docs/latex/wx/tprint.tex

   1 \section{Printing overview}\label{printingoverview}
   2
   3 Classes: \helpref{wxPrintout}{wxprintout},
   4 \helpref{wxPrinter}{wxprinter},
   5 \helpref{wxPrintPreview}{wxprintpreview},
   6 \helpref{wxPrinterDC}{wxprinterdc},
   7 \helpref{wxPrintDialog}{wxprintdialog},
   8 \helpref{wxPrintData}{wxprintdata},
   9 \helpref{wxPrintDialogData}{wxprintdialogdata},
  10 \helpref{wxPageSetupDialog}{wxpagesetupdialog},
  11 \helpref{wxPageSetupDialogData}{wxpagesetupdialogdata}
  12
  13 The printing framework relies on the application to provide classes
  14 whose member functions can respond to particular requests, such
  15 as `print this page' or `does this page exist in the document?'.
  16 This method allows wxWidgets to take over the housekeeping duties of
  17 turning preview pages, calling the print dialog box, creating
  18 the printer device context, and so on: the application can concentrate
  19 on the rendering of the information onto a device context.
  20
  21 The \helpref{document/view framework}{docviewoverview} creates a default
  22 wxPrintout object for every view, calling wxView::OnDraw to achieve a
  23 prepackaged print/preview facility.
  24
  25 A document's printing ability is represented in an application by a
  26 derived wxPrintout class. This class prints a page on request, and can
  27 be passed to the Print function of a wxPrinter object to actually print
  28 the document, or can be passed to a wxPrintPreview object to initiate
  29 previewing. The following code (from the printing sample) shows how easy
  30 it is to initiate printing, previewing and the print setup dialog, once the wxPrintout
  31 functionality has been defined. Notice the use of MyPrintout for
  32 both printing and previewing. All the preview user interface functionality
  33 is taken care of by wxWidgets. For details on how MyPrintout is defined,
  34 please look at the printout sample code.
  35
  36 \begin{verbatim}
  37     case WXPRINT_PRINT:
  38     {
  39       wxPrinter printer;
  40       MyPrintout printout("My printout");
  41       printer.Print(this, &printout, true);
  42       break;
  43     }
  44     case WXPRINT_PREVIEW:
  45     {
  46       // Pass two printout objects: for preview, and possible printing.
  47       wxPrintPreview *preview = new wxPrintPreview(new MyPrintout, new MyPrintout);
  48       wxPreviewFrame *frame = new wxPreviewFrame(preview, this, "Demo Print Preview", wxPoint(100, 100), wxSize(600, 650));
  49       frame->Centre(wxBOTH);
  50       frame->Initialize();
  51       frame->Show(true);
  52       break;
  53     }
  54 \end{verbatim}
  55
  56 \section{Printing under Unix (GTK+)}\label{unixprinting}
  57
  58 Printing under Unix has always been a cause of problems as Unix
  59 does not provide a standard way to display text and graphics
  60 on screen and print it to a printer using the same application
  61 programming interface - instead, displaying on screen is done
  62 via the X11 library while printing has to be done with using
  63 PostScript commands. This was particularly difficult to handle
  64 for the case of fonts with the result that only a selected
  65 number of application could offer WYSIWYG under Unix. Equally,
  66 wxWidgets offered its own printing implementation using PostScript
  67 which never really matched the screen display.
  68
  69 Starting with version 2.8.X, the GNOME project provides printing
  70 support through the libgnomeprint and libgnomeprintui libraries
  71 by which especially the font problem is mostly solved. Beginning
  72 with version 2.5.4, the GTK+ port of wxWidgets can make use of
  73 these libraries if wxWidgets is configured accordingly and if the
  74 libraries are present. You need to configure wxWidgets with the
  75 {\it configure --with-gnomeprint} switch and you application will
  76 then search for the GNOME print libraries at runtime. If they
  77 are found, printing will be done through these, otherwise the
  78 application will fall back to the old PostScript printing code.
  79 Note that the application will not require the GNOME print libraries
  80 to be installed in order to run (there will be no dependency on
  81 these libraries).
  82
  83 It is expected that the printing code that is currently implemented
  84 in the GNOME print libraries will be moved into GTK+ later.
  85