scistag.imagestag.svg.SvgRenderer¶

class SvgRenderer[source]¶

Bases: object

SVG rendering class which renders an SVG using the Cairo SVG library.

Important: This class requires Cairo being installed on your system. For Linux and OS X users this is usually a one-liner, see https://www.cairographics.org/download/.

All standard SciStag Docker images already contain the pre-installed Cairo SVG and other base tools, so there is nothing for you to do. (https://hub.docker.com/r/scistag)

If you are a Windows user: It is in general possible to build Cairo for Windows too but after days of recherche and just stumbling over often more than 10+ years outdated last updates on the official sites I decided that this is not a “clean” solution. In consequence I converted all essential SVGs tof pre-rendered PNGs - such as basic UI graphics, emojis, country flags etc. - to the module so that SVG rendering is not required in general for using 98% of the functions of SciStag.

To suppress this message call scistag.imagestag.SvgRenderer.set_verbose() at the beginning of your script. Alternatively you can set the SCISTAG_SUPPORT_SVG environment variable to 0.

If you do need hi-quality live rendered SVGs in your application we recommend using Docker for Windows and using one of our provided Docker images available on https://hub.docker.com/r/scistag.

If you do not want to dockerize your application then running and debugging your application via WSL2 is also workaround, see https://thecodeblogger.com/2020/09/24/wsl-setup-vs-code-for-python-development/ or https://www.jetbrains.com/help/pycharm/using-wsl-as-a-remote-interpreter.html

To keep track of the status see https://github.com/SciStag/SciStag/issues/2

Usage: ` py from scistag.imagestack import SvgRenderer my_svg = open("example.svg").read() image = SvgRenderer.render(my_svg) `

Methods

`available`	Returns if SVG rendering is available :rtype: `bool` :return: True if it is
`render`	Renders an SVG
`set_verbose`	Defines if warnings about Cairo not being available shall be suppressed

Attributes

`__dict__`
`__doc__`
`__module__`
`__weakref__`	list of weak references to the object (if defined)
`_access_lock`
`_cairo_available`
`_initialized`
`_svg_to_png`
`_verbose`

classmethod _setup()[source]¶: Setups the svg renderer and tries to initialize Cairo :return:

classmethod available()[source]¶: Returns if SVG rendering is available :rtype: bool :return: True if it is

classmethod render(svg_data, output_width=None, output_height=None, bg_color=None)[source]¶

Renders an SVG

Parameters

svg_data (bytes) – The SVG’s data
output_width – The desired output with. Optional.
output_height – The desired output height. Optional.
bg_color (ColorTypes | None) – If specified the background will be filled with this color

Return type

Image | None

Returns

The image if the rendering was successful. None otherwise.

classmethod set_verbose(value=True)[source]¶

Defines if warnings about Cairo not being available shall be suppressed

Parameters: value – The new value. True = suppress warnings