{"action":"created","issue":{"url":"https://api.github.com/repos/handsontable/handsontable/issues/3192","repository_url":"https://api.github.com/repos/handsontable/handsontable","labels_url":"https://api.github.com/repos/handsontable/handsontable/issues/3192/labels{/name}","comments_url":"https://api.github.com/repos/handsontable/handsontable/issues/3192/comments","events_url":"https://api.github.com/repos/handsontable/handsontable/issues/3192/events","html_url":"https://github.com/handsontable/handsontable/issues/3192","id":131402837,"number":3192,"title":"Issues with viewportRowRenderingOffset:auto while implementing custom expand collapse logic","user":{"login":"samsonkhisty","id":3254606,"avatar_url":"https://avatars.githubusercontent.com/u/3254606?v=3","gravatar_id":"","url":"https://api.github.com/users/samsonkhisty","html_url":"https://github.com/samsonkhisty","followers_url":"https://api.github.com/users/samsonkhisty/followers","following_url":"https://api.github.com/users/samsonkhisty/following{/other_user}","gists_url":"https://api.github.com/users/samsonkhisty/gists{/gist_id}","starred_url":"https://api.github.com/users/samsonkhisty/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/samsonkhisty/subscriptions","organizations_url":"https://api.github.com/users/samsonkhisty/orgs","repos_url":"https://api.github.com/users/samsonkhisty/repos","events_url":"https://api.github.com/users/samsonkhisty/events{/privacy}","received_events_url":"https://api.github.com/users/samsonkhisty/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":1,"created_at":"2016-02-04T16:34:46Z","updated_at":"2016-02-05T11:16:09Z","closed_at":null,"body":"Hi there again, \r\n\r\nI'm trying to implement my expand collapse logic like so\r\n\r\n![screen shot 2016-02-04 at 11 15 36 am](https://cloud.githubusercontent.com/assets/3254606/12821270/ab45793a-cb30-11e5-8220-3a62269447f1.png)\r\n\r\nI've added a click event handler on the icons which will simply update a field `hidden_children` to the parent and `hidden` to all the children below and call `render` and I have a custom rendered that will change the icon on the parent and adds class `hide` to the children with `hidden:true`\r\n\r\nI've got the bulk of the feature working, however ran into some issues: \r\n\r\n* If I leave the `viewportRowRenderingOffset: auto` as default, and collapse some rows in my view such that the rows which are normally outside the viewport are now into view. They are not rendered yet. \r\n\r\n* My next issue is again with  `viewportRowRenderingOffset: auto`, It introduces some weird scroll behavior on cell clicks if some data is collapsed. Not sure how to debug into this: \r\n![viewportrowrenderingoffset](https://cloud.githubusercontent.com/assets/3254606/12821909/7cf15646-cb33-11e5-9bed-55796fd75bba.gif)\r\n\r\n* If I change to `viewportRowRenderingOffset: myData.length`, this works as intended however, for a table with huge rows there is lag in collapsing and expanding. It seems slow. \r\n\r\nThanks in advance."},"comment":{"url":"https://api.github.com/repos/handsontable/handsontable/issues/comments/180303566","html_url":"https://github.com/handsontable/handsontable/issues/3192#issuecomment-180303566","issue_url":"https://api.github.com/repos/handsontable/handsontable/issues/3192","id":180303566,"user":{"login":"AMBudnik","id":10757813,"avatar_url":"https://avatars.githubusercontent.com/u/10757813?v=3","gravatar_id":"","url":"https://api.github.com/users/AMBudnik","html_url":"https://github.com/AMBudnik","followers_url":"https://api.github.com/users/AMBudnik/followers","following_url":"https://api.github.com/users/AMBudnik/following{/other_user}","gists_url":"https://api.github.com/users/AMBudnik/gists{/gist_id}","starred_url":"https://api.github.com/users/AMBudnik/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/AMBudnik/subscriptions","organizations_url":"https://api.github.com/users/AMBudnik/orgs","repos_url":"https://api.github.com/users/AMBudnik/repos","events_url":"https://api.github.com/users/AMBudnik/events{/privacy}","received_events_url":"https://api.github.com/users/AMBudnik/received_events","type":"User","site_admin":false},"created_at":"2016-02-05T11:16:09Z","updated_at":"2016-02-05T11:16:09Z","body":"Hi @samsonkhisty \r\nGreat feature you're working on! I really would like to take a little part in your progress but without a demo it is very hard. Can you create one (for example in JSBin or JSFiddle)?"}}