[cairo] Using cario in wxwidgets

[Timothée Lecomte]

Hello !

I'm trying to use cairo in wxwidgets. In order to obtain a simple "hello
world" program, I get the following code to compile properly, but I
don't get any text from cairo. Can somebody give me come help ?

Thanks,

Timothée Lecomte


Here is the code :

////

/// ============================================================================/
/// declarations/
/// ============================================================================/

/// ----------------------------------------------------------------------------/
/// headers/
/// ----------------------------------------------------------------------------/

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

#ifndef WX_PRECOMP
    #include "wx/wx.h"
#endif

#ifdef __WXGTK__
	#include <gtk/gtk.h>
	#include <gdk/gdk.h>
	#include <gdk/gdkx.h>
	#include <cairo-xlib.h>
#else
    #error Not implemented yet
#endif

/// ----------------------------------------------------------------------------/
/// resources/
/// ----------------------------------------------------------------------------/

//* The function that creates a X11 surface from wxwidgets information *//
 cairo_surface_t* create_cairo_surface(wxWindow* wxwin, int width, int height);


/// Define a new application type, each program should derive a class from wxApp/
*class* MyApp : *public* wxApp
{
*public*:
/// this one is called on application startup/
    *virtual* bool OnInit();
};

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

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

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

*class* MyPanel : *public* wxPanel
{
	*public* :
		//* constructor*//
		MyPanel( wxWindow* parent);
		void OnPaint(wxPaintEvent& event);

		//* destructor*//
		~MyPanel() {};

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

/// ----------------------------------------------------------------------------/
/// event tables and other macros for wxWidgets/
/// ----------------------------------------------------------------------------/

/// the event tables connect the wxWidgets events with the functions/
BEGIN_EVENT_TABLE(MyFrame, wxFrame)
END_EVENT_TABLE()

BEGIN_EVENT_TABLE(MyPanel, wxPanel)
    EVT_PAINT(MyPanel::OnPaint)
END_EVENT_TABLE()

/// Create a new application object/
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(_T("Minimal wxWidgets App"));

    /// show it/
    frame->Show(*true*);

    *return* *true*;
}

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

/// frame constructor/
MyFrame::MyFrame(const wxString& title)
       : wxFrame(NULL, wxID_ANY, title)
{
    MyPanel *panel = *new* MyPanel(*this*);
}


MyPanel::MyPanel( wxWindow* parent)
	: wxPanel( parent, -1,  wxDefaultPosition, parent->GetClientSize())
{
}

void MyPanel::OnPaint(wxPaintEvent& event)
{
	cairo_surface_t *surface;
	cairo_t *cr;
	int width, height;

	GetClientSize(&width,&height);

	surface = create_cairo_surface(*this*, width, height);

	cr = cairo_create(surface);
	
	cairo_set_source_rgb(cr, 1, 1, 1);
	
	cairo_save(cr);
	cairo_set_font_size (cr, 10);
	cairo_move_to (cr, 10, 10);
	//*cairo_rotate(cr, 3.14/ 2);*//
	cairo_show_text (cr, "Hello World.");
	cairo_restore(cr);
	*if* (cairo_status (cr)) {
		printf("Cairo is unhappy: %s\n",
			cairo_status_to_string (cairo_status (cr)));
		exit(0);
	}

 	cairo_destroy(cr);
	cairo_surface_destroy (surface);
}

cairo_surface_t* create_cairo_surface(wxWindow* wxwin, int width, int height)
{
#ifdef __WXGTK__
    GdkWindow * window = gtk_widget_get_parent_window(wxwin->GetHandle());
    *return* cairo_xlib_surface_create(
        GDK_WINDOW_XDISPLAY(window),
        GDK_WINDOW_XID(window),
        GDK_VISUAL_XVISUAL(gdk_drawable_get_visual(window)),
        width,
        height );
#else
    #error This port is not supported by Cairo
#endif
}