What are best practices for using SVG icons on Android?

I am about to create my first Android native (so not browser based) app and looking for some good practices regarding icon creating/provisioning. Since it should support multiple devices/resolutions I thought it is best to use SVG to create them. There is at least this lib: http://code.google.com/p/svg-android/ that promises to offer support for SVG on Android.

So far, I have not found resources describing the usage of this or another library as a means to render SVG Icons on the device, so I am a bit reluctant in using it. The best I have seen so far is using SVG as the source format for pre-rendering png based icons in different resolutions.

So my questions is: Are SVG icons a good option to use directly on the device without a png pre-rendering step (does it work at all), and if, why does nobody seem to use this approach?

Solution 1:

From Lollipop (API 21) onwards, Android defines the VectorDrawable class, for defining drawables based on vector graphics. Android Studio 1.4 adds the "Vector Asset Studio" to make them easier to work with, including an SVG import feature and a new Gradle plugin that generates PNG versions of VectorDrawable icons at build time for API 20 and earlier. There's also a third-party tool for converting SVGs to VectorDrawables. Bear in mind that although vector drawables can be defined in XML, the file format is not SVG and not all SVG files can be successfully converted. Simple graphics like icons should work OK.

If you still need to generate PNGs yourself, you'll need to generate your icons at various resolutions. For ease of generating those PNGs I design icons as SVG and then export to the various sizes using Inkscape which is free and cross-platform. It's got some nice features for designing icons, including the Icon Preview view (see below), and it generates nice crisp PNGs.

Solution 2:

For Android older than Lollipop, your best practice for SVG on Android is going to be to use a tool to convert your SVG to PNG at the size(s) you're interested in. Existing SVG support for Android is not comprehensive of what you're likely to find in an SVG file, and even if it were, the support is not built into the OS so using them directly for icons is definitely out.

Beginning with Lollipop (API 21) see What are best practices for using SVG icons on Android?. Thanks to @MarkWhitaker @AustynMahoney for pointing this out.