C++ wxString::IsNull方法代码示例

// Original constructor that does not takes origin and extent. If you use this,
// *DO* give origin/extent arguments to wxMakeMetafilePlaceable.
wxMetafileDCImpl::wxMetafileDCImpl(wxDC *owner, const wxString& file)
    : wxMSWDCImpl(owner)
{
    m_metaFile = NULL;
    m_minX = 10000;
    m_minY = 10000;
    m_maxX = -10000;
    m_maxY = -10000;
    //  m_title = NULL;

    if (!file.IsNull() && wxFileExists(file))
        wxRemoveFile(file);

    if (!file.IsNull() && (file != wxEmptyString))
        m_hDC = (WXHDC) CreateMetaFile(file);
    else
        m_hDC = (WXHDC) CreateMetaFile(NULL);

    m_ok = (m_hDC != (WXHDC) 0) ;

    // Actual Windows mapping mode, for future reference.
    m_windowsMappingMode = wxMM_TEXT;

    SetMapMode(wxMM_TEXT); // NOTE: does not set HDC mapmode (this is correct)
}

void wxError( const wxString &msg, const wxString &title )
{
  wxFprintf( stderr, _("Error ") );
  if (!title.IsNull()) wxFprintf( stderr, wxT("%s "), WXSTRINGCAST(title) );
  if (!msg.IsNull()) wxFprintf( stderr, wxT(": %s"), WXSTRINGCAST(msg) );
  wxFprintf( stderr, wxT(".\n") );
}

void wxFatalError( const wxString &msg, const wxString &title )
{
  wxFprintf( stderr, _("Error ") );
  if (!title.IsNull()) wxFprintf( stderr, wxT("%s "), WXSTRINGCAST(title) );
  if (!msg.IsNull()) wxFprintf( stderr, wxT(": %s"), WXSTRINGCAST(msg) );
  wxFprintf( stderr, wxT(".\n") );
  exit(3); // the same exit code as for abort()
}

void wxComboBox::SetValue( const wxString& value )
{
    wxCHECK_RET( m_widget != NULL, wxT("invalid combobox") );

    GtkWidget *entry = GTK_COMBO(m_widget)->entry;
    wxString tmp;
    if (!value.IsNull()) tmp = value;
    gtk_entry_set_text( GTK_ENTRY(entry), wxGTK_CONV( tmp ) );

    InvalidateBestSize();
}

void wxComboBox::Replace( long from, long to, const wxString& value )
{
    wxCHECK_RET( m_widget != NULL, wxT("invalid combobox") );

    GtkWidget *entry = GTK_COMBO(m_widget)->entry;
    gtk_editable_delete_text( GTK_EDITABLE(entry), (gint)from, (gint)to );
    if (value.IsNull()) return;
    gint pos = (gint)to;

#if wxUSE_UNICODE
    wxCharBuffer buffer = wxConvUTF8.cWX2MB( value );
    gtk_editable_insert_text( GTK_EDITABLE(entry), (const char*) buffer, strlen( (const char*) buffer ), &pos );
#else
    gtk_editable_insert_text( GTK_EDITABLE(entry), value.c_str(), value.length(), &pos );
#endif
}

void wxComboBox::SetValue( const wxString& value )
{
    wxCHECK_RET( m_widget != NULL, wxT("invalid combobox") );

    GtkEntry *entry = NULL;
#ifdef __WXGTK24__
    if (!gtk_check_version(2,4,0))
        entry = GTK_ENTRY( GTK_BIN(m_widget)->child );
    else
#endif
        entry = GTK_ENTRY( GTK_COMBO(m_widget)->entry );

    wxString tmp;
    if (!value.IsNull()) tmp = value;
    gtk_entry_set_text( entry, wxGTK_CONV( tmp ) );

    InvalidateBestSize();
}

bool wxDialog::Create(
  wxWindow*                         pParent
, wxWindowID                        vId
, const wxString&                   rsTitle
, const wxPoint&                    rPos
, const wxSize&                     rSize
, long                              lStyle
, const wxString&                   rsName
)
{
    Init();
    SetExtraStyle(GetExtraStyle() | wxTOPLEVEL_EX_DIALOG);

    //
    // Save focus before doing anything which can potentially change it
    //
    m_pOldFocus = FindFocus();

    //
    // All dialogs should really have this style
    //
    lStyle |= wxTAB_TRAVERSAL;

    if (!wxTopLevelWindow::Create( pParent
                                  ,vId
                                  ,rsTitle
                                  ,rPos
                                  ,rSize
                                  ,lStyle
                                  ,rsName
                                 ))
        return FALSE;
    SetFont(wxSystemSettings::GetFont(wxSYS_DEFAULT_GUI_FONT));

    //
    // Must defer setting the title until after dialog is created and sized
    //
    if (!rsTitle.IsNull())
        SetTitle(rsTitle);
    return TRUE;
} // end of wxDialog::Create

wxSoundStreamESD::wxSoundStreamESD(const wxString& hostname)
{
#ifndef HAVE_ESD_H
    m_snderror = wxSOUND_INVDEV;
    return;
#else
    wxSoundFormatPcm pcm_default;

    // First, we make some basic test: is there ESD on this computer ?
    m_esd_ok = false;

    if (hostname.IsNull())
        m_fd_output = esd_play_stream(ESD_PLAY | ESD_STREAM, 22050,
                                      hostname.mb_str(), MY_ESD_NAME);
    else
        m_fd_output = esd_play_stream(ESD_PLAY | ESD_STREAM, 22050,
                                      NULL, MY_ESD_NAME);
    if (m_fd_output == -1) {
        // Answer: no. We return with an error.
        m_snderror = wxSOUND_INVDEV;
        return;
    }

    // Close this unuseful stream.
    esd_close(m_fd_output);

    m_hostname = hostname;

    // Set the default audio format
    SetSoundFormat(pcm_default);

    // Initialize some variable
    m_snderror = wxSOUND_NOERROR;
    m_esd_stop = true;
    m_q_filled = true;
    m_esd_ok   = true;
    m_fd_output= -1;
    m_fd_input = -1;
#endif // defined HAVE_ESD_H
}

void wxComboBox::Replace( long from, long to, const wxString& value )
{
    wxCHECK_RET( m_widget != NULL, wxT("invalid combobox") );

    GtkEntry *entry = NULL;
#ifdef __WXGTK24__
    if (!gtk_check_version(2,4,0))
        entry = GTK_ENTRY( GTK_BIN(m_widget)->child );
    else
#endif
        entry = GTK_ENTRY( GTK_COMBO(m_widget)->entry );

    gtk_editable_delete_text( GTK_EDITABLE(entry), (gint)from, (gint)to );
    if (value.IsNull()) return;
    gint pos = (gint)to;

#if wxUSE_UNICODE
    wxCharBuffer buffer = wxConvUTF8.cWX2MB( value );
    gtk_editable_insert_text( GTK_EDITABLE(entry), (const char*) buffer, strlen( (const char*) buffer ), &pos );
#else
    gtk_editable_insert_text( GTK_EDITABLE(entry), value.c_str(), value.length(), &pos );
#endif
}

bool wxMatrix2D::LoadFile( const wxString &filename, const wxArrayInt *cols )
{
    if (filename.IsNull()) return false;

    // valid separators for data
//  const char comma = 44;  // comma
    const char tab = 9;     // tab
    const char space = 32;  // space
//  const char cr = 13;     // carrage return

    wxFile loadfile;
    loadfile.Open( filename, wxFile::read );

    if (!loadfile.IsOpened()) return false;

    m_file_comments.Clear();
//  m_file_comments_positions.Clear();

    wxFileInputStream filestream( loadfile );
    wxTextInputStream textstream( filestream );

    int sizeof_data = 4000;
    double *data = (double*)malloc(sizeof_data*sizeof(double));
    if (data == (double*)NULL) return false;

    wxString line_str, num_str;

    int i, a, b, pos;
    int num_cols = 0;
    int num_rows = 0;
    int num_points = 0;
    int num_lines = 0;
    double point;

    bool fail = false;


    while ( !filestream.Eof() && !fail )
    {
        ++num_lines;

        line_str = textstream.ReadLine();
        if ( filestream.Eof() ) break;

        line_str.Trim(false);
        line_str.Trim(true);


        if (line_str.Left(1) == wxT("#"))
        {
            m_file_comments.Add( line_str );
            //m_file_comments_positions.Add(num_lines);
        }
        else
        {
            ++num_rows;

            // do this once to figure out how many columns of data there is unless already given
            if ( num_cols < 1 )
            {
                for (i = 0; i < 10000; ++i)
                {
                    line_str.Trim(false);
                    a = line_str.Find(space);
                    b = line_str.Find(tab);

                    if ( (a != -1) && (b != -1) ) pos = wxMin( a, b );
                    else if ( a != -1 ) pos = a;
                    else pos = b;

                    if ( pos != -1 ) num_str = line_str.Left( pos );
                    else num_str = line_str;

                    if ( num_str.ToDouble(&point) )
                    {
                        printf("i%d pts%d cols%d rows%d pos%d pt%lf \n", i, num_points, num_cols, num_rows, pos, point); fflush(stdout);
                        //data[i] = point;
                        ++num_cols;
                        line_str = line_str.Right( line_str.Len() - num_str.Len() );
                        ++num_points;
                    }
                    else
                    {
                        i = 10000;
                        break;
                    }
                }
            }
            else
            {
                if ( num_points > sizeof_data - num_cols*2 )
                {
                    data = (double*)realloc( data, sizeof_data+1000 );
                }
                for (i = 0; i < num_cols; ++i)
                {
                    line_str.Trim(false);
                    a = line_str.Find(space);
                    b = line_str.Find(tab);

//.........这里部分代码省略.........

bool wxTextCtrl::Create(wxWindow *parent,
                        wxWindowID id,
                        const wxString& value,
                        const wxPoint& pos,
                        const wxSize& size,
                        long style,
                        const wxValidator& validator,
                        const wxString& name)
{
    if( !CreateControl( parent, id, pos, size, style, validator, name ) )
        return false;
    PreCreation();

    m_tempCallbackStruct = NULL;
    m_modified = false;
    m_processedDefault = false;

    Widget parentWidget = (Widget) parent->GetClientWidget();

    Bool wantHorizScroll = (m_windowStyle & wxHSCROLL) != 0 ? True : False;
    // If we don't have horizontal scrollbars, we want word wrap.
    // OpenMotif 2.1 crashes if wantWordWrap is True in Japanese
    // locale (and probably other multibyte locales). The check might be
    // more precise
#if wxCHECK_LESSTIF() || wxCHECK_MOTIF_VERSION( 2, 2 )
    Bool wantWordWrap = wantHorizScroll == True ? False : True;
#else
    Bool wantWordWrap = False;
#endif

    if (m_windowStyle & wxTE_MULTILINE)
    {
        Arg args[8];
        int count = 0;
        XtSetArg (args[count], XmNscrollHorizontal, wantHorizScroll); ++count;
        if( m_font.IsOk() )
            XtSetArg (args[count], (String) wxFont::GetFontTag(),
                      m_font.GetFontType( XtDisplay(parentWidget) ) ); ++count;
        XtSetArg (args[count], XmNwordWrap, wantWordWrap); ++count;
        XtSetArg (args[count], XmNvalue, (const char*)value.mb_str()); ++count;
        XtSetArg (args[count], XmNeditable,
                  style & wxTE_READONLY ? False : True); ++count;
        XtSetArg (args[count], XmNeditMode, XmMULTI_LINE_EDIT ); ++count;

        m_mainWidget =
            (WXWidget) XmCreateScrolledText(parentWidget,
                                            name.char_str(),
                                            args, count);

        XtManageChild ((Widget) m_mainWidget);
    }
    else
    {
        m_mainWidget = (WXWidget)XtVaCreateManagedWidget
                                 (
                                  name.mb_str(),
                                  xmTextWidgetClass,
                                  parentWidget,
                                  wxFont::GetFontTag(), m_font.GetFontType( XtDisplay(parentWidget) ),
                                  XmNvalue, (const char*)value.mb_str(),
                                  XmNeditable, (style & wxTE_READONLY) ?
                                      False : True,
                                  NULL
                                 );

#if 0
        // TODO: Is this relevant? What does it do?
        int noCols = 2;
        if (!value.IsNull() && (value.length() > (unsigned int) noCols))
            noCols = value.length();
        XtVaSetValues((Widget) m_mainWidget,
                      XmNcolumns, noCols,
                      NULL);
#endif
    }

    // remove border if asked for
    if ( style & wxNO_BORDER )
    {
        XtVaSetValues((Widget)m_mainWidget,
                      XmNshadowThickness, 0,
                      NULL);
    }

    // install callbacks
    XtAddCallback((Widget) m_mainWidget, XmNvalueChangedCallback, (XtCallbackProc)wxTextWindowChangedProc, (XtPointer)this);

    XtAddCallback((Widget) m_mainWidget, XmNmodifyVerifyCallback, (XtCallbackProc)wxTextWindowModifyProc, (XtPointer)this);

    XtAddCallback((Widget) m_mainWidget, XmNactivateCallback, (XtCallbackProc)wxTextWindowActivateProc, (XtPointer)this);

    XtAddCallback((Widget) m_mainWidget, XmNfocusCallback, (XtCallbackProc)wxTextWindowGainFocusProc, (XtPointer)this);

    XtAddCallback((Widget) m_mainWidget, XmNlosingFocusCallback, (XtCallbackProc)wxTextWindowLoseFocusProc, (XtPointer)this);

    PostCreation();
    AttachWidget (parent, m_mainWidget, (WXWidget) NULL,
                  pos.x, pos.y, size.x, size.y);

    return true;
//.........这里部分代码省略.........

void AppendIfFilled(wxString &str, const wxString &delimiter, const wxString &what)
{
	if (!what.IsNull())
		str += delimiter + what;
}

// This form is deprecated
wxPrinterDC::wxPrinterDC(
  const wxString&                   rsDriverName
, const wxString&                   rsDeviceName
, const wxString&                   rsFile
, bool                              bInteractive
, int                               nOrientation
)
{
    DEVOPENSTRUC    vDevOpen = { (char*)rsDeviceName.c_str()
                                ,(char*)rsDriverName.c_str()
                                ,NULL
                                ,NULL
                                ,NULL
                                ,NULL
                                ,NULL
                                ,NULL
                                ,NULL
                               };

    m_isInteractive = bInteractive;

    if (!rsFile.IsNull() && rsFile != wxT(""))
        m_printData.SetFilename(rsFile);

/*
    Implement PM's version of this
#if wxUSE_COMMON_DIALOGS
    if (interactive)
    {
        PRINTDLG pd;

        pd.lStructSize = sizeof( PRINTDLG );
        pd.hwndOwner=(HWND) NULL;
        pd.hDevMode=(HANDLE)NULL;
        pd.hDevNames=(HANDLE)NULL;
        pd.Flags=PD_RETURNDC | PD_NOSELECTION | PD_NOPAGENUMS;
        pd.nFromPage=0;
        pd.nToPage=0;
        pd.nMinPage=0;
        pd.nMaxPage=0;
        pd.nCopies=1;
        pd.hInstance=(HINSTANCE)NULL;

        if ( PrintDlg( &pd ) != 0 )
        {
            m_hDC = (WXHDC) pd.hDC;
            m_ok = TRUE;
        }
        else
        {
            m_ok = FALSE;
            return;
        }

        //     m_dontDelete = TRUE;
    }
    else
#endif
*/
        if ((!rsDriverName.IsNull() && rsDriverName != wxT("")) &&
            (!rsDeviceName.IsNull() && rsDeviceName != wxT("")) &&
            (!rsFile.IsNull() && rsFile != wxT("")))
        {
            m_hDC = (WXHDC) ::DevOpenDC( vHabmain
                                        ,OD_QUEUED
                                        ,"*"
                                        ,5L
                                        ,(PDEVOPENDATA)&vDevOpen
                                        ,NULLHANDLE
                                       );
            m_ok = m_hDC ? TRUE: FALSE;
        }
        else
        {
            wxPrintData             vPrintData;

            vPrintData.SetOrientation(nOrientation);
            m_hDC = wxGetPrinterDC(vPrintData);
            m_ok = m_hDC ? TRUE: FALSE;
        }

        if (m_hDC)
        {
            //     int width = GetDeviceCaps(m_hDC, VERTRES);
            //     int height = GetDeviceCaps(m_hDC, HORZRES);
            SetMapMode(wxMM_TEXT);
        }
        SetBrush(*wxBLACK_BRUSH);
        SetPen(*wxBLACK_PEN);
} // end of wxPrinterDC::wxPrinterDC