class Gtk::PrintContext

• Gtk::PrintContext
• GObject::Object
• Reference
• Object

Overview

A Gtk::PrintContext encapsulates context information that is required when drawing pages for printing.

This includes the cairo context and important parameters like page size and resolution. It also lets you easily create Pango::Layout and Pango::Context objects that match the font metrics of the cairo surface.

Gtk::PrintContext objects get passed to the [signal@Gtk.PrintOperation::begin-print], [signal@Gtk.PrintOperation::end-print], [signal@Gtk.PrintOperation::request-page-setup] and [signal@Gtk.PrintOperation::draw-page] signals on the Gtk::PrintOperation object.

Using Gtk::PrintContext in a ::draw-page callback

WARNING ⚠️ The following code is in c ⚠️

static void
draw_page (Gtk::PrintOperation *operation,
           Gtk::PrintContext   *context,
           int                page_nr)
{
  cairo_::t *cr;
  Pango::Layout *layout;
  Pango::FontDescription *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_pango_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);
}

Defined in:

Constructors

• .new

  Initialize a new PrintContext.

Class Method Summary

• .g_type : UInt64

  Returns the type id (GType) registered in GLib type system.

Instance Method Summary

• #==(other : self)

  Returns true if this reference is the same as other.

• #cairo_context : Cairo::Context

  Obtains the cairo context that is associated with the Gtk::PrintContext.

• #create_pango_context : Pango::Context

  Creates a new Pango::Context that can be used with the Gtk::PrintContext.

• #create_pango_layout : Pango::Layout

  Creates a new Pango::Layout that is suitable for use with the Gtk::PrintContext.

• #dpi_x : Float64

  Obtains the horizontal resolution of the Gtk::PrintContext, in dots per inch.

• #dpi_y : Float64

  Obtains the vertical resolution of the Gtk::PrintContext, in dots per inch.

• #hard_margins(top : Float64, bottom : Float64, left : Float64, right : Float64) : Bool

  Obtains the hardware printer margins of the Gtk::PrintContext, in units.

• #hash(hasher)

  See Object#hash(hasher)

• #height : Float64

  Obtains the height of the Gtk::PrintContext, in pixels.

• #page_setup : Gtk::PageSetup

  Obtains the Gtk::PageSetup that determines the page dimensions of the Gtk::PrintContext.

• #pango_fontmap : Pango::FontMap

  Returns a Pango::FontMap that is suitable for use with the Gtk::PrintContext.

• #set_cairo_context(cr : Cairo::Context, dpi_x : Float64, dpi_y : Float64) : Nil

  Sets a new cairo context on a print context.

• #width : Float64

  Obtains the width of the Gtk::PrintContext, in pixels.

Constructor Detail

Class Method Detail

Instance Method Detail