Pango::LayoutLine Class Reference

A Pango::LayoutLine represents one of the lines resulting from laying out a paragraph via Pango::Layout. More...

#include <pangomm/layoutline.h>

Public Member Functions
void	reference () const
	Increment the reference count for this object.
void	unreference () const
	Decrement the reference count for this object.
PangoLayoutLine *	gobj ()
	Provides access to the underlying C instance.
const PangoLayoutLine *	gobj () const
	Provides access to the underlying C instance.
PangoLayoutLine *	gobj_copy () const
	Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.
	LayoutLine ()=delete
	LayoutLine (const LayoutLine &)=delete
LayoutLine &	operator= (const LayoutLine &)=delete
bool	is_paragraph_start () const
	Returns whether this is the first line of the paragraph.
Direction	get_resolved_direction () const
	Returns the resolved direction of the line.
bool	x_to_index (int x_pos, int & index, int &trailing) const
	Converts from x offset to the byte index of the corresponding character within the text of the layout.
int	index_to_x (int index, bool trailing) const
	Converts an index within a line to a x position.
std::vector< std::pair< int, int > >	get_x_ranges (int start_index, int end_index) const
	Get a list of visual ranges corresponding to a given logical range.
void	get_extents (Rectangle &ink_rect, Rectangle &logical_rect) const
	Compute the logical and ink extents of a layout line.
int	get_height () const
	Computes the height of the line, as the maximum of the heights of fonts used in this line.
Rectangle	get_ink_extents () const
	Compute the ink extents of a layout line.
Rectangle	get_logical_extents () const
	Compute the logical extents of a layout line.
void	get_pixel_extents (Rectangle &ink_rect, Rectangle &logical_rect) const
	Compute the logical and ink extents of a layout line.
Rectangle	get_pixel_ink_extents () const
	Compute the ink extents of a layout line in device units.
Rectangle	get_pixel_logical_extents () const
	Compute the logical extents of a layout line in device units.
void	show_in_cairo_context (const Cairo::RefPtr< Cairo::Context > &context)
	Draws this LayoutLine in the specified Cairo context.
void	add_to_cairo_context (const Cairo::RefPtr< Cairo::Context > &context)
	Adds the text in this LayoutLine to the current path in the specified Cairo context.
Glib::RefPtr< Pango::Layout >	get_layout ()
Glib::RefPtr< const Pango::Layout >	get_layout () const
int	get_length () const
int	get_start_index () const

Protected Member Functions
void	operator delete (void *, std::size_t)

Related Symbols
(Note that these are not member symbols.)
Glib::RefPtr< Pango::LayoutLine >	wrap (PangoLayoutLine *object, bool take_copy=false)
	A Glib::wrap() method for this object.

Detailed Description

A Pango::LayoutLine represents one of the lines resulting from laying out a paragraph via Pango::Layout.

Pango::LayoutLine objects are obtained by calling Pango::Layout::get_line() and are only valid until the text, attributes, or settings of the parent Pango::Layout are modified. Routines for rendering Pango::Layout objects are provided in code specific to each rendering system.

Constructor & Destructor Documentation

LayoutLine() [1/2]

Pango::LayoutLine::LayoutLine ( )

delete

LayoutLine() [2/2]

Pango::LayoutLine::LayoutLine ( const LayoutLine &  )

delete

Member Function Documentation

add_to_cairo_context()

void Pango::LayoutLine::add_to_cairo_context

(

const Cairo::RefPtr< Cairo::Context > &

context

)

Adds the text in this LayoutLine to the current path in the specified Cairo context.

The origin of the glyphs (the left edge of the line) will be at the current point of the cairo context.

Parameters

context

A Cairo context.

get_extents()

void Pango::LayoutLine::get_extents	(	Rectangle &	ink_rect,
		Rectangle &	logical_rect
	)		const

Compute the logical and ink extents of a layout line.

See the documentation for Pango::Font::get_glyph_extents() for details about the interpretation of the rectangles.

Parameters

ink_rect	Rectangle used to store the extents of the glyph string as drawn.
logical_rect	Rectangle used to store the logical extents of the glyph string.

get_height()

int Pango::LayoutLine::get_height

(

)

const

Computes the height of the line, as the maximum of the heights of fonts used in this line.

Note that the actual baseline-to-baseline distance between lines of text is influenced by other factors, such as Pango::Layout::set_spacing() and Pango::Layout::set_line_spacing().

Since pangomm 2.54:

Returns

Line height.

get_ink_extents()

Rectangle Pango::LayoutLine::get_ink_extents

(

)

const

Compute the ink extents of a layout line.

Returns

The extents of the layout line as drawn.

get_layout() [1/2]

Glib::RefPtr< Pango::Layout > Pango::LayoutLine::get_layout

(

)

get_layout() [2/2]

Glib::RefPtr< const Pango::Layout > Pango::LayoutLine::get_layout

(

)

const

get_length()

int Pango::LayoutLine::get_length

(

)

const

get_logical_extents()

Rectangle Pango::LayoutLine::get_logical_extents

(

)

const

Compute the logical extents of a layout line.

Returns

The logical extents of the layout line.

get_pixel_extents()

void Pango::LayoutLine::get_pixel_extents	(	Rectangle &	ink_rect,
		Rectangle &	logical_rect
	)		const

Compute the logical and ink extents of a layout line.

See the documentation for Pango::Font::get_glyph_extents() for details about the interpretation of the rectangles. The returned rectangles are in device units, as opposed to get_extents(), which returns the extents in units of device unit / PANGO_SCALE.

Parameters

ink_rect	Rectangle used to store the extents of the glyph string as drawn.
logical_rect	Rectangle used to store the logical extents of the glyph string.

get_pixel_ink_extents()

Rectangle Pango::LayoutLine::get_pixel_ink_extents

(

)

const

Compute the ink extents of a layout line in device units.

Returns

The extents of the layout line as drawn.

get_pixel_logical_extents()

Rectangle Pango::LayoutLine::get_pixel_logical_extents

(

)

const

Compute the logical extents of a layout line in device units.

Returns

The logical extents of the layout line.

get_resolved_direction()

Direction Pango::LayoutLine::get_resolved_direction

(

)

const

Returns the resolved direction of the line.

Since pangomm 2.54:

Returns

The resolved direction of the line.

get_start_index()

int Pango::LayoutLine::get_start_index

(

)

const

get_x_ranges()

std::vector< std::pair< int, int > > Pango::LayoutLine::get_x_ranges	(	int	start_index,
		int	end_index
	)		const

Get a list of visual ranges corresponding to a given logical range.

This list is not necessarily minimal - there may be consecutive ranges which are adjacent. The ranges will be sorted from left to right. The ranges are with respect to the left edge of the entire layout, not with respect to the line.

Parameters

start_index	The start byte index of the logical range. If the value of start_index is less than the start index for the line, then the first range will extend all the way to the leading edge of the layout. Otherwise it will start at the leading edge of the first character.
end_index	The end byte index of the logical range. If the value of end_index is greater than the end index for the line, then the last range will extend all the way to the trailing edge of the layout. Otherwise, it will end at the trailing edge of the last character.

Returns

An array of ranges represented by pairs of integers marking the start and end pixel coordinates of the ranges.

gobj() [1/2]

PangoLayoutLine * Pango::LayoutLine::gobj

(

)

Provides access to the underlying C instance.

gobj() [2/2]

const PangoLayoutLine * Pango::LayoutLine::gobj

(

)

const

Provides access to the underlying C instance.

gobj_copy()

PangoLayoutLine * Pango::LayoutLine::gobj_copy

(

)

const

Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.

index_to_x()

int Pango::LayoutLine::index_to_x	(	int	index,
		bool	trailing
	)		const

Converts an index within a line to a x position.

Parameters

index	Byte offset of a grapheme within the layout.
trailing	A boolean indicating the edge of the grapheme to retrieve the position of. If false, the trailing edge of the grapheme, if true the leading of the grapheme.

Returns

The x offset (in thousands of a device unit).

is_paragraph_start()

bool Pango::LayoutLine::is_paragraph_start

(

)

const

Returns whether this is the first line of the paragraph.

Since pangomm 2.54:

Returns

true if this is the first line.

operator delete()

void Pango::LayoutLine::operator delete ( void *  , std::size_t    )

protected

operator=()

LayoutLine & Pango::LayoutLine::operator= ( const LayoutLine &  )

delete

reference()

void Pango::LayoutLine::reference

(

)

const

Increment the reference count for this object.

You should never need to do this manually - use the object via a RefPtr instead.

show_in_cairo_context()

void Pango::LayoutLine::show_in_cairo_context

(

const Cairo::RefPtr< Cairo::Context > &

context

)

Draws this LayoutLine in the specified Cairo context.

The origin of the glyphs (the left edge of the line) will be drawn at the current point of the cairo context.

Parameters

context

A Cairo context.

unreference()

void Pango::LayoutLine::unreference

(

)

const

Decrement the reference count for this object.

You should never need to do this manually - use the object via a RefPtr instead.

x_to_index()

bool Pango::LayoutLine::x_to_index	(	int	x_pos,
		int &	index,
		int &	trailing
	)		const

Converts from x offset to the byte index of the corresponding character within the text of the layout.

If x_pos is outside the line, index and trailing will point to the very first or very last position in the line. This determination is based on the resolved direction of the paragraph; for example, if the resolved direction is right-to-left, then an X position to the right of the line (after it) results in 0 being stored in index and trailing. An X position to the left of the line results in index pointing to the (logical) last grapheme in the line and trailing being set to the number of characters in that grapheme. The reverse is true for a left-to-right line.

Parameters

x_pos	The X offset (in Pango units) from the left edge of the line.
index	Location to store calculated byte index for the grapheme in which the user clicked.
trailing	Location to store an integer indicating where in the grapheme the user clicked. It will either be zero, or the number of characters in the grapheme. 0 represents the leading edge of the grapheme.

Returns

false if x_pos was outside the line, true if inside.

Friends And Related Symbol Documentation

wrap()

Glib::RefPtr< Pango::LayoutLine > wrap ( PangoLayoutLine *  object, bool  take_copy = false  )

related

A Glib::wrap() method for this object.

Parameters

object	The C instance.
take_copy	False if the result should take ownership of the C instance. True if it should take a new copy or ref.

Returns

A C++ instance that wraps this C instance.