Class: Pango::Layout

Inherits:
Object
  • Object
show all
Extended by:
GLib::Deprecatable
Defined in:
lib/pango/layout.rb,
lib/pango/deprecated.rb

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(context) ⇒ Pango::Layout

Create a new PangoLayout object with attributes initialized to
default values for a particular PangoContext.

Parameters:

Class Method Details

.deserialize(context, bytes, flags) ⇒ Pango::Layout

Loads data previously created via [methodPango.Layout.serialize].

For a discussion of the supported format, see that function.

Note: to verify that the returned layout is identical to
the one that was serialized, you can compare bytes to the
result of serializing the layout again.

Parameters:

Returns:

Instance Method Details

#alignment ⇒ Pango::Alignment

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

Returns:

#alignment=(alignment) ⇒ nil

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

The default alignment is %PANGO_ALIGN_LEFT.

Parameters:

Returns:

  • (nil)

#attributes ⇒ Pango::AttrList

Gets the attribute list for the layout, if any.

Returns:

#attributes=(attrs) ⇒ nil

Sets the text attributes for a layout object.

References attrs, so the caller can unref its reference.

Parameters:

Returns:

  • (nil)

#auto_dir ⇒ Boolean

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

See [methodPango.Layout.set_auto_dir].

Returns:

  • (Boolean) —

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

#auto_dir=(auto_dir) ⇒ nil

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
PangoContext. (See [methodPango.Context.set_base_dir]).

When the auto-computed direction of a paragraph differs from the
base direction of the context, the interpretation of
%PANGO_ALIGN_LEFT and %PANGO_ALIGN_RIGHT are swapped.

Parameters:

  • auto_dir (Boolean) —

    if true, compute the bidirectional base direction
    from the layout's contents

Returns:

  • (nil)

#baseline ⇒ Integer

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

Returns:

  • (Integer) —

    baseline of first line, from top of layout

#character_count ⇒ Integer

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

Returns:

  • (Integer) —

    the number of Unicode characters
    in the text of layout

#context ⇒ Pango::Context

Retrieves the PangoContext used for this layout.

Returns:

#context_changed ⇒ nil

Forces recomputation of any state in the PangoLayout 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.

Returns:

  • (nil)

#copy ⇒ Pango::Layout

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:

#ellipsize ⇒ Pango::EllipsizeMode

Gets the type of ellipsization being performed for layout.

See [methodPango.Layout.set_ellipsize].

Use [methodPango.Layout.is_ellipsized] to query whether any
paragraphs were actually ellipsized.

Returns:

#ellipsize=(ellipsize) ⇒ nil

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
[methodPango.Layout.set_width] and [methodPango.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.

The default value is %PANGO_ELLIPSIZE_NONE.

See [methodPango.Layout.set_height] for details.

Parameters:

Returns:

  • (nil)

#font_description ⇒ Pango::FontDescription

Gets the font description for the layout, if any.

Returns:

  • (Pango::FontDescription) —

    a pointer to the
    layout's font description, or nil if the font description
    from the layout's context is inherited.

#get_caret_pos(index_, strong_pos, weak_pos) ⇒ nil

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

This is a variant of [methodPango.Layout.get_cursor_pos] that applies
font metric information about caret slope and offset to the positions
it returns.

Parameters:

  • index_ (Integer) —

    the byte index of the cursor

  • strong_pos (Pango::Rectangle) —

    location to store the strong cursor position

  • weak_pos (Pango::Rectangle) —

    location to store the weak cursor position

Returns:

  • (nil)

#get_cursor_pos(index_, strong_pos, weak_pos) ⇒ nil

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.

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.

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_ (Integer) —

    the byte index of the cursor

  • strong_pos (Pango::Rectangle) —

    location to store the strong cursor position

  • weak_pos (Pango::Rectangle) —

    location to store the weak cursor position

Returns:

  • (nil)

#get_direction(index) ⇒ Pango::Direction

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

Parameters:

  • index (Integer) —

    the byte index of the char

Returns:

#get_extents(ink_rect, logical_rect) ⇒ nil

Computes the logical and ink extents of layout.

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.

Parameters:

  • ink_rect (Pango::Rectangle) —

    rectangle used to store the extents of the
    layout as drawn

  • logical_rect (Pango::Rectangle) —

    rectangle used to store the logical
    extents of the layout

Returns:

  • (nil)

#get_line(line) ⇒ Pango::LayoutLine

Retrieves a particular line from a PangoLayout.

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

Parameters:

  • line (Integer) —

    the index of a line, which must be between 0 and
    pango_layout_get_line_count(layout) - 1, inclusive.

Returns:

  • (Pango::LayoutLine) —

    the requested PangoLayoutLine,
    or nil 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
    PangoLayout.

#get_line_readonly(line) ⇒ Pango::LayoutLine

Retrieves a particular line from a PangoLayout.

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

Parameters:

  • line (Integer) —

    the index of a line, which must be between 0 and
    pango_layout_get_line_count(layout) - 1, inclusive.

Returns:

  • (Pango::LayoutLine) —

    the requested PangoLayoutLine,
    or nil 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
    PangoLayout. No changes should be made to the line.

#get_log_attrs(attrs, n_attrs) ⇒ nil

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

Parameters:

  • attrs (Array<Pango::LogAttr>) —

    location to store a pointer to an array of logical attributes.
    This value must be freed with g_free().

  • n_attrs (Integer) —

    location to store the number of the attributes in the
    array. (The stored value 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:

  • (nil)

#get_log_attrs_readonly(n_attrs) ⇒ Array<Pango::LogAttr>

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

This is a faster alternative to [methodPango.Layout.get_log_attrs].
The returned array is part of layout 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.

Parameters:

  • n_attrs (Integer) —

    location to store the number of the attributes in
    the array

Returns:

  • (Array<Pango::LogAttr>) —

    an array of logical attributes

#get_pixel_extents(ink_rect, logical_rect) ⇒ nil

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

This function just calls [methodPango.Layout.get_extents] followed by
two [funcextents_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 [funcPango.extents_to_pixels]).

Parameters:

  • ink_rect (Pango::Rectangle) —

    rectangle used to store the extents of the
    layout as drawn

  • logical_rect (Pango::Rectangle) —

    rectangle used to store the logical
    extents of the layout

Returns:

  • (nil)

#get_pixel_size(width, height) ⇒ nil

Determines the logical width and height of a PangoLayout in device
units.

[methodPango.Layout.get_size] returns the width and height
scaled by %PANGO_SCALE. This is simply a convenience function
around [methodPango.Layout.get_pixel_extents].

Parameters:

  • width (Integer) —

    location to store the logical width

  • height (Integer) —

    location to store the logical height

Returns:

  • (nil)

#get_size(width, height) ⇒ nil

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

This is simply a convenience function around [methodPango.Layout.get_extents].

Parameters:

  • width (Integer) —

    location to store the logical width

  • height (Integer) —

    location to store the logical height

Returns:

  • (nil)

#height ⇒ Integer

Gets the height of layout used for ellipsization.

See [methodPango.Layout.set_height] for details.

Returns:

  • (Integer) —

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

#height=(height) ⇒ nil

Sets the height to which the PangoLayout 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_ELLIPSIZE_NONE.
The behavior is undefined if a height other than -1 is set and
ellipsization mode is set to %PANGO_ELLIPSIZE_NONE, and may change in the
future.

Parameters:

  • height (Integer) —

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

Returns:

  • (nil)

#indent ⇒ Integer

Gets the paragraph indent width in Pango units.

A negative value indicates a hanging indentation.

Returns:

  • (Integer) —

    the indent in Pango units

#indent=(indent) ⇒ nil

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_ALIGN_CENTER.

The default value is 0.

Parameters:

  • indent (Integer) —

    the amount by which to indent

Returns:

  • (nil)

#index_to_line_x(index_, trailing, line, x_pos) ⇒ nil

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_ (Integer) —

    the byte index of a grapheme within the layout

  • trailing (Boolean) —

    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 (Integer) —

    location to store resulting line index. (which will
    between 0 and pango_layout_get_line_count(layout) - 1)

  • x_pos (Integer) —

    location to store resulting position within line
    (%PANGO_SCALE units per device unit)

Returns:

  • (nil)

#index_to_pos(index_, pos) ⇒ nil

Converts from an index within a PangoLayout to the onscreen position
corresponding to the grapheme at that index.

The returns 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.

Parameters:

  • index_ (Integer) —

    byte index within layout

  • pos (Pango::Rectangle) —

    rectangle in which to store the position of the grapheme

Returns:

  • (nil)

#is_ellipsized ⇒ Boolean

Queries whether the layout had to ellipsize any paragraphs.

This returns true if the ellipsization mode for layout
is not %PANGO_ELLIPSIZE_NONE, a positive width is set on layout,
and there are paragraphs exceeding that width that have to be
ellipsized.

Returns:

  • (Boolean) —

    true if any paragraphs had to be ellipsized,
    false otherwise

#is_wrapped ⇒ Boolean

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_ELLIPSIZE_NONE,
and there are paragraphs exceeding the layout width that have
to be wrapped.

Returns:

  • (Boolean) —

    true if any paragraphs had to be wrapped, false
    otherwise

#iter ⇒ Pango::LayoutIter

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

Returns:

  • (Pango::LayoutIter) —

    the new PangoLayoutIter

#justify ⇒ Boolean

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

Returns:

  • (Boolean) —

    the justify value

#justify=(justify) ⇒ nil

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 [methodPango.Layout.set_justify_last_line].

Parameters:

  • justify (Boolean) —

    whether the lines in the layout should be justified

Returns:

  • (nil)

#justify_last_line ⇒ Boolean

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

Returns:

  • (Boolean) —

    the justify value

#justify_last_line=(justify) ⇒ nil

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

This only has an effect if [methodPango.Layout.set_justify] has
been called as well.

The default value is false.

Parameters:

  • justify (Boolean) —

    whether the last line in the layout should be justified

Returns:

  • (nil)

#line_count ⇒ Integer

Retrieves the count of lines for the layout.

Returns:

  • (Integer) —

    the line count

#line_spacing ⇒ Pango::gfloat

Gets the line spacing factor of layout.

See [methodPango.Layout.set_line_spacing].

Returns:

  • (Pango::gfloat)

#line_spacing=(factor) ⇒ nil

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 [methodPango.Layout.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 [funcPango.attr_line_height_new].

Parameters:

  • factor (Pango::gfloat) —

    the new line spacing factor

Returns:

  • (nil)

#lines ⇒ GLib::SList<Pango::LayoutLine>

Returns the lines of the layout as a list.

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

Returns:

  • (GLib::SList<Pango::LayoutLine>) —

    a GSList
    containing the lines in the layout. This points to internal data of the
    PangoLayout and must be used with care. It will become invalid on any
    change to the layout's text or properties.

#lines_readonly ⇒ GLib::SList<Pango::LayoutLine>

Returns the lines of the layout as a list.

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

Returns:

  • (GLib::SList<Pango::LayoutLine>) —

    a GSList
    containing the lines in the layout. This points to internal data of the
    PangoLayout 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.

#move_cursor_visually(strong, old_index, old_trailing, direction, new_index, new_trailing) ⇒ nil

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 (Boolean) —

    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 (Integer) —

    the byte index of the current cursor position

  • old_trailing (Integer) —

    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 (Integer) —

    direction to move cursor. A negative
    value indicates motion to the left

  • new_index (Integer) —

    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 (Integer) —

    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.

Returns:

  • (nil)

#serial ⇒ Integer

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 PangoContext 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 PangoLayout,
and is useful for example to decide whether a layout needs redrawing.
To force the serial to be increased, use
[methodPango.Layout.context_changed].

Returns:

  • (Integer) —

    The current serial number of layout.

#serialize(flags) ⇒ GLib::Bytes

Serializes the layout for later deserialization via [funcPango.Layout.deserialize].

There are no guarantees about the format of the output across different
versions of Pango and [funcPango.Layout.deserialize] will reject data
that it cannot parse.

The intended use of this function is testing, benchmarking and debugging.
The format is not meant as a permanent storage format.

Parameters:

Returns:

  • (GLib::Bytes) —

    a GBytes containing the serialized form of layout

#set_font_description(description) ⇒ Object Also known as: font_description= 



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# File 'lib/pango/layout.rb', line 20

def set_font_description(description)
  unless description.is_a?(FontDescription)
    description = FontDescription.new(description)
  end
  set_font_description_raw(description)
end

#set_font_description_raw ⇒ Object 



19
 
# File 'lib/pango/layout.rb', line 19

alias_method :set_font_description_raw, :set_font_description

#set_markup(markup) ⇒ nil Also known as: markup=

Sets the layout text and attribute list from marked-up text.

See Pango Markup).

Replaces the current text and attribute list.

This is the same as [methodPango.Layout.set_markup_with_accel],
but the markup text isn't scanned for accelerators.

Parameters:

  • markup (String) —

    marked-up text

  • length (Integer) —

    length of marked-up text in bytes, or -1 if markup is
    NUL-terminated

Returns:

  • (nil) 


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# File 'lib/pango/layout.rb', line 36

def set_markup(markup)
  set_markup_raw(markup, markup.bytesize)
end

#set_markup_raw ⇒ nil

Sets the layout text and attribute list from marked-up text.

See Pango Markup).

Replaces the current text and attribute list.

This is the same as [methodPango.Layout.set_markup_with_accel],
but the markup text isn't scanned for accelerators.

Parameters:

  • markup (String) —

    marked-up text

  • length (Integer) —

    length of marked-up text in bytes, or -1 if markup is
    NUL-terminated

Returns:

  • (nil) 



# File 'lib/pango/layout.rb', line 35

#set_markup_with_accel(markup, length, accel_marker, accel_char) ⇒ nil

Sets the layout text and attribute list from marked-up text.

See Pango Markup).

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.

Parameters:

  • markup (String) —

    marked-up text (see Pango Markup)

  • length (Integer) —

    length of marked-up text in bytes, or -1 if markup is
    NUL-terminated

  • accel_marker (String) —

    marker for accelerators in the text

  • accel_char (String) —

    return location
    for first located accelerator

Returns:

  • (nil)

#set_text(text) ⇒ nil Also known as: text=

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 [methodPango.Layout.set_markup] or
[methodPango.Layout.set_markup_with_accel] on layout before, you
may want to call [methodPango.Layout.set_attributes] to clear the
attributes set on the layout from the markup as this function does
not clear attributes.

Parameters:

  • text (String) —

    the text

  • length (Integer) —

    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.

Returns:

  • (nil) 


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# File 'lib/pango/layout.rb', line 30

def set_text(text)
  set_text_raw(text, text.bytesize)
end

#set_text_raw ⇒ nil

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 [methodPango.Layout.set_markup] or
[methodPango.Layout.set_markup_with_accel] on layout before, you
may want to call [methodPango.Layout.set_attributes] to clear the
attributes set on the layout from the markup as this function does
not clear attributes.

Parameters:

  • text (String) —

    the text

  • length (Integer) —

    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.

Returns:

  • (nil) 



# File 'lib/pango/layout.rb', line 29

#single_paragraph_mode ⇒ Boolean

Obtains whether layout is in single paragraph mode.

See [methodPango.Layout.set_single_paragraph_mode].

Returns:

  • (Boolean) —

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

#single_paragraph_mode=(setting) ⇒ nil

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 (Boolean) —

    new setting

Returns:

  • (nil)

#spacing ⇒ Integer

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

Returns:

  • (Integer) —

    the spacing in Pango units

#spacing=(spacing) ⇒ nil

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 [methodPango.Layout.set_line_spacing].
In that case, the spacing set with this function is ignored.

Note: for semantics that are closer to the CSS line-height
property, see [funcPango.attr_line_height_new].

Parameters:

  • spacing (Integer) —

    the amount of spacing

Returns:

  • (nil)

#tabs ⇒ Pango::TabArray

Gets the current PangoTabArray used by this layout.

If no PangoTabArray has been set, then the default tabs are
in use and nil is returned. Default tabs are every 8 spaces.

The return value should be freed with [methodPango.TabArray.free].

Returns:

  • (Pango::TabArray) —

    a copy of the tabs for this layout

#tabs=(tabs) ⇒ nil

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

PangoLayout 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 nil, 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_ALIGN_LEFT.

Parameters:

  • tabs (Pango::TabArray) —

    a PangoTabArray

Returns:

  • (nil)

#text ⇒ String

Gets the text in the layout.

The returned text should not be freed or modified.

Returns:

  • (String) —

    the text in the layout

#unknown_glyphs_count ⇒ Integer

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_ATTR_FALLBACK, to check if a
certain font supports all the characters in the string.

Returns:

  • (Integer) —

    The number of unknown glyphs in layout

#width ⇒ Integer

Gets the width to which the lines of the PangoLayout should wrap.

Returns:

  • (Integer) —

    the width in Pango units, or -1 if no width set.

#width=(width) ⇒ nil

Sets the width to which the lines of the PangoLayout should wrap or
ellipsized.

The default value is -1: no width set.

Parameters:

  • width (Integer) —

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

Returns:

  • (nil)

#wrap ⇒ Pango::WrapMode

Gets the wrap mode for the layout.

Use [methodPango.Layout.is_wrapped] to query whether
any paragraphs were actually wrapped.

Returns:

#wrap=(wrap) ⇒ nil

Sets the wrap mode.

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

The default value is %PANGO_WRAP_WORD.

Parameters:

Returns:

  • (nil)

#write_to_file(flags, filename) ⇒ Boolean

A convenience method to serialize a layout to a file.

It is equivalent to calling [methodPango.Layout.serialize]
followed by [funcGLib.file_set_contents].

See those two functions for details on the arguments.

It is mostly intended for use inside a debugger to quickly dump
a layout to a file for later inspection.

Parameters:

Returns:

  • (Boolean) —

    true if saving was successful

#xy_to_index(x, y, index_, trailing) ⇒ Boolean

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 [methodPango.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 (Integer) —

    the X offset (in Pango units) from the left edge of the layout

  • y (Integer) —

    the Y offset (in Pango units) from the top edge of the layout

  • index_ (Integer) —

    location to store calculated byte index

  • trailing (Integer) —

    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:

  • (Boolean) —

    true if the coordinates were inside text, false otherwise