user/interface/Font.dox

/*
 * Copyright 2013-2019 Haiku, Inc. All rights reserved.
 * Distributed under the terms of the MIT License.
 *
 * Authors:
 *		John Scipione, jscipione@gmail.com
 *
 * Corresponds to:
 *		headers/os/interface/Font.h	 hrev52784
 *		src/kits/interface/Font.cpp	 hrev52784
 */


/*!
	\file Font.h
	\ingroup interface
	\ingroup libbe
	\brief BFont class definition, unicode_block class definition, and
	       font-related struct and enum definitions.
*/


/*!
	\var B_CHAR_SPACING

	Position each character without adjustment. Best mode for printing.

	\since BeOS R3
*/


/*!
	\var B_STRING_SPACING

	Optimizes the position of each character within its space. Collisions
	are unlikely but characters may touch each other. Best mode to use when
	the screen needs to match what appears on the printed page.

	\since BeOS R3
*/


/*!
	\var B_BITMAP_SPACING

	The widths of the characters are chosen so that they never collide and
	rarely touch. Best mode for drawing small amounts of text.

	\since BeOS R3
*/


/*!
	\var B_FIXED_SPACING

	Positions characters at a constant width. Best mode for fixed-width fonts.

	\since BeOS R3
*/


/*!
	\enum font_direction
	\ingroup interface

	Determines the direction of the text rendered by the font,
	left-to-right or right-to-left.

	\since BeOS R3
*/


/*!
	\var font_direction B_FONT_LEFT_TO_RIGHT

	Left to right.

	\since BeOS R3
*/


/*!
	\var font_direction B_FONT_RIGHT_TO_LEFT

	Right to left.

	\since BeOS R3
*/


/*!
	\var B_DISABLE_ANTIALIASING

	Disable antialiasing. Used by BFont::Flags() and BFont::SetFlags().

	\since BeOS R3
*/


/*!
	\var B_FORCE_ANTIALIASING

	Force antialiasing. Used by BFont::Flags() and BFont::SetFlags().

	\since BeOS R3
*/


/*!
	\var B_TRUNCATE_END

	Truncate from the end of the string.

	\since BeOS R3
*/


/*!
	\var B_TRUNCATE_BEGINNING

	Truncate from the beginning of the string.

	\since BeOS R3
*/


/*!
	\var B_TRUNCATE_MIDDLE

	Truncate from the middle of the string.

	\since BeOS R3
*/


/*!
	\var B_TRUNCATE_SMART

	Truncate while keeping each string unique.

	\since BeOS R3
*/


/*!
	\var B_UNICODE_UTF8

	UTF-8 font encoding.

	\since BeOS R3
*/


/*!
	\var B_ISO_8859_1

	ISO 8859-1 aka Latin 1 "Western European" font encoding.

	\since BeOS R3
*/


/*!
	\var B_ISO_8859_2

	ISO 8859-2 aka Latin 2 "Eastern European" font encoding.

	\since BeOS R3
*/


/*!
	\var B_ISO_8859_3

	ISO 8859-3 aka Latin 3 "South European" font encoding.

	\since BeOS R3
*/


/*!
	\var B_ISO_8859_4

	ISO 8859-4 aka Latin 4 "Northern European" font encoding.

	\since BeOS R3
*/


/*!
	\var B_ISO_8859_5

	ISO 8859-5 "Latin/Cyrillic" font encoding.

	\since BeOS R3
*/


/*!
	\var B_ISO_8859_6

	ISO 8859-6 "Latin/Arabic" font encoding.

	\since BeOS R3
*/


/*!
	\var B_ISO_8859_7

	ISO 8859-7 "Latin/Greek" font encoding.

	\since BeOS R3
*/


/*!
	\var B_ISO_8859_8

	ISO 8859-8 "Latin/Hebrew" font encoding.

	\since BeOS R3
*/


/*!
	\var B_ISO_8859_9

	ISO 8859-9 aka Latin 5 "Latin/Turkish" font encoding.

	\since BeOS R3
*/


/*!
	\var B_ISO_8859_10

	ISO 8859-10 aka Latin 6 "Nordic" font encoding.

	\since BeOS R3
*/


/*!
	\var B_MACINTOSH_ROMAN

	Macintosh Roman font encoding.

	\since BeOS R3
*/


/*!
	\var B_HAS_TUNED_FONT

	Indicates that the font has been adjusted to look good on the screen.

	\since BeOS R4
*/


/*!
	\var B_IS_FIXED

	Indicates that the font is non-proportional.

	\since BeOS R4
*/


/*!
	\var B_ITALIC_FACE

	Italic font face flag.

	\since BeOS R4
*/


/*!
	\var B_UNDERSCORE_FACE

	Underscore font face flag.

	\since BeOS R4
*/


/*!
	\var B_NEGATIVE_FACE

	Negative font face flag.

	\since BeOS R4
*/


/*!
	\var B_OUTLINED_FACE

	Outline font face flag.

	\since BeOS R4
*/


/*!
	\var B_STRIKEOUT_FACE

	Strikeout font face flag.

	\since BeOS R4
*/


/*!
	\var B_BOLD_FACE

	Bold font face flag.

	\since BeOS R4
*/


/*!
	\var B_REGULAR_FACE

	Regular font face flag.

	\since BeOS R4
*/


/*!
	\var B_CONDENSED_FACE

	Condensed font face flag.

	\since Haiku R1
*/


/*!
	\var B_LIGHT_FACE

	Light font face flag.

	\since Haiku R1
*/


/*!
	\var B_HEAVY_FACE

	Heavy font face flag.

	\since Haiku R1
*/


/*!
	\enum font_metric_mode

	Font metric mode, screen or printing.

	\since BeOS R4
*/


/*!
	\var font_metric_mode B_SCREEN_METRIC

	Screen font metric mode.

	\since BeOS R4
*/


/*!
	\var font_metric_mode B_PRINTING_METRIC

	Printing font metric mode.

	\since BeOS R4
*/


/*!
	\enum font_file_format
	\ingroup interface

	Font file format, TrueType™ or PostScript™ Type1.

	\see BFont::FileFormat()

	\since BeOS R4
*/


/*!
	\var font_file_format B_TRUETYPE_WINDOWS

	TrueType™ font file format.

	\since BeOS R4
*/


/*!
	\var font_file_format B_POSTSCRIPT_TYPE1_WINDOWS

	PostScript™ Type1 font file format.

	\since BeOS R4
*/


/*!
	\class unicode_block
	\ingroup interface
	\ingroup libbe
	\brief Describes the blocks of Unicode characters supported by a font.

	\see BFont::Blocks()

	\since BeOS R4
*/


/*!
	\fn unicode_block::unicode_block()
	\brief Construct a \c unicode_block and set block data to 0.

	You must initialize the block data before before using this object.

	\since BeOS R4
*/


/*!
	\fn unicode_block::unicode_block(uint64 block2, uint64 block1)
	\brief Construct a \c unicode_block object and initialize it with the
	       supplied Unicode block range.

	\param block2 End block.
	\param block1 Begin block.

	\since BeOS R4
*/


/*!
	\fn bool unicode_block::Includes(const unicode_block& block) const
	\brief Determines if \a block is a subset of the \c unicode_block object.

	\param block The Unicode block to check.

	\returns Whether or not \a block is a subset of the \c unicode_block
	         object.
	\retval true \a block is a subset of the current \c unicode_block.
	\retval false \a block is NOT a subset of the current \c unicode_block.

	\since BeOS R4
*/


/*!
	\name Operators
*/


//! @{


/*!
	\fn unicode_block unicode_block::operator&(const unicode_block& block) const
	\brief Creates and returns a new \c unicode_block object that is the
	       intersection of \a block and the \c unicode_block object.

	\param block The Unicode block to intersect with.

	\returns The intersection of \a block and the \c unicode_block object.

	\since BeOS R4
*/


/*!
	\fn unicode_block unicode_block::operator|(const unicode_block& block) const
	\brief Creates and returns a new \c unicode_block object that is the union
	       of \a block and the \c unicode_block object.

	\param block The Unicode block to form a union with.

	\returns The union of \a block and the \c unicode_block object.

	\since BeOS R4
*/


/*!
	\fn unicode_block& unicode_block::operator=(const unicode_block& block)
	\brief Copies \a block data into the left-hand side object.

	\param block The unicode block to copy from.

	\returns A copy of \a block.

	\since BeOS R4
*/


/*!
	\fn bool unicode_block::operator==(const unicode_block& block) const
	\brief Determines if the block object are exactly equal.

	\param block The unicode block to compare against.

	\returns \c true if the block object are exactly equal, \c false
		otherwise.

	\since BeOS R4
*/


/*!
	\fn bool unicode_block::operator!=(const unicode_block& block) const
	\brief Determines if the block object are not equal.

	\param block The unicode block to compare against.

	\returns \c true if the block object are NOT equal, \c false
		if the block objects are exactly equal.

	\since BeOS R4
*/


//! @}


/*!
	\struct edge_info
	\ingroup interface
	\ingroup libbe
	\brief The distance that a character outline is inset from its escapement
		boundaries.

	Edge values, like escapements, need to be multiplied by the font size to
	get the correct value for the font.

	\see BFont::GetEdges()

	\since BeOS R3
*/


/*!
	\var edge_info::left

	The distance that the character outline is inset from the left
	escapement boundary.

	\since BeOS R3
*/


/*!
	\var edge_info::right

	The distance that the character outline is inset from the right
	escapement boundary.

	\since BeOS R3
*/


/*!
	\struct font_height
	\ingroup interface
	\ingroup libbe
	\brief The amount of vertical space surrounding a character.

	\see BFont::GetHeight()

	\since BeOS R3
*/


/*!
	\var font_height::ascent

	The distance characters can ascend above the baseline.

	\since BeOS R3
*/


/*!
	\var font_height::descent

	The distance characters can descend below the baseline.

	\since BeOS R3
*/


/*!
	\var font_height::leading

	The distance between lines, descent above to ascent below.

	\since BeOS R3
*/


/*!
	\struct escapement_delta
	\ingroup interface
	\ingroup libbe
	\brief A struct that allows you to specify extra horizontal space to surround
		each character with.

	Escapements need to be multiplied by the font size to get the correct
	value for the font.

	\see BFont::GetEscapements()

	\since BeOS R3
*/


/*!
	\var escapement_delta::nonspace

	The amount of horizontal space to surround a visible glyph character with.

	\since BeOS R3
*/


/*!
	\var escapement_delta::space

	The amount of horizontal space to surround a whitespace character with, for
	example \c B_TAB or \c B_SPACE.

	\since BeOS R3
*/


/*!
	\struct font_cache_info
	\ingroup interface
	\ingroup libbe
	\brief Font cache parameters.

	\since BeOS R3
*/


/*!
	\var font_cache_info::sheared_font_penalty

	Sheared font penalty.

	\since BeOS R3
*/


/*!
	\var font_cache_info::rotated_font_penalty

	Rotated font penalty.

	\since BeOS R3
*/


/*!
	\var font_cache_info::oversize_threshold

	Oversize threshold.

	\since BeOS R3
*/


/*!
	\var font_cache_info::oversize_penalty

	Oversize penalty.

	\since BeOS R3
*/


/*!
	\var font_cache_info::cache_size

	Cache size.

	\since BeOS R3
*/


/*!
	\var font_cache_info::spacing_size_threshold

	Spacing size threshold.

	\since BeOS R3
*/


/*!
	\struct tuned_font_info
	\ingroup interface
	\ingroup libbe
	\brief Tuning information of fonts used to make it look better when
		displayed on-screen.

	\see BFont::GetTunedInfo()
	\see BFont::CountTuned()

	\since BeOS R3
*/


/*!
	\var tuned_font_info::size

	Font size.

	\since BeOS R3
*/


/*!
	\var tuned_font_info::shear

	Font shear.

	\since BeOS R3
*/


/*!
	\var tuned_font_info::rotation

	Font rotation.

	\since BeOS R3
*/


/*!
	\var tuned_font_info::flags

	Font flags.

	\since BeOS R3
*/


/*!
	\var tuned_font_info::face

	Font face.

	\since BeOS R3
*/


/*!
	\fn int32 count_font_families()
	\brief Gets the number of installed font families

	\return The number of installed font families

	\since BeOS R3
*/


/*!
	\fn int32 count_font_styles(font_family family)
	\brief Gets the number of styles available for a font family.

	\return The number of styles available for a font family.

	\since BeOS R3
*/


/*!
	\fn status_t get_font_family(int32 index, font_family *_name,
		uint32 *_flags)
	\brief Retrieves the family name at the specified index.

	\param index Unique font identifier code.
	\param _name font_family String to receive the name of the family.
	\param _flags if non-<tt>NULL</tt>, the values of the flags \c IS_FIXED
		and \c B_HAS_TUNED_FONT are returned.

	\return A status code, \c B_OK on success or an error code.
	\retval B_BAD_VALUE \a _name is \c NULL.
	\retval B_ERROR \a index does not correspond to a font family.

	\since BeOS R3
*/


/*!
	\fn status_t get_font_style(font_family family, int32 index,
		font_style *_name, uint32 *_flags)
	\brief Retrieves the family name at the specified index.

	\param family The font family.
	\param index Unique font identifier code.
	\param _name string to receive the name of the family.
	\param _flags if non-<tt>NULL</tt>, the values of the flags \c IS_FIXED
		and \c B_HAS_TUNED_FONT are returned

	\return A status code, \c B_OK on success or an error code.
	\retval B_ERROR \a index does not correspond to a font style.

	\since BeOS R3
*/


/*!
	\fn status_t get_font_style(font_family family, int32 index,
		font_style *_name, uint16 *_face, uint32 *_flags)
	\brief Retrieves the family name at the specified index.

	The face value returned by this function is not very reliable. At the same
	time, the value returned should be fairly reliable, returning the proper
	flag for 90%-99% of font names.

	\param family The font family.
	\param index Unique font identifier code.
	\param _name String to receive the name of the family.
	\param _face recipient of font face value, such as \c B_REGULAR_FACE.
	\param _flags if non-<tt>NULL</tt>, the values of the flags \c IS_FIXED
		and \c B_HAS_TUNED_FONT are returned.

	\return A status code, \c B_OK on success or an error code.
	\retval B_ERROR \a index does not correspond to a font style.

	\since BeOS R3
*/


/*!
	\fn bool update_font_families(bool checkOnly)
	\brief Updates the font families list.

	\param checkOnly Parameter is ignored.

	\return \c true if the font list has changed, \c false if not.

	\since BeOS R3
*/


/*!
	\class BFont
	\ingroup interface
	\ingroup libbe
	\brief Represents a typeface including its family, style and size.

	The Interface Kit provides three prebuilt BFont objects which can be used
	but not modified.
	- \c const BFont* \c be_plain_font A plain font used by many controls.
	- \c const BFont* \c be_bold_font A bold font used by titles.
	- \c const BFont* \c be_fixed_font A fixed-width font.

	A BFont object does nothing on its own but is used in combination with
	a view or control. Here is an example of creating a BFont object from a
	system font and assigning it to a view:

\code
	BFont font(be_plain_font);
	font.SetSize(12.0);
	font.SetEncoding(B_ISO_8859_1);
	view->SetFont(&font);
\endcode

	You may also create a BFont object from a view, modify it and reassign it
	back to the view like this:

\code
	BFont font;
	view->GetFont(&font);
	font.SetFace(B_ITALIC_FACE);
	font.SetSpacing(B_CHAR_SPACING);
	myView->SetFont(&font);
\endcode

	You can change the way a font renders with the SetFamilyAndStyle(),
	SetFamilyAndFace(), SetSize(), SetShear(), SetRotation(),
	SetFalseBoldWidth(), SetSpacing(), SetEncoding(), SetFace(), and
	SetFlags() methods.

	More information about the space taken up by a font can be determined
	by querying a BFont object using the following methods:
	StringWidth(), GetStringWidths() GetEscapements(), GetEdges(),
	GetHeight(), BoundingBox() GetBoundingBoxesAsGlyphs(),
	GetBoundingBoxesAsString(), and GetBoundingBoxesForStrings().

	You can also perform intelligent string truncation with the
	TruncateString() and GetTruncatedStrings() methods.

	\since BeOS R3
*/


/*!
	\fn BFont::BFont()
	\brief Creates a BFont object initialized to \c be_plain_font.

	\see BView::GetFont()

	\since BeOS R3
*/


/*!
	\fn BFont::BFont(const BFont& font)
	\brief Creates and initializes a BFont object from another BFont object.

	\param font The BFont object to initialize from.

	\since BeOS R3
*/


/*!
	\fn BFont::BFont(const BFont* font)
	\brief Creates and initializes a BFont object from a pointer to a BFont
	       object.

	\param font The pointer to a BFont object to initialize from.

	\since BeOS R3
*/


/*!
	\fn BFont::BFont(const BFont* font)
	\brief Creates and initializes a BFont object from a pointer to a BFont
	       object.

	\param font The pointer to a BFont object to initialize from.

	\since BeOS R3
*/


/*!
	\fn status_t BFont::SetFamilyAndStyle(const font_family family,
		const font_style style)
	\brief Sets the font's family and style all at once.

	\param family Font family to set.
	\param style Font style to set.

	\returns A status code, \c B_OK on success or an error code.
	\retval B_BAD_VALUE \a family is \c NULL and \a style is \c NULL.
	\retval B_NAME_NOT_FOUND Family or style do not exist.

	\since BeOS R3
*/


/*!
	\fn void BFont::SetFamilyAndStyle(uint32 code)
	\brief Sets the font's family and style from a font identifier.

	\param code Unique font identifier obtained from the server.

	\since BeOS R3
*/


/*!
	\fn status_t BFont::SetFamilyAndFace(const font_family family, uint16 face)
	\brief Sets the font's family and face all at once.

	\param family Font family to set.
	\param face Font face to set.

	\note To comply with the BeBook, this function will only set valid values,
		i.e. passing a nonexistent family will cause only the face to be set.
		Additionally, if a particular face does not exist in a family, the
		closest match will be chosen.

	\returns A status code, \c B_OK on success or an error code.
	\retval B_ERROR Family does not exists or face has an invalid value.

	\since BeOS R4
*/


/*!
	\fn void BFont::SetSize(float size)
	\brief Sets the font size.

	\param size The point size to set the font to.

	\since BeOS R3
*/


/*!
	\fn void BFont::SetShear(float shear)
	\brief Sets the angle in degrees relative to the baseline.

	The default shear is 90.0° measured counterclockwise. The shear
	range is from 45.0° to 135.0°.

	\param shear The shear in degrees to set the font to.

	\since BeOS R3
*/


/*!
	\fn void BFont::SetRotation(float rotation)
	\brief Sets the font rotation from the baseline in degrees.

	The default baseline is 0° and rotates counterclockwise. Rotation is not
	supported by BTextView.

	\param rotation The rotation in degrees to set the font to.

	\since BeOS R3
*/


/*!
	\fn void BFont::SetFalseBoldWidth(float width)
	\brief Sets the false bold width.

	\param width The false bold width to set.

	\since Haiku R1
*/


/*!
	\fn void BFont::SetSpacing(uint8 spacing)
	\brief Sets how characters are horizontally spaced relative to each other.

	- \c B_CHAR_SPACING Position each character without adjustment. Best mode
		for printing. Characters may collide or overlap at small font sizes.
	- \c B_STRING_SPACING Optimizes the position of each character within its
		space. Collisions are unlikely but characters may touch each other.
		Best mode to use when the screen needs to match what appears on the
		printed page. Adding new characters requires the entire string to
		be redrawn.
	- \c B_BITMAP_SPACING The widths of the characters are chosen so that they
		never collide and rarely touch. Best mode for drawing small amounts
		of text. Character widths are integral values. Spacing on screen will
		not match spacing used by \c B_CHAR_SPACING mode for printing.
	- \c B_FIXED_SPACING Positions characters at a constant width. Must be
		used with fixed-width fonts otherwise \c B_CHAR_SPACING mode is used.
		All characters have an identical integral escapement.

	\c B_STRING_SPACING and \c B_BITMAP_SPACING modes are relevant only for
	font sizes from 7.0pt to 18.0pt, above and below that range
	\c B_CHAR_SPACING produces nicer results. \c B_CHAR_SPACING is also always
	used for rotated or sheared text and when antialiasing is disabled.

	\param spacing The spacing mode to set.

	\see BView::DrawString()
	\see GetEscapements()

	\since BeOS R3
*/


/*!
	\fn void BFont::SetEncoding(uint8 encoding)
	\brief Sets the character encoding of the font for example
		\c B_UNICODE_UTF8 or \c B_ISO_8859_1.

	The following character encodings are supported:
	- \c B_UNICODE_UTF8
	- \c B_ISO_8859_1 aka Latin 1 aka "Western European".
	- \c B_ISO_8859_2 aka Latin 2 aka "Eastern European".
	- \c B_ISO_8859_3 aka Latin 3 aka "South European".
	- \c B_ISO_8859_4 aka Latin 4 aka "Northern European".
	- \c B_ISO_8859_5 aka "Latin/Cyrillic".
	- \c B_ISO_8859_6 aka "Latin/Arabic".
	- \c B_ISO_8859_7 aka "Latin/Greek".
	- \c B_ISO_8859_8 aka "Latin/Hebrew".
	- \c B_ISO_8859_9 aka Latin 5 aka "Latin/Turkish".
	- \c B_ISO_8859_10 aka Latin 6 aka "Nordic".
	- \c B_MACINTOSH_ROMAN

	UTF-8 is the standard encoding used by classes in the Interface Kit. It
	is part of the Unicode® standard and allows Haiku to represent characters
	from all over the world while maintaining backwards compatibility with
	7-bit ASCII codes.

	Each of the encodings extend the ASCII codes and differ from each other
	only when the highest bit is set to 1, in other words, the value is
	greater than 127. Furthermore each of the encodings except for UTF-8
	are represented by a single byte and consequently encompass a limited set
	of characters. Most of the encodings are in the ISO/IEC 8859 family of
	character codes with the notable exception of Macintosh Roman which is
	the standard encoding used by the classic Mac OS®.

	If the value of the first byte of a UTF-8 character is greater than 127
	it indicates that the character is a multibyte character and therefore you
	must look at the next byte (and possibly the third byte, or rarely even
	forth byte) to get the whole character.

	Setting the character encoding on a view determines how BView::DrawString()
	interprets the values passed to it and also how BView::KeyDown() interprets
	the values representing the keys that the user presses.

	\param encoding The character encoding to set the font to.

	\since BeOS R3
*/


/*!
	\fn void BFont::SetFace(uint16 face)
	\brief Sets the font face according to the flags set by \a face.

	The following font face flags are supported:
	- \c B_ITALIC_FACE Characters are slanted to the right.
	- \c B_UNDERSCORE_FACE Characters are underlined.
	- \c B_NEGATIVE_FACE High and low colors are reversed when drawing
		characters.
	- \c B_OUTLINED_FACE Characters are drawn hollowed out.
	- \c B_STRIKEOUT_FACE A horizontal line is drawn through their middle.
	- \c B_BOLD_FACE Characters are bold.
	- \c B_REGULAR_FACE Characters are drawn normally.
	- \c B_CONDENSED_FACE Characters are drawn condensed. Not in BeOS 5.
 	- \c B_LIGHT_FACE Characters are drawn thiner than normal. Not in BeOS 5.
	- \c B_HEAVY_FACE Characters are drawn heavier than normal. Not in BeOS 5.

	\param face The bitmap of font face flags to set.

	\since BeOS R3
*/


/*!
	\fn void BFont::SetFlags(uint32 flags)
	\brief Sets font flags controlling antialiasing.

	The following flags are supported:
	- \c B_DISABLE_ANTIALIASING Disable antialiasing.
	- \c B_FORCE_ANTIALIASING Force antialiasing.

	\param flags The bitmap of flags to set.

	\since Haiku R1
*/


/*!
	\fn void BFont::GetFamilyAndStyle(font_family* family,
		font_style *style) const
	\brief Writes out the name of the font family and/or font style.

	This method may be called with either \a family or \a style set to
	\c NULL in order to get one or the other.

	\param family A font_family pointer to be filled out.
	\param style  A font_style pointer to be filled out.

	\since BeOS R3
*/


/*!
	\fn uint32 BFont::FamilyAndStyle() const
	\brief Gets the code of the font family and style combination.

	\returns The family and style combination encoded as a unique integer.

	\see SetFamilyAndStyle(uint32 code)

	\since BeOS R3
*/


/*!
	\fn float BFont::Size() const
	\brief Gets the font size.

	\returns The font size in points.

	\see SetSize()

	\since BeOS R3
*/


/*!
	\fn float BFont::Shear() const
	\brief Gets the font shear.

	\returns The font shear as an angle from 45.0° to 135.0°.

	\see SetShear()

	\since BeOS R3
*/


/*!
	\fn float BFont::Rotation() const
	\brief Gets the font rotation.

	\returns The font rotation as an angle in degrees.

	\see SetRotation()

	\since BeOS R3
*/


/*!
	\fn float BFont::FalseBoldWidth() const
	\brief Gets the width of the font as if it were bold.

	\returns The font width of the bold font variety.

	\see SetFalseBoldWidth()

	\since Haiku R1
*/


/*!
	\fn uint8 BFont::Spacing() const
	\brief Gets the spacing constant.

	\returns The spacing constant.

	\see SetSpacing()

	\since BeOS R3
*/


/*!
	\fn uint8 BFont::Encoding() const
	\brief Gets the character encoding constant.

	\returns The character encoding constant.

	\see SetEncoding()

	\since BeOS R3
*/


/*!
	\fn uint16 BFont::Face() const
	\brief Gets the font face flags bitmap.

	\returns The font face flags bitmap.

	\see SetFace()

	\since BeOS R3
*/


/*!
	\fn uint32 BFont::Flags() const
	\brief Gets the antialiasing flags.

	\returns The antialiasing flags.

	\see SetFlags()

	\since BeOS R3
*/


/*!
	\fn font_direction BFont::Direction() const
	\brief Gets the font direction, left-to-right or right-to left.

	\returns The font direction.

	\since BeOS R3
*/


/*!
	\fn bool BFont::IsFixed() const
	\brief Gets whether or not the font is fixed width.

	\returns \c true if the font is fixed width, \c false otherwise.

	\since BeOS R4
*/


/*!
	\fn bool BFont::IsFullAndHalfFixed() const
	\brief Returns whether or not the font is fixed-width and contains both
		full and half-width characters.

	A full-and-half-fixed font is one that contains characters of only
	two sizes, so that CJK languages can be properly supported.

	\note This was unimplemented in BeOS R5, but is implemented in Haiku.

	\since BeOS R4
*/


/*!
	\fn BRect BFont::BoundingBox() const
	\brief Gets a BRect that encloses the font text.

	\returns A BRect that encloses the font text.

	\since BeOS R4
*/


/*!
	\fn unicode_block BFont::Blocks() const
	\brief Gets a \c unicode_block object that identifies the Unicode blocks
	       supported by this font face and family.

	\returns A \c unicode_block object containing supported Unicode blocks.

	\since BeOS R4
*/


/*!
	\fn bool BFont::IncludesBlock(uint32 start, uint32 end) const
	\brief Gets whether the font includes the specified Unicode block.

	\since Haiku R1
*/


/*!
	\fn font_file_format BFont::FileFormat() const
	\brief Gets whether the font is a TrueType™ or PostScript™ Type1 font.

	\returns A \c font_file_format struct containing the font file format.

	\since BeOS R4
*/


/*!
	\fn int32 BFont::CountTuned() const
	\brief Gets the number of tuned fonts for the font family and style.

	\returns The number of tuned fonts.

	\since BeOS R3
*/


/*!
	\fn void BFont::GetTunedInfo(int32 index, tuned_font_info *info) const
	\brief Writes information about the tuned font at \a index into \a info.

	The index begins at 0 and counts tuned fonts for current font family and
	style only.

	\param index The index of desired tuned font.
	\param info The \a turned_font_info struct to be filled out.

	\since BeOS R3
*/


/*!
	\fn void BFont::TruncateString(BString *inOut, uint32 mode,
		float width) const
	\brief Truncates \a inOut to be no longer than \a width using the
	       supplied truncation \a mode.

	The following truncation modes are supported:
	- \c B_NO_TRUNCATION Does nothing.
	- \c B_TRUNCATE_BEGINNING Truncate from the beginning of the string.
	- \c B_TRUNCATE_MIDDLE Truncate from the middle of the string.
	- \c B_TRUNCATE_END Truncate from the end of the string.
	- \c B_TRUNCATE_SMART Truncate from anywhere, but do so so that each
		string is made unique after being truncated.

	\param inOut The BString to truncate.
	\param mode Truncation mode to use.
	\param width The maximum width to truncate to.

	\since BeOS R5
*/


/*!
	\fn void BFont::GetTruncatedStrings(const char *stringArray[],
		int32 numStrings, uint32 mode, float width,
		BString resultArray[]) const
	\brief Write truncated BString objects to \a resultArray given source
	       BString objects in \a stringArray.

	The following truncation modes are supported:
	- \c B_TRUNCATE_BEGINNING Truncate from the beginning of the string.
	- \c B_TRUNCATE_MIDDLE Truncate from the middle of the string.
	- \c B_TRUNCATE_END Truncate from the end of the string.
	- \c B_TRUNCATE_SMART Truncate from anywhere, but do so so that each
	     string is made unique after being truncated.

	\param stringArray The source string array.
	\param numStrings The number of strings in \a stringArray.
	\param mode Truncation mode to use.
	\param width The maximum width to truncate to.
	\param resultArray The destination string array.

	\since BeOS R5
*/


/*!
	\fn void BFont::GetTruncatedStrings(const char *stringArray[],
		int32 numStrings, uint32 mode, float width, char *resultArray[]) const
	\brief Write truncated strings to \a resultArray given source
	       BString objects in \a stringArray.

	\a resultArray is an array of pointers to string buffers which should be
	allocated ahead of time and should be at least 3 bytes longer than the
	matching input string. The 3 extra bytes provide enough room for the
	truncated output given that GetTruncatedStrings() truncates only a
	single-byte character from the input string and replaces it with an
	ellipsis character (which takes three bytes for the UTF-8 encoding),
	and adds a \c NUL-terminator.

	The following truncation modes are supported:
	- \c B_TRUNCATE_BEGINNING Truncate from the beginning of the string.
	- \c B_TRUNCATE_MIDDLE Truncate from the middle of the string.
	- \c B_TRUNCATE_END Truncate from the end of the string.
	- \c B_TRUNCATE_SMART Truncate from anywhere, but do so so that each
	     string is made unique after being truncated.

	\param stringArray The source string array.
	\param numStrings The number of strings in \a stringArray.
	\param mode Truncation mode to use.
	\param width The maximum width to truncate to.
	\param resultArray The destination string array.

	\since BeOS R5
*/


/*!
	\fn float BFont::StringWidth(const char *string) const
	\brief Determines the amount of space required to draw \a string in the
	       current font.

	\param string The source string.

	\returns The width required to draw the string.

	\since BeOS R3
*/


/*!
	\fn float BFont::StringWidth(const char *string, int32 length) const
	\brief Determines the amount of space required to draw \a string in the
	       current font up to \a length characters.

	\param string The source string.
	\param length The number of characters in \a string to consider.

	\returns The width required to draw the string.

	\since BeOS R3
*/


/*!
	\fn void BFont::GetStringWidths(const char *stringArray[],
		const int32 lengthArray[], int32 numStrings, float widthArray[]) const
	\brief Determines the amount of space required to draw each string in
	       \a stringArray and writes the result in \a widthArray.

	\param stringArray The source string array.
	\param lengthArray The number of characters to consider for each string in
		\a stringArray
	\param numStrings The number of strings in \a stringArray.
	\param widthArray The destination array to put the widths required to draw
		each string.

	\since BeOS R3
*/


/*!
	\fn void BFont::GetEscapements(const char charArray[], int32 numChars,
		float escapementArray[]) const
	\brief Determines the escapements for each char in \a charArray and writes
		the result in \a escapementArray.

	\param charArray The source character array.
	\param numChars The number of characters to consider in \a charArray.
	\param escapementArray The destination array to put the escapements.

	\since BeOS R3
*/


/*!
	\fn void BFont::GetEscapements(const char charArray[], int32 numChars,
		escapement_delta* delta, float escapementArray[]) const
	\brief Determines the escapements for each char in \a charArray and writes
		the result in \a escapementArray with consideration to the horizontal
		space provided by the escapement \a delta.

	The escapement_delta structure contains the following values:
	- \c nonspace The amount of horizontal space to surround a visible glyph
		character with.
	- \c space The amount of horizontal space to surround a whitespace character
		with, for example \c B_TAB or \c B_SPACE.

	\param charArray The source character array.
	\param numChars The number of characters to consider in \a charArray.
	\param delta The escapement_delta structure to use.
	\param escapementArray The destination array to put the escapements.

	\since BeOS R3
*/


/*!
	\fn void BFont::GetEscapements(const char charArray[], int32 numChars,
		escapement_delta *delta, BPoint escapementArray[]) const
	\brief Determines the escapements for each char in \a charArray and writes
		the result in \a escapementArray as an array of BPoint objects
		with consideration to the horizontal space provided by the escapement
		\a delta.

	The escapement_delta structure contains the following values:
	- \c nonspace The amount of horizontal space to surround a visible glyph
		character with.
	- \c space The amount of horizontal space to surround a whitespace character
		with, for example \c B_TAB or \c B_SPACE.

	\param charArray The source character array.
	\param numChars The number of characters to consider in \a charArray.
	\param delta The escapement_delta structure to use.
	\param escapementArray The destination array of escapements as BPoint
		objects.

	\since BeOS R4
*/


/*!
	\fn void BFont::GetEscapements(const char charArray[], int32 numChars,
		escapement_delta *delta, BPoint escapementArray[],
		BPoint offsetArray[]) const
	\brief Determines the escapements for each char in \a charArray and writes
		the result in \a escapementArray as an array of BPoint objects
		with consideration to the horizontal space provided by the escapement
		\a delta and writes the offsets to \a offsetArray.

	The escapement_delta structure contains the following values:
	- \c nonspace The amount of horizontal space to surround a visible glyph
		character with.
	- \c space The amount of horizontal space to surround a whitespace character
		with, for example \c B_TAB or \c B_SPACE.

	\param charArray The source character array.
	\param numChars The number of characters to consider in \a charArray.
	\param delta The escapement_delta structure to use.
	\param escapementArray The destination array of escapements as BPoint
		objects.
	\param offsetArray The destination array of offsets as BPoint objects.

	\since BeOS R4
*/


/*!
	\fn void BFont::GetEdges(const char charArray[], int32 numChars,
		edge_info edgeArray[]) const
	\brief Determines the edge information for each character in \a charArray
		and writes the result in \a edgeArray.

	The \c edge_info struct contains the following values:
	- \c left The distance that the character outline is inset from the left
		escapement boundary.
	- \c right  The distance that the character outline is inset from the
		right escapement boundary.

	\param charArray The source character array.
	\param numChars The number of characters to consider in \a charArray.
	\param edgeArray The destination array of \c edge_info structs.

	\since BeOS R3
*/


/*!
	\fn void BFont::GetHeight(font_height *_height) const
	\brief Fills out the \c font_height struct with the amount of vertical
		space surrounding a character.

	The \c font_height struct contains the following values:
	- \c ascent The distance characters can ascend above the baseline.
	- \c descent The distance characters can descend below the baseline.
	- \c leading The distance between lines, descent above to ascent below.

	\param _height The \c font_height struct to fill out.

	\since BeOS R3
*/


/*!
	\fn void BFont::GetBoundingBoxesAsGlyphs(const char charArray[],
		int32 numChars, font_metric_mode mode, BRect boundingBoxArray[]) const
	\brief Writes an array of BRect objects to \a boundingBoxArray
		representing the bounding rectangles of each character in
		\a charArray.

	Each BRect object corresponds to the glyph of one character.

	The \c font_metric_mode should contain one of the following values:
	- \c B_SCREEN_METRIC The bounding boxes should use the screen metric.
	- \c B_PRINTING_METRIC The bounding boxes should use the print metric.

	\param charArray The source character array.
	\param numChars The number of characters to consider in \a charArray.
	\param mode The \c font_metric_mode to use, screen or printing.
	\param boundingBoxArray The destination array of BRect bounding boxes.

	\since BeOS R4
*/


/*!
	\fn void BFont::GetBoundingBoxesAsString(const char charArray[],
		int32 numChars, font_metric_mode mode, escapement_delta *delta,
		BRect boundingBoxArray[]) const
	\brief Writes an array of BRect objects to \a boundingBoxArray representing
		the bounding rectangles of each character in \a charArray with
		consideration to the horizontal space provided by the escapement
		\a delta.

	Each BRect object corresponds to the glyph of one character.

	The \c font_metric_mode should contain one of the following values:
	- \c B_SCREEN_METRIC The bounding boxes should use the screen metric.
	- \c B_PRINTING_METRIC The bounding boxes should use the print metric.

	The provided escapement \a delta is applied as part of the bounding box
	calculations. This lets you specify a character spacing is looser or
	tighter than normal.

	The escapement_delta structure contains the following values:
	- \c nonspace The amount of horizontal space to surround a visible glyph
		character with.
	- \c space The amount of horizontal space to surround a whitespace character
		with, for example \c B_TAB or \c B_SPACE.

	\param charArray The source character array.
	\param numChars The number of characters to consider in \a charArray.
	\param mode The \c font_metric_mode to use, screen or printing.
	\param delta The escapement_delta structure to use.
	\param boundingBoxArray The destination array of BRect bounding boxes.

	\since BeOS R4
*/


/*!
	\fn void BFont::GetBoundingBoxesForStrings(const char *stringArray[],
		int32 numStrings, font_metric_mode mode, escapement_delta deltas[],
		BRect boundingBoxArray[]) const
	\brief Writes an array of BRect objects to \a boundingBoxArray representing
		the bounding rectangles of each string in \a stringArray with
		consideration to the horizontal space provided by the escapement
		\a deltas.

	Each BRect object corresponds to the bounding box of the entire string.

	The \c font_metric_mode should contain one of the following values:
	- \c B_SCREEN_METRIC The bounding boxes should use the screen metric.
	- \c B_PRINTING_METRIC The bounding boxes should use the print metric.

	The provided escapement \a deltas are applied as part of the bounding box
	calculations. This lets you specify a character spacing is looser or tighter
	than normal.

	The escapement_delta structure contains the following values:
	- \c nonspace The amount of horizontal space to surround a visible glyph
		character with.
	- \c space The amount of horizontal space to surround a whitespace character
		with, for example \c B_TAB or \c B_SPACE.

	\param stringArray The source string array.
	\param numStrings The number of strings to consider in \a stringArray.
	\param mode The \c font_metric_mode to use, screen or printing.
	\param deltas The array of escapement_delta structures to use.
	\param boundingBoxArray The destination array of BRect bounding boxes.

	\since BeOS R4
*/


/*!
	\fn void BFont::GetGlyphShapes(const char charArray[], int32 numChars,
		BShape *glyphShapeArray[]) const
	\brief Writes an array of BShape objects to \a glyphShapeArray
		representing the glyph shapes of each character in
		\a charArray.

	Each BShape object corresponds to the glyph of one character.

	\param charArray The source character array.
	\param numChars The number of characters to consider in \a charArray.
	\param glyphShapeArray The destination array of BShape glyphs.

	\since BeOS R4
*/


/*!
	\fn void BFont::GetHasGlyphs(const char charArray[], int32 numChars,
		bool hasArray[]) const
	\brief Fills out \a hasArray with whether or not the font has a glyph
		for each character in \a charArray.

	\c true is written in \a hasArray if a glyph is found for the character,
	\c false otherwise.

	\remark After the introduction of fallback fonts for missing glyphs,
	this is not exaclty what the name or the original desciption imply. As
	the objective of this method is to know if a string can be presented
	to the user without getting "no glyph" symbols, it will still write
	\c true if the queried font does not provide a glyph for a character
	but a fallback font does.

	\param charArray The source character array.
	\param numChars The number of characters to consider in \a charArray.
	\param hasArray The destination array of booleans.

	\since BeOS R4
*/


/*!
	\fn void BFont::GetHasGlyphs(const char charArray[], int32 numChars,
		bool hasArray[], bool useFallbacks) const
	\brief Fills out \a hasArray with whether or not the font has a glyph
		for each character in \a charArray.

	\c true is written in \a hasArray if the character has a glyph in the
	current font and \c false otherwise. Fallback fonts are also considered
	in the search if \a useFallbacks is \c true.

	\param charArray The source character array.
	\param numChars The number of characters to consider in \a charArray.
	\param hasArray The destination array of booleans.
	\param useFallbacks Whether to consider fallback fonts in the answer.

	\since Haiku R1
*/


/*!
	\fn BFont& BFont::operator=(const BFont &font)
	\brief Assignment overload method.

	\param font The BFont object to assign from.

	\since BeOS R3
*/


/*!
	\fn bool BFont::operator==(const BFont &font) const
	\brief Equality comparison overload method.

	\param font The BFont object to compare the current font to.

	\returns \c true if the fonts objects are identical, \c false otherwise.

	\since BeOS R3
*/


/*!
	\fn bool BFont::operator!=(const BFont &font) const
	\brief Inequality comparison overload method.

	\param font The BFont object to compare the current font to.

	\returns \c true if the fonts objects are NOT identical, \c true
		otherwise.

	\since BeOS R3
*/


/*!
	\fn void BFont::PrintToStream() const
	\brief Writes information about the font to \c stdout.

	printf("BFont { %s (%d), %s (%d) 0x%x %f/%f %fpt (%f %f %f), %d }\n",
		family, fFamilyID, style, fStyleID, fFace, fShear, fRotation, fSize,
		fHeight.ascent, fHeight.descent, fHeight.leading, fEncoding);

	\since BeOS R3
*/