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:: com :: sun :: star :: rendering ::

interface XTextLayout
Description
This is the central interface for text layouting.

This is the central interface for text-related tasks more complicated than simple string rendering. Note that all query methods are subject to the current layout state of this object. That is, calls to justify() or applyLogicalAdvancements() are likely to change subsequent output of those query methods.

Similar to XCanvasFont, all measurements and coordinates accepted and returned by this interface are relative to the font's local coordinate system (which only equals device coordinate space, if the combined render transformation used during text output is the identity transformation). Conversely, if the combined transformation used during text output is not the identity transformation, all measurements returned by this interface should be subjected to that transformation, to yield values in device coordinate space. Depending on the underlying font technology, actual device output might be off by up to one device pixel from the transformed metrics.

Since
OOo 2.0

Methods' Summary
queryTextShapes Extract the polygonal shapes of the layouted text. 
queryInkMeasures Query the ink bounding boxes for every glyph in the layouted text. 
queryMeasures Query the logical bounding boxes of every character in the given text string. 
queryLogicalAdvancements Query the advancements for every character in the input string. 
applyLogicalAdvancements Apply explicit advancements for every character in the layout string. 
queryTextBounds Query the overall bounding box of the text. 
justify Justify the text to the given size. 
combinedJustify Justify a number of text layouts to the given size. 
getTextHit This method determines the hit position in the text. 
getCaret This method converts an insertion index to a caret. 
getNextInsertionIndex This method calculates a new insertion index. 
queryVisualHighlighting This method generates a highlight polygon. 
queryLogicalHighlighting This method generates a highlight polygon. 
getBaselineOffset This method yields the baseline offset. 
getMainTextDirection This method returns the main writing direction. 
getFont Request the associated font for this layout..  
getText Request the text this layout contains.  
Methods' Details
queryTextShapes
sequence< XPolyPolygon2D >
queryTextShapes();

Description
Extract the polygonal shapes of the layouted text.

Each glyph is represented by a separate XPolyPolygon2D in the returned sequence.

Returns
a sequence of XPolyPolygon2D in font coordinate space, one for every glyph.
queryInkMeasures
sequence< ::com::sun::star::geometry::RealRectangle2D >
queryInkMeasures();

Description
Query the ink bounding boxes for every glyph in the layouted text.

Ink, or tight bounding boxes in this case means that for e.g. an 'a', the bounding box for the XPolyPolygon2D describing the glyph 'a' is returned, not the logical dimensions of the character in the font.

Returns
a sequence of rectangles in font coordinate space, specifying the bounds, one for every glyph.
See also
XTextLayout::queryMeasures()
queryMeasures
sequence< ::com::sun::star::geometry::RealRectangle2D >
queryMeasures();

Description
Query the logical bounding boxes of every character in the given text string.

Logical bounding boxes means the space that the font allocates for the given character, which, e.g. for a '.', might be significantly broader than the bounds returned via XTextLayout::queryInkMeasures().

Returns
a sequence of rectangles specifying the bounds in font coordinate space, one for every glyph.
See also
XTextLayout::queryInkMeasures()
queryLogicalAdvancements
sequence< double >
queryLogicalAdvancements();

Description
Query the advancements for every character in the input string.

This method returns a sequence of advancements, one for each character in the input string (not for every glyph. There might be multiple glyphs per input character, or multiple input characters per glyph). Adding up all advancements yields the total advancement of this layout. To manipulate the layout of a string on the level of characters, this method can be used to query for the layout's default advancements, which can subsequently be changed and applied to the layout via XTextLayout::applyLogicalAdvancements().

Returns
a sequence of ::double specifying the advancements per character in font coordinate space.
See also
XTextLayout::applyLogicalAdvancements()
applyLogicalAdvancements
void
applyLogicalAdvancements( [in] sequence< double >  aAdvancements )
raises( ::com::sun::star::lang::IllegalArgumentException );

Description
Apply explicit advancements for every character in the layout string.

This method applies the specified advancements to every logical character in the input string (not for every glyph. There might be multiple glyphs per input character, or multiple input characters per glyph). This is useful to explicitely manipulate the exact output positions of characters, e.g. relative to a reference output device.

Parameter aAdvancements
A sequence of character advancements, in font coordinate space.
Throws
com::sun::star::lang::IllegalArgumentException if the size of aAdvancements does not match the number of characters in the text.
See also
XTextLayout::queryLogicalAdvancements()
queryTextBounds
::com::sun::star::geometry::RealRectangle2D
queryTextBounds();

Description
Query the overall bounding box of the text.

This method is similar to XTextLayout::queryTextMeasures, only that the overall bounds are returned by this method.

Returns
the overall bounding box for the given layout, in font coordinate space.
justify
double
justify( [in] double  nSize )
raises( ::com::sun::star::lang::IllegalArgumentException );

Description
Justify the text to the given size.

This method is the core of the XTextLayout interface, because it layouts the text in a typographically correct way into the available space.

Parameter nSize
The requested size of the text after justification (either width or height, depending on the writing mode). This parameter is interpreted in font coordinate space.
Returns
the actual size of the text after the justification in the font coordinate space. Depending on the font and the script type, this might be somewhat different from the size requested. If the requested size was smaller than the justification algorithm could compress the text, this value might even be significantly larger than nSize.
Throws
com::sun::star::lang::IllegalArgumentException if nSize is 0 or negative.
combinedJustify
double
combinedJustify( [in] sequence< XTextLayout >  aNextLayouts,
[in] double  nSize )
raises( ::com::sun::star::lang::IllegalArgumentException );

Description
Justify a number of text layouts to the given size.

This method can be used to combine the layout of a text line into a single justification run. This is e.g. useful if the line consists of several text portions (e.g. because of different fonts or colors), but it is desirable to spread the available space more globally across the different layout objects. If, for example, one layout object contains significantly more whitespace or Kashidas than the rest, this method can assign proportionally more space to this layout object.

Parameter aNextLayouts
A sequence of layouts following this one in logical text order.
Parameter nSize
The requested size of the text for all XTextLayouts after justification in font coordinate space (either width or height, depending on the writing mode).
Returns
the actual size of the text after the justification, in font coordinate space. Depending on the font and the script type, this might be somewhat different from the size requested. If the requested size was smaller than the justification algorithm could compress the text, this value might even be significantly larger than nSize.
Throws
com::sun::star::lang::IllegalArgumentException if one of the parameters are not in the valid range.
getTextHit
TextHit
getTextHit( [in] ::com::sun::star::geometry::RealPoint2D  aHitPoint );

Description
This method determines the hit position in the text.

This method determines the index of the character hit at the specified position (in font coordinate space).

Parameter aHitPoint
The position in font coordinate space to determine the underlying character index for.
getCaret
Caret
getCaret( [in] long  nInsertionIndex,
[in] boolean  bExcludeLigatures )
raises( ::com::sun::star::lang::IndexOutOfBoundsException );

Description
This method converts an insertion index to a caret.

This method generates caret information for a given insertion point in the layout text.

Parameter nInsertionIndex
The insertion index, as e.g. returned by XTextLayout::getTextHit(). This value must be in the range 0 up to the number of characters in the string.
Parameter bExcludeLigatures
Set this to true, to skip the positions inside ligatures as valid caret placements. That means, on cannot e.g. set the caret between the 'f' and the 'i' in a 'fi' ligature.
Returns
the generated Caret structure.
Throws
com::sun::star::lang::IndexOutOfBoundsException if nInsertionIndex is outside the permissible range.
getNextInsertionIndex
long
getNextInsertionIndex( [in] long  nStartIndex,
[in] long  nCaretAdvancement,
[in] boolean  bExcludeLigatures )
raises( ::com::sun::star::lang::IndexOutOfBoundsException );

Description
This method calculates a new insertion index.

This method calculates a new insertion index, given a start index and the number of characters to skip. This is most useful for caret traveling.

Parameter nStartIndex
The insertion index to start from.
Parameter nCaretAdvancement
For values greater than 0, the caret is visually moved to the right. For values smaller than 0, the caret is visually moved to the left.
Returns
the new insertion index.
Throws
com::sun::star::lang::IndexOutOfBoundsException if nStartIndex or nCaretAdvancement is outside the permissible range.
queryVisualHighlighting
XPolyPolygon2D
queryVisualHighlighting( [in] long  nStartIndex,
[in] long  nEndIndex )
raises( ::com::sun::star::lang::IndexOutOfBoundsException );

Description
This method generates a highlight polygon.

This method generates a highlighting polygon from two insertion indices. This polygon will be visually continuous, i.e. will not have non-highlighted text in between.

Parameter nStartIndex
Start of the selection range.
Parameter nEndIndex
End of the selection range.
Returns
the highlight polygon in the font coordinate space.
Throws
com::sun::star::lang::IndexOutOfBoundsException if nStartIndex or nEndIndex are outside the permissible range.
queryLogicalHighlighting
XPolyPolygon2D
queryLogicalHighlighting( [in] long  nStartIndex,
[in] long  nEndIndex )
raises( ::com::sun::star::lang::IndexOutOfBoundsException );

Description
This method generates a highlight polygon.

This method generates a highlighting polygon from two insertion indices. This polygon will not always be visually continuous, if e.g. the text direction changes in the middle of the selection, the might be parts visually between start and end position that are not selected.

Parameter nStartIndex
Start of the selection range.
Parameter nEndIndex
End of the selection range.
Returns
the highlight polygon in the font coordinate space.
Throws
com::sun::star::lang::IndexOutOfBoundsException if nStartIndex or nEndIndex are outside the permissible range.
getBaselineOffset
double
getBaselineOffset();

Description
This method yields the baseline offset.

This method returns the baseline offset for this layout object, either measured from the top or the left edge, depending on the writing direction (horizontally or vertically). Since rendering this layout via XCanvas::drawTextLayout() outputs relative to the layout object's baseline, this method can be used to e.g. output relative to the left, top edge.

Returns
the distance of the main baseline from the top or the left edge of this object, depending on the writing direction.
getMainTextDirection
byte
getMainTextDirection();

Description
This method returns the main writing direction.

This method returns the main writing direction of this layout, i.e. either LEFT_TO_RIGHT or RIGHT_TO_LEFT.

Returns
the main text direction of this layout.
getFont
XCanvasFont
getFont();

Description
Request the associated font for this layout..
Returns
the associated font for this layout.
getText
StringContext
getText();

Description
Request the text this layout contains.
Returns
the text this layout contains.
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