GI.Pango.Structs.GlyphString

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.

Exported types

newtype GlyphString

Memory-managed wrapper type.

Constructors

GlyphString (ManagedPtr GlyphString)

Instances

Eq GlyphString

Defined in GI.Pango.Structs.GlyphString

Methods

(==) :: GlyphString -> GlyphString -> Bool

(/=) :: GlyphString -> GlyphString -> Bool

GBoxed GlyphString

Defined in GI.Pango.Structs.GlyphString

ManagedPtrNewtype GlyphString

Defined in GI.Pango.Structs.GlyphString

Methods

toManagedPtr :: GlyphString -> ManagedPtr GlyphString

TypedObject GlyphString

Defined in GI.Pango.Structs.GlyphString

Methods

glibType :: IO GType

HasParentTypes GlyphString

Defined in GI.Pango.Structs.GlyphString

tag ~ 'AttrSet => Constructible GlyphString tag

Defined in GI.Pango.Structs.GlyphString

Methods

new :: MonadIO m => (ManagedPtr GlyphString -> GlyphString) -> [AttrOp GlyphString tag] -> m GlyphString

IsGValue (Maybe GlyphString)

Convert GlyphString to and from GValue. See toGValue and fromGValue.

Defined in GI.Pango.Structs.GlyphString

Methods

gvalueGType_ :: IO GType

gvalueSet_ :: Ptr GValue -> Maybe GlyphString -> IO ()

gvalueGet_ :: Ptr GValue -> IO (Maybe GlyphString)

type ParentTypes GlyphString

Defined in GI.Pango.Structs.GlyphString

type ParentTypes GlyphString = '[] :: [Type]

newZeroGlyphString :: MonadIO m => m GlyphString

Construct a GlyphString struct initialized to zero.

Methods

Click to display all available methods, including inherited ones

Methods

copy, extents, extentsRange, free, indexToX, indexToXFull, xToIndex.

Getters

getLogicalWidths, getWidth.

Setters

setSize.

copy

glyphStringCopy

Arguments

:: (HasCallStack, MonadIO m)

=> GlyphString

string: a PangoGlyphString

-> m (Maybe GlyphString)

Returns: the newly allocated PangoGlyphString

Copy a glyph string and associated storage.

extents

glyphStringExtents

Arguments

:: (HasCallStack, MonadIO m, IsFont a)

=> GlyphString

glyphs: a PangoGlyphString

-> a

font: a PangoFont

-> m (Rectangle, Rectangle)

Compute the logical and ink extents of a glyph string.

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

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

extentsRange

glyphStringExtentsRange

Arguments

:: (HasCallStack, MonadIO m, IsFont a)

=> GlyphString

glyphs: a PangoGlyphString

-> Int32

start: start index

-> Int32

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

-> a

font: a PangoFont

-> m (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).

free

glyphStringFree

Arguments

:: (HasCallStack, MonadIO m)

=> GlyphString

string: a PangoGlyphString, may be Nothing

-> m ()

Free a glyph string and associated storage.

getLogicalWidths

glyphStringGetLogicalWidths

Arguments

:: (HasCallStack, MonadIO m)

=> GlyphString

glyphs: a PangoGlyphString

-> Text

text: the text corresponding to the glyphs

-> Int32

length: the length of text, in bytes

-> Int32

embeddingLevel: the embedding level of the string

-> [Int32]

logicalWidths: 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.

-> m ()

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 glyphItemGetLogicalWidths.

getWidth

glyphStringGetWidth

Arguments

:: (HasCallStack, MonadIO m)

=> GlyphString

glyphs: a PangoGlyphString

-> m Int32

Returns: the logical width of the glyph string.

Computes the logical width of the glyph string.

This can also be computed using glyphStringExtents. 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.

Since: 1.14

indexToX

glyphStringIndexToX

Arguments

:: (HasCallStack, MonadIO m)

=> GlyphString

glyphs: the glyphs return from [funcshape]

-> Text

text: the text for the run

-> Int32

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

-> Analysis

analysis: the analysis information return from [funcitemize]

-> Int32

index_: the byte index within text

-> Bool

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

-> m Int32

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.

<picture> <source srcset="glyphstring-positions-dark.png" media="(prefers-color-scheme: dark)"> <img alt="Glyph positions" src="glyphstring-positions-light.png"> </picture>

indexToXFull

glyphStringIndexToXFull

Arguments

:: (HasCallStack, MonadIO m)

=> GlyphString

glyphs: the glyphs return from [funcshape]

-> Text

text: the text for the run

-> Int32

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

-> Analysis

analysis: the analysis information return from [funcitemize]

-> Maybe LogAttr

attrs: PangoLogAttr array for text

-> Int32

index_: the byte index within text

-> Bool

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

-> m Int32

Converts from character position to x position.

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

Since: 1.50

new

glyphStringNew

Arguments

:: (HasCallStack, MonadIO m)

=> m GlyphString

Returns: the newly allocated PangoGlyphString, which should be freed with glyphStringFree.

Create a new PangoGlyphString.

setSize

glyphStringSetSize

Arguments

:: (HasCallStack, MonadIO m)

=> GlyphString

string: a PangoGlyphString.

-> Int32

newLen: the new length of the string

-> m ()

Resize a glyph string to the given length.

xToIndex

glyphStringXToIndex

Arguments

:: (HasCallStack, MonadIO m)

=> GlyphString

glyphs: the glyphs returned from [funcshape]

-> Text

text: the text for the run

-> Int32

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

-> Analysis

analysis: the analysis information return from [funcitemize]

-> Int32

xPos: the x offset (in Pango units)

-> m (Int32, Int32)

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.

Properties

logClusters

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

getGlyphStringLogClusters :: MonadIO m => GlyphString -> m Int32

Get the value of the “log_clusters” field. When overloading is enabled, this is equivalent to

get glyphString #logClusters

setGlyphStringLogClusters :: MonadIO m => GlyphString -> Int32 -> m ()

Set the value of the “log_clusters” field. When overloading is enabled, this is equivalent to

set glyphString [ #logClusters := value ]

numGlyphs

number of glyphs in this glyph string

getGlyphStringNumGlyphs :: MonadIO m => GlyphString -> m Int32

Get the value of the “num_glyphs” field. When overloading is enabled, this is equivalent to

get glyphString #numGlyphs

setGlyphStringNumGlyphs :: MonadIO m => GlyphString -> Int32 -> m ()

Set the value of the “num_glyphs” field. When overloading is enabled, this is equivalent to

set glyphString [ #numGlyphs := value ]