GtkPrintContext

GtkPrintContext — Encapsulates context for drawing pages

Synopsis


#include <gtk/gtk.h>


                    GtkPrintContext;
cairo_t*            gtk_print_context_get_cairo_context (GtkPrintContext *context);
void                gtk_print_context_set_cairo_context (GtkPrintContext *context,
                                                         cairo_t *cr,
                                                         double dpi_x,
                                                         double dpi_y);
GtkPageSetup*       gtk_print_context_get_page_setup    (GtkPrintContext *context);
gdouble             gtk_print_context_get_width         (GtkPrintContext *context);
gdouble             gtk_print_context_get_height        (GtkPrintContext *context);
gdouble             gtk_print_context_get_dpi_x         (GtkPrintContext *context);
gdouble             gtk_print_context_get_dpi_y         (GtkPrintContext *context);
PangoFontMap*       gtk_print_context_get_pango_fontmap (GtkPrintContext *context);
PangoContext*       gtk_print_context_create_pango_context
                                                        (GtkPrintContext *context);
PangoLayout*        gtk_print_context_create_pango_layout
                                                        (GtkPrintContext *context);

Object Hierarchy


  GObject
   +----GtkPrintContext

Description

A GtkPrintContext encapsulates context information that is required when drawing pages for printing, such as the cairo context and important parameters like page size and resolution. It also lets you easily create PangoLayout and PangoContext objects that match the font metrics of the cairo surface.

GtkPrintContext objects gets passed to the ::begin-print, ::end-print, ::request-page-setup and ::draw-page signals on the GtkPrintOperation.

Example 40. Using GtkPrintContext in a ::draw-page callback

static void
draw_page (GtkPrintOperation *operation,
	   GtkPrintContext   *context,
	   int                page_nr)
{
  cairo_t *cr;
  PangoLayout *layout;
  PangoFontDescription *desc;
  
  cr = gtk_print_context_get_cairo_context (context);

  /* Draw a red rectangle, as wide as the paper (inside the margins) */
  cairo_set_source_rgb (cr, 1.0, 0, 0);
  cairo_rectangle (cr, 0, 0, gtk_print_context_get_width (context), 50);
  
  cairo_fill (cr);

  /* Draw some lines */
  cairo_move_to (cr, 20, 10);
  cairo_line_to (cr, 40, 20);
  cairo_arc (cr, 60, 60, 20, 0, M_PI);
  cairo_line_to (cr, 80, 20);
  
  cairo_set_source_rgb (cr, 0, 0, 0);
  cairo_set_line_width (cr, 5);
  cairo_set_line_cap (cr, CAIRO_LINE_CAP_ROUND);
  cairo_set_line_join (cr, CAIRO_LINE_JOIN_ROUND);
  
  cairo_stroke (cr);

  /* Draw some text */ 
  layout = gtk_print_context_create_layout (context);
  pango_layout_set_text (layout, "Hello World! Printing is easy", -1);
  desc = pango_font_description_from_string ("sans 28");
  pango_layout_set_font_description (layout, desc);
  pango_font_description_free (desc);

  cairo_move_to (cr, 30, 20);
  pango_cairo_layout_path (cr, layout);

  /* Font Outline */
  cairo_set_source_rgb (cr, 0.93, 1.0, 0.47);
  cairo_set_line_width (cr, 0.5);
  cairo_stroke_preserve (cr);

  /* Font Fill */
  cairo_set_source_rgb (cr, 0, 0.0, 1.0);
  cairo_fill (cr);
  
  g_object_unref (layout);
}

Printing support was added in GTK+ 2.10.

Details

GtkPrintContext

typedef struct _GtkPrintContext GtkPrintContext;

gtk_print_context_get_cairo_context ()

cairo_t*            gtk_print_context_get_cairo_context (GtkPrintContext *context);

Obtains the cairo context that is associated with the GtkPrintContext.

context : a GtkPrintContext
Returns : the cairo context of context

Since 2.10

gtk_print_context_set_cairo_context ()

void                gtk_print_context_set_cairo_context (GtkPrintContext *context,
                                                         cairo_t *cr,
                                                         double dpi_x,
                                                         double dpi_y);

Sets a new cairo context on a print context.

This function is intended to be used when implementing an internal print preview, it is not needed for printing, since GTK+ itself creates a suitable cairo context in that case.

context : a GtkPrintContext
cr : the cairo context
dpi_x : the horizontal resolution to use with cr
dpi_y : the vertical resolution to use with cr

Since 2.10

gtk_print_context_get_page_setup ()

GtkPageSetup*       gtk_print_context_get_page_setup    (GtkPrintContext *context);

Obtains the GtkPageSetup that determines the page dimensions of the GtkPrintContext.

context : a GtkPrintContext
Returns : the page setup of context

Since 2.10

gtk_print_context_get_width ()

gdouble             gtk_print_context_get_width         (GtkPrintContext *context);

Obtains the width of the GtkPrintContext, in pixels.

context : a GtkPrintContext
Returns : the width of context

Since 2.10

gtk_print_context_get_height ()

gdouble             gtk_print_context_get_height        (GtkPrintContext *context);

Obtains the height of the GtkPrintContext, in pixels.

context : a GtkPrintContext
Returns : the height of context

Since 2.10

gtk_print_context_get_dpi_x ()

gdouble             gtk_print_context_get_dpi_x         (GtkPrintContext *context);

Obtains the horizontal resolution of the GtkPrintContext, in dots per inch.

context : a GtkPrintContext
Returns : the horizontal resolution of context

Since 2.10

gtk_print_context_get_dpi_y ()

gdouble             gtk_print_context_get_dpi_y         (GtkPrintContext *context);

Obtains the vertical resolution of the GtkPrintContext, in dots per inch.

context : a GtkPrintContext
Returns : the vertical resolution of context

Since 2.10

gtk_print_context_get_pango_fontmap ()

PangoFontMap*       gtk_print_context_get_pango_fontmap (GtkPrintContext *context);

Returns a PangoFontMap that is suitable for use with the GtkPrintContext.

context : a GtkPrintContext
Returns : the font map of context

Since 2.10

gtk_print_context_create_pango_context ()

PangoContext*       gtk_print_context_create_pango_context
                                                        (GtkPrintContext *context);

Creates a new PangoContext that can be used with the GtkPrintContext.

context : a GtkPrintContext
Returns : a new Pango context for context

Since 2.10

gtk_print_context_create_pango_layout ()

PangoLayout*        gtk_print_context_create_pango_layout
                                                        (GtkPrintContext *context);

Creates a new PangoLayout that is suitable for use with the GtkPrintContext.

context : a GtkPrintContext
Returns : a new Pango layout for context

Since 2.10