flutter_svg
Draw SVG files using Flutter.
Getting Started
Basic usage (to create an SVG rendering widget from an asset):
final String assetName = 'assets/image.svg';
final Widget svg = SvgPicture.asset(
assetName,
semanticsLabel: 'Acme Logo'
);
You can color/tint the image like so:
final String assetName = 'assets/up_arrow.svg';
final Widget svgIcon = SvgPicture.asset(
assetName,
colorFilter: ColorFilter.mode(Colors.red, BlendMode.srcIn),
semanticsLabel: 'A red up arrow'
);
The default placeholder is an empty box (LimitedBox
) - although if a height
or width
is specified on the SvgPicture
, a SizedBox
will be used instead
(which ensures better layout experience). There is currently no way to show an
Error visually, however errors will get properly logged to the console in debug
mode.
You can also specify a placeholder widget. The placeholder will display during parsing/loading (normally only relevant for network access).
// Will print error messages to the console.
final String assetName = 'assets/image_that_does_not_exist.svg';
final Widget svg = SvgPicture.asset(
assetName,
);
final Widget networkSvg = SvgPicture.network(
'https://site-that-takes-a-while.com/image.svg',
semanticsLabel: 'A shark?!',
placeholderBuilder: (BuildContext context) => Container(
padding: const EdgeInsets.all(30.0),
child: const CircularProgressIndicator()),
);
If you'd like to render the SVG to some other canvas, you can do something like:
import 'package:flutter_svg/flutter_svg.dart';
final String rawSvg = '''<svg ...>...</svg>''';
final PictureInfo pictureInfo = await vg.loadPicture(SvgStringLoader(rawSvg), null);
// You can draw the picture to a canvas:
canvas.drawPicture(pictureInfo.picture);
// Or convert the picture to an image:
final ui.Image image = pictureInfo.picture.toImage(...);
pictureInfo.picture.dispose();
The SvgPicture
helps to automate this logic, and it provides some convenience
wrappers for getting assets from multiple sources. Unlike the vector_graphics
package, this package does not render the data to an Image
at any point.
This carries a performance penalty for some common use cases, but also allows
for more flexibility around scaling.
Precompiling and Optimizing SVGs
The vector_graphics backend supports SVG compilation which produces a binary
format that is faster to parse and can optimize SVGs to reduce the amount of
clipping, masking, and overdraw. The SVG compilation is provided by
package:vector_graphics_compiler
.
dart run vector_graphics_compiler -i assets/foo.svg -o assets/foo.svg.vec
The output foo.svg.vec
can be loaded using the default constructor of
SvgPicture
.
import 'package:flutter_svg/flutter_svg.dart';
import 'package:vector_graphics/vector_graphics.dart';
final Widget svg = SvgPicture(
const AssetBytesLoader('assets/foo.svg.vec')
);
Check SVG compatibility
An SVG can be tested for compatibility with the vector graphics backend by running the compiler locally to see if any errors are thrown.
dart run vector_graphics_compiler -i $SVG_FILE -o $TEMPORARY_OUTPUT_TO_BE_DELETED --no-optimize-masks --no-optimize-clips --no-optimize-overdraw --no-tessellate
Recommended Adobe Illustrator SVG Configuration
- In Styling: choose Presentation Attributes instead of Inline CSS because CSS is not fully supported.
- In Images: choose Embded not Linked to other file to get a single svg with no dependency to other files.
- In Objects IDs: choose layer names to add every layer name to svg tags or you can use minimal,it is optional.
SVG sample attribution
SVGs in /assets/w3samples
pulled from W3 sample files
SVGs in /assets/deborah_ufw
provided by @deborah-ufw
SVGs in /assets/simple
are pulled from trivial examples or generated to test
basic functionality - some of them come directly from the SVG 1.1 spec. Some
have also come or been adapted from issues raised in this repository.
SVGs in /assets/wikimedia
are pulled from Wikimedia Commons
Android Drawables in /assets/android_vd
are pulled from Android Documentation
and examples.
The Flutter Logo created based on the Flutter Logo Widget © Google.
The Dart logo is from dartlang.org © Google
SVGs in /assets/noto-emoji
are from Google i18n noto-emoji,
licensed under the Apache license.
Please submit SVGs that can't render properly (e.g. that don't render here the way they do in chrome), as long as they're not using anything "probably out of scope" (above).