal_Quit, "E&xit");
      menuNav->Append(Minimal_Back, "Go &BACK");
      menuNav->Append(Minimal_Forward, "Go &FORWARD");

    // now append the freshly created menu to the menu bar...
      wxMenuBar *menuBar = new wxMenuBar;
      menuBar->Append(menuFile, "&File");
      menuBar->Append(menuNav, "&Navigate");

    // ... and attach this menu bar to the frame
      SetMenuBar(menuBar);

      CreateStatusBar(1);

      html = new wxHtmlWindow(this);
      html -> SetRelatedFrame(this, "VFS Demo: '%s'");
      html -> SetRelatedStatusBar(1);
      html -> LoadPage("start.htm");
   }

// event handlers

   void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event))
   {
    // TRUE is to force the frame to close
      Close(TRUE);
   }

   void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event))
   {
   }

   void MyFrame::OnBack(wxCommandEvent& WXUNUSED(event))
   {
   if (!html -> HistoryBack()) wxMessageBox("You reached prehistory
era!");
   }

   void MyFrame::OnForward(wxCommandEvent& WXUNUSED(event))
   {
   if (!html -> HistoryForward()) wxMessageBox("No more items in
history!");
   }

----- Code End ----------------------------------

[wxperl-users] Virtual FS sample

Perl wrappers for the wxWidgets C++ toolkit

[wxperl-users] Virtual FS sample