PrintContext
open class PrintContext : GLibObject.Object, PrintContextProtocol
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 GtkPrintOperation::begin-print
,
GtkPrintOperation::end-print
, GtkPrintOperation::request-page-setup
and
GtkPrintOperation::draw-page
signals on the GtkPrintOperation
.
Using GtkPrintContext in a GtkPrintOperation::draw-page
callback
(C Language Example):
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);
}
Printing support was added in GTK+ 2.10.
The PrintContext
type acts as a reference-counted owner of an underlying GtkPrintContext
instance.
It provides the methods that can operate on this data type through PrintContextProtocol
conformance.
Use PrintContext
as a strong reference or owner of a GtkPrintContext
instance.
-
Designated initialiser from the underlying `C` data type.
This creates an instance without performing an unbalanced retain i.e., ownership is transferred to the
PrintContext
instance.Declaration
Swift
@inlinable public init(_ op: UnsafeMutablePointer<GtkPrintContext>)
Parameters
op
pointer to the underlying object
-
Designated initialiser from a constant pointer to the underlying
C
data type. This creates an instance without performing an unbalanced retain i.e., ownership is transferred to thePrintContext
instance.Declaration
Swift
@inlinable public init(_ op: UnsafePointer<GtkPrintContext>)
Parameters
op
pointer to the underlying object
-
Optional initialiser from a non-mutating
gpointer
to the underlyingC
data type. This creates an instance without performing an unbalanced retain i.e., ownership is transferred to thePrintContext
instance.Declaration
Swift
@inlinable override public init!(gpointer op: gpointer?)
Parameters
op
gpointer to the underlying object
-
Optional initialiser from a non-mutating
gconstpointer
to the underlyingC
data type. This creates an instance without performing an unbalanced retain i.e., ownership is transferred to thePrintContext
instance.Declaration
Swift
@inlinable override public init!(gconstpointer op: gconstpointer?)
Parameters
op
pointer to the underlying object
-
Optional initialiser from a constant pointer to the underlying
C
data type. This creates an instance without performing an unbalanced retain i.e., ownership is transferred to thePrintContext
instance.Declaration
Swift
@inlinable public init!(_ op: UnsafePointer<GtkPrintContext>?)
Parameters
op
pointer to the underlying object
-
Optional initialiser from the underlying
C
data type. This creates an instance without performing an unbalanced retain i.e., ownership is transferred to thePrintContext
instance.Declaration
Swift
@inlinable public init!(_ op: UnsafeMutablePointer<GtkPrintContext>?)
Parameters
op
pointer to the underlying object
-
Designated initialiser from the underlying
C
data type. Will retainGtkPrintContext
. i.e., ownership is transferred to thePrintContext
instance.Declaration
Swift
@inlinable public init(retaining op: UnsafeMutablePointer<GtkPrintContext>)
Parameters
op
pointer to the underlying object
-
Reference intialiser for a related type that implements
PrintContextProtocol
Will retainGtkPrintContext
.Declaration
Swift
@inlinable public init<T>(printContext other: T) where T : PrintContextProtocol
Parameters
other
an instance of a related type that implements
PrintContextProtocol
-
Unsafe typed initialiser. Do not use unless you know the underlying data type the pointer points to conforms to
PrintContextProtocol
.Declaration
Swift
@inlinable override public init<T>(cPointer p: UnsafeMutablePointer<T>)
Parameters
cPointer
pointer to the underlying object
-
Unsafe typed, retaining initialiser. Do not use unless you know the underlying data type the pointer points to conforms to
PrintContextProtocol
.Declaration
Swift
@inlinable override public init<T>(retainingCPointer cPointer: UnsafeMutablePointer<T>)
Parameters
cPointer
pointer to the underlying object
-
Unsafe untyped initialiser. Do not use unless you know the underlying data type the pointer points to conforms to
PrintContextProtocol
.Declaration
Swift
@inlinable override public init(raw p: UnsafeRawPointer)
Parameters
p
raw pointer to the underlying object
-
Unsafe untyped, retaining initialiser. Do not use unless you know the underlying data type the pointer points to conforms to
PrintContextProtocol
.Declaration
Swift
@inlinable override public init(retainingRaw raw: UnsafeRawPointer)
-
Unsafe untyped initialiser. Do not use unless you know the underlying data type the pointer points to conforms to
PrintContextProtocol
.Declaration
Swift
@inlinable public required init(raw p: UnsafeMutableRawPointer)
Parameters
p
mutable raw pointer to the underlying object
-
Unsafe untyped, retaining initialiser. Do not use unless you know the underlying data type the pointer points to conforms to
PrintContextProtocol
.Declaration
Swift
@inlinable required public init(retainingRaw raw: UnsafeMutableRawPointer)
Parameters
raw
mutable raw pointer to the underlying object
-
Unsafe untyped initialiser. Do not use unless you know the underlying data type the pointer points to conforms to
PrintContextProtocol
.Declaration
Swift
@inlinable override public init(opaquePointer p: OpaquePointer)
Parameters
p
opaque pointer to the underlying object
-
Unsafe untyped, retaining initialiser. Do not use unless you know the underlying data type the pointer points to conforms to
PrintContextProtocol
.Declaration
Swift
@inlinable override public init(retainingOpaquePointer p: OpaquePointer)
Parameters
p
opaque pointer to the underlying object