Class PrintContext

java.lang.Object
org.javagi.base.ProxyInstance
org.gnome.gobject.TypeInstance
org.gnome.gobject.GObject
org.gnome.gtk.PrintContext
All Implemented Interfaces:
Proxy
@Generated("org.javagi.JavaGI") public class PrintContext extends GObject

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 Layout and Context objects that match the font metrics of the cairo surface.

GtkPrintContext objects get passed to the Gtk.PrintOperation::begin-print, Gtk.PrintOperation::end-print, Gtk.PrintOperation::request-page-setup and Gtk.PrintOperation::draw-page signals on the PrintOperation object.

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_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);
}

  • Constructor Details

    • PrintContext

      public PrintContext(MemorySegment address)
      Create a PrintContext instance for the provided memory address.
      Parameters:
      address - the memory address of the native object

    • PrintContext

      public PrintContext()
      Create a new PrintContext.

  • Method Details

    • getType

      public static @Nullable Type getType()
      Get the GType of the PrintContext class.
      Returns:
      the GType

    • getMemoryLayout

      public static MemoryLayout getMemoryLayout()
      The memory layout of the native struct.
      Returns:
      the memory layout

    • asParent

      protected PrintContext asParent()
      Return this instance as if it were its parent type. Comparable to the Java super keyword, but ensures the parent typeclass is also used in native code.
      Overrides:
      asParent in class GObject
      Returns:
      the instance as if it were its parent type

    • createPangoContext

      public Context createPangoContext()
      Creates a new PangoContext that can be used with the GtkPrintContext.
      Returns:
      a new Pango context for this PrintContext

    • createPangoLayout

      public Layout createPangoLayout()
      Creates a new PangoLayout that is suitable for use with the GtkPrintContext.
      Returns:
      a new Pango layout for this PrintContext

    • getCairoContext

      public org.freedesktop.cairo.Context getCairoContext()
      Obtains the cairo context that is associated with the GtkPrintContext.
      Returns:
      the cairo context of this PrintContext

    • getDpiX

      public double getDpiX()
      Obtains the horizontal resolution of the GtkPrintContext, in dots per inch.
      Returns:
      the horizontal resolution of this PrintContext

    • getDpiY

      public double getDpiY()
      Obtains the vertical resolution of the GtkPrintContext, in dots per inch.
      Returns:
      the vertical resolution of this PrintContext

    • getHardMargins

      public boolean getHardMargins(Out<Double> top, Out<Double> bottom, Out<Double> left, Out<Double> right)
      Obtains the hardware printer margins of the GtkPrintContext, in units.
      Parameters:
      top - top hardware printer margin
      bottom - bottom hardware printer margin
      left - left hardware printer margin
      right - right hardware printer margin
      Returns:
      true if the hard margins were retrieved

    • getHeight

      public double getHeight()
      Obtains the height of the GtkPrintContext, in pixels.
      Returns:
      the height of this PrintContext

    • getPageSetup

      public PageSetup getPageSetup()
      Obtains the GtkPageSetup that determines the page dimensions of the GtkPrintContext.
      Returns:
      the page setup of this PrintContext

    • getPangoFontmap

      public FontMap getPangoFontmap()
      Returns a PangoFontMap that is suitable for use with the GtkPrintContext.
      Returns:
      the font map of this PrintContext

    • getWidth

      public double getWidth()
      Obtains the width of the GtkPrintContext, in pixels.
      Returns:
      the width of this PrintContext

    • setCairoContext

      public void setCairoContext(org.freedesktop.cairo.Context cr, double dpiX, double dpiY)

      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.

      Parameters:
      cr - the cairo context
      dpiX - the horizontal resolution to use with cr
      dpiY - the vertical resolution to use with cr

    • builder

      public static PrintContext.Builder<? extends PrintContext.Builder> builder()
      A PrintContext.Builder object constructs a PrintContext with the specified properties. Use the various set...() methods to set properties, and finish construction with PrintContext.Builder.build().
      Returns:
      the builder object