GI.Pango.Structs.GlyphItem

A GlyphItem is a pair of a Item and the glyphs resulting from shaping the text corresponding to an item. As an example of the usage of GlyphItem, the results of shaping text with Layout is a list of LayoutLine, each of which contains a list of GlyphItem.

Exported types

newtype GlyphItem

Memory-managed wrapper type.

Constructors

GlyphItem (ManagedPtr GlyphItem)

Instances

BoxedObject GlyphItem

Defined in GI.Pango.Structs.GlyphItem

Methods

boxedType :: GlyphItem -> IO GType

tag ~ AttrSet => Constructible GlyphItem tag

Defined in GI.Pango.Structs.GlyphItem

Methods

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

newZeroGlyphItem :: MonadIO m => m GlyphItem

Construct a GlyphItem struct initialized to zero.

noGlyphItem :: Maybe GlyphItem

A convenience alias for Nothing :: Maybe GlyphItem.

Methods

applyAttrs

glyphItemApplyAttrs

Arguments

:: (HasCallStack, MonadIO m)

=> GlyphItem

glyphItem: a shaped item

-> Text

text: text that list applies to

-> AttrList

list: a AttrList

-> m [GlyphItem]

Returns: a list of glyph items resulting from splitting glyphItem. Free the elements using glyphItemFree, the list using g_slist_free().

Splits a shaped item (PangoGlyphItem) into multiple items based on an attribute list. The idea is that if you have attributes that don't affect shaping, such as color or underline, to avoid affecting shaping, you filter them out (attrListFilter), apply the shaping process and then reapply them to the result using this function.

All attributes that start or end inside a cluster are applied to that cluster; for instance, if half of a cluster is underlined and the other-half strikethrough, then the cluster will end up with both underline and strikethrough attributes. In these cases, it may happen that item->extra_attrs for some of the result items can have multiple attributes of the same type.

This function takes ownership of glyphItem; it will be reused as one of the elements in the list.

Since: 1.2

copy

glyphItemCopy

Arguments

:: (HasCallStack, MonadIO m)

=> GlyphItem

orig: a GlyphItem, may be Nothing

-> m (Maybe GlyphItem)

Returns: the newly allocated GlyphItem, which should be freed with glyphItemFree, or Nothing if orig was Nothing.

Make a deep copy of an existing GlyphItem structure.

Since: 1.20

free

glyphItemFree

Arguments

:: (HasCallStack, MonadIO m)

=> GlyphItem

glyphItem: a GlyphItem, may be Nothing

-> m ()

Frees a GlyphItem and resources to which it points.

Since: 1.6

getLogicalWidths

glyphItemGetLogicalWidths

Arguments

:: (HasCallStack, MonadIO m)

=> GlyphItem

glyphItem: a GlyphItem

-> Text

text: text that glyphItem corresponds to (glyph_item->item->offset is an offset from the start of text)

-> [Int32]

logicalWidths: an array whose length is the number of characters in glyph_item (equal to glyph_item->item->num_chars) to be filled in with the resulting character widths.

-> m ()

Given a GlyphItem and the corresponding text, determine the screen 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 glyphStringGetLogicalWidths.

Since: 1.26

letterSpace

glyphItemLetterSpace

Arguments

:: (HasCallStack, MonadIO m)

=> GlyphItem

glyphItem: a GlyphItem

-> Text

text: text that glyphItem corresponds to (glyph_item->item->offset is an offset from the start of text)

-> [LogAttr]

logAttrs: logical attributes for the item (the first logical attribute refers to the position before the first character in the item)

-> Int32

letterSpacing: amount of letter spacing to add in Pango units. May be negative, though too large negative values will give ugly results.

-> m ()

Adds spacing between the graphemes of glyphItem to give the effect of typographic letter spacing.

Since: 1.6

split

glyphItemSplit

Arguments

:: (HasCallStack, MonadIO m)

=> GlyphItem

orig: a Item

-> Text

text: text to which positions in orig apply

-> Int32

splitIndex: byte index of position to split item, relative to the start of the item

-> m GlyphItem

Returns: the newly allocated item representing text before splitIndex, which should be freed with glyphItemFree.

Modifies orig to cover only the text after splitIndex, and returns a new item that covers the text before splitIndex that used to be in orig. You can think of splitIndex as the length of the returned item. splitIndex may not be 0, and it may not be greater than or equal to the length of orig (that is, there must be at least one byte assigned to each item, you can't create a zero-length item).

This function is similar in function to itemSplit (and uses it internally.)

Since: 1.2

Properties

glyphs

corresponding GlyphString.

clearGlyphItemGlyphs :: MonadIO m => GlyphItem -> m ()

Set the value of the “glyphs” field to Nothing. When overloading is enabled, this is equivalent to

clear #glyphs

getGlyphItemGlyphs :: MonadIO m => GlyphItem -> m (Maybe GlyphString)

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

get glyphItem #glyphs

setGlyphItemGlyphs :: MonadIO m => GlyphItem -> Ptr GlyphString -> m ()

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

set glyphItem [ #glyphs := value ]

item

corresponding Item.

clearGlyphItemItem :: MonadIO m => GlyphItem -> m ()

Set the value of the “item” field to Nothing. When overloading is enabled, this is equivalent to

clear #item

getGlyphItemItem :: MonadIO m => GlyphItem -> m (Maybe Item)

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

get glyphItem #item

setGlyphItemItem :: MonadIO m => GlyphItem -> Ptr Item -> m ()

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

set glyphItem [ #item := value ]