GlyphString

class GlyphString(**kwargs)

A PangoGlyphString is used to store strings of glyphs with geometry and visual attribute information.

The storage for the glyph information is owned by the structure which simplifies memory management.

Constructors

class GlyphString

classmethod new() → GlyphString

Create a new PangoGlyphString.

Methods

class GlyphString

extents(font: Font) → tuple[Rectangle, Rectangle]

Compute the logical and ink extents of a glyph string.

See the documentation for get_glyph_extents for details about the interpretation of the rectangles.

Examples of logical (red) and ink (green) rects:

Parameters:

font – a PangoFont

extents_range(start: int, end: int, font: Font) → tuple[Rectangle, Rectangle]

Computes the extents of a sub-portion of a glyph string.

The extents are relative to the start of the glyph string range (the origin of their coordinate system is at the start of the range, not at the start of the entire glyph string).

Parameters:

• start – start index

• end – end index (the range is the set of bytes with indices such that start <= index < end)

• font – a PangoFont

free() → None

Free a glyph string and associated storage.

get_logical_widths(text: str, length: int, embedding_level: int, logical_widths: Sequence[int]) → None

Given a PangoGlyphString and corresponding text, determine the width corresponding to each character.

When multiple characters compose a single cluster, the width of the entire cluster is divided equally among the characters.

See also get_logical_widths.

Parameters:

• text – the text corresponding to the glyphs

• length – the length of text, in bytes

• embedding_level – the embedding level of the string

• logical_widths – an array whose length is the number of characters in text (equal to g_utf8_strlen (text, length) unless text has NUL bytes) to be filled in with the resulting character widths.

get_width() → int

Computes the logical width of the glyph string.

This can also be computed using extents. However, since this only computes the width, it’s much faster. This is in fact only a convenience function that computes the sum of geometry.width for each glyph in the glyphs.

Added in version 1.14.

index_to_x(text: str, length: int, analysis: Analysis, index_: int, trailing: bool) → int

Converts from character position to x position.

The X position is measured from the left edge of the run. Character positions are obtained using font metrics for ligatures where available, and computed by dividing up each cluster into equal portions, otherwise.

Parameters:

• text – the text for the run

• length – the number of bytes (not characters) in text.

• analysis – the analysis information return from itemize

• index – the byte index within text

• trailing – whether we should compute the result for the beginning (False) or end (True) of the character.

index_to_x_full(text: str, length: int, analysis: Analysis, attrs: LogAttr | None, index_: int, trailing: bool) → int

Converts from character position to x position.

This variant of index_to_x additionally accepts a PangoLogAttr array. The grapheme boundary information in it can be used to disambiguate positioning inside some complex clusters.

Added in version 1.50.

Parameters:

• text – the text for the run

• length – the number of bytes (not characters) in text.

• analysis – the analysis information return from itemize

• attrs – PangoLogAttr array for text

• index – the byte index within text

• trailing – whether we should compute the result for the beginning (False) or end (True) of the character.

set_size(new_len: int) → None

Resize a glyph string to the given length.

Parameters:

new_len – the new length of the string

x_to_index(text: str, length: int, analysis: Analysis, x_pos: int) → tuple[int, int]

Convert from x offset to character position.

Character positions are computed by dividing up each cluster into equal portions. In scripts where positioning within a cluster is not allowed (such as Thai), the returned value may not be a valid cursor position; the caller must combine the result with the logical attributes for the text to compute the valid cursor position.

Parameters:

• text – the text for the run

• length – the number of bytes (not characters) in text.

• analysis – the analysis information return from itemize

• x_pos – the x offset (in Pango units)

Fields

class GlyphString

glyphs

Array of glyph information

log_clusters

Logical cluster info, indexed by the byte index within the text corresponding to the glyph string

num_glyphs

Number of glyphs in this glyph string

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