Package ch.bailu.gtk.pango
Class Layout
java.lang.Object
ch.bailu.gtk.type.Type
ch.bailu.gtk.type.Pointer
ch.bailu.gtk.gobject.Object
ch.bailu.gtk.pango.Layout
- All Implemented Interfaces:
PointerInterface
A `PangoLayout` structure represents an entire paragraph of text.
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. `PangoLayout` provides a high-level driver for formatting
entire paragraphs of text at once. This includes paragraph-level
functionality such as line breaking, justification, alignment and
ellipsization.
A `PangoLayout` 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 a number of parameters to adjust the formatting of a
`PangoLayout`. The following image shows adjustable parameters
(on the left) and font metrics (on the right):
<picture>
<source srcset="layout-dark.png" media="(prefers-color-scheme: dark)">
<img alt="Pango Layout Parameters" src="layout-light.png">
</picture>
The following images demonstrate the effect of alignment and
justification on the layout of text:
| | |
| --- | --- |
| ![align=left](align-left.png) | ![align=left, justify](align-left-justify.png) |
| ![align=center](align-center.png) | ![align=center, justify](align-center-justify.png) |
| ![align=right](align-right.png) | ![align=right, justify](align-right-justify.png) |
It is possible, as well, to ignore the 2-D setup,
and simply treat the results of a `PangoLayout` as a list of lines.
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. `PangoLayout` provides a high-level driver for formatting
entire paragraphs of text at once. This includes paragraph-level
functionality such as line breaking, justification, alignment and
ellipsization.
A `PangoLayout` 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 a number of parameters to adjust the formatting of a
`PangoLayout`. The following image shows adjustable parameters
(on the left) and font metrics (on the right):
<picture>
<source srcset="layout-dark.png" media="(prefers-color-scheme: dark)">
<img alt="Pango Layout Parameters" src="layout-light.png">
</picture>
The following images demonstrate the effect of alignment and
justification on the layout of text:
| | |
| --- | --- |
| ![align=left](align-left.png) | ![align=left, justify](align-left-justify.png) |
| ![align=center](align-center.png) | ![align=center, justify](align-center-justify.png) |
| ![align=right](align-right.png) | ![align=right, justify](align-right-justify.png) |
It is possible, as well, to ignore the 2-D setup,
and simply treat the results of a `PangoLayout` as a list of lines.
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Nested Class Summary
Nested classes/interfaces inherited from class ch.bailu.gtk.gobject.Object
Object.OnBindingTransformFunc, Object.OnDestroyNotify, Object.OnDuplicateFunc, Object.OnNotify, Object.OnToggleNotify, Object.OnWeakNotify
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Field Summary
Fields inherited from class ch.bailu.gtk.gobject.Object
SIGNAL_ON_NOTIFY
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Constructor Summary
ConstructorDescriptionCreate a new `PangoLayout` object with attributes initialized to
default values for a particular `PangoContext`.Layout
(PointerContainer pointer) -
Method Summary
Modifier and TypeMethodDescriptionvoid
Forces recomputation of any state in the `PangoLayout` that
might depend on the layout's context.copy()
Creates a deep copy-by-value of the layout.static Layout
deserialize
(Context context, Bytes bytes, int flags) Loads data previously created via [method@Pango.Layout.serialize].int
Gets the alignment for the layout: how partial lines are
positioned within the horizontal space available.Gets the attribute list for the layout, if any.boolean
Gets whether to calculate the base direction for the layout
according to its contents.int
Gets the Y position of baseline of the first line in @layout.void
getCaretPos
(int index_, Rectangle strong_pos, Rectangle 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.int
Returns the number of Unicode characters in the
the text of @layout.static ClassHandler
Retrieves the `PangoContext` used for this layout.void
getCursorPos
(int index_, Rectangle strong_pos, Rectangle 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.int
getDirection
(int index) Gets the text direction at the given character position in @layout.int
Gets the type of ellipsization being performed for @layout.void
getExtents
(Rectangle ink_rect, Rectangle logical_rect) Computes the logical and ink extents of @layout.Gets the font description for the layout, if any.int
Gets the height of layout used for ellipsization.int
Gets the paragraph indent width in Pango units.static int
getIter()
Returns an iterator to iterate over the visual extents of the layout.boolean
Gets whether each complete line should be stretched to fill the entire
width of the layout.boolean
Gets whether the last line should be stretched
to fill the entire width of the layout.getLine
(int line) Retrieves a particular line from a `PangoLayout`.int
Retrieves the count of lines for the @layout.getLineReadonly
(int line) Retrieves a particular line from a `PangoLayout`.getLines()
Returns the lines of the @layout as a list.float
Gets the line spacing factor of @layout.Returns the lines of the @layout as a list.static long
static TypeSystem.TypeSize
void
getPixelExtents
(Rectangle ink_rect, Rectangle logical_rect) Computes the logical and ink extents of @layout in device units.void
getPixelSize
(Int width, Int height) Determines the logical width and height of a `PangoLayout` in device
units.int
Returns the current serial number of @layout.boolean
Obtains whether @layout is in single paragraph mode.void
Determines the logical width and height of a `PangoLayout` in Pango
units.int
Gets the amount of spacing between the lines of the layout.getTabs()
Gets the current `PangoTabArray` used by this layout.getText()
Gets the text in the layout.static long
static TypeSystem.TypeSize
int
Counts the number of unknown glyphs in @layout.int
getWidth()
Gets the width to which the lines of the `PangoLayout` should wrap.int
getWrap()
Gets the wrap mode for the layout.void
indexToLineX
(int index_, boolean trailing, Int line, Int x_pos) Converts from byte @index_ within the @layout to line and X position.void
indexToPos
(int index_, Rectangle pos) Converts from an index within a `PangoLayout` to the onscreen position
corresponding to the grapheme at that index.boolean
Queries whether the layout had to ellipsize any paragraphs.boolean
Queries whether the layout had to wrap any paragraphs.void
moveCursorVisually
(boolean 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 direction.serialize
(int flags) Serializes the @layout for later deserialization via [func@Pango.Layout.deserialize].void
setAlignment
(int alignment) Sets the alignment for the layout: how partial lines are
positioned within the horizontal space available.void
setAttributes
(AttrList attrs) Sets the text attributes for a layout object.void
setAutoDir
(boolean auto_dir) Sets whether to calculate the base direction
for the layout according to its contents.void
setEllipsize
(int ellipsize) Sets the type of ellipsization being performed for @layout.void
Sets the default font description for the layout.void
setHeight
(int height) Sets the height to which the `PangoLayout` should be ellipsized at.void
setIndent
(int indent) Sets the width in Pango units to indent each paragraph.void
setJustify
(boolean justify) Sets whether each complete line should be stretched to fill the
entire width of the layout.void
setJustifyLastLine
(boolean justify) Sets whether the last line should be stretched to fill the
entire width of the layout.void
setLineSpacing
(float factor) Sets a factor for line spacing.void
Sets the layout text and attribute list from marked-up text.void
Sets the layout text and attribute list from marked-up text.void
setSingleParagraphMode
(boolean setting) Sets the single paragraph mode of @layout.void
setSpacing
(int spacing) Sets the amount of spacing in Pango units between
the lines of the layout.void
Sets the tabs to use for @layout, overriding the default tabs.void
Sets the text of the layout.void
Sets the text of the layout.void
setWidth
(int width) Sets the width to which the lines of the `PangoLayout` should wrap or
ellipsized.void
setWrap
(int wrap) Sets the wrap mode.boolean
writeToFile
(int flags, Str filename) A convenience method to serialize a layout to a file.boolean
writeToFile
(int flags, String filename) A convenience method to serialize a layout to a file.boolean
Converts from X and Y position within a layout to the byte index to the
character at that logical position.Methods inherited from class ch.bailu.gtk.gobject.Object
addToggleRef, bindProperty, bindProperty, bindPropertyFull, bindPropertyFull, bindPropertyWithClosures, bindPropertyWithClosures, compatControl, connect, connect, disconnect, disconnect, dupData, dupData, dupQdata, forceFloating, freezeNotify, get, get, getData, getData, getProperty, getProperty, getQdata, interfaceFindProperty, interfaceInstallProperty, isFloating, notify, notify, notifyByPspec, onNotify, ref, refSink, removeToggleRef, replaceData, replaceData, replaceQdata, runDispose, set, set, setData, setData, setDataFull, setDataFull, setProperty, setProperty, setQdata, setQdataFull, stealData, stealData, stealQdata, takeRef, thawNotify, unref, watchClosure, weakRef, weakUnref
Methods inherited from class ch.bailu.gtk.type.Pointer
asCPointer, cast, connectSignal, disconnectSignals, disconnectSignals, equals, hashCode, throwIfNull, throwNullPointerException, toString, unregisterCallbacks, unregisterCallbacks
Methods inherited from class ch.bailu.gtk.type.Type
asCPointer, asCPointer, asCPointerNotNull, asJnaPointer, asJnaPointer, asPointer, asPointer, cast, cast, throwIfNull
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
Methods inherited from interface ch.bailu.gtk.type.PointerInterface
asCPointerNotNull, asJnaPointer, asPointer, isNotNull, isNull
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Constructor Details
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Layout
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Layout
Create a new `PangoLayout` object with attributes initialized to
default values for a particular `PangoContext`.- Parameters:
context
- a `PangoContext`
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Method Details
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getClassHandler
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contextChanged
public void contextChanged()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. -
copy
Creates a deep copy-by-value of the layout.
The attribute list, tab array, and text from the original layout
are all copied by value.- Returns:
- the newly allocated `PangoLayout`
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getAlignment
public int getAlignment()Gets the alignment for the layout: how partial lines are
positioned within the horizontal space available.- Returns:
- the alignment
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getAttributes
Gets the attribute list for the layout, if any.- Returns:
- a `PangoAttrList`
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getAutoDir
public boolean getAutoDir()Gets whether to calculate the base direction for the layout
according to its contents.
See [method@Pango.Layout.set_auto_dir].- Returns:
- %TRUE if the bidirectional base direction is computed from the layout's contents, %FALSE otherwise
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getBaseline
public int getBaseline()Gets the Y position of baseline of the first line in @layout.- Returns:
- baseline of first line, from top of @layout
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getCaretPos
Given an index within a layout, determines the positions that of the
strong and weak cursors if the insertion point is at that index.
This is a variant of [method@Pango.Layout.get_cursor_pos] that applies
font metric information about caret slope and offset to the positions
it returns.
<picture>
<source srcset="caret-metrics-dark.png" media="(prefers-color-scheme: dark)">
<img alt="Caret metrics" src="caret-metrics-light.png">
</picture>- Parameters:
index_
- the byte index of the cursorstrong_pos
- location to store the strong cursor positionweak_pos
- location to store the weak cursor position
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getCharacterCount
public int getCharacterCount()Returns the number of Unicode characters in the
the text of @layout.- Returns:
- the number of Unicode characters in the text of @layout
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getContext
Retrieves the `PangoContext` used for this layout.- Returns:
- the `PangoContext` for the layout
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getCursorPos
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
with the height of the run extents.
<picture>
<source srcset="cursor-positions-dark.png" media="(prefers-color-scheme: dark)">
<img alt="Cursor positions" src="cursor-positions-light.png">
</picture>
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.
The following example shows text with both a strong and a weak cursor.
<picture>
<source srcset="split-cursor-dark.png" media="(prefers-color-scheme: dark)">
<img alt="Strong and weak cursors" src="split-cursor-light.png">
</picture>
The strong cursor has a little arrow pointing to the right, the weak
cursor to the left. Typing a 'c' in this situation will insert the
character after the 'b', and typing another Hebrew character, like 'ג',
will insert it at the end.- Parameters:
index_
- the byte index of the cursorstrong_pos
- location to store the strong cursor positionweak_pos
- location to store the weak cursor position
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getDirection
public int getDirection(int index) Gets the text direction at the given character position in @layout.- Parameters:
index
- the byte index of the char- Returns:
- the text direction at @index
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getEllipsize
public int getEllipsize()Gets the type of ellipsization being performed for @layout.
See [method@Pango.Layout.set_ellipsize].
Use [method@Pango.Layout.is_ellipsized] to query whether any
paragraphs were actually ellipsized.- Returns:
- the current ellipsization mode for @layout
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getExtents
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:
ink_rect
- rectangle used to store the extents of the layout as drawnlogical_rect
- rectangle used to store the logical extents of the layout
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getFontDescription
Gets the font description for the layout, if any.- Returns:
- a pointer to the layout's font description, or %NULL if the font description from the layout's context is inherited.
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getHeight
public int getHeight()Gets the height of layout used for ellipsization.
See [method@Pango.Layout.set_height] for details.- Returns:
- the height, in Pango units if positive, or number of lines if negative.
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getIndent
public int getIndent()Gets the paragraph indent width in Pango units.
A negative value indicates a hanging indentation.- Returns:
- the indent in Pango units
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getIter
Returns an iterator to iterate over the visual extents of the layout.- Returns:
- the new `PangoLayoutIter`
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getJustify
public boolean getJustify()Gets whether each complete line should be stretched to fill the entire
width of the layout.- Returns:
- the justify value
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getJustifyLastLine
public boolean getJustifyLastLine()Gets whether the last line should be stretched
to fill the entire width of the layout.- Returns:
- the justify value
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getLine
Retrieves a particular line from a `PangoLayout`.
Use the faster [method@Pango.Layout.get_line_readonly] if you do not
plan to modify the contents of the line (glyphs, glyph widths, etc.).- Parameters:
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`.
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getLineCount
public int getLineCount()Retrieves the count of lines for the @layout.- Returns:
- the line count
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getLineReadonly
Retrieves a particular line from a `PangoLayout`.
This is a faster alternative to [method@Pango.Layout.get_line],
but the user is not expected to modify the contents of the line
(glyphs, glyph widths, etc.).- Parameters:
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.
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getLineSpacing
public float getLineSpacing()Gets the line spacing factor of @layout.
See [method@Pango.Layout.set_line_spacing].- Returns:
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getLines
Returns the lines of the @layout as a list.
Use the faster [method@Pango.Layout.get_lines_readonly] if you do not
plan to modify the contents of the lines (glyphs, glyph widths, etc.).- 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.
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getLinesReadonly
Returns the lines of the @layout as a list.
This is a faster alternative to [method@Pango.Layout.get_lines],
but the user is not expected to modify the contents of the lines
(glyphs, glyph widths, etc.).- 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.
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getPixelExtents
Computes the logical and ink extents of @layout in device units.
This function just calls [method@Pango.Layout.get_extents] followed by
two [func@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 [func@Pango.extents_to_pixels]).- Parameters:
ink_rect
- rectangle used to store the extents of the layout as drawnlogical_rect
- rectangle used to store the logical extents of the layout
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getPixelSize
Determines the logical width and height of a `PangoLayout` in device
units.
[method@Pango.Layout.get_size] returns the width and height
scaled by %PANGO_SCALE. This is simply a convenience function
around [method@Pango.Layout.get_pixel_extents].- Parameters:
width
- location to store the logical widthheight
- location to store the logical height
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getSerial
public int getSerial()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
[method@Pango.Layout.context_changed].- Returns:
- The current serial number of @layout.
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getSingleParagraphMode
public boolean getSingleParagraphMode()Obtains whether @layout is in single paragraph mode.
See [method@Pango.Layout.set_single_paragraph_mode].- Returns:
- %TRUE if the layout does not break paragraphs at paragraph separator characters, %FALSE otherwise
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getSize
Determines the logical width and height of a `PangoLayout` in Pango
units.
This is simply a convenience function around [method@Pango.Layout.get_extents].- Parameters:
width
- location to store the logical widthheight
- location to store the logical height
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getSpacing
public int getSpacing()Gets the amount of spacing between the lines of the layout.- Returns:
- the spacing in Pango units
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getTabs
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 [method@Pango.TabArray.free].- Returns:
- a copy of the tabs for this layout
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getText
Gets the text in the layout.
The returned text should not be freed or modified.- Returns:
- the text in the @layout
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getUnknownGlyphsCount
public int getUnknownGlyphsCount()Counts the number of unknown glyphs in @layout.
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.- Returns:
- The number of unknown glyphs in @layout
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getWidth
public int getWidth()Gets the width to which the lines of the `PangoLayout` should wrap.- Returns:
- the width in Pango units, or -1 if no width set.
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getWrap
public int getWrap()Gets the wrap mode for the layout.
Use [method@Pango.Layout.is_wrapped] to query whether
any paragraphs were actually wrapped.- Returns:
- active wrap mode.
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indexToLineX
Converts from byte @index_ within the @layout to line and X position.
The X position is measured from the left edge of the line.- Parameters:
index_
- the byte index of a grapheme within the layouttrailing
- 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 graphemeline
- location to store resulting line index. (which will between 0 and pango_layout_get_line_count(layout) - 1)x_pos
- location to store resulting position within line (%PANGO_SCALE units per device unit)
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indexToPos
Converts from an index within a `PangoLayout` to the onscreen position
corresponding to the grapheme at that index.
The returns 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:
index_
- byte index within @layoutpos
- rectangle in which to store the position of the grapheme
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isEllipsized
public boolean isEllipsized()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.- Returns:
- %TRUE if any paragraphs had to be ellipsized, %FALSE otherwise
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isWrapped
public boolean isWrapped()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.- Returns:
- %TRUE if any paragraphs had to be wrapped, %FALSE otherwise
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moveCursorVisually
public void moveCursorVisually(boolean strong, int old_index, int old_trailing, int direction, @Nonnull Int new_index, @Nonnull Int new_trailing) Computes a new cursor position from an old position and a direction.
If @direction is positive, then the new position will cause the strong
or weak cursor to be displayed one position to right of where it was
with the old cursor position. If @direction is negative, it will be
moved to the left.
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 this function may move the cursor over multiple characters
when multiple characters combine to form a single grapheme.- Parameters:
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 current cursor positionold_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 leftnew_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.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.
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serialize
Serializes the @layout for later deserialization via [func@Pango.Layout.deserialize].
There are no guarantees about the format of the output across different
versions of Pango and [func@Pango.Layout.deserialize] will reject data
that it cannot parse.
The intended use of this function is testing, benchmarking and debugging.
The format is not meant as a permanent storage format.- Parameters:
flags
- `PangoLayoutSerializeFlags`- Returns:
- a `GBytes` containing the serialized form of @layout
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setAlignment
public void setAlignment(int alignment) Sets the alignment for the layout: how partial lines are
positioned within the horizontal space available.
The default alignment is %PANGO_ALIGN_LEFT.- Parameters:
alignment
- the alignment
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setAttributes
Sets the text attributes for a layout object.
References @attrs, so the caller can unref its reference.- Parameters:
attrs
- a `PangoAttrList`
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setAutoDir
public void setAutoDir(boolean auto_dir) Sets whether to calculate the base direction
for the layout according to its contents.
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 [method@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:
auto_dir
- if %TRUE, compute the bidirectional base direction from the layout's contents
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setEllipsize
public void setEllipsize(int 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
[method@Pango.Layout.set_width] and [method@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.
The default value is %PANGO_ELLIPSIZE_NONE.
See [method@Pango.Layout.set_height] for details.- Parameters:
ellipsize
- the new ellipsization mode for @layout
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setFontDescription
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:
desc
- the new `PangoFontDescription` to unset the current font description
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setHeight
public void setHeight(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 the first line of each paragraph is ellipsized.
This behavior may be changed in the future to act per layout instead of per
paragraph. File a bug against pango at
[https://gitlab.gnome.org/gnome/pango](https://gitlab.gnome.org/gnome/pango)
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:
height
- the desired height of the layout in Pango units if positive, or desired number of lines if negative.
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setIndent
public void setIndent(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.
The default value is 0.- Parameters:
indent
- the amount by which to indent
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setJustify
public void setJustify(boolean justify) Sets whether each complete line should be stretched to fill the
entire width of the layout.
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.
Note that tabs and justification conflict with each other:
Justification will move content away from its tab-aligned
positions.
The default value is %FALSE.
Also see [method@Pango.Layout.set_justify_last_line].- Parameters:
justify
- whether the lines in the layout should be justified
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setJustifyLastLine
public void setJustifyLastLine(boolean justify) Sets whether the last line should be stretched to fill the
entire width of the layout.
This only has an effect if [method@Pango.Layout.set_justify] has
been called as well.
The default value is %FALSE.- Parameters:
justify
- whether the last line in the layout should be justified
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setLineSpacing
public void setLineSpacing(float factor) Sets a factor for line spacing.
Typical values are: 0, 1, 1.5, 2. The default values is 0.
If @factor is non-zero, lines are placed so that
baseline2 = baseline1 + factor * height2
where height2 is the line height of the second line
(as determined by the font(s)). In this case, the spacing
set with [method@Pango.Layout.set_spacing] is ignored.
If @factor is zero (the default), spacing is applied as before.
Note: for semantics that are closer to the CSS line-height
property, see [func@Pango.attr_line_height_new].- Parameters:
factor
- the new line spacing factor
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setMarkup
Sets the layout text and attribute list from marked-up text.
See [Pango Markup](pango_markup.html)).
Replaces the current text and attribute list.
This is the same as [method@Pango.Layout.set_markup_with_accel],
but the markup text isn't scanned for accelerators.- Parameters:
markup
- marked-up textlength
- length of marked-up text in bytes, or -1 if @markup is `NUL`-terminated
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setMarkup
Sets the layout text and attribute list from marked-up text.
See [Pango Markup](pango_markup.html)).
Replaces the current text and attribute list.
This is the same as [method@Pango.Layout.set_markup_with_accel],
but the markup text isn't scanned for accelerators.- Parameters:
markup
- marked-up textlength
- length of marked-up text in bytes, or -1 if @markup is `NUL`-terminated
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setSingleParagraphMode
public void setSingleParagraphMode(boolean setting) Sets the single paragraph mode of @layout.
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.
The default value is %FALSE.- Parameters:
setting
- new setting
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setSpacing
public void setSpacing(int spacing) Sets the amount of spacing in Pango units between
the lines of the layout.
When placing lines with spacing, Pango arranges things so that
line2.top = line1.bottom + spacing
The default value is 0.
Note: Since 1.44, Pango is using the line height (as determined
by the font) for placing lines when the line spacing factor is set
to a non-zero value with [method@Pango.Layout.set_line_spacing].
In that case, the @spacing set with this function is ignored.
Note: for semantics that are closer to the CSS line-height
property, see [func@Pango.attr_line_height_new].- Parameters:
spacing
- the amount of spacing
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setTabs
Sets the tabs to use for @layout, overriding the default tabs.
`PangoLayout` will place content at the next tab position
whenever it meets a Tab character (U+0009).
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.
Note that tabs and justification conflict with each other:
Justification will move content away from its tab-aligned
positions. The same is true for alignments other than
%PANGO_ALIGN_LEFT.- Parameters:
tabs
- a `PangoTabArray`
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setText
Sets the text of the layout.
This function validates @text and renders invalid UTF-8
with a placeholder glyph.
Note that if you have used [method@Pango.Layout.set_markup] or
[method@Pango.Layout.set_markup_with_accel] on @layout before, you
may want to call [method@Pango.Layout.set_attributes] to clear the
attributes set on the layout from the markup as this function does
not clear attributes.- Parameters:
text
- the textlength
- 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.
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setText
Sets the text of the layout.
This function validates @text and renders invalid UTF-8
with a placeholder glyph.
Note that if you have used [method@Pango.Layout.set_markup] or
[method@Pango.Layout.set_markup_with_accel] on @layout before, you
may want to call [method@Pango.Layout.set_attributes] to clear the
attributes set on the layout from the markup as this function does
not clear attributes.- Parameters:
text
- the textlength
- 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.
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setWidth
public void setWidth(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:
width
- the desired width in Pango units, or -1 to indicate that no wrapping or ellipsization should be performed.
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setWrap
public void setWrap(int wrap) Sets the wrap mode.
The wrap mode only has effect if a width is set on the layout
with [method@Pango.Layout.set_width]. To turn off wrapping,
set the width to -1.
The default value is %PANGO_WRAP_WORD.- Parameters:
wrap
- the wrap mode
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writeToFile
A convenience method to serialize a layout to a file.
It is equivalent to calling [method@Pango.Layout.serialize]
followed by [func@GLib.file_set_contents].
See those two functions for details on the arguments.
It is mostly intended for use inside a debugger to quickly dump
a layout to a file for later inspection.- Parameters:
flags
- `PangoLayoutSerializeFlags`filename
- the file to save it to- Returns:
- %TRUE if saving was successful
- Throws:
AllocationError
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writeToFile
A convenience method to serialize a layout to a file.
It is equivalent to calling [method@Pango.Layout.serialize]
followed by [func@GLib.file_set_contents].
See those two functions for details on the arguments.
It is mostly intended for use inside a debugger to quickly dump
a layout to a file for later inspection.- Parameters:
flags
- `PangoLayoutSerializeFlags`filename
- the file to save it to- Returns:
- %TRUE if saving was successful
- Throws:
AllocationError
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xyToIndex
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 [method@Pango.LayoutLine.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:
x
- the X offset (in Pango units) from the left edge of the layouty
- the Y offset (in Pango units) from the top edge of the layoutindex_
- location to store calculated byte indextrailing
- 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.- Returns:
- %TRUE if the coordinates were inside text, %FALSE otherwise
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deserialize
public static Layout deserialize(@Nonnull Context context, @Nonnull Bytes bytes, int flags) throws AllocationError Loads data previously created via [method@Pango.Layout.serialize].
For a discussion of the supported format, see that function.
Note: to verify that the returned layout is identical to
the one that was serialized, you can compare @bytes to the
result of serializing the layout again.- Parameters:
context
- a `PangoContext`bytes
- the bytes containing the dataflags
- `PangoLayoutDeserializeFlags`- Returns:
- a new `PangoLayout`
- Throws:
AllocationError
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getTypeID
public static long getTypeID() -
getParentTypeID
public static long getParentTypeID() -
getTypeSize
-
getParentTypeSize
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getInstanceSize
public static int getInstanceSize()
-