pangomm: Pango::Layout Class Reference

A Pango::Layout represents an entire paragraph of text. More...

#include <pangomm/layout.h>

Inheritance diagram for Pango::Layout:

Public Member Functions
	Layout (Layout && src) noexcept

Layout &	operator= (Layout && src) noexcept

	~Layout () noexcept override

PangoLayout *	gobj ()
	Provides access to the underlying C GObject. More...

const PangoLayout *	gobj () const
	Provides access to the underlying C GObject. More...

PangoLayout *	gobj_copy ()
	Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs. More...

void	update_from_cairo_context (const Cairo::RefPtr< Cairo::Context > & context)
	Updates the private Pango Context of a Pango Layout created with create(const Cairo::RefPtr<Cairo::Context>&) to match the current transformation and target surface of a Cairo Context. More...

Glib::RefPtr< Layout >	copy ()
	Creates a deep copy-by-value of the layout. More...

Glib::RefPtr< Context >	get_context () const
	Retrieves the `Pango::Context` used for this layout. More...

void	set_attributes (AttrList & attrs)
	Sets the text attributes for a layout object. More...

AttrList	get_attributes () const
	Gets the attribute list for the layout, if any. More...

void	set_text (const Glib::ustring & text)
	Set the text of the layout. More...

Glib::ustring	get_text () const
	Gets the text in the layout. More...

int	get_character_count () const
	Returns the number of Unicode characters in the the text of layout. More...

void	set_markup (const Glib::ustring & markup)
	Sets the layout text and attribute list from marked-up text (see markup format). More...

void	set_markup (const Glib::ustring & markup, gunichar accel_marker, gunichar & accel_char)
	Sets the layout text and attribute list from marked-up text (see markup format). More...

void	set_font_description (const FontDescription & desc)
	Set the default font description for the layout. More...

void	unset_font_description ()

FontDescription	get_font_description () const
	Gets the font description for the layout, if any. More...

void	set_width (int width)
	Sets the width to which the lines of the `Pango::Layout` should wrap or ellipsized. More...

int	get_width () const
	Gets the width to which the lines of the `Pango::Layout` should wrap. More...

void	set_height (int height)
	Sets the height to which the `Pango::Layout` should be ellipsized at. More...

int	get_height () const
	Gets the height of layout used for ellipsization. More...

void	set_wrap (WrapMode wrap)
	Sets the wrap mode. More...

WrapMode	get_wrap () const
	Gets the wrap mode for the layout. More...

bool	is_wrapped () const
	Queries whether the layout had to wrap any paragraphs. More...

void	set_indent (int indent)
	Sets the width in Pango units to indent each paragraph. More...

int	get_indent () const
	Gets the paragraph indent width in Pango units. More...

void	set_spacing (int spacing)
	Sets the amount of spacing in Pango units between the lines of the layout. More...

int	get_spacing () const
	Gets the amount of spacing between the lines of the layout. More...

void	set_line_spacing (float factor)
	Sets a factor for line spacing. More...

float	get_line_spacing () const
	Gets the line spacing factor of layout. More...

void	set_justify (bool justify=true)
	Sets whether each complete line should be stretched to fill the entire width of the layout. More...

bool	get_justify () const
	Gets whether each complete line should be stretched to fill the entire width of the layout. More...

bool	get_auto_dir () const
	Gets whether to calculate the base direction for the layout according to its contents. More...

void	set_auto_dir (bool auto_dir=true)
	Sets whether to calculate the base direction for the layout according to its contents. More...

void	set_alignment (Alignment alignment)
	Sets the alignment for the layout: how partial lines are positioned within the horizontal space available. More...

Alignment	get_alignment () const
	Gets the alignment for the layout: how partial lines are positioned within the horizontal space available. More...

void	set_tabs (TabArray & tabs)
	Sets the tabs to use for layout, overriding the default tabs. More...

TabArray	get_tabs () const
	Get the current Pango::TabArray used by this layout. More...

void	set_single_paragraph_mode (bool setting=true)
	Sets the single paragraph mode of layout. More...

bool	get_single_paragraph_mode () const
	Obtains whether layout is in single paragraph mode. More...

void	set_ellipsize (EllipsizeMode ellipsize)
	Sets the type of ellipsization being performed for layout. More...

EllipsizeMode	get_ellipsize () const
	Gets the type of ellipsization being performed for layout. More...

bool	is_ellipsized () const
	Queries whether the layout had to ellipsize any paragraphs. More...

int	get_unknown_glyphs_count () const
	Counts the number of unknown glyphs in layout. More...

void	context_changed ()
	Forces recomputation of any state in the `Pango::Layout` that might depend on the layout's context. More...

guint	get_serial () const
	Returns the current serial number of layout. More...

std::vector< LogAttr >	get_log_attrs () const
	Retrieve a vector of logical attributes for each character in the layout. More...

Rectangle	index_to_pos (int index) const
	Convert from an index within the layout to the onscreen position corresponding to the grapheme at that index, which is represented as rectangle. More...

void	index_to_line_x (int index_, bool trailing, int & line, int & x_pos) const
	Converts from byte index within the layout to line and X position. More...

void	get_cursor_pos (int index, Rectangle & strong_pos, Rectangle & weak_pos) const
	Given an index within a layout, determines the positions that of the strong and weak cursors if the insertion point is at that index. More...

Rectangle	get_cursor_strong_pos (int index) const
	Given an index within the layout, determine the positions that of the strong cursors if the insertion point is at that index. More...

Rectangle	get_cursor_weak_pos (int index) const
	Given an index within the layout, determine the positions that of the weak cursors if the insertion point is at that index. More...

void	move_cursor_visually (bool strong, int old_index, int old_trailing, int direction, int & new_index, int & new_trailing) const
	Computes a new cursor position from an old position and a direction. More...

bool	xy_to_index (int x, int y, int & index, int & trailing) const
	Converts from X and Y position within a layout to the byte index to the character at that logical position. More...

void	get_extents (Rectangle & ink_rect, Rectangle & logical_rect) const
	Compute the logical and ink extents of layout. More...

Rectangle	get_ink_extents () const
	Compute the ink extents of layout. More...

Rectangle	get_logical_extents () const
	Compute the logical extents of layout. More...

void	get_pixel_extents (Rectangle & ink_rect, Rectangle & logical_rect) const
	Compute the logical and ink extents of layout in device units. More...

Rectangle	get_pixel_ink_extents () const
	Compute the ink extents of the layout in device units. More...

Rectangle	get_pixel_logical_extents () const
	Compute the logical extents of the layout in device units. More...

void	get_size (int & width, int & height) const
	Determines the logical width and height of a `Pango::Layout` in Pango units. More...

void	get_pixel_size (int & width, int & height) const
	Determines the logical width and height of a `Pango::Layout` in device units. More...

int	get_baseline () const
	Gets the Y position of baseline of the first line in layout. More...

int	get_line_count () const
	Retrieves the count of lines for the layout. More...

Glib::RefPtr< LayoutLine >	get_line (int line)
	Retrieves a particular line from a Pango::Layout. More...

Glib::RefPtr< const LayoutLine >	get_line (int line) const
	Retrieves a particular line from a Pango::Layout. More...

Glib::RefPtr< const LayoutLine >	get_const_line (int line) const
	Retrieves a particular line from a Pango::Layout. More...

std::vector< Glib::RefPtr< LayoutLine > >	get_lines ()
	Returns the lines of the layout as a vector. More...

std::vector< Glib::RefPtr< const LayoutLine > >	get_lines () const
	Returns the lines of the layout as a vector. More...

std::vector< Glib::RefPtr< const LayoutLine > >	get_const_lines () const
	Returns the lines of the layout as a vector. More...

LayoutIter	get_iter ()
	Gets an iterator to iterate over the visual extents of the layout. More...

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. More...

void	show_in_cairo_context (const Cairo::RefPtr< Cairo::Context > & context)
	Draws a Layout in the specified Cairo context. More...

Static Public Member Functions
static GType	get_type ()
	Get the GType for this class, for use with the underlying GObject type system. More...

static Glib::RefPtr< Layout >	create (const Glib::RefPtr< Context > & context)

static Glib::RefPtr< Layout >	create (const Cairo::RefPtr< Cairo::Context > & context)
	Creates a layout object set up to match the current transformation and target surface of the Cairo context. More...

Protected Member Functions
	Layout (const Glib::RefPtr< Context > & context)

Related Functions
(Note that these are not member functions.)
Glib::RefPtr< Pango::Layout >	wrap (PangoLayout * object, bool take_copy=false)
	A Glib::wrap() method for this object. More...

Detailed Description

A Pango::Layout represents an entire paragraph of text.

It is initialized with a Pango::Context, UTF-8 string and set of attributes for that string. Once that is done, the set of formatted lines can be extracted from the object, the layout can be rendered, and conversion between logical character positions within the layout's text, and the physical position of the resulting glyphs can be made.

Constructor & Destructor Documentation

◆ Layout() [1/2]

Pango::Layout::Layout ( Layout && src )

noexcept

◆ ~Layout()

Pango::Layout::~Layout ( )

overridenoexcept

◆ Layout() [2/2]

Pango::Layout::Layout ( const Glib::RefPtr< Context > & context )

explicitprotected

Member Function Documentation

◆ add_to_cairo_context()

void Pango::Layout::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.

◆ context_changed()

void Pango::Layout::context_changed ( )

Forces recomputation of any state in the Pango::Layout that might depend on the layout's context.

This function should be called if you make changes to the context subsequent to creating the layout.

◆ copy()

Glib::RefPtr< Layout > Pango::Layout::copy ( )

Creates a deep copy-by-value of the layout.

The attribute list, tab array, and text from the original layout are all copied by value.

Returns: The newly allocated Pango::Layout.

◆ create() [1/2]

static Glib::RefPtr< Layout > Pango::Layout::create ( const Cairo::RefPtr< Cairo::Context > & context )

static

Creates a layout object set up to match the current transformation and target surface of the Cairo context.

This layout can then be used for text measurement with functions like get_size() or drawing with methods like show_in_cairo_contet(). If you change the transformation or target surface for context, you need to call update_from_cairo_context()

This is the most convenient way to use Cairo with Pango. However it is slightly inefficient since it creates a separate Pango Context object for each layout. This might matter in an application that is laying out large amounts of text.

Parameters

context A Cairo context.

Returns: The newly created Pango Layout.

◆ create() [2/2]

static Glib::RefPtr< Layout > Pango::Layout::create ( const Glib::RefPtr< Context > & context )

static

◆ get_alignment()

Alignment Pango::Layout::get_alignment ( ) const

Gets the alignment for the layout: how partial lines are positioned within the horizontal space available.

Returns: The alignment.

◆ get_attributes()

AttrList Pango::Layout::get_attributes ( ) const

Gets the attribute list for the layout, if any.

Returns: A Pango::AttrList.

◆ get_auto_dir()

bool Pango::Layout::get_auto_dir ( ) const

Gets whether to calculate the base direction for the layout according to its contents.

See set_auto_dir().

Since pangomm 1.4:

Returns: true if the bidirectional base direction is computed from the layout's contents, false otherwise.

◆ get_baseline()

int Pango::Layout::get_baseline ( ) const

Gets the Y position of baseline of the first line in layout.

Since pangomm 1.22:

Returns: Baseline of first line, from top of layout.

◆ get_character_count()

int Pango::Layout::get_character_count ( ) const

Returns the number of Unicode characters in the the text of layout.

Since pangomm 1.30:

Returns: The number of Unicode characters in the text of layout.

◆ get_const_line()

Glib::RefPtr< const LayoutLine > Pango::Layout::get_const_line ( int line ) const

Retrieves a particular line from a Pango::Layout.

This is a faster alternative to get_line(), but the user is not expected to modify the contents of the line (glyphs, glyph widths, etc.).

Since pangomm 2.50:

Parameters

line	The index of a line, which must be between 0 and `get_line_count() - 1`, inclusive.

Returns: The requested Pango::LayoutLine, or an empty RefPtr if the index is out of range. This layout line will become invalid if changes are made to the Pango::Layout. No changes should be made to the line.

◆ get_const_lines()

std::vector< Glib::RefPtr< const LayoutLine > > Pango::Layout::get_const_lines ( ) const

Returns the lines of the layout as a vector.

This is a faster alternative to get_lines(), but the user is not expected to modify the contents of the lines (glyphs, glyph widths, etc.).

Since pangomm 2.50:

Returns: A std::vector containing the lines in the layout. This points to internal data of the Pango::Layout and must be used with care. It will become invalid on any change to the layout's text or properties. No changes should be made to the lines.

◆ get_context()

Glib::RefPtr< Context > Pango::Layout::get_context ( ) const

Retrieves the Pango::Context used for this layout.

Returns: The Pango::Context for the layout.

◆ get_cursor_pos()

void Pango::Layout::get_cursor_pos	(	int	index,
		Rectangle &	strong_pos,
		Rectangle &	weak_pos
	)		const

Given an index within a layout, determines the positions that of the strong and weak cursors if the insertion point is at that index.

The position of each cursor is stored as a zero-width rectangle with the height of the run extents.

<picture> <source srcset="cursor-positions-dark.png" media="(prefers-color-scheme: dark)"> Cursor positions </picture>

The strong cursor location is the location where characters of the directionality equal to the base direction of the layout are inserted. The weak cursor location is the location where characters of the directionality opposite to the base direction of the layout are inserted.

The following example shows text with both a strong and a weak cursor.

<picture> <source srcset="split-cursor-dark.png" media="(prefers-color-scheme: dark)"> Strong and weak cursors </picture>

The strong cursor has a little arrow pointing to the right, the weak cursor to the left. Typing a 'c' in this situation will insert the character after the 'b', and typing another Hebrew character, like 'ג', will insert it at the end.

Parameters

index	The byte index of the cursor.
strong_pos	Location to store the strong cursor position.
weak_pos	Location to store the weak cursor position.

◆ get_cursor_strong_pos()

Rectangle Pango::Layout::get_cursor_strong_pos ( int index ) const

Given an index within the layout, determine the positions that of the strong cursors if the insertion point is at that index.

Parameters

index The byte index of the cursor.

Returns: The strong cursor position.

◆ get_cursor_weak_pos()

Rectangle Pango::Layout::get_cursor_weak_pos ( int index ) const

Given an index within the layout, determine the positions that of the weak cursors if the insertion point is at that index.

Parameters

index The byte index of the cursor.

Returns: The weak cursor position.

◆ get_ellipsize()

EllipsizeMode Pango::Layout::get_ellipsize ( ) const

Gets the type of ellipsization being performed for layout.

See set_ellipsize().

Use is_ellipsized() to query whether any paragraphs were actually ellipsized.

Since pangomm 1.6:

Returns: The current ellipsization mode for layout.

◆ get_extents()

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

Compute the logical and ink extents of layout.

Logical extents are usually what you want for positioning things. The extents are given in layout coordinates; layout coordinates begin at the top left corner of the layout.

Parameters

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

◆ get_font_description()

FontDescription Pango::Layout::get_font_description ( ) const

Gets the font description for the layout, if any.

Since pangomm 1.8:

Returns: A pointer to the layout's font description, or nullptr if the font description from the layout's context is inherited.

◆ get_height()

int Pango::Layout::get_height ( ) const

Gets the height of layout used for ellipsization.

See set_height() for details.

Since pangomm 1.20:

Returns: The height, in Pango units if positive, or number of lines if negative.

◆ get_indent()

int Pango::Layout::get_indent ( ) const

Gets the paragraph indent width in Pango units.

A negative value indicates a hanging indentation.

Returns: The indent in Pango units.

◆ get_ink_extents()

Rectangle Pango::Layout::get_ink_extents ( ) const

Compute the ink extents of layout.

Returns: The extents of the layout as drawn.

◆ get_iter()

LayoutIter Pango::Layout::get_iter ( )

Gets an iterator to iterate over the visual extents of the layout.

Returns: The iterator.

Since pangomm 2.28:

◆ get_justify()

bool Pango::Layout::get_justify ( ) const

Gets whether each complete line should be stretched to fill the entire width of the layout.

Returns: The justify value.

◆ get_line() [1/2]

Glib::RefPtr< LayoutLine > Pango::Layout::get_line ( int line )

Retrieves a particular line from a Pango::Layout.

Use the faster get_const_line() if you do not plan to modify the contents of the line (glyphs, glyph widths, etc.).

Parameters

line	The index of a line, which must be between 0 and `get_line_count() - 1`, inclusive.

Returns: The requested Pango::LayoutLine, or an empty RefPtr if the index is out of range. This layout line will become invalid if changes are made to the Pango::Layout.

◆ get_line() [2/2]

Glib::RefPtr< const LayoutLine > Pango::Layout::get_line ( int line ) const

Retrieves a particular line from a Pango::Layout.

Parameters

line	The index of a line, which must be between 0 and `get_line_count() - 1`, inclusive.

Returns: The requested Pango::LayoutLine, or an empty RefPtr if the index is out of range. This layout line will become invalid if changes are made to the Pango::Layout. No changes should be made to the line.

◆ get_line_count()

int Pango::Layout::get_line_count ( ) const

Retrieves the count of lines for the layout.

Returns: The line count.

◆ get_line_spacing()

float Pango::Layout::get_line_spacing ( ) const

Gets the line spacing factor of layout.

See set_line_spacing().

Since pangomm 1.44:

◆ get_lines() [1/2]

std::vector< Glib::RefPtr< LayoutLine > > Pango::Layout::get_lines ( )

Returns the lines of the layout as a vector.

Use the faster get_const_lines() if you do not plan to modify the contents of the lines (glyphs, glyph widths, etc.).

Returns: A std::vector containing the lines in the layout. This points to internal data of the Pango::Layout and must be used with care. It will become invalid on any change to the layout's text or properties.

◆ get_lines() [2/2]

std::vector< Glib::RefPtr< const LayoutLine > > Pango::Layout::get_lines ( ) const

Returns the lines of the layout as a vector.

Returns: A std::vector containing the lines in the layout. This points to internal data of the Pango::Layout and must be used with care. It will become invalid on any change to the layout's text or properties. No changes should be made to the lines.

◆ get_log_attrs()

std::vector< LogAttr > Pango::Layout::get_log_attrs ( ) const

Retrieve a vector of logical attributes for each character in the layout.

The number of attributes returned will be one more than the total number of characters in the layout, since there need to be attributes corresponding to both the position before the first character and the position after the last character.

Returns: A vector of logical attributes.

◆ get_logical_extents()

Rectangle Pango::Layout::get_logical_extents ( ) const

Compute the logical extents of layout.

Returns: The logical extents of the layout.

◆ get_pixel_extents()

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

Compute the logical and ink extents of layout in device units.

See get_extents(); this function just calls get_extents() and then converts the extents to pixels using the Pango::SCALE factor.

Parameters

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

◆ get_pixel_ink_extents()

Rectangle Pango::Layout::get_pixel_ink_extents ( ) const

Compute the ink extents of the layout in device units.

Returns: The extents of the layout as drawn.

◆ get_pixel_logical_extents()

Rectangle Pango::Layout::get_pixel_logical_extents ( ) const

Compute the logical extents of the layout in device units.

Returns: The logical extents of the layout.

◆ get_pixel_size()

void Pango::Layout::get_pixel_size	(	int &	width,
		int &	height
	)		const

Determines the logical width and height of a Pango::Layout in device units.

get_size() returns the width and height scaled by Pango::SCALE. This is simply a convenience function around get_pixel_extents().

Parameters

width	Location to store the logical width.
height	Location to store the logical height.

◆ get_serial()

guint Pango::Layout::get_serial ( ) const

Returns the current serial number of layout.

The serial number is initialized to an small number larger than zero when a new layout is created and is increased whenever the layout is changed using any of the setter functions, or the Pango::Context it uses has changed. The serial may wrap, but will never have the value 0. Since it can wrap, never compare it with "less than", always use "not equals".

This can be used to automatically detect changes to a Pango::Layout, and is useful for example to decide whether a layout needs redrawing. To force the serial to be increased, use context_changed().

Since pangomm 1.32.4:

Returns: The current serial number of layout.

◆ get_single_paragraph_mode()

bool Pango::Layout::get_single_paragraph_mode ( ) const

Obtains whether layout is in single paragraph mode.

See set_single_paragraph_mode().

Returns: true if the layout does not break paragraphs at paragraph separator characters, false otherwise.

◆ get_size()

void Pango::Layout::get_size	(	int &	width,
		int &	height
	)		const

Determines the logical width and height of a Pango::Layout in Pango units.

This is simply a convenience function around get_extents().

Parameters

width	Location to store the logical width.
height	Location to store the logical height.

◆ get_spacing()

int Pango::Layout::get_spacing ( ) const

Gets the amount of spacing between the lines of the layout.

Returns: The spacing in Pango units.

◆ get_tabs()

TabArray Pango::Layout::get_tabs ( ) const

Get the current Pango::TabArray used by this layout.

If no Pango::TabArray has been set, then the default tabs are in use and an invalid instance is returned. Default tabs are every 8 spaces.

Returns: A copy of the tabs for this layout.

◆ get_text()

Glib::ustring Pango::Layout::get_text ( ) const

Gets the text in the layout.

The returned text should not be freed or modified.

Returns: The text in the layout.

◆ get_type()

static GType Pango::Layout::get_type ( )

static

Get the GType for this class, for use with the underlying GObject type system.

◆ get_unknown_glyphs_count()

int Pango::Layout::get_unknown_glyphs_count ( ) const

Counts the number of unknown glyphs in layout.

This function can be used to determine if there are any fonts available to render all characters in a certain string, or when used in combination with Pango::AttrType::FALLBACK, to check if a certain font supports all the characters in the string.

Since pangomm 1.16:

Returns: The number of unknown glyphs in layout.

◆ get_width()

int Pango::Layout::get_width ( ) const

Gets the width to which the lines of the Pango::Layout should wrap.

Returns: The width in Pango units, or -1 if no width set.

◆ get_wrap()

WrapMode Pango::Layout::get_wrap ( ) const

Gets the wrap mode for the layout.

Use is_wrapped() to query whether any paragraphs were actually wrapped.

Returns: Active wrap mode.

◆ gobj() [1/2]

PangoLayout * Pango::Layout::gobj ( )

inline

Provides access to the underlying C GObject.

◆ gobj() [2/2]

const PangoLayout * Pango::Layout::gobj ( ) const

inline

Provides access to the underlying C GObject.

◆ gobj_copy()

PangoLayout * Pango::Layout::gobj_copy ( )

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

◆ index_to_line_x()

void Pango::Layout::index_to_line_x	(	int	index_,
		bool	trailing,
		int &	line,
		int &	x_pos
	)		const

Converts from byte index within the layout to line and X position.

The X position is measured from the left edge of the line.

Parameters

index	The byte index of a grapheme within the layout.
trailing	An integer indicating the edge of the grapheme to retrieve the position of. If > 0, the trailing edge of the grapheme, if 0, the leading of the grapheme.
line	Location to store resulting line index. (which will between 0 and pango_layout_get_line_count(layout) - 1).
x_pos	Location to store resulting position within line (Pango::SCALE units per device unit).

◆ index_to_pos()

Rectangle Pango::Layout::index_to_pos ( int index ) const

Convert from an index within the layout to the onscreen position corresponding to the grapheme at that index, which is represented as rectangle.

Note that x in the returned rectangle is always the leading edge of the grapheme and x + width the trailing edge of the grapheme. If the directionality of the grapheme is right-to-left, then width will be negative.

Parameters

index Byte index within layout.

Returns: The position of the grapheme.

◆ is_ellipsized()

bool Pango::Layout::is_ellipsized ( ) const

Queries whether the layout had to ellipsize any paragraphs.

This returns true if the ellipsization mode for layout is not Pango::EllipsizeMode::NONE, a positive width is set on layout, and there are paragraphs exceeding that width that have to be ellipsized.

Since pangomm 1.16:

Returns: true if any paragraphs had to be ellipsized, false otherwise.

◆ is_wrapped()

bool Pango::Layout::is_wrapped ( ) const

Queries whether the layout had to wrap any paragraphs.

This returns true if a positive width is set on layout, ellipsization mode of layout is set to Pango::EllipsizeMode::NONE, and there are paragraphs exceeding the layout width that have to be wrapped.

Since pangomm 1.16:

Returns: true if any paragraphs had to be wrapped, false otherwise.

◆ move_cursor_visually()

void Pango::Layout::move_cursor_visually	(	bool	strong,
		int	old_index,
		int	old_trailing,
		int	direction,
		int &	new_index,
		int &	new_trailing
	)		const

Computes a new cursor position from an old position and a direction.

If direction is positive, then the new position will cause the strong or weak cursor to be displayed one position to right of where it was with the old cursor position. If direction is negative, it will be moved to the left.

In the presence of bidirectional text, the correspondence between logical and visual order will depend on the direction of the current run, and there may be jumps when the cursor is moved off of the end of a run.

Motion here is in cursor positions, not in characters, so a single call to this function may move the cursor over multiple characters when multiple characters combine to form a single grapheme.

Parameters

strong	Whether the moving cursor is the strong cursor or the weak cursor. The strong cursor is the cursor corresponding to text insertion in the base direction for the layout.
old_index	The byte index of the current cursor position.
old_trailing	If 0, the cursor was at the leading edge of the grapheme indicated by old_index, if > 0, the cursor was at the trailing edge.
direction	Direction to move cursor. A negative value indicates motion to the left.
new_index	Location to store the new cursor byte index. A value of -1 indicates that the cursor has been moved off the beginning of the layout. A value of G_MAXINT indicates that the cursor has been moved off the end of the layout.
new_trailing	Number of characters to move forward from the location returned for new_index to get the position where the cursor should be displayed. This allows distinguishing the position at the beginning of one line from the position at the end of the preceding line. new_index is always on the line where the cursor should be displayed.

◆ operator=()

Layout & Pango::Layout::operator= ( Layout && src )

noexcept

◆ set_alignment()

void Pango::Layout::set_alignment ( Alignment alignment )

Sets the alignment for the layout: how partial lines are positioned within the horizontal space available.

The default alignment is Pango::Alignment::LEFT.

Parameters

alignment The alignment.

◆ set_attributes()

void Pango::Layout::set_attributes ( AttrList & attrs )

Sets the text attributes for a layout object.

References attrs, so the caller can unref its reference.

Parameters

attrs A Pango::AttrList.

◆ set_auto_dir()

void Pango::Layout::set_auto_dir ( bool auto_dir = true )

Sets whether to calculate the base direction for the layout according to its contents.

When this flag is on (the default), then paragraphs in layout that begin with strong right-to-left characters (Arabic and Hebrew principally), will have right-to-left layout, paragraphs with letters from other scripts will have left-to-right layout. Paragraphs with only neutral characters get their direction from the surrounding paragraphs.

When false, the choice between left-to-right and right-to-left layout is done according to the base direction of the layout's Pango::Context. (See Pango::Context::set_base_dir()).

When the auto-computed direction of a paragraph differs from the base direction of the context, the interpretation of Pango::Alignment::LEFT and Pango::Alignment::RIGHT are swapped.

Since pangomm 1.4:

Parameters

auto_dir If true, compute the bidirectional base direction from the layout's contents.

◆ set_ellipsize()

void Pango::Layout::set_ellipsize ( EllipsizeMode ellipsize )

Sets the type of ellipsization being performed for layout.

Depending on the ellipsization mode ellipsize text is removed from the start, middle, or end of text so they fit within the width and height of layout set with set_width() and set_height().

If the layout contains characters such as newlines that force it to be layed out in multiple paragraphs, then whether each paragraph is ellipsized separately or the entire layout is ellipsized as a whole depends on the set height of the layout.

The default value is Pango::EllipsizeMode::NONE.

See set_height() for details.

Since pangomm 1.6:

Parameters

ellipsize The new ellipsization mode for layout.

◆ set_font_description()

void Pango::Layout::set_font_description ( const FontDescription & desc )

Set the default font description for the layout.

If no font description is set on the layout, the font description from the layout's context is used.

Parameters

desc	The new pango font description.

◆ set_height()

void Pango::Layout::set_height ( int height )

Sets the height to which the Pango::Layout should be ellipsized at.

There are two different behaviors, based on whether height is positive or negative.

If height is positive, it will be the maximum height of the layout. Only lines would be shown that would fit, and if there is any text omitted, an ellipsis added. At least one line is included in each paragraph regardless of how small the height value is. A value of zero will render exactly one line for the entire layout.

If height is negative, it will be the (negative of) maximum number of lines per paragraph. That is, the total number of lines shown may well be more than this value if the layout contains multiple paragraphs of text. The default value of -1 means that the first line of each paragraph is ellipsized. This behavior may be changed in the future to act per layout instead of per paragraph. File a bug against pango at https://gitlab.gnome.org/gnome/pango if your code relies on this behavior.

Height setting only has effect if a positive width is set on layout and ellipsization mode of layout is not Pango::EllipsizeMode::NONE. The behavior is undefined if a height other than -1 is set and ellipsization mode is set to Pango::EllipsizeMode::NONE, and may change in the future.

Since pangomm 1.20:

Parameters

height The desired height of the layout in Pango units if positive, or desired number of lines if negative.

◆ set_indent()

void Pango::Layout::set_indent ( int indent )

Sets the width in Pango units to indent each paragraph.

A negative value of indent will produce a hanging indentation. That is, the first line will have the full width, and subsequent lines will be indented by the absolute value of indent.

The indent setting is ignored if layout alignment is set to Pango::Alignment::CENTER.

The default value is 0.

Parameters

indent The amount by which to indent.

◆ set_justify()

void Pango::Layout::set_justify ( bool justify = true )

Sets whether each complete line should be stretched to fill the entire width of the layout.

Stretching is typically done by adding whitespace, but for some scripts (such as Arabic), the justification may be done in more complex ways, like extending the characters.

Note that this setting is not implemented and so is ignored in Pango older than 1.18.

Note that tabs and justification conflict with each other: Justification will move content away from its tab-aligned positions.

The default value is false.

Also see set_justify_last_line().

Parameters

justify Whether the lines in the layout should be justified.

◆ set_line_spacing()

void Pango::Layout::set_line_spacing ( float factor )

Sets a factor for line spacing.

Typical values are: 0, 1, 1.5, 2. The default values is 0.

If factor is non-zero, lines are placed so that

baseline2 = baseline1 + factor * height2

where height2 is the line height of the second line (as determined by the font(s)). In this case, the spacing set with set_spacing() is ignored.

If factor is zero (the default), spacing is applied as before.

Note: for semantics that are closer to the CSS line-height property, see pango_attr_line_height_new().

Since pangomm 1.44:

Parameters

factor The new line spacing factor.

◆ set_markup() [1/2]

void Pango::Layout::set_markup ( const Glib::ustring & markup )

Sets the layout text and attribute list from marked-up text (see markup format).

Replaces the current text and attribute list.

Parameters

markup Some marked-up text.

◆ set_markup() [2/2]

void Pango::Layout::set_markup	(	const Glib::ustring &	markup,
		gunichar	accel_marker,
		gunichar &	accel_char
	)

Sets the layout text and attribute list from marked-up text (see markup format).

Replaces the current text and attribute list.

If accel_marker is nonzero, the given character will mark the character following it as an accelerator. For example, the accel marker might be an ampersand or underscore. All characters marked as an accelerator will receive a Pango::UNDERLINE_LOW attribute, and the first character so marked will be returned in accel_char. Two accel_marker characters following each other produce a single literal accel_marker character.

Parameters

markup	Some marked-up text.
accel_marker	Marker for accelerators in the text.
accel_char	Return location for any located accelerators.

◆ set_single_paragraph_mode()

void Pango::Layout::set_single_paragraph_mode ( bool setting = true )

Sets the single paragraph mode of layout.

If setting is true, do not treat newlines and similar characters as paragraph separators; instead, keep all text in a single paragraph, and display a glyph for paragraph separator characters. Used when you want to allow editing of newlines on a single text line.

The default value is false.

Parameters

setting New setting.

◆ set_spacing()

void Pango::Layout::set_spacing ( int spacing )

Sets the amount of spacing in Pango units between the lines of the layout.

When placing lines with spacing, Pango arranges things so that

line2.top = line1.bottom + spacing

The default value is 0.

Note: Since 1.44, Pango is using the line height (as determined by the font) for placing lines when the line spacing factor is set to a non-zero value with set_line_spacing(). In that case, the spacing set with this function is ignored.; for semantics that are closer to the CSS line-height property, see pango_attr_line_height_new().

Parameters

spacing The amount of spacing.

◆ set_tabs()

void Pango::Layout::set_tabs ( TabArray & tabs )

Sets the tabs to use for layout, overriding the default tabs.

Pango::Layout will place content at the next tab position whenever it meets a Tab character (U+0009).

By default, tabs are every 8 spaces. If tabs is nullptr, the default tabs are reinstated. tabs is copied into the layout; you must free your copy of tabs yourself.

Note that tabs and justification conflict with each other: Justification will move content away from its tab-aligned positions. The same is true for alignments other than Pango::Alignment::LEFT.

Parameters

tabs	A `Pango::TabArray`.

◆ set_text()

void Pango::Layout::set_text ( const Glib::ustring & text )

Set the text of the layout.

Parameters

text	The text for the layout.

◆ set_width()

void Pango::Layout::set_width ( int width )

Sets the width to which the lines of the Pango::Layout should wrap or ellipsized.

The default value is -1: no width set.

Parameters

width The desired width in Pango units, or -1 to indicate that no wrapping or ellipsization should be performed.

◆ set_wrap()

void Pango::Layout::set_wrap ( WrapMode wrap )

Sets the wrap mode.

The wrap mode only has effect if a width is set on the layout with set_width(). To turn off wrapping, set the width to -1.

The default value is Pango::WrapMode::WORD.

Parameters

wrap	The wrap mode.

◆ show_in_cairo_context()

void Pango::Layout::show_in_cairo_context ( const Cairo::RefPtr< Cairo::Context > & context )

Draws a Layout in the specified Cairo context.

The top-left corner of the Layout will be drawn at the current point of the cairo context.

Parameters

context A Cairo context.

Since pangomm 2.16:

◆ unset_font_description()

void Pango::Layout::unset_font_description ( )

◆ update_from_cairo_context()

void Pango::Layout::update_from_cairo_context ( const Cairo::RefPtr< Cairo::Context > & context )

Updates the private Pango Context of a Pango Layout created with create(const Cairo::RefPtr<Cairo::Context>&) to match the current transformation and target surface of a Cairo Context.

Parameters

context A Cairo context.

◆ xy_to_index()

bool Pango::Layout::xy_to_index	(	int	x,
		int	y,
		int &	index,
		int &	trailing
	)		const

Converts from X and Y position within a layout to the byte index to the character at that logical position.

If the Y position is not inside the layout, the closest position is chosen (the position will be clamped inside the layout). If the X position is not within the layout, then the start or the end of the line is chosen as described for Pango::LayoutLine::x_to_index(). If either the X or Y positions were not inside the layout, then the function returns false; on an exact hit, it returns true.

Parameters

x	The X offset (in Pango units) from the left edge of the layout.
y	The Y offset (in Pango units) from the top edge of the layout.
index	Location to store calculated byte index.
trailing	Location to store a 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: true if the coordinates were inside text, false otherwise.

Friends And Related Function Documentation

◆ wrap()

Glib::RefPtr< Pango::Layout > wrap	(	PangoLayout *	object,
		bool	take_copy = `false`
	)

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.

Public Member Functions

Static Public Member Functions

Protected Member Functions

Related Functions

Detailed Description

Constructor & Destructor Documentation

◆ Layout() [1/2]

◆ ~Layout()

◆ Layout() [2/2]

Member Function Documentation

◆ add_to_cairo_context()

◆ context_changed()

◆ copy()

◆ create() [1/2]

◆ create() [2/2]

◆ get_alignment()

◆ get_attributes()

◆ get_auto_dir()

◆ get_baseline()

◆ get_character_count()

◆ get_const_line()

◆ get_const_lines()

◆ get_context()

◆ get_cursor_pos()

◆ get_cursor_strong_pos()

◆ get_cursor_weak_pos()

◆ get_ellipsize()

◆ get_extents()

◆ get_font_description()

◆ get_height()

◆ get_indent()

◆ get_ink_extents()

◆ get_iter()

◆ get_justify()

◆ get_line() [1/2]

◆ get_line() [2/2]

◆ get_line_count()

◆ get_line_spacing()

◆ get_lines() [1/2]

◆ get_lines() [2/2]

◆ get_log_attrs()

◆ get_logical_extents()

◆ get_pixel_extents()

◆ get_pixel_ink_extents()

◆ get_pixel_logical_extents()

◆ get_pixel_size()

◆ get_serial()

◆ get_single_paragraph_mode()

◆ get_size()

◆ get_spacing()

◆ get_tabs()

◆ get_text()

◆ get_type()

◆ get_unknown_glyphs_count()

◆ get_width()

◆ get_wrap()

◆ gobj() [1/2]

◆ gobj() [2/2]

◆ gobj_copy()

◆ index_to_line_x()

◆ index_to_pos()

◆ is_ellipsized()

◆ is_wrapped()

◆ move_cursor_visually()

◆ operator=()

◆ set_alignment()

◆ set_attributes()

◆ set_auto_dir()

◆ set_ellipsize()

◆ set_font_description()

◆ set_height()

◆ set_indent()

◆ set_justify()

◆ set_line_spacing()

◆ set_markup() [1/2]

◆ set_markup() [2/2]

◆ set_single_paragraph_mode()

◆ set_spacing()

◆ set_tabs()

◆ set_text()