gi-pango-1.0.25: Pango bindings
CopyrightWill Thompson and Iñaki García Etxebarria
LicenseLGPL-2.1
MaintainerIñaki García Etxebarria
Safe HaskellSafe-Inferred
LanguageHaskell2010

GI.Pango.Structs.LayoutIter

Description

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

To obtain a PangoLayoutIter, use layoutGetIter.

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

Synopsis

Exported types

newtype LayoutIter Source #

Memory-managed wrapper type.

Methods

atLastLine

layoutIterAtLastLine Source #

Arguments

:: (HasCallStack, MonadIO m) 
=> LayoutIter

iter: a PangoLayoutIter

-> m Bool

Returns: True if iter is on the last line

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

copy

layoutIterCopy Source #

Arguments

:: (HasCallStack, MonadIO m) 
=> LayoutIter

iter: a PangoLayoutIter

-> m (Maybe LayoutIter)

Returns: the newly allocated PangoLayoutIter

Copies a PangoLayoutIter.

Since: 1.20

free

layoutIterFree Source #

Arguments

:: (HasCallStack, MonadIO m) 
=> LayoutIter

iter: a PangoLayoutIter, may be Nothing

-> m () 

Frees an iterator that's no longer in use.

getBaseline

layoutIterGetBaseline Source #

Arguments

:: (HasCallStack, MonadIO m) 
=> LayoutIter

iter: a PangoLayoutIter

-> m Int32

Returns: baseline of current line

Gets the Y position of the current line's baseline, in layout coordinates.

Layout coordinates have the origin at the top left of the entire layout.

getCharExtents

layoutIterGetCharExtents Source #

Arguments

:: (HasCallStack, MonadIO m) 
=> LayoutIter

iter: a PangoLayoutIter

-> m Rectangle 

Gets the extents of the current character, in layout coordinates.

Layout coordinates have the origin at 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.

getClusterExtents

layoutIterGetClusterExtents Source #

Arguments

:: (HasCallStack, MonadIO m) 
=> LayoutIter

iter: a PangoLayoutIter

-> m (Rectangle, Rectangle) 

Gets the extents of the current cluster, in layout coordinates.

Layout coordinates have the origin at the top left of the entire layout.

getIndex

layoutIterGetIndex Source #

Arguments

:: (HasCallStack, MonadIO m) 
=> LayoutIter

iter: a PangoLayoutIter

-> m Int32

Returns: current byte index

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 Nothing run (see layoutIterGetRun).

getLayout

layoutIterGetLayout Source #

Arguments

:: (HasCallStack, MonadIO m) 
=> LayoutIter

iter: a PangoLayoutIter

-> m Layout

Returns: the layout associated with iter

Gets the layout associated with a PangoLayoutIter.

Since: 1.20

getLayoutExtents

layoutIterGetLayoutExtents Source #

Arguments

:: (HasCallStack, MonadIO m) 
=> LayoutIter

iter: a PangoLayoutIter

-> m (Rectangle, Rectangle) 

Obtains the extents of the PangoLayout being iterated over.

getLine

layoutIterGetLine Source #

Arguments

:: (HasCallStack, MonadIO m) 
=> LayoutIter

iter: a PangoLayoutIter

-> m LayoutLine

Returns: the current line

Gets the current line.

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

getLineExtents

layoutIterGetLineExtents Source #

Arguments

:: (HasCallStack, MonadIO m) 
=> LayoutIter

iter: a PangoLayoutIter

-> m (Rectangle, Rectangle) 

Obtains the extents of the current line.

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 layoutLineGetExtents.

getLineReadonly

layoutIterGetLineReadonly Source #

Arguments

:: (HasCallStack, MonadIO m) 
=> LayoutIter

iter: a PangoLayoutIter

-> m LayoutLine

Returns: the current line, that should not be modified

Gets the current line for read-only access.

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

Since: 1.16

getLineYrange

layoutIterGetLineYrange Source #

Arguments

:: (HasCallStack, MonadIO m) 
=> LayoutIter

iter: a PangoLayoutIter

-> m (Int32, Int32) 

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 layoutSetSpacing has been called to set layout spacing. The Y positions are in layout coordinates (origin at top left of the entire layout).

Note: Since 1.44, Pango uses line heights for placing lines, and there may be gaps between the ranges returned by this function.

getRun

layoutIterGetRun Source #

Arguments

:: (HasCallStack, MonadIO m) 
=> LayoutIter

iter: a PangoLayoutIter

-> m (Maybe GlyphItem)

Returns: the current run

Gets the current run.

When iterating by run, at the end of each line, there's a position with a Nothing run, so this function can return Nothing. The Nothing 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 layoutIterGetRunReadonly if you do not plan to modify the contents of the run (glyphs, glyph widths, etc.).

getRunBaseline

layoutIterGetRunBaseline Source #

Arguments

:: (HasCallStack, MonadIO m) 
=> LayoutIter

iter: a PangoLayoutIter

-> m Int32 

Gets the Y position of the current run's baseline, in layout coordinates.

Layout coordinates have the origin at the top left of the entire layout.

The run baseline can be different from the line baseline, for example due to superscript or subscript positioning.

Since: 1.50

getRunExtents

layoutIterGetRunExtents Source #

Arguments

:: (HasCallStack, MonadIO m) 
=> LayoutIter

iter: a PangoLayoutIter

-> m (Rectangle, Rectangle) 

Gets the extents of the current run in layout coordinates.

Layout coordinates have the origin at the top left of the entire layout.

getRunReadonly

layoutIterGetRunReadonly Source #

Arguments

:: (HasCallStack, MonadIO m) 
=> LayoutIter

iter: a PangoLayoutIter

-> m (Maybe GlyphItem)

Returns: the current run, that should not be modified

Gets the current run for read-only access.

When iterating by run, at the end of each line, there's a position with a Nothing run, so this function can return Nothing. The Nothing 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 layoutIterGetRun, but the user is not expected to modify the contents of the run (glyphs, glyph widths, etc.).

Since: 1.16

nextChar

layoutIterNextChar Source #

Arguments

:: (HasCallStack, MonadIO m) 
=> LayoutIter

iter: a PangoLayoutIter

-> m Bool

Returns: whether motion was possible

Moves iter forward to the next character in visual order.

If iter was already at the end of the layout, returns False.

nextCluster

layoutIterNextCluster Source #

Arguments

:: (HasCallStack, MonadIO m) 
=> LayoutIter

iter: a PangoLayoutIter

-> m Bool

Returns: whether motion was possible

Moves iter forward to the next cluster in visual order.

If iter was already at the end of the layout, returns False.

nextLine

layoutIterNextLine Source #

Arguments

:: (HasCallStack, MonadIO m) 
=> LayoutIter

iter: a PangoLayoutIter

-> m Bool

Returns: whether motion was possible

Moves iter forward to the start of the next line.

If iter is already on the last line, returns False.

nextRun

layoutIterNextRun Source #

Arguments

:: (HasCallStack, MonadIO m) 
=> LayoutIter

iter: a PangoLayoutIter

-> m Bool

Returns: whether motion was possible

Moves iter forward to the next run in visual order.

If iter was already at the end of the layout, returns False.