Layout Objects

Layout Objects — High-level layout driver objects

Functions

PangoLayout * pango_layout_new ()
PangoLayout * pango_layout_copy ()
PangoContext * pango_layout_get_context ()
void pango_layout_context_changed ()
guint pango_layout_get_serial ()
void pango_layout_set_text ()
const char * pango_layout_get_text ()
gint pango_layout_get_character_count ()
void pango_layout_set_markup ()
void pango_layout_set_markup_with_accel ()
void pango_layout_set_attributes ()
PangoAttrList * pango_layout_get_attributes ()
void pango_layout_set_font_description ()
const PangoFontDescription * pango_layout_get_font_description ()
void pango_layout_set_width ()
int pango_layout_get_width ()
void pango_layout_set_height ()
int pango_layout_get_height ()
void pango_layout_set_wrap ()
PangoWrapMode pango_layout_get_wrap ()
gboolean pango_layout_is_wrapped ()
void pango_layout_set_ellipsize ()
PangoEllipsizeMode pango_layout_get_ellipsize ()
gboolean pango_layout_is_ellipsized ()
void pango_layout_set_indent ()
int pango_layout_get_indent ()
int pango_layout_get_spacing ()
void pango_layout_set_spacing ()
void pango_layout_set_justify ()
gboolean pango_layout_get_justify ()
void pango_layout_set_auto_dir ()
gboolean pango_layout_get_auto_dir ()
void pango_layout_set_alignment ()
PangoAlignment pango_layout_get_alignment ()
void pango_layout_set_tabs ()
PangoTabArray * pango_layout_get_tabs ()
void pango_layout_set_single_paragraph_mode ()
gboolean pango_layout_get_single_paragraph_mode ()
int pango_layout_get_unknown_glyphs_count ()
void pango_layout_get_log_attrs ()
const PangoLogAttr * pango_layout_get_log_attrs_readonly ()
void pango_layout_index_to_pos ()
void pango_layout_index_to_line_x ()
gboolean pango_layout_xy_to_index ()
void pango_layout_get_cursor_pos ()
void pango_layout_move_cursor_visually ()
void pango_layout_get_extents ()
void pango_layout_get_pixel_extents ()
void pango_layout_get_size ()
void pango_layout_get_pixel_size ()
int pango_layout_get_baseline ()
int pango_layout_get_line_count ()
PangoLayoutLine * pango_layout_get_line ()
PangoLayoutLine * pango_layout_get_line_readonly ()
GSList * pango_layout_get_lines ()
GSList * pango_layout_get_lines_readonly ()
PangoLayoutIter * pango_layout_get_iter ()
PangoLayoutIter * pango_layout_iter_copy ()
void pango_layout_iter_free ()
gboolean pango_layout_iter_next_run ()
gboolean pango_layout_iter_next_char ()
gboolean pango_layout_iter_next_cluster ()
gboolean pango_layout_iter_next_line ()
gboolean pango_layout_iter_at_last_line ()
int pango_layout_iter_get_index ()
int pango_layout_iter_get_baseline ()
PangoLayoutRun * pango_layout_iter_get_run ()
PangoLayoutRun * pango_layout_iter_get_run_readonly ()
PangoLayoutLine * pango_layout_iter_get_line ()
PangoLayoutLine * pango_layout_iter_get_line_readonly ()
PangoLayout * pango_layout_iter_get_layout ()
void pango_layout_iter_get_char_extents ()
void pango_layout_iter_get_cluster_extents ()
void pango_layout_iter_get_run_extents ()
void pango_layout_iter_get_line_yrange ()
void pango_layout_iter_get_line_extents ()
void pango_layout_iter_get_layout_extents ()
PangoLayoutLine * pango_layout_line_ref ()
void pango_layout_line_unref ()
void pango_layout_line_get_extents ()
void pango_layout_line_get_pixel_extents ()
void pango_layout_line_index_to_x ()
gboolean pango_layout_line_x_to_index ()
void pango_layout_line_get_x_ranges ()

Object Hierarchy

    GBoxed
    ├── PangoLayoutIter
    ╰── PangoLayoutLine
    GEnum
    ├── PangoAlignment
    ├── PangoEllipsizeMode
    ╰── PangoWrapMode
    GObject
    ╰── PangoLayout

Description

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. The objects and functions in this section provide a high-level driver for formatting entire paragraphs of text at once.

Functions

pango_layout_new ()

PangoLayout *
pango_layout_new (PangoContext *context);

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

Parameters

context

a PangoContext

 

Returns

the newly allocated PangoLayout, with a reference count of one, which should be freed with g_object_unref().


pango_layout_copy ()

PangoLayout *
pango_layout_copy (PangoLayout *src);

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

Parameters

src

a PangoLayout

 

Returns

the newly allocated PangoLayout, with a reference count of one, which should be freed with g_object_unref().

[transfer full]


pango_layout_get_context ()

PangoContext *
pango_layout_get_context (PangoLayout *layout);

Retrieves the PangoContext used for this layout.

Parameters

layout

a PangoLayout

 

Returns

the PangoContext 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.

[transfer none]


pango_layout_context_changed ()

void
pango_layout_context_changed (PangoLayout *layout);

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.

Parameters

layout

a PangoLayout

 

pango_layout_get_serial ()

guint
pango_layout_get_serial (PangoLayout *layout);

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 pango_layout_context_changed().

Parameters

layout

a PangoLayout

 

Returns

The current serial number of layout .

Since: 1.32.4


pango_layout_set_text ()

void
pango_layout_set_text (PangoLayout *layout,
                       const char *text,
                       int length);

Sets the text of the layout.

Note that if you have used pango_layout_set_markup() or pango_layout_set_markup_with_accel() on layout 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.

Parameters

layout

a PangoLayout

 

text

a valid UTF-8 string

 

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 length is positive.

 

pango_layout_get_text ()

const char *
pango_layout_get_text (PangoLayout *layout);

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

Parameters

layout

a PangoLayout

 

Returns

the text in the layout .


pango_layout_get_character_count ()

gint
pango_layout_get_character_count (PangoLayout *layout);

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

Parameters

layout

a PangoLayout

 

Returns

the number of Unicode characters in the text of layout

Since: 1.30


pango_layout_set_markup ()

void
pango_layout_set_markup (PangoLayout *layout,
                         const char *markup,
                         int length);

Same as pango_layout_set_markup_with_accel(), but the markup text isn't scanned for accelerators.

Parameters

layout

a PangoLayout

 

markup

marked-up text

 

length

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

 

pango_layout_set_markup_with_accel ()

void
pango_layout_set_markup_with_accel (PangoLayout *layout,
                                    const char *markup,
                                    int length,
                                    gunichar accel_marker,
                                    gunichar *accel_char);

Sets the layout text and attribute list from marked-up text (see

markup format). Replaces

the current text and attribute list.

If accel_marker is nonzero, the given character will mark the character following it as an accelerator. For example, 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

layout

a PangoLayout

 

markup

marked-up text (see markup format)

 

length

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

 

accel_marker

marker for accelerators in the text

 

accel_char

return location for first located accelerator, or NULL.

[out caller-allocates][allow-none]

pango_layout_set_attributes ()

void
pango_layout_set_attributes (PangoLayout *layout,
                             PangoAttrList *attrs);

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

Parameters

layout

a PangoLayout

 

attrs

a PangoAttrList, can be NULL.

[allow-none][transfer none]

pango_layout_get_attributes ()

PangoAttrList *
pango_layout_get_attributes (PangoLayout *layout);

Gets the attribute list for the layout, if any.

Parameters

layout

a PangoLayout

 

Returns

a PangoAttrList.

[transfer none]


pango_layout_set_font_description ()

void
pango_layout_set_font_description (PangoLayout *layout,
                                   const PangoFontDescription *desc);

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.

Parameters

layout

a PangoLayout

 

desc

the new PangoFontDescription, or NULL to unset the current font description.

[allow-none]

pango_layout_get_font_description ()

const PangoFontDescription *
pango_layout_get_font_description (PangoLayout *layout);

Gets the font description for the layout, if any.

Parameters

layout

a PangoLayout

 

Returns

a pointer to the layout's font description, or NULL 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.

[nullable]

Since: 1.8


pango_layout_set_width ()

void
pango_layout_set_width (PangoLayout *layout,
                        int width);

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

Parameters

layout

a PangoLayout.

 

width

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

 

pango_layout_get_width ()

int
pango_layout_get_width (PangoLayout *layout);

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

Parameters

layout

a PangoLayout

 

Returns

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


pango_layout_set_height ()

void
pango_layout_set_height (PangoLayout *layout,
                         int height);

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 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 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

layout

a PangoLayout.

 

height

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

 

Since: 1.20


pango_layout_get_height ()

int
pango_layout_get_height (PangoLayout *layout);

Gets the height of layout used for ellipsization. See pango_layout_set_height() for details.

Parameters

layout

a PangoLayout

 

Returns

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

Since: 1.20


pango_layout_set_wrap ()

void
pango_layout_set_wrap (PangoLayout *layout,
                       PangoWrapMode wrap);

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.

Parameters

layout

a PangoLayout

 

wrap

the wrap mode

 

pango_layout_get_wrap ()

PangoWrapMode
pango_layout_get_wrap (PangoLayout *layout);

Gets the wrap mode for the layout.

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

Parameters

layout

a PangoLayout

 

Returns

active wrap mode.


pango_layout_is_wrapped ()

gboolean
pango_layout_is_wrapped (PangoLayout *layout);

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.

Parameters

layout

a PangoLayout

 

Returns

TRUE if any paragraphs had to be wrapped, FALSE otherwise.

Since: 1.16


pango_layout_set_ellipsize ()

void
pango_layout_set_ellipsize (PangoLayout *layout,
                            PangoEllipsizeMode 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 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.

Parameters

layout

a PangoLayout

 

ellipsize

the new ellipsization mode for layout

 

Since: 1.6


pango_layout_get_ellipsize ()

PangoEllipsizeMode
pango_layout_get_ellipsize (PangoLayout *layout);

Gets the type of ellipsization being performed for layout . See pango_layout_set_ellipsize()

Parameters

layout

a PangoLayout

 

Returns

the current ellipsization mode for layout .

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

Since: 1.6


pango_layout_is_ellipsized ()

gboolean
pango_layout_is_ellipsized (PangoLayout *layout);

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.

Parameters

layout

a PangoLayout

 

Returns

TRUE if any paragraphs had to be ellipsized, FALSE otherwise.

Since: 1.16


pango_layout_set_indent ()

void
pango_layout_set_indent (PangoLayout *layout,
                         int indent);

Sets the width in Pango units to indent each paragraph. A negative value of indent will produce a hanging indentation. That is, the first line will have the full width, and subsequent lines will be indented by the absolute value of indent .

The indent setting is ignored if layout alignment is set to PANGO_ALIGN_CENTER.

Parameters

layout

a PangoLayout.

 

indent

the amount by which to indent.

 

pango_layout_get_indent ()

int
pango_layout_get_indent (PangoLayout *layout);

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

Parameters

layout

a PangoLayout

 

Returns

the indent in Pango units.


pango_layout_get_spacing ()

int
pango_layout_get_spacing (PangoLayout *layout);

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

Parameters

layout

a PangoLayout

 

Returns

the spacing in Pango units.


pango_layout_set_spacing ()

void
pango_layout_set_spacing (PangoLayout *layout,
                          int spacing);

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

Parameters

layout

a PangoLayout.

 

spacing

the amount of spacing

 

pango_layout_set_justify ()

void
pango_layout_set_justify (PangoLayout *layout,
                          gboolean justify);

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.

Parameters

layout

a PangoLayout

 

justify

whether the lines in the layout should be justified.

 

pango_layout_get_justify ()

gboolean
pango_layout_get_justify (PangoLayout *layout);

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

Parameters

layout

a PangoLayout

 

Returns

the justify.


pango_layout_set_auto_dir ()

void
pango_layout_set_auto_dir (PangoLayout *layout,
                           gboolean auto_dir);

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 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 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_ALIGN_LEFT and PANGO_ALIGN_RIGHT are swapped.

Parameters

layout

a PangoLayout

 

auto_dir

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

 

Since: 1.4


pango_layout_get_auto_dir ()

gboolean
pango_layout_get_auto_dir (PangoLayout *layout);

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

Parameters

layout

a PangoLayout

 

Returns

TRUE if the bidirectional base direction is computed from the layout's contents, FALSE otherwise.

Since: 1.4


pango_layout_set_alignment ()

void
pango_layout_set_alignment (PangoLayout *layout,
                            PangoAlignment alignment);

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

Parameters

layout

a PangoLayout

 

alignment

the alignment

 

pango_layout_get_alignment ()

PangoAlignment
pango_layout_get_alignment (PangoLayout *layout);

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

Parameters

layout

a PangoLayout

 

Returns

the alignment.


pango_layout_set_tabs ()

void
pango_layout_set_tabs (PangoLayout *layout,
                       PangoTabArray *tabs);

Sets the tabs to use for layout , overriding the default tabs (by default, tabs are every 8 spaces). If tabs is NULL, the default tabs are reinstated. tabs is copied into the layout; you must free your copy of tabs yourself.

Parameters

layout

a PangoLayout

 

tabs

a PangoTabArray, or NULL.

[allow-none]

pango_layout_get_tabs ()

PangoTabArray *
pango_layout_get_tabs (PangoLayout *layout);

Gets the current PangoTabArray used by this layout. If no PangoTabArray has been set, then the default tabs are in use and NULL is returned. Default tabs are every 8 spaces. The return value should be freed with pango_tab_array_free().

Parameters

layout

a PangoLayout

 

Returns

a copy of the tabs for this layout, or NULL.

[nullable]


pango_layout_set_single_paragraph_mode ()

void
pango_layout_set_single_paragraph_mode
                               (PangoLayout *layout,
                                gboolean 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.

Parameters

layout

a PangoLayout

 

setting

new setting

 

pango_layout_get_single_paragraph_mode ()

gboolean
pango_layout_get_single_paragraph_mode
                               (PangoLayout *layout);

Obtains the value set by pango_layout_set_single_paragraph_mode().

Parameters

layout

a PangoLayout

 

Returns

TRUE if the layout does not break paragraphs at paragraph separator characters, FALSE otherwise.


pango_layout_get_unknown_glyphs_count ()

int
pango_layout_get_unknown_glyphs_count (PangoLayout *layout);

Counts the number unknown glyphs in layout . 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_ATTR_FALLBACK, to check if a certain font supports all the characters in the string.

Parameters

layout

a PangoLayout

 

Returns

The number of unknown glyphs in layout .

Since: 1.16


pango_layout_get_log_attrs ()

void
pango_layout_get_log_attrs (PangoLayout *layout,
                            PangoLogAttr **attrs,
                            gint *n_attrs);

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

Parameters

layout

a PangoLayout

 

attrs

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

[out][array length=n_attrs][transfer container]

n_attrs

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.).

[out]

pango_layout_get_log_attrs_readonly ()

const PangoLogAttr *
pango_layout_get_log_attrs_readonly (PangoLayout *layout,
                                     gint *n_attrs);

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

This is a faster alternative to pango_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

layout

a PangoLayout

 

n_attrs

location to store the number of the attributes in the array.

[out]

Returns

an array of logical attributes.

[array length=n_attrs]

Since: 1.30


pango_layout_index_to_pos ()

void
pango_layout_index_to_pos (PangoLayout *layout,
                           int index_,
                           PangoRectangle *pos);

Converts from an index within a PangoLayout 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.

Parameters

layout

a PangoLayout

 

index_

byte index within layout

 

pos

rectangle in which to store the position of the grapheme.

[out]

pango_layout_index_to_line_x ()

void
pango_layout_index_to_line_x (PangoLayout *layout,
                              int index_,
                              gboolean trailing,
                              int *line,
                              int *x_pos);

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

Parameters

layout

a PangoLayout

 

index_

the byte index of a grapheme within the layout.

 

trailing

an integer indicating the edge of the grapheme to retrieve the position of. If > 0, the trailing edge of the grapheme, if 0, the leading of the grapheme.

 

line

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

[out][allow-none]

x_pos

location to store resulting position within line (PANGO_SCALE units per device unit), or NULL.

[out][allow-none]

pango_layout_xy_to_index ()

gboolean
pango_layout_xy_to_index (PangoLayout *layout,
                          int x,
                          int y,
                          int *index_,
                          int *trailing);

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_layout_line_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

layout

a PangoLayout

 

x

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

 

y

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

 

index_

location to store calculated byte index.

[out]

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.

[out]

Returns

TRUE if the coordinates were inside text, FALSE otherwise.


pango_layout_get_cursor_pos ()

void
pango_layout_get_cursor_pos (PangoLayout *layout,
                             int index_,
                             PangoRectangle *strong_pos,
                             PangoRectangle *weak_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. 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.

Parameters

layout

a PangoLayout

 

index_

the byte index of the cursor

 

strong_pos

location to store the strong cursor position (may be NULL).

[out][allow-none]

weak_pos

location to store the weak cursor position (may be NULL).

[out][allow-none]

pango_layout_move_cursor_visually ()

void
pango_layout_move_cursor_visually (PangoLayout *layout,
                                   gboolean strong,
                                   int old_index,
                                   int old_trailing,
                                   int direction,
                                   int *new_index,
                                   int *new_trailing);

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.

Parameters

layout

a PangoLayout.

 

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 grapheme for the old index

 

old_trailing

if 0, the cursor was at the leading edge of the grapheme indicated by old_index , if > 0, the cursor was at the trailing edge.

 

direction

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

 

new_index

location to store the new cursor byte index. A value of -1 indicates that the cursor has been moved off the beginning of the layout. A value of G_MAXINT indicates that the cursor has been moved off the end of the layout.

[out]

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.

[out]

pango_layout_get_extents ()

void
pango_layout_get_extents (PangoLayout *layout,
                          PangoRectangle *ink_rect,
                          PangoRectangle *logical_rect);

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

layout

a PangoLayout

 

ink_rect

rectangle used to store the extents of the layout as drawn or NULL to indicate that the result is not needed.

[out][allow-none]

logical_rect

rectangle used to store the logical extents of the layout or NULL to indicate that the result is not needed.

[out][allow-none]

pango_layout_get_pixel_extents ()

void
pango_layout_get_pixel_extents (PangoLayout *layout,
                                PangoRectangle *ink_rect,
                                PangoRectangle *logical_rect);

Computes the logical and ink extents of layout 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()).

Parameters

layout

a PangoLayout

 

ink_rect

rectangle used to store the extents of the layout as drawn or NULL to indicate that the result is not needed.

[out][allow-none]

logical_rect

rectangle used to store the logical extents of the layout or NULL to indicate that the result is not needed.

[out][allow-none]

pango_layout_get_size ()

void
pango_layout_get_size (PangoLayout *layout,
                       int *width,
                       int *height);

Determines the logical width and height of a PangoLayout in Pango units (device units scaled by PANGO_SCALE). This is simply a convenience function around pango_layout_get_extents().

Parameters

layout

a PangoLayout

 

width

location to store the logical width, or NULL.

[out caller-allocates][allow-none]

height

location to store the logical height, or NULL.

[out caller-allocates][allow-none]

pango_layout_get_pixel_size ()

void
pango_layout_get_pixel_size (PangoLayout *layout,
                             int *width,
                             int *height);

Determines the logical width and height of a PangoLayout 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().

Parameters

layout

a PangoLayout

 

width

location to store the logical width, or NULL.

[out][allow-none]

height

location to store the logical height, or NULL.

[out][allow-none]

pango_layout_get_baseline ()

int
pango_layout_get_baseline (PangoLayout *layout);

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

Parameters

layout

a PangoLayout

 

Returns

baseline of first line, from top of layout .

Since: 1.22


pango_layout_get_line_count ()

int
pango_layout_get_line_count (PangoLayout *layout);

Retrieves the count of lines for the layout .

Parameters

layout

PangoLayout

 

Returns

the line count.


pango_layout_get_line ()

PangoLayoutLine *
pango_layout_get_line (PangoLayout *layout,
                       int line);

Retrieves a particular line from a PangoLayout.

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

Parameters

layout

a PangoLayout

 

line

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

 

Returns

the requested PangoLayoutLine, or NULL 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.

[transfer none][nullable]


pango_layout_get_line_readonly ()

PangoLayoutLine *
pango_layout_get_line_readonly (PangoLayout *layout,
                                int line);

Retrieves a particular line from a PangoLayout.

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.).

Parameters

layout

a PangoLayout

 

line

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

 

Returns

the requested PangoLayoutLine, or NULL 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.

[transfer none][nullable]

Since: 1.16


pango_layout_get_lines ()

GSList *
pango_layout_get_lines (PangoLayout *layout);

Returns the lines of the layout 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.).

Parameters

layout

a PangoLayout

 

Returns

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.

[element-type Pango.LayoutLine][transfer none]


pango_layout_get_lines_readonly ()

GSList *
pango_layout_get_lines_readonly (PangoLayout *layout);

Returns the lines of the layout 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.).

Parameters

layout

a PangoLayout

 

Returns

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.

[element-type Pango.LayoutLine][transfer none]

Since: 1.16


pango_layout_get_iter ()

PangoLayoutIter *
pango_layout_get_iter (PangoLayout *layout);

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

Parameters

layout

a PangoLayout

 

Returns

the new PangoLayoutIter that should be freed using pango_layout_iter_free().


pango_layout_iter_copy ()

PangoLayoutIter *
pango_layout_iter_copy (PangoLayoutIter *iter);

Copies a PangoLayoutIter.

Parameters

iter

a PangoLayoutIter, may be NULL.

[nullable]

Returns

the newly allocated PangoLayoutIter, which should be freed with pango_layout_iter_free(), or NULL if iter was NULL.

[nullable]

Since: 1.20


pango_layout_iter_free ()

void
pango_layout_iter_free (PangoLayoutIter *iter);

Frees an iterator that's no longer in use.

Parameters

iter

a PangoLayoutIter, may be NULL.

[nullable]

pango_layout_iter_next_run ()

gboolean
pango_layout_iter_next_run (PangoLayoutIter *iter);

Moves iter forward to the next run in visual order. If iter was already at the end of the layout, returns FALSE.

Parameters

iter

a PangoLayoutIter

 

Returns

whether motion was possible.


pango_layout_iter_next_char ()

gboolean
pango_layout_iter_next_char (PangoLayoutIter *iter);

Moves iter forward to the next character in visual order. If iter was already at the end of the layout, returns FALSE.

Parameters

iter

a PangoLayoutIter

 

Returns

whether motion was possible.


pango_layout_iter_next_cluster ()

gboolean
pango_layout_iter_next_cluster (PangoLayoutIter *iter);

Moves iter forward to the next cluster in visual order. If iter was already at the end of the layout, returns FALSE.

Parameters

iter

a PangoLayoutIter

 

Returns

whether motion was possible.


pango_layout_iter_next_line ()

gboolean
pango_layout_iter_next_line (PangoLayoutIter *iter);

Moves iter forward to the start of the next line. If iter is already on the last line, returns FALSE.

Parameters

iter

a PangoLayoutIter

 

Returns

whether motion was possible.


pango_layout_iter_at_last_line ()

gboolean
pango_layout_iter_at_last_line (PangoLayoutIter *iter);

Determines whether iter is on the last line of the layout.

Parameters

iter

a PangoLayoutIter

 

Returns

TRUE if iter is on the last line.


pango_layout_iter_get_index ()

int
pango_layout_iter_get_index (PangoLayoutIter *iter);

Gets the current byte index. Note that iterating forward by char moves in visual order, not logical order, so indexes may not be sequential. Also, the index may be equal to the length of the text in the layout, if on the NULL run (see pango_layout_iter_get_run()).

Parameters

iter

a PangoLayoutIter

 

Returns

current byte index.


pango_layout_iter_get_baseline ()

int
pango_layout_iter_get_baseline (PangoLayoutIter *iter);

Gets the Y position of the current line's baseline, in layout coordinates (origin at top left of the entire layout).

Parameters

iter

a PangoLayoutIter

 

Returns

baseline of current line.


pango_layout_iter_get_run ()

PangoLayoutRun *
pango_layout_iter_get_run (PangoLayoutIter *iter);

Gets the current run. When iterating by run, at the end of each line, there's a position with a NULL run, so this function can return NULL. The NULL run at the end of each line ensures that all lines have at least one run, even lines consisting of only a newline.

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

Parameters

iter

a PangoLayoutIter

 

Returns

the current run.

[transfer none][nullable]


pango_layout_iter_get_run_readonly ()

PangoLayoutRun *
pango_layout_iter_get_run_readonly (PangoLayoutIter *iter);

Gets the current run. When iterating by run, at the end of each line, there's a position with a NULL run, so this function can return NULL. The NULL run at the end of each line ensures that all lines have at least one run, even lines consisting of only a newline.

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

Parameters

iter

a PangoLayoutIter

 

Returns

the current run, that should not be modified.

[transfer none][nullable]

Since: 1.16


pango_layout_iter_get_line ()

PangoLayoutLine *
pango_layout_iter_get_line (PangoLayoutIter *iter);

Gets the current line.

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

Parameters

iter

a PangoLayoutIter

 

Returns

the current line.


pango_layout_iter_get_line_readonly ()

PangoLayoutLine *
pango_layout_iter_get_line_readonly (PangoLayoutIter *iter);

Gets the current line for read-only access.

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

Parameters

iter

a PangoLayoutIter

 

Returns

the current line, that should not be modified.

[transfer none]

Since: 1.16


pango_layout_iter_get_layout ()

PangoLayout *
pango_layout_iter_get_layout (PangoLayoutIter *iter);

Gets the layout associated with a PangoLayoutIter.

Parameters

iter

a PangoLayoutIter

 

Returns

the layout associated with iter .

[transfer none]

Since: 1.20


pango_layout_iter_get_char_extents ()

void
pango_layout_iter_get_char_extents (PangoLayoutIter *iter,
                                    PangoRectangle *logical_rect);

Gets the extents of the current character, in layout coordinates (origin is the top left of the entire layout). Only logical extents can sensibly be obtained for characters; ink extents make sense only down to the level of clusters.

Parameters

iter

a PangoLayoutIter

 

logical_rect

rectangle to fill with logical extents.

[out caller-allocates]

pango_layout_iter_get_cluster_extents ()

void
pango_layout_iter_get_cluster_extents (PangoLayoutIter *iter,
                                       PangoRectangle *ink_rect,
                                       PangoRectangle *logical_rect);

Gets the extents of the current cluster, in layout coordinates (origin is the top left of the entire layout).

Parameters

iter

a PangoLayoutIter

 

ink_rect

rectangle to fill with ink extents, or NULL.

[out][allow-none]

logical_rect

rectangle to fill with logical extents, or NULL.

[out][allow-none]

pango_layout_iter_get_run_extents ()

void
pango_layout_iter_get_run_extents (PangoLayoutIter *iter,
                                   PangoRectangle *ink_rect,
                                   PangoRectangle *logical_rect);

Gets the extents of the current run in layout coordinates (origin is the top left of the entire layout).

Parameters

iter

a PangoLayoutIter

 

ink_rect

rectangle to fill with ink extents, or NULL.

[out][allow-none]

logical_rect

rectangle to fill with logical extents, or NULL.

[out][allow-none]

pango_layout_iter_get_line_yrange ()

void
pango_layout_iter_get_line_yrange (PangoLayoutIter *iter,
                                   int *y0_,
                                   int *y1_);

Divides the vertical space in the PangoLayout being iterated over between the lines in the layout, and returns the space belonging to the current line. A line's range includes the line's logical extents, plus half of the spacing above and below the line, if pango_layout_set_spacing() has been called to set layout spacing. The Y positions are in layout coordinates (origin at top left of the entire layout).

Parameters

iter

a PangoLayoutIter

 

y0_

start of line, or NULL.

[out][allow-none]

y1_

end of line, or NULL.

[out][allow-none]

pango_layout_iter_get_line_extents ()

void
pango_layout_iter_get_line_extents (PangoLayoutIter *iter,
                                    PangoRectangle *ink_rect,
                                    PangoRectangle *logical_rect);

Obtains the extents of the current line. ink_rect or logical_rect can be NULL if you aren't interested in them. Extents are in layout coordinates (origin is the top-left corner of the entire PangoLayout). Thus the extents returned by this function will be the same width/height but not at the same x/y as the extents returned from pango_layout_line_get_extents().

Parameters

iter

a PangoLayoutIter

 

ink_rect

rectangle to fill with ink extents, or NULL.

[out][allow-none]

logical_rect

rectangle to fill with logical extents, or NULL.

[out][allow-none]

pango_layout_iter_get_layout_extents ()

void
pango_layout_iter_get_layout_extents (PangoLayoutIter *iter,
                                      PangoRectangle *ink_rect,
                                      PangoRectangle *logical_rect);

Obtains the extents of the PangoLayout being iterated over. ink_rect or logical_rect can be NULL if you aren't interested in them.

Parameters

iter

a PangoLayoutIter

 

ink_rect

rectangle to fill with ink extents, or NULL.

[out][allow-none]

logical_rect

rectangle to fill with logical extents, or NULL.

[out][allow-none]

pango_layout_line_ref ()

PangoLayoutLine *
pango_layout_line_ref (PangoLayoutLine *line);

Increase the reference count of a PangoLayoutLine by one.

Parameters

line

a PangoLayoutLine, may be NULL.

[nullable]

Returns

the line passed in.

Since: 1.10


pango_layout_line_unref ()

void
pango_layout_line_unref (PangoLayoutLine *line);

Decrease the reference count of a PangoLayoutLine by one. If the result is zero, the line and all associated memory will be freed.

Parameters

line

a PangoLayoutLine

 

pango_layout_line_get_extents ()

void
pango_layout_line_get_extents (PangoLayoutLine *line,
                               PangoRectangle *ink_rect,
                               PangoRectangle *logical_rect);

Computes the logical and ink extents of a layout line. See pango_font_get_glyph_extents() for details about the interpretation of the rectangles.

Parameters

line

a PangoLayoutLine

 

ink_rect

rectangle used to store the extents of the glyph string as drawn, or NULL.

[out][allow-none]

logical_rect

rectangle used to store the logical extents of the glyph string, or NULL.

[out][allow-none]

pango_layout_line_get_pixel_extents ()

void
pango_layout_line_get_pixel_extents (PangoLayoutLine *layout_line,
                                     PangoRectangle *ink_rect,
                                     PangoRectangle *logical_rect);

Computes the logical and ink extents of layout_line in device units. This function just calls pango_layout_line_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()).

Parameters

layout_line

a PangoLayoutLine

 

ink_rect

rectangle used to store the extents of the glyph string as drawn, or NULL.

[out][allow-none]

logical_rect

rectangle used to store the logical extents of the glyph string, or NULL.

[out][allow-none]

pango_layout_line_index_to_x ()

void
pango_layout_line_index_to_x (PangoLayoutLine *line,
                              int index_,
                              gboolean trailing,
                              int *x_pos);

Converts an index within a line to a X position.

Parameters

line

a PangoLayoutLine

 

index_

byte offset 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.

 

x_pos

location to store the x_offset (in Pango unit).

[out]

pango_layout_line_x_to_index ()

gboolean
pango_layout_line_x_to_index (PangoLayoutLine *line,
                              int x_pos,
                              int *index_,
                              int *trailing);

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

Parameters

line

a PangoLayoutLine

 

x_pos

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

 

index_

location to store calculated byte index for the grapheme in which the user clicked.

[out]

trailing

location to store an integer indicating where in the grapheme the user clicked. It will either be zero, or the number of characters in the grapheme. 0 represents the leading edge of the grapheme.

[out]

Returns

FALSE if x_pos was outside the line, TRUE if inside


pango_layout_line_get_x_ranges ()

void
pango_layout_line_get_x_ranges (PangoLayoutLine *line,
                                int start_index,
                                int end_index,
                                int **ranges,
                                int *n_ranges);

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

Parameters

line

a PangoLayoutLine

 

start_index

Start byte index of the logical range. If this value is less than the start index for the line, then the first range will extend all the way to the leading edge of the layout. Otherwise it will start at the leading edge of the first character.

 

end_index

Ending byte index of the logical range. If this value is greater than the end index for the line, then the last range will extend all the way to the trailing edge of the layout. Otherwise, it will end at the trailing edge of the last character.

 

ranges

location to store a pointer to an array of ranges. The array will be of length 2*n_ranges, with each range starting at (*ranges)[2*n] and of width (*ranges)[2*n + 1] - (*ranges)[2*n]. This array must be freed with g_free(). The coordinates are relative to the layout and are in Pango units.

[out][array length=n_ranges][transfer full]

n_ranges

The number of ranges stored in ranges .

 

Types and Values

PangoLayout

typedef struct _PangoLayout PangoLayout;

The PangoLayout structure represents an entire paragraph of text. It is initialized with a PangoContext, 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 PangoLayout, which are illustrated in Figure 1, “Adjustable parameters for a PangoLayout”. It is possible, as well, to ignore the 2-D setup, and simply treat the results of a PangoLayout as a list of lines.

Figure 1. Adjustable parameters for a PangoLayout

Adjustable parameters for a PangoLayout


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


PangoLayoutIter

typedef struct _PangoLayoutIter PangoLayoutIter;

A PangoLayoutIter structure can be used to iterate over the visual extents of a PangoLayout.

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


enum PangoWrapMode

A PangoWrapMode describes how to wrap the lines of a PangoLayout to the desired width.

Members

PANGO_WRAP_WORD

wrap lines at word boundaries.

 

PANGO_WRAP_CHAR

wrap lines at character boundaries.

 

PANGO_WRAP_WORD_CHAR

wrap lines at word boundaries, but fall back to character boundaries if there is not enough space for a full word.

 

PANGO_TYPE_WRAP_MODE

#define PANGO_TYPE_WRAP_MODE (pango_wrap_mode_get_type ())

enum PangoEllipsizeMode

The PangoEllipsizeMode type describes what sort of (if any) ellipsization should be applied to a line of text. In the ellipsization process characters are removed from the text in order to make it fit to a given width and replaced with an ellipsis.

Members

PANGO_ELLIPSIZE_NONE

No ellipsization

 

PANGO_ELLIPSIZE_START

Omit characters at the start of the text

 

PANGO_ELLIPSIZE_MIDDLE

Omit characters in the middle of the text

 

PANGO_ELLIPSIZE_END

Omit characters at the end of the text

 

PANGO_TYPE_ELLIPSIZE_MODE

#define PANGO_TYPE_ELLIPSIZE_MODE (pango_ellipsize_mode_get_type ())

enum PangoAlignment

A PangoAlignment describes how to align the lines of a PangoLayout within the available space. If the PangoLayout is set to justify using pango_layout_set_justify(), this only has effect for partial lines.

Members

PANGO_ALIGN_LEFT

Put all available space on the right

 

PANGO_ALIGN_CENTER

Center the line within the available space

 

PANGO_ALIGN_RIGHT

Put all available space on the left

 

PANGO_TYPE_ALIGNMENT

#define PANGO_TYPE_ALIGNMENT (pango_alignment_get_type ())

struct PangoLayoutLine

struct PangoLayoutLine {
  PangoLayout *layout;
  gint         start_index;     /* start of line as byte index into layout->text */
  gint         length;		/* length of line in bytes */
  GSList      *runs;
  guint        is_paragraph_start : 1;  /* TRUE if this is the first line of the paragraph */
  guint        resolved_dir : 3;  /* Resolved PangoDirection of line */
};

The PangoLayoutLine structure represents one of the lines resulting from laying out a paragraph via PangoLayout. PangoLayoutLine structures are obtained by calling pango_layout_get_line() and are only valid until the text, attributes, or settings of the parent PangoLayout are modified.

Routines for rendering PangoLayout objects are provided in code specific to each rendering system.

Members

PangoLayout *layout;

the layout this line belongs to, might be NULL.

[allow-none]

gint start_index;

start of line as byte index into layout->text

 

gint length;

length of line in bytes

 

GSList *runs;

list of runs in the line, from left to right.

[allow-none][element-type]

guint is_paragraph_start : 1;

TRUE if this is the first line of the paragraph

 

guint resolved_dir : 3;

Resolved PangoDirection of line

 

PangoLayoutRun

typedef PangoGlyphItem PangoLayoutRun;

The PangoLayoutRun structure represents a single run within a PangoLayoutLine; it is simply an alternate name for PangoGlyphItem. See the PangoGlyphItem docs for details on the fields.