Gnome::Pango::Layout
#------------------------------------------------------------------------------- #--[Class Description]---------------------------------------------------------- #-------------------------------------------------------------------------------
Description
A Gnome::Pango::Layout structure represents an entire paragraph of text.
While complete access to the layout capabilities of Pango is provided using the detailed interfaces for itemization and shaping, using that functionality directly involves writing a fairly large amount of code. Gnome::Pango::Layout provides a high-level driver for formatting entire paragraphs of text at once. This includes paragraph-level functionality such as line breaking, justification, alignment and ellipsization.
A Gnome::Pango::Layout is initialized with a Gnome::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 a number of parameters to adjust the formatting of a Gnome::Pango::Layout. The following image shows adjustable parameters (on the left) and font metrics (on the right):
<picture> <source srcset="layout-dark.png" media="(prefers-color-scheme: dark)"> <img alt="Pango Layout Parameters" src="layout-light.png"> </picture>
The following images demonstrate the effect of alignment and justification on the layout of text:
| | | | --- | --- | | =for image :src<asset_files/images/align-left.png> :width<30%> :class<inline> | =for image :src<asset_files/images/align-left-justify.png> :width<30%> :class<inline> | | =for image :src<asset_files/images/align-center.png> :width<30%> :class<inline> | =for image :src<asset_files/images/align-center-justify.png> :width<30%> :class<inline> | | =for image :src<asset_files/images/align-right.png> :width<30%> :class<inline> | =for image :src<asset_files/images/align-right-justify.png> :width<30%> :class<inline> |
It is possible, as well, to ignore the 2-D setup, and simply treat the results of a Gnome::Pango::Layout as a list of lines.
#------------------------------------------------------------------------------- #--[Class Initialization]------------------------------------------------------- #-------------------------------------------------------------------------------
Class initialization
new
:native-object
Create an object using a native object from an object of the same type found elsewhere. See also Gnome::N::TopLevelSupportClass.
multi method new ( N-Object() :$native-object! )
#-------------------------------------------------------------------------------
new-layout
Create a new Gnome::Pango::Layout object with attributes initialized to default values for a particular Gnome::Pango::Context.
method new-layout ( N-Object() $context --> Gnome::Pango::Layout \)
$context; a Gnome::Pango::Context.
#------------------------------------------------------------------------------- #--[Methods]-------------------------------------------------------------------- #-------------------------------------------------------------------------------
Methods
#-------------------------------------------------------------------------------
context-changed
Forces recomputation of any state in the Gnome::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.
method context-changed ( )
#-------------------------------------------------------------------------------
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.
method copy (--> N-Object )
Return value; the newly allocated Gnome::Pango::Layout.
#-------------------------------------------------------------------------------
get-alignment
Gets the alignment for the layout: how partial lines are positioned within the horizontal space available.
method get-alignment (--> PangoAlignment )
Return value; the alignment.
#-------------------------------------------------------------------------------
get-attributes
Gets the attribute list for the layout, if any.
method get-attributes (--> N-Object )
Return value; a Gnome::Pango::N-AttrList.
#-------------------------------------------------------------------------------
get-auto-dir
Gets whether to calculate the base direction for the layout according to its contents.
See .set-auto-dir().
method get-auto-dir (--> Bool )
Return value; True if the bidirectional base direction
is computed from the layout's contents, False otherwise.
#-------------------------------------------------------------------------------
get-baseline
Gets the Y position of baseline of the first line in $layout.
method get-baseline (--> Int )
Return value; baseline of first line, from top of $layout.
#-------------------------------------------------------------------------------
get-caret-pos
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 .get-cursor-pos() that applies
font metric information about caret slope and offset to the positions
it returns.
<picture> <source srcset="caret-metrics-dark.png" media="(prefers-color-scheme: dark)"> <img alt="Caret metrics" src="caret-metrics-light.png"> </picture>
method get-caret-pos ( Int() $index, N-Object $strong-pos, N-Object $weak-pos )
$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-character-count
Returns the number of Unicode characters in the
the text of $layout.
method get-character-count (--> Int )
Return value; the number of Unicode characters
in the text of $layout.
#-------------------------------------------------------------------------------
get-context
Retrieves the Gnome::Pango::Context used for this layout.
method get-context (--> N-Object )
Return value; the Gnome::Pango::Context for the layout.
#-------------------------------------------------------------------------------
get-cursor-pos
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)"> <img alt="Cursor positions" src="cursor-positions-light.png"> </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)"> <img alt="Strong and weak cursors" src="split-cursor-light.png"> </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 '×', will insert it at the end.
method get-cursor-pos ( Int() $index, N-Object $strong-pos, N-Object $weak-pos )
$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-direction
Gets the text direction at the given character position in $layout.
method get-direction ( Int() $index --> PangoDirection )
$index; the byte index of the char.
Return value; the text direction at $index.
#-------------------------------------------------------------------------------
get-ellipsize
Gets the type of ellipsization being performed for $layout.
See .set-ellipsize().
Use .is-ellipsized() to query whether any
paragraphs were actually ellipsized.
method get-ellipsize (--> PangoEllipsizeMode )
Return value; the current ellipsization mode for $layout.
#-------------------------------------------------------------------------------
get-extents
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.
method get-extents ( N-Object $ink-rect, N-Object $logical-rect )
$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
Gets the font description for the layout, if any.
method get-font-description (--> N-Object )
Return value; a pointer to the layout's font description, or undefined if the font description from the layout's context is inherited..
#-------------------------------------------------------------------------------
get-height
Gets the height of layout used for ellipsization.
See .set-height() for details.
method get-height (--> Int )
Return value; the height, in Pango units if positive, or number of lines if negative..
#-------------------------------------------------------------------------------
get-indent
Gets the paragraph indent width in Pango units.
A negative value indicates a hanging indentation.
method get-indent (--> Int )
Return value; the indent in Pango units.
#-------------------------------------------------------------------------------
get-iter
Returns an iterator to iterate over the visual extents of the layout.
method get-iter (--> N-Object )
Return value; the new Gnome::Pango::T-layout.
#-------------------------------------------------------------------------------
get-justify
Gets whether each complete line should be stretched to fill the entire width of the layout.
method get-justify (--> Bool )
Return value; the justify value.
#-------------------------------------------------------------------------------
get-justify-last-line
Gets whether the last line should be stretched to fill the entire width of the layout.
method get-justify-last-line (--> Bool )
Return value; the justify value.
#-------------------------------------------------------------------------------
get-line
Retrieves a particular line from a Gnome::Pango::Layout.
Use the faster .get-line-readonly() if you do not
plan to modify the contents of the line (glyphs, glyph widths, etc.).
method get-line ( Int() $line --> N-Object )
$line; the index of a line, which must be between 0 and pango_layout_get_line_count(layout) - 1`, inclusive..
Return value; the requested Gnome::Pango::N-LayoutLine, or undefined 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 Gnome::Pango::Layout..
#-------------------------------------------------------------------------------
get-line-count
Retrieves the count of lines for the $layout.
method get-line-count (--> Int )
Return value; the line count.
#-------------------------------------------------------------------------------
get-line-readonly
Retrieves a particular line from a Gnome::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.).
method get-line-readonly ( Int() $line --> N-Object )
$line; the index of a line, which must be between 0 and pango_layout_get_line_count(layout) - 1`, inclusive..
Return value; the requested Gnome::Pango::N-LayoutLine, or undefined 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 Gnome::Pango::Layout. No changes should be made to the line..
#-------------------------------------------------------------------------------
get-line-spacing
Gets the line spacing factor of $layout.
See .set-line-spacing().
method get-line-spacing (--> Num )
Return value; No documentation about its value and use.
#-------------------------------------------------------------------------------
get-lines
Returns the lines of the $layout as a list.
Use the faster .get-lines-readonly() if you do not
plan to modify the contents of the lines (glyphs, glyph widths, etc.).
method get-lines (--> N-SList )
Return value; a Gnome::Glib::N-SList containing the lines in the layout. This points to internal data of the Gnome::Pango::Layout and must be used with care. It will become invalid on any change to the layout's text or properties..
#-------------------------------------------------------------------------------
get-lines-readonly
Returns the lines of the $layout as a list.
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.).
method get-lines-readonly (--> N-SList )
Return value; a Gnome::Glib::N-SList containing the lines in the layout. This points to internal data of the Gnome::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
Retrieves an array of logical attributes for each character in
the $layout.
method get-log-attrs ( N-Object $attrs, Array[Int] $n-attrs )
$attrs; (transfer ownership: container) location to store a pointer to an array of logical attributes. This value must be freed with g_free().
$n-attrs; (transfer ownership: full) 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.).
#-------------------------------------------------------------------------------
get-log-attrs-readonly
Retrieves an array of logical attributes for each character in
the $layout.
This is a faster alternative to .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.
method get-log-attrs-readonly ( Array[Int] $n-attrs --> N-Object )
$n-attrs; (transfer ownership: full) location to store the number of the attributes in the array.
Return value; an array of logical attributes.
#-------------------------------------------------------------------------------
get-pixel-extents
Computes the logical and ink extents of $layout in device units.
This function just calls .get-extents() followed by
two [func $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 .extents-to-pixels()).
method get-pixel-extents ( N-Object $ink-rect, N-Object $logical-rect )
$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-size
Determines the logical width and height of a Gnome::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().
method get-pixel-size ( Array[Int] $width, Array[Int] $height )
$width; (transfer ownership: full) location to store the logical width.
$height; (transfer ownership: full) location to store the logical height.
#-------------------------------------------------------------------------------
get-serial
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 Gnome::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 Gnome::Pango::Layout,
and is useful for example to decide whether a layout needs redrawing.
To force the serial to be increased, use
.context-changed().
method get-serial (--> UInt )
Return value; The current serial number of $layout..
#-------------------------------------------------------------------------------
get-single-paragraph-mode
Obtains whether $layout is in single paragraph mode.
See .set-single-paragraph-mode().
method get-single-paragraph-mode (--> Bool )
Return value; True if the layout does not break paragraphs
at paragraph separator characters, False otherwise.
#-------------------------------------------------------------------------------
get-size
Determines the logical width and height of a Gnome::Pango::Layout in Pango units.
This is simply a convenience function around .get-extents().
method get-size ( Array[Int] $width, Array[Int] $height )
$width; (transfer ownership: full) location to store the logical width.
$height; (transfer ownership: full) location to store the logical height.
#-------------------------------------------------------------------------------
get-spacing
Gets the amount of spacing between the lines of the layout.
method get-spacing (--> Int )
Return value; the spacing in Pango units.
#-------------------------------------------------------------------------------
get-tabs
Gets the current Gnome::Pango::N-TabArray used by this layout.
If no Gnome::Pango::N-TabArray has been set, then the default tabs are in use and undefined is returned. Default tabs are every 8 spaces.
The return value should be freed with .free() in class Gnome::Pango::N-TabArray.
method get-tabs (--> N-Object )
Return value; a copy of the tabs for this layout.
#-------------------------------------------------------------------------------
get-text
Gets the text in the layout.
The returned text should not be freed or modified.
method get-text (--> Str )
Return value; the text in the $layout.
#-------------------------------------------------------------------------------
get-unknown-glyphs-count
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.
method get-unknown-glyphs-count (--> Int )
Return value; The number of unknown glyphs in $layout.
#-------------------------------------------------------------------------------
get-width
Gets the width to which the lines of the Gnome::Pango::Layout should wrap.
method get-width (--> Int )
Return value; the width in Pango units, or -1 if no width set..
#-------------------------------------------------------------------------------
get-wrap
Gets the wrap mode for the layout.
Use .is-wrapped() to query whether
any paragraphs were actually wrapped.
method get-wrap (--> PangoWrapMode )
Return value; active wrap mode..
#-------------------------------------------------------------------------------
index-to-line-x
Converts from byte $index- within the $layout to line and X position.
The X position is measured from the left edge of the line.
method index-to-line-x ( Int() $index, Bool() $trailing, Array[Int] $line, Array[Int] $x-pos )
$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; (transfer ownership: full) location to store resulting line index. (which will between 0 and pango_layout_get_line_count(layout) - 1).
$x-pos; (transfer ownership: full) location to store resulting position within line (
PANGO_SCALEunits per device unit).
#-------------------------------------------------------------------------------
index-to-pos
Converts from an index within a Gnome::Pango::Layout 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.
method index-to-pos ( Int() $index, N-Object $pos )
$index; byte index within
$layout.$pos; rectangle in which to store the position of the grapheme
#-------------------------------------------------------------------------------
is-ellipsized
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.
method is-ellipsized (--> Bool )
Return value; True if any paragraphs had to be ellipsized,
False otherwise.
#-------------------------------------------------------------------------------
is-wrapped
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.
method is-wrapped (--> Bool )
Return value; True if any paragraphs had to be wrapped, False
otherwise.
#-------------------------------------------------------------------------------
move-cursor-visually
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.
method move-cursor-visually ( Bool() $strong, Int() $old-index, Int() $old-trailing, Int() $direction, Array[Int] $new-index, Array[Int] $new-trailing )
$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.
$new-index; (transfer ownership: full) location to store the new cursor byte index. A value of -1 indicates that the cursor has been moved off the beginning of the layout. A value of
G_MAXINTindicates that the cursor has been moved off the end of the layout..$new-trailing; (transfer ownership: full) number of characters to move forward from the location returned for
$new-indexto get the position where the cursor should be displayed. This allows distinguishing the position at the beginning of one line from the position at the end of the preceding line.$new-indexis always on the line where the cursor should be displayed..
#-------------------------------------------------------------------------------
serialize
Serializes the $layout for later deserialization via .Layout.deserialize().
There are no guarantees about the format of the output across different
versions of Pango and .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.
method serialize ( UInt $flags --> N-Object )
$flags;
bit field PangoLayoutSerializeFlags defined in Gnome::Pango::T-layout.
Return value; a Gnome::Glib::N-Bytes containing the serialized form of $layout.
#-------------------------------------------------------------------------------
set-alignment
Sets the alignment for the layout: how partial lines are positioned within the horizontal space available.
The default alignment is PANGO_ALIGN_LEFT.
method set-alignment ( PangoAlignment $alignment )
$alignment; the alignment.
#-------------------------------------------------------------------------------
set-attributes
Sets the text attributes for a layout object.
References $attrs, so the caller can unref its reference.
method set-attributes ( N-Object $attrs )
$attrs; a Gnome::Pango::N-AttrList
#-------------------------------------------------------------------------------
set-auto-dir
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
Gnome::Pango::Context. (See .set-base-dir() in class Gnome::Pango::Context).
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.
method set-auto-dir ( Bool() $auto-dir )
$auto-dir; if
True, compute the bidirectional base direction from the layout's contents.
#-------------------------------------------------------------------------------
set-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_ELLIPSIZE_NONE.
See .set-height() for details.
method set-ellipsize ( PangoEllipsizeMode $ellipsize )
$ellipsize; the new ellipsization mode for
$layout.
#-------------------------------------------------------------------------------
set-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.
method set-font-description ( N-Object $desc )
$desc; the new Gnome::Pango::N-FontDescription to unset the current font description
#-------------------------------------------------------------------------------
set-height
Sets the height to which the Gnome::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](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.
method set-height ( Int() $height )
$height; the desired height of the layout in Pango units if positive, or desired number of lines if negative..
#-------------------------------------------------------------------------------
set-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_ALIGN_CENTER.
The default value is 0.
method set-indent ( Int() $indent )
$indent; the amount by which to indent.
#-------------------------------------------------------------------------------
set-justify
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().
method set-justify ( Bool() $justify )
$justify; whether the lines in the layout should be justified.
#-------------------------------------------------------------------------------
set-justify-last-line
Sets whether the last line should be stretched to fill the entire width of the layout.
This only has an effect if .set-justify() has
been called as well.
The default value is False.
method set-justify-last-line ( Bool() $justify )
$justify; whether the last line in the layout should be justified.
#-------------------------------------------------------------------------------
set-line-spacing
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 .attr-line-height-new().
method set-line-spacing ( Num() $factor )
$factor; the new line spacing factor.
#-------------------------------------------------------------------------------
set-markup
Sets the layout text and attribute list from marked-up text.
See [Pango Markup](pango_markup.html)).
Replaces the current text and attribute list.
This is the same as .set-markup-with-accel(),
but the markup text isn't scanned for accelerators.
method set-markup ( Str $markup, Int() $length )
$markup; marked-up text.
$length; length of marked-up text in bytes, or -1 if
$markupis NUL-terminated.
#-------------------------------------------------------------------------------
set-markup-with-accel
Sets the layout text and attribute list from marked-up text.
See [Pango Markup](pango_markup.html)).
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.
method set-markup-with-accel ( Str $markup, Int() $length, UInt() $accel-marker, Str $accel-char )
$markup; marked-up text (see [Pango Markup](pango_markup.html)).
$length; length of marked-up text in bytes, or -1 if
$markupis NUL-terminated.$accel-marker; marker for accelerators in the text.
$accel-char; (transfer ownership: full) return location for first located accelerator.
#-------------------------------------------------------------------------------
set-single-paragraph-mode
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.
method set-single-paragraph-mode ( Bool() $setting )
$setting; new setting.
#-------------------------------------------------------------------------------
set-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.
Note: for semantics that are closer to the CSS line-height
property, see .attr-line-height-new().
method set-spacing ( Int() $spacing )
$spacing; the amount of spacing.
#-------------------------------------------------------------------------------
set-tabs
Sets the tabs to use for $layout, overriding the default tabs.
Gnome::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 undefined, 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.
method set-tabs ( N-Object $tabs )
$tabs; a Gnome::Pango::N-TabArray
#-------------------------------------------------------------------------------
set-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 .set-markup() or
.set-markup-with-accel() on $layout before, you
may want to call .set-attributes() to clear the
attributes set on the layout from the markup as this function does
not clear attributes.
method set-text ( Str $text, Int() $length )
$text; the text.
$length; maximum length of
$text, in bytes. -1 indicates that the string is nul-terminated and the length should be calculated. The text will also be truncated on encountering a nul-termination even when$lengthis positive..
#-------------------------------------------------------------------------------
set-width
Sets the width to which the lines of the Gnome::Pango::Layout should wrap or ellipsized.
The default value is -1: no width set.
method set-width ( Int() $width )
$width; the desired width in Pango units, or -1 to indicate that no wrapping or ellipsization should be performed..
#-------------------------------------------------------------------------------
set-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_WRAP_WORD.
method set-wrap ( PangoWrapMode $wrap )
$wrap; the wrap mode.
#-------------------------------------------------------------------------------
write-to-file
A convenience method to serialize a layout to a file.
It is equivalent to calling .serialize()
followed by .file-set-contents() in package Gnome::GLib.
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.
method write-to-file ( UInt $flags, Str $filename, CArray[N-Error] $err --> Bool )
$flags;
bit field PangoLayoutSerializeFlags defined in Gnome::Pango::T-layout.$filename; the file to save it to.
$err; Error object. When defined, an error can be returned when there is one. Use
Pointerwhen you want to ignore the error. .
Return value; True if saving was successful.
#-------------------------------------------------------------------------------
xy-to-index
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 .x-to-index() in class Gnome::Pango::N-LayoutLine. If either
the X or Y positions were not inside the layout, then the function returns
False; on an exact hit, it returns True.
method xy-to-index ( Int() $x, Int() $y, Array[Int] $index, Array[Int] $trailing --> Bool )
$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; (transfer ownership: full) location to store calculated byte index.
$trailing; (transfer ownership: full) 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 value; True if the coordinates were inside text, False otherwise.
#------------------------------------------------------------------------------- #--[Functions]------------------------------------------------------------------ #-------------------------------------------------------------------------------
Functions
#-------------------------------------------------------------------------------
deserialize
Loads data previously created via .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.
method deserialize ( N-Object() $context, N-Object $bytes, UInt $flags, CArray[N-Error] $err --> N-Object )
$context; a Gnome::Pango::Context.
$bytes; the bytes containing the data
$flags;
bit field PangoLayoutDeserializeFlags defined in Gnome::Pango::T-layout.$err; Error object. When defined, an error can be returned when there is one. Use
Pointerwhen you want to ignore the error. .
Return value; a new Gnome::Pango::Layout.