SvgImage Class Reference

An SVG image. More...

#include <svgimage.h>

Public Member Functions
	SvgImage ()
	SvgImage (const std::string &uri, const SizeF &size={})
	SvgImage (const SvgImage &)=delete
	SvgImage (SvgImage &&) noexcept
	~SvgImage () noexcept
EGT_NODISCARD RectF	id_box (const std::string &id) const
	Get the position and size of an element in the SVG.
EGT_NODISCARD bool	id_exists (const std::string &id) const
	Test if an element exists in the SVG image.
EGT_NODISCARD Image	id_image (const std::string &id) const
	Render the image of the specific element in the SVG file.
	operator Image () const
	Overload to convert to an Image.
SvgImage &	operator= (const SvgImage &)=delete
SvgImage &	operator= (SvgImage &&) noexcept
EGT_NODISCARD Image	render (const std::string &id={}, const RectF &rect={}) const
	Render the SVG optionally with only the specified element id in the SVG file.
EGT_NODISCARD SizeF	size () const
	Get the SVG size.
void	size (const SizeF &size)
	Set the size you want any rendered Image to be.
void	uri (const std::string &uri)
	Set the URI.

Protected Member Functions
EGT_NODISCARD shared_cairo_surface_t	do_render (const std::string &id={}, const RectF &rect={}) const
	Render and return a new surface.
void	load ()
	Load the SVG file.

Protected Attributes
std::unique_ptr< SvgImpl >	m_impl
	Implementation pointer.
SizeF	m_size
	User set size.
std::string	m_uri
	User set URI.

Detailed Description

An SVG image.

This class is not just for working with a single Image. It allows loading an SVG file or data once, and then rendering any number of images at different sizes or made up of different elements from the SVG file.

SvgImage svg("file.svg");

For using individual elements from a SVG file and render them separately the document must be created with element IDs. In the dashboard example for instance, one of the dash_background.svg element has the attribute:

id="right_blink"

Several methods in the SvgImage class allow the use of such elements when the id parameter is present. Element IDs must follow the syntax of an URL fragment identifier. For example, use "#right_blink" (hash right_blink) to obtain a handle on the SVG element mentioned just above; which gives:

SvgImage custom1svg("file:dash_background.svg", SizeF(200, 0));
auto img_box = custom1svg.id_box("#right_blink");

Note

Some standard effects in SVG files are expensive to render. For example, some patterns and gradients. In those cases, you can convert elements in the SVG itself to raster images to speed up rendering here.

Constructor & Destructor Documentation

SvgImage() [1/4]

SvgImage

(

)

SvgImage() [2/4]

SvgImage ( const std::string &  uri, const SizeF &  size = {}  )

explicit

Parameters

uri	Resource path.

See also

Resources

Parameters

[in]

size

Size of the image.

See also

SvgImage::size() for more information about specifying size.

SvgImage() [3/4]

SvgImage ( const SvgImage &  )

delete

SvgImage() [4/4]

SvgImage ( SvgImage &&  )

noexcept

~SvgImage()

~SvgImage ( )

noexcept

Member Function Documentation

do_render()

EGT_NODISCARD shared_cairo_surface_t do_render ( const std::string &  id = {}, const RectF &  rect = {}  ) const

protected

Render and return a new surface.

id_box()

EGT_NODISCARD RectF id_box

(

const std::string &

id

)

const

Get the position and size of an element in the SVG.

Parameters

[in]

id

The id of the SVG element. Element IDs must follow the syntax of an URL fragment identifier. For example, use "#right_blink" (hash right_blink) to obtain a handle on the SVG element with id="right_blink".

id_exists()

EGT_NODISCARD bool id_exists

(

const std::string &

id

)

const

Test if an element exists in the SVG image.

Parameters

[in]

id

The id of the SVG element. Element IDs must follow the syntax of an URL fragment identifier. For example, use "#right_blink" (hash right_blink) to obtain a handle on the SVG element with id="right_blink".

Returns

true if found

id_image()

EGT_NODISCARD Image id_image ( const std::string &  id ) const

inline

Render the image of the specific element in the SVG file.

This is the same as calling:

render("id", svg.id_box("id"))

Note

The size of the returned image will be the size of the specific element in the SVG file.

See also

render().

load()

void load ( )

protected

Load the SVG file.

operator Image()

operator Image

(

)

const

Overload to convert to an Image.

This is the same as calling render().

operator=() [1/2]

SvgImage & operator= ( const SvgImage &  )

delete

operator=() [2/2]

SvgImage & operator= ( SvgImage &&  )

noexcept

render()

EGT_NODISCARD Image render	(	const std::string &	id = {},
		const RectF &	rect = {}
	)		const

Render the SVG optionally with only the specified element id in the SVG file.

Note

If no rect is specified or an empty rect is specified, the raster Image returned will be the same size as the entire SVG.

Parameters

[in]	id	Optional id of the SVG element to render. If no id is specified, all elements in the SVG will be rendered. Element IDs must follow the syntax of an URL fragment identifier. For example, use "#right_blink" (hash right_blink) to obtain a handle on the SVG element with id="right_blink".
[in]	rect	Optional rect to clip to.

size() [1/2]

EGT_NODISCARD SizeF size

(

)

const

Get the SVG size.

size() [2/2]

void size ( const SizeF &  size )

inline

Set the size you want any rendered Image to be.

This is somewhat special. If you specify zero for one of the dimensions, the other dimension will be automatically computed keeping the same aspect ratio.

If both dimensions are zero, the default size will be loaded from the SVG file.

uri()

void uri

(

const std::string &

uri

)

Set the URI.

If this results in changing the URI for this instance, this will cause a re-load of the SVG file

Member Data Documentation

m_impl

std::unique_ptr<SvgImpl> m_impl

protected

Implementation pointer.

m_size

SizeF m_size

protected

User set size.

Use size() to get the calculated size.

m_uri

std::string m_uri

protected

User set URI.