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author | Simon Knox <simon@gitlab.com> | 2018-02-20 13:31:28 +0300 |
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committer | Simon Knox <simon@gitlab.com> | 2018-02-20 13:31:28 +0300 |
commit | cccde4b1cace9c4686825eba2d4eabff1a34433e (patch) | |
tree | 8915dda76be5c21d98fa34b9b50064498aa9d62c /doc/development | |
parent | 5048c8d5050cd432381d845997c5e7991e6590f1 (diff) |
Add animation performance guide to frontend docs
Diffstat (limited to 'doc/development')
-rw-r--r-- | doc/development/fe_guide/performance.md | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/doc/development/fe_guide/performance.md b/doc/development/fe_guide/performance.md index 14ac1133cc0..98e43931a02 100644 --- a/doc/development/fe_guide/performance.md +++ b/doc/development/fe_guide/performance.md @@ -36,6 +36,15 @@ If you are asynchronously adding content which contains lazy images then you nee `gl.lazyLoader.searchLazyImages()` which will search for lazy images and load them if needed. But in general it should be handled automatically through a `MutationObserver` in the lazy loading function. +### Animations + +Only animate `opacity` & `transform` properties. Other properties (such as `top`, `left`, `margin`, and `padding`) all cause +Layout to be recalculated, which is much more expensive. For details on this, see "Styles that Affect Layout" in +[High Performance Animations][high-perf-animations]. + +If you _do_ need to change layout (e.g. a sidebar that pushes main content over), prefer [FLIP][flip] to change expensive +properties once, and handle the actual animation with transforms. + ## Reducing Asset Footprint ### Page-specific JavaScript @@ -87,6 +96,7 @@ General tips: - Compress and minify assets wherever possible (For CSS/JS, Sprockets and webpack do this for us). - If some functionality can reasonably be achieved without adding extra libraries, avoid them. - Use page-specific JavaScript as described above to dynamically load libraries that are only needed on certain pages. +- [High Performance Animations][high-perf-animations] ------- @@ -105,3 +115,5 @@ General tips: [d3]: https://d3js.org/ [chartjs]: http://www.chartjs.org/ [page-specific-js-example]: https://gitlab.com/gitlab-org/gitlab-ce/blob/13bb9ed77f405c5f6ee4fdbc964ecf635c9a223f/app/views/projects/graphs/_head.html.haml#L6-8 +[high-perf-animations]: https://www.html5rocks.com/en/tutorials/speed/high-performance-animations/ +[flip]: https://aerotwist.com/blog/flip-your-animations/ |