If you have an expanded group at the end of a scrollable grid of icons with only one row of icons, and you scroll to the bottom, then long-press its drag handle to collapse it, the grid will be forced to scroll (as it has reduced in size) and the collapsed group will temporarily show with an incorrect offset. As soon as you move your finger again, it will be correct. The scroll position changes are also quite janky (as the main thread isn't updated as frequently as the compositor, and even if it was, would be unlikely to keep up) - this is a separate bug though, which I will file. The fix may end up fixing both, however.

Comment on attachment 8573365 [details] [gaia] Cwiiis:bug1120882-dont-resize-during-drag > mozilla-b2g:master This fixes the problem by just not resizing the grid during a drag. Because the grid never gets larger during a drag and the grid is always re-rendered after a drag, we can just skip sending the resize signal during drags and rely on the render-on-finish to re-send it.

Comment on attachment 8573365 [details] [gaia] Cwiiis:bug1120882-dont-resize-during-drag > mozilla-b2g:master This seems like there's a hard dependency on bug 1120884 which still has some questions there, so clearing review for now. Can you either roll this into that bug, or flag me after bug 1120884 has landed?

Comment on attachment 8573365 [details] [gaia] Cwiiis:bug1120882-dont-resize-during-drag > mozilla-b2g:master Nice and smooth, thanks!

http://docs.taskcluster.net/tools/task-graph-inspector/#ONlamdpnTyWMdg2MxZX3SA The pull request failed to pass integration tests. It could not be landed, please try again.

Sorry autolander (tests are green, one unrelated intermittent that passed on a retrigger) - merged manually: https://github.com/mozilla-b2g/gaia/commit/3325c49b8ca9b238399acf045efbbb7993269d66

(In reply to Chris Lord [:cwiiis] from comment #6) > Sorry autolander (tests are green, one unrelated intermittent that passed on > a retrigger) - merged manually: > https://github.com/mozilla-b2g/gaia/commit/ > 3325c49b8ca9b238399acf045efbbb7993269d66 Autolander/taskcluster must be drunk. Logs are not too helpful here, I've filed bug 1142130 to track this down.

Comment on attachment 8573365 [details] [gaia] Cwiiis:bug1120882-dont-resize-during-drag > mozilla-b2g:master [Approval Request Comment] [Bug caused by] (feature/regressing bug #): [User impact] if declined: Confusing/bad-looking behaviour when dragging the last group on the homescreen (or any group that causes the grid to shrink when scrolled to the bottom). [Testing completed]: Manual testing and been on master for a while. [Risk to taking this patch] (and alternatives if risky): Very low risk. [String changes made]: None.

NI myself for following verification.

v2.2: https://github.com/mozilla-b2g/gaia/commit/587f5a7b43f626c4836032fbeff41fa3fa2dc5f1

Verify this bug with below builds *2.2 Build ID 20150323162503 Gaia Revision e54c4ed1cc188f70ddf1156534d364005dc45490 Gaia Date 2015-03-23 19:09:26 Gecko Revision https://hg.mozilla.org/releases/mozilla-b2g37_v2_2/rev/7ba1778d237b Gecko Version 37.0 Device Name flame Firmware(Release) 4.4.2 Firmware(Incremental) eng.cltbld.20150323.200543 Firmware Date Mon Mar 23 20:05:54 EDT 2015 Bootloader L1TC000118D0 *master Serial: f2cfccfb (State: device) Build ID 20150323160205 Gaia Revision 8eac260ee81a8aca05770d18c5736536d44ee7a7 Gaia Date 2015-03-23 02:41:53 Gecko Revision https://hg.mozilla.org/mozilla-central/rev/bc85c479668a Gecko Version 39.0a1 Device Name flame Firmware(Release) 4.4.2 Firmware(Incremental) eng.cltbld.20150323.193421 Firmware Date Mon Mar 23 19:34:34 EDT 2015 Bootloader L1TC100118D0