Pango.Layout

Subclasses:None

Methods

Inherited:GObject.Object (37) Structs:GObject.ObjectClass (5)

class	new (context)
	context_changed ()
	copy ()
	get_alignment ()
	get_attributes ()
	get_auto_dir ()
	get_baseline ()
	get_character_count ()
	get_context ()
	get_cursor_pos (index_)
	get_direction (index)
	get_ellipsize ()
	get_extents ()
	get_font_description ()
	get_height ()
	get_indent ()
	get_iter ()
	get_justify ()
	get_line (line)
	get_line_count ()
	get_line_readonly (line)
	get_line_spacing ()
	get_lines ()
	get_lines_readonly ()
	get_log_attrs ()
	get_log_attrs_readonly ()
	get_pixel_extents ()
	get_pixel_size ()
	get_serial ()
	get_single_paragraph_mode ()
	get_size ()
	get_spacing ()
	get_tabs ()
	get_text ()
	get_unknown_glyphs_count ()
	get_width ()
	get_wrap ()
	index_to_line_x (index_, trailing)
	index_to_pos (index_)
	is_ellipsized ()
	is_wrapped ()
	move_cursor_visually (strong, old_index, old_trailing, direction)
	set_alignment (alignment)
	set_attributes (attrs)
	set_auto_dir (auto_dir)
	set_ellipsize (ellipsize)
	set_font_description (desc)
	set_height (height)
	set_indent (indent)
	set_justify (justify)
	set_line_spacing (factor)
	set_markup (markup, length)
	set_markup_with_accel (markup, length, accel_marker)
	set_single_paragraph_mode (setting)
	set_spacing (spacing)
	set_tabs (tabs)
	set_text (text, length)
	set_width (width)
	set_wrap (wrap)
	xy_to_index (x, y)

Virtual Methods

Inherited:GObject.Object (7)

Properties

None

Signals

Inherited:GObject.Object (1)

Fields

Inherited:GObject.Object (1)

Class Details

class Pango.Layout(**kwargs)

Bases:GObject.Object Abstract:No Structure:Pango.LayoutClass

The Pango.Layout structure 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.

There are also a number of parameters to adjust the formatting of a Pango.Layout, which are illustrated in . It is possible, as well, to ignore the 2-D setup, and simply treat the results of a Pango.Layout as a list of lines.

Adjustable parameters (on the left) and font metrics (on the right) for a Pango.Layout

The Pango.Layout structure is opaque, and has no user-visible fields.

classmethod new(context)

Parameters:context (Pango.Context) – a Pango.Context Returns:the newly allocated Pango.Layout, with a reference count of one, which should be freed with GObject.Object.unref(). Return type:Pango.Layout

Create a new Pango.Layout object with attributes initialized to default values for a particular Pango.Context.

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()

Returns:the newly allocated Pango.Layout, with a reference count of one, which should be freed with GObject.Object.unref(). Return type:Pango.Layout

Does a deep copy-by-value of the self layout. The attribute list, tab array, and text from the original layout are all copied by value.

get_alignment()

Returns:the alignment. Return type:Pango.Alignment

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

get_attributes()

Returns:a Pango.AttrList or None if none was set. Return type:Pango.AttrList or None

Gets the attribute list for the layout, if any.

get_auto_dir()

Returns:True if the bidirectional base direction is computed from the layout’s contents, False otherwise. Return type:bool

Gets whether to calculate the bidirectional base direction for the layout according to the contents of the layout. See Pango.Layout.set_auto_dir().

New in version 1.4.

get_baseline()

Returns:baseline of first line, from top of self. Return type:int

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

New in version 1.22.

get_character_count()

Returns:the number of Unicode characters in the text of self Return type:int

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

New in version 1.30.

get_context()

Returns:the Pango.Context for the layout. This does not have an additional refcount added, so if you want to keep a copy of this around, you must reference it yourself. Return type:Pango.Context

Retrieves the Pango.Context used for this layout.

get_cursor_pos(index_)

Parameters:index (int) – the byte index of the cursor Returns:

strong_pos:location to store the strong cursor position (may be None) weak_pos:location to store the weak cursor position (may be None)

Return type:(strong_pos: Pango.Rectangle, weak_pos: Pango.Rectangle)

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. 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.

get_direction(index)

Parameters:index (int) – the byte index of the str Returns:the text direction at index Return type:Pango.Direction

Gets the text direction at the given character position in self.

New in version 1.46.

get_ellipsize()

Returns:the current ellipsization mode for self.

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

Return type:Pango.EllipsizeMode

Gets the type of ellipsization being performed for self. See Pango.Layout.set_ellipsize()

New in version 1.6.

get_extents()

Returns:

ink_rect:rectangle used to store the extents of the layout as drawn or None to indicate that the result is not needed. logical_rect:rectangle used to store the logical extents of the layout or None to indicate that the result is not needed.

Return type:(ink_rect: Pango.Rectangle, logical_rect: Pango.Rectangle)

Computes the logical and ink extents of self. Logical extents are usually what you want for positioning things. Note that both extents may have non-zero x and y. You may want to use those to offset where you render the layout. Not doing that is a very typical bug that shows up as right-to-left layouts not being correctly positioned in a layout with a set width.

The extents are given in layout coordinates and in Pango units; layout coordinates begin at the top left corner of the layout.

get_font_description()

Returns:a pointer to the layout’s font description, or None if the font description from the layout’s context is inherited. This value is owned by the layout and must not be modified or freed. Return type:Pango.FontDescription or None

Gets the font description for the layout, if any.

New in version 1.8.

get_height()

Returns:the height, in Pango units if positive, or number of lines if negative. Return type:int

Gets the height of layout used for ellipsization. See Pango.Layout.set_height() for details.

New in version 1.20.

get_indent()

Returns:the indent in Pango units. Return type:int

Gets the paragraph indent width in Pango units. A negative value indicates a hanging indentation.

get_iter()

Returns:the new Pango.LayoutIter that should be freed using Pango.LayoutIter.free(). Return type:Pango.LayoutIter

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

get_justify()

Returns:the justify. Return type:bool

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

get_line(line)

Parameters:line (int) – the index of a line, which must be between 0 and pango_layout_get_line_count(layout) - 1, inclusive. Returns:the requested Pango.LayoutLine, or None if the index is out of range. This layout line can be ref’ed and retained, but will become invalid if changes are made to the Pango.Layout. Return type:Pango.LayoutLine or None

Retrieves a particular line from a Pango.Layout.

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

get_line_count()

Returns:the line count. Return type:int

Retrieves the count of lines for the self.

get_line_readonly(line)

Parameters:line (int) – the index of a line, which must be between 0 and pango_layout_get_line_count(layout) - 1, inclusive. Returns:the requested Pango.LayoutLine, or None if the index is out of range. This layout line can be ref’ed and retained, but will become invalid if changes are made to the Pango.Layout. No changes should be made to the line. Return type:Pango.LayoutLine or None

Retrieves a particular line from a Pango.Layout.

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

New in version 1.16.

get_line_spacing()

Return type:float

Gets the value that has been set with Pango.Layout.set_line_spacing().

New in version 1.44.

get_lines()

Returns:a GLib.SList 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. Return type:[Pango.LayoutLine]

Returns the lines of the self as a list.

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

get_lines_readonly()

Returns:a GLib.SList 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. Return type:[Pango.LayoutLine]

Returns the lines of the self as a list.

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

New in version 1.16.

get_log_attrs()

Returns:location to store a pointer to an array of logical attributes This value must be freed with GLib.free(). Return type:attrs: [Pango.LogAttr]

Retrieves an array of logical attributes for each character in the self.

get_log_attrs_readonly()

Returns:an array of logical attributes Return type:[Pango.LogAttr]

Retrieves an array of logical attributes for each character in the self.

This is a faster alternative to Pango.Layout.get_log_attrs(). The returned array is part of self and must not be modified. Modifying the layout will invalidate the returned array.

The number of attributes returned in n_attrs 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.

New in version 1.30.

get_pixel_extents()

Returns:

ink_rect:rectangle used to store the extents of the layout as drawn or None to indicate that the result is not needed. logical_rect:rectangle used to store the logical extents of the layout or None to indicate that the result is not needed.

Return type:(ink_rect: Pango.Rectangle, logical_rect: Pango.Rectangle)

Computes the logical and ink extents of self in device units. This function just calls Pango.Layout.get_extents() followed by two Pango.extents_to_pixels() calls, rounding ink_rect and logical_rect such that the rounded rectangles fully contain the unrounded one (that is, passes them as first argument to Pango.extents_to_pixels()).

get_pixel_size()

Returns:

width:location to store the logical width, or None height:location to store the logical height, or None

Return type:(width: int, height: int)

Determines the logical width and height of a Pango.Layout in device units. (Pango.Layout.get_size() returns the width and height scaled by Pango.SCALE.) This is simply a convenience function around Pango.Layout.get_pixel_extents().

get_serial()

Returns:The current serial number of self. Return type:int

Returns the current serial number of self. 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 Pango.Layout.context_changed().

New in version 1.32.4.

get_single_paragraph_mode()

Returns:True if the layout does not break paragraphs at paragraph separator characters, False otherwise. Return type:bool

Obtains the value set by Pango.Layout.set_single_paragraph_mode().

get_size()

Returns:

width:location to store the logical width, or None height:location to store the logical height, or None

Return type:(width: int, height: int)

Determines the logical width and height of a Pango.Layout in Pango units (device units scaled by Pango.SCALE). This is simply a convenience function around Pango.Layout.get_extents().

get_spacing()

Returns:the spacing in Pango units. Return type:int

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

get_tabs()

Returns:a copy of the tabs for this layout, or None. Return type:Pango.TabArray or None

Gets the current Pango.TabArray used by this layout. If no Pango.TabArray has been set, then the default tabs are in use and None is returned. Default tabs are every 8 spaces. The return value should be freed with Pango.TabArray.free().

get_text()

Returns:the text in the self. Return type:str

Gets the text in the layout. The returned text should not be freed or modified.

get_unknown_glyphs_count()

Returns:The number of unknown glyphs in self. Return type:int

Counts the number unknown glyphs in self. That is, zero if glyphs for all characters in the layout text were found, or more than zero otherwise.

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.

New in version 1.16.

get_width()

Returns:the width in Pango units, or -1 if no width set. Return type:int

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

get_wrap()

Returns:active wrap mode. Return type:Pango.WrapMode

Gets the wrap mode for the layout.

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

index_to_line_x(index_, trailing)

Parameters:

• index (int) – the byte index of a grapheme within the layout.
• trailing (bool) – 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.

Returns:

line:location to store resulting line index. (which will between 0 and Pango.Layout.get_line_count(layout) - 1), or None x_pos:location to store resulting position within line (Pango.SCALE units per device unit), or None

Return type:

(line: int, x_pos: int)

Converts from byte index_ within the self to line and X position. (X position is measured from the left edge of the line)

index_to_pos(index_)

Parameters:index (int) – byte index within self Returns:rectangle in which to store the position of the grapheme Return type:pos: Pango.Rectangle

Converts from an index within a Pango.Layout to the onscreen position corresponding to the grapheme at that index, which is represented as rectangle. Note that pos->x is always the leading edge of the grapheme and pos->x + pos->width the trailing edge of the grapheme. If the directionality of the grapheme is right-to-left, then pos->width will be negative.

is_ellipsized()

Returns:True if any paragraphs had to be ellipsized, False otherwise. Return type:bool

Queries whether the layout had to ellipsize any paragraphs.

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

New in version 1.16.

is_wrapped()

Returns:True if any paragraphs had to be wrapped, False otherwise. Return type:bool

Queries whether the layout had to wrap any paragraphs.

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

New in version 1.16.

move_cursor_visually(strong, old_index, old_trailing, direction)

Parameters:

• strong (bool) – 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 (int) – the byte index of the grapheme for the old index
• old_trailing (int) – 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 (int) – direction to move cursor. A negative value indicates motion to the left.

Returns:

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 GObject.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.

Return type:

(new_index: int, new_trailing: int)

Computes a new cursor position from an old position and a count of positions to move visually. If direction is positive, then the new strong cursor position will be one position to the right of the old cursor position. If direction is negative, then the new strong cursor position will be one position to the left of the old cursor position.

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 Pango.Layout.move_cursor_visually() may move the cursor over multiple characters when multiple characters combine to form a single grapheme.

set_alignment(alignment)

Parameters:alignment (Pango.Alignment) – the alignment

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

set_attributes(attrs)

Parameters:attrs (Pango.AttrList or None) – a Pango.AttrList, can be None

Sets the text attributes for a layout object. References attrs, so the caller can unref its reference.

set_auto_dir(auto_dir)

Parameters:auto_dir (bool) – if True, compute the bidirectional base direction from the layout’s contents.

Sets whether to calculate the bidirectional base direction for the layout according to the contents of the layout; when this flag is on (the default), then paragraphs in self 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.

New in version 1.4.

set_ellipsize(ellipsize)

Parameters:ellipsize (Pango.EllipsizeMode) – the new ellipsization mode for self

Sets the type of ellipsization being performed for self. 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 Pango.Layout.set_width() and Pango.Layout.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. See Pango.Layout.set_height() for details.

New in version 1.6.

set_font_description(desc)

Parameters:desc (Pango.FontDescription or None) – the new Pango.FontDescription, or None to unset the current font description

Sets 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.

set_height(height)

Parameters:height (int) – the desired height of the layout in Pango units if positive, or desired number of lines if negative.

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 first line of each paragraph is ellipsized. This behvaior may be changed in the future to act per layout instead of per paragraph. File a bug against pango at http://bugzilla.gnome.org/ if your code relies on this behavior.

Height setting only has effect if a positive width is set on self and ellipsization mode of self 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.

New in version 1.20.

set_indent(indent)

Parameters:indent (int) – the amount by which to 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.

set_justify(justify)

Parameters:justify (bool) – whether the lines in the layout should be justified.

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

set_line_spacing(factor)

Parameters:factor (float) – the new line spacing 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 Pango.Layout.set_spacing() is ignored.

If factor is zero, spacing is applied as before.

New in version 1.44.

set_markup(markup, length)

Parameters:

• markup (str) – marked-up text
• length (int) – length of marked-up text in bytes, or -1 if markup is null-terminated

Same as Pango.Layout.set_markup_with_accel(), but the markup text isn’t scanned for accelerators.

set_markup_with_accel(markup, length, accel_marker)

Parameters:

• markup (str) – marked-up text (see markup format)
• length (int) – length of marked-up text in bytes, or -1 if markup is null-terminated
• accel_marker (str) – marker for accelerators in the text

Returns:

return location for first located accelerator, or None

Return type:

accel_char: str

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, 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.

set_single_paragraph_mode(setting)

Parameters:setting (bool) – new setting

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.

set_spacing(spacing)

Parameters:spacing (int) – the amount of spacing

Sets the amount of spacing in Pango unit between the lines of the layout. When placing lines with spacing, Pango arranges things so that

line2.top = line1.bottom + spacing

Note: Since 1.44, Pango defaults to using the line height (as determined by the font) for placing lines. The spacing set with this function is only taken into account when the line-height factor is set to zero with Pango.Layout.set_line_spacing().

set_tabs(tabs)

Parameters:tabs (Pango.TabArray or None) – a Pango.TabArray, or None

Sets the tabs to use for self, overriding the default tabs (by default, tabs are every 8 spaces). If tabs is None, the default tabs are reinstated. tabs is copied into the layout; you must free your copy of tabs yourself.

set_text(text, length)

Parameters:

• text (str) – the text
• length (int) – maximum length of text, in bytes. -1 indicates that the string is nul-terminated and the length should be calculated. The text will also be truncated on encountering a nul-termination even when length is positive.

Sets the text of the layout.

This function validates text and renders invalid UTF-8 with a placeholder glyph.

Note that if you have used Pango.Layout.set_markup() or Pango.Layout.set_markup_with_accel() on self before, you may want to call Pango.Layout.set_attributes() to clear the attributes set on the layout from the markup as this function does not clear attributes.

set_width(width)

Parameters:width (int) – the desired width in Pango units, or -1 to indicate that no wrapping or ellipsization should be performed.

Sets the width to which the lines of the Pango.Layout should wrap or ellipsized. The default value is -1: no width set.

set_wrap(wrap)

Parameters:wrap (Pango.WrapMode) – the wrap mode

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

xy_to_index(x, y)

Parameters:

• x (int) – the X offset (in Pango units) from the left edge of the layout.
• y (int) – the Y offset (in Pango units) from the top edge of the layout

Returns:

True if the coordinates were inside text, False otherwise.

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.

Return type:

(bool, index_: int, trailing: int)

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.