Wt::WLength Class Reference

A value class that describes a CSS length. More...

#include <Wt/WLength.h>

Public Types
typedef LengthUnit	Unit
	Typedef for enum Wt::LengthUnit.

Public Member Functions
	WLength ()
	Creates an 'auto' length.
template<std::size_t N>
	WLength (const char(&str)[N])
	Creates a length by parsing the argument as a css length string.
	WLength (const std::string &str)
	Creates a length by parsing the argument as a css length string.
	WLength (double value, LengthUnit unit=LengthUnit::Pixel)
	Creates a length with value and unit.
bool	isAuto () const
	Returns whether the length is 'auto'.
double	value () const
	Returns the value.
LengthUnit	unit () const
	Returns the unit.
const std::string	cssText () const
	Returns the CSS text.
bool	operator== (const WLength &other) const
	Comparison operator.
bool	operator!= (const WLength &other) const
	Comparison operator.
double	toPixels (double fontSize=16.0) const
	Returns the (approximate) length in pixels.

Static Public Attributes
static WLength	Auto
	An 'auto' length.

Detailed Description

A value class that describes a CSS length.

The class combines a value with a unit. There is a special value auto which has a different meaning depending on the context.

Constructor & Destructor Documentation

WLength() [1/4]

Wt::WLength::WLength

(

)

Creates an 'auto' length.

Specifies an 'auto' length.

See also

Auto

WLength() [2/4]

template<std::size_t N>

Wt::WLength::WLength

(

const char(&)

str[N]

)

Creates a length by parsing the argument as a css length string.

This supports all CSS length formats that have an API counterpart.

This is an overload for the std::string version that accepts a string literal.

WLength() [3/4]

Wt::WLength::WLength

(

const std::string &

str

)

Creates a length by parsing the argument as a css length string.

This supports all CSS length formats that have an API counterpart.

WLength() [4/4]

Wt::WLength::WLength	(	double	value,
		LengthUnit	unit = LengthUnit::Pixel
	)

Creates a length with value and unit.

This constructor is also used for the implicit conversion of a double to a WLength, assuming a pixel unit.

Member Function Documentation

isAuto()

bool Wt::WLength::isAuto

(

)

const

Returns whether the length is 'auto'.

See also

WLength(), Auto

toPixels()

double Wt::WLength::toPixels

(

double

fontSize = 16.0

)

const

Returns the (approximate) length in pixels.

When the length isAuto(), 0 is returned, otherwise the approximate length in pixels.

Note

For percentages (LengthUnit::Percentage), and units relative to viewport size (LengthUnit::ViewportWidth, LengthUnit::ViewportHeight, LengthUnit::ViewportMin, LengthUnit::ViewportMax), a percentage of the font size is used.

unit()

LengthUnit Wt::WLength::unit

(

)

const

Returns the unit.

See also

value()

value()

double Wt::WLength::value

(

)

const

Returns the value.

See also

unit()

Member Data Documentation

Auto

WLength Wt::WLength::Auto

static

An 'auto' length.

See also

WLength()