Struct gtk4::PrintContext

#[repr(transparent)]
pub struct PrintContext { /* private fields */ }

A 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.

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

Using GtkPrintContext in a ::draw-page callback

⚠️ The following code is in c ⚠️

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);
}

Implements

glib::ObjectExt

Implementations

impl PrintContext

pub fn create_pango_context(&self) -> Context

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

Returns

a new Pango context for @self

pub fn create_pango_layout(&self) -> Layout

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

Returns

a new Pango layout for @self

pub fn cairo_context(&self) -> Context

Obtains the cairo context that is associated with the PrintContext.

Returns

the cairo context of @self

pub fn dpi_x(&self) -> f64

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

Returns

the horizontal resolution of @self

pub fn dpi_y(&self) -> f64

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

Returns

the vertical resolution of @self

pub fn hard_margins(&self) -> Option<(f64, f64, f64, f64)>

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

Returns

true if the hard margins were retrieved

top

top hardware printer margin

bottom

bottom hardware printer margin

left

left hardware printer margin

right

right hardware printer margin

pub fn height(&self) -> f64

Obtains the height of the PrintContext, in pixels.

Returns

the height of @self

pub fn page_setup(&self) -> PageSetup

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

Returns

the page setup of @self

pub fn pango_fontmap(&self) -> FontMap

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

Returns

the font map of @self

pub fn width(&self) -> f64

Obtains the width of the PrintContext, in pixels.

Returns

the width of @self

pub fn set_cairo_context(&self, cr: &Context, dpi_x: f64, dpi_y: f64)

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.

cr

the cairo context

dpi_x

the horizontal resolution to use with @cr

dpi_y

the vertical resolution to use with @cr

Trait Implementations

impl Clone for PrintContext

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for PrintContext

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for PrintContext

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Hash for PrintContext

fn hash<H>(&self, state: &mut H)where H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for PrintContext

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Selfwhere Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Selfwhere Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Selfwhere Self: Sized + PartialOrd<Self>,

Restrict a value to a certain interval.

impl ParentClassIs for PrintContext

type Parent = Object

impl<OT: ObjectType> PartialEq<OT> for PrintContext

fn eq(&self, other: &OT) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<OT: ObjectType> PartialOrd<OT> for PrintContext

fn partial_cmp(&self, other: &OT) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl StaticType for PrintContext

fn static_type() -> Type

Returns the type identifier of Self.

impl Eq for PrintContext