{"action":"created","issue":{"url":"https://api.github.com/repos/nolanlawson/pokedex.org/issues/35","labels_url":"https://api.github.com/repos/nolanlawson/pokedex.org/issues/35/labels{/name}","comments_url":"https://api.github.com/repos/nolanlawson/pokedex.org/issues/35/comments","events_url":"https://api.github.com/repos/nolanlawson/pokedex.org/issues/35/events","html_url":"https://github.com/nolanlawson/pokedex.org/issues/35","id":123898134,"number":35,"title":"Poor performance on Firefox for Android","user":{"login":"nolanlawson","id":283842,"avatar_url":"https://avatars.githubusercontent.com/u/283842?v=3","gravatar_id":"","url":"https://api.github.com/users/nolanlawson","html_url":"https://github.com/nolanlawson","followers_url":"https://api.github.com/users/nolanlawson/followers","following_url":"https://api.github.com/users/nolanlawson/following{/other_user}","gists_url":"https://api.github.com/users/nolanlawson/gists{/gist_id}","starred_url":"https://api.github.com/users/nolanlawson/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/nolanlawson/subscriptions","organizations_url":"https://api.github.com/users/nolanlawson/orgs","repos_url":"https://api.github.com/users/nolanlawson/repos","events_url":"https://api.github.com/users/nolanlawson/events{/privacy}","received_events_url":"https://api.github.com/users/nolanlawson/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":8,"created_at":"2015-12-25T21:28:08Z","updated_at":"2016-01-14T16:57:13Z","closed_at":null,"body":"This is something that's bugged me since the start of the project.\r\n\r\nOn Chrome for Android, the app is virtually indistinguishable from a native app. Scrolling is smooth, animations are crisp, everything looks lovely. Mission accomplished!\r\n\r\nOn Firefox for Android (or FirefoxOS), though, the scrolling is jerky and the transition animations are slow to start and slow to run. In fact, I had to put in [a hack](https://github.com/nolanlawson/pokedex.org/blob/e0d46357a25f37b7ed17e57ce36873ab8d3889f9/src/js/client/main/utils.js#L11-L21) to run the animations in two stages, because otherwise there wasn't even a chance they'd run at 60 FPS.\r\n\r\nI tested this on a Nexus 5 (both Lollipop+Firefox and FxOS), a Flame phone (FxOS), and a Nexus 5X (Marshmallow). In all cases I was using Firefox Beta (latest I tested was 44). TBQH the performance is better on a Galaxy Nexus running Chrome Beta, which is sad.\r\n\r\nI considered two possible culprits for the slowness, but neither turned out to be correct:\r\n\r\n1. **The base64-encoded CSS sprites.** I thought: maybe this is slower in Firefox than just using regular PNG files? I tried removing these CSS files entirely, though, and the performance was still bad.\r\n2. **The number of elements in the list.** Even when you filter to create a smaller list (e.g. enter \"s\" so that it shows all Pokémon whose names start with \"s\"), the scrolling and animation performance is still bad, even though far fewer DOM elements are in the list.\r\n\r\nSo what else could it be? I'm not sure whether this is indicative of a perf problem in the app, or in Firefox itself. Regardless, it bums me out, because Firefox for Android is my preferred browser, and my own app doesn't run well on it. :(\r\n\r\n/cc @mbrubeck @wanderview @flaki"},"comment":{"url":"https://api.github.com/repos/nolanlawson/pokedex.org/issues/comments/171702682","html_url":"https://github.com/nolanlawson/pokedex.org/issues/35#issuecomment-171702682","issue_url":"https://api.github.com/repos/nolanlawson/pokedex.org/issues/35","id":171702682,"user":{"login":"montogeek","id":1002461,"avatar_url":"https://avatars.githubusercontent.com/u/1002461?v=3","gravatar_id":"","url":"https://api.github.com/users/montogeek","html_url":"https://github.com/montogeek","followers_url":"https://api.github.com/users/montogeek/followers","following_url":"https://api.github.com/users/montogeek/following{/other_user}","gists_url":"https://api.github.com/users/montogeek/gists{/gist_id}","starred_url":"https://api.github.com/users/montogeek/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/montogeek/subscriptions","organizations_url":"https://api.github.com/users/montogeek/orgs","repos_url":"https://api.github.com/users/montogeek/repos","events_url":"https://api.github.com/users/montogeek/events{/privacy}","received_events_url":"https://api.github.com/users/montogeek/received_events","type":"User","site_admin":false},"created_at":"2016-01-14T16:57:13Z","updated_at":"2016-01-14T16:57:13Z","body":"There are some recommendations about use will-change in the MDN docs site.\r\nhttps://developer.mozilla.org/en/docs/Web/CSS/will-change"}}