Hi Alex, thanks for the help. I agree that validateNow() is a bad things and breaks the deferred validation.
However everything else in updateCaretForDataProviderChange is done in "immediate" way And validateNow() is also called at other places in the same method: - line 5418 : validateNow () when managing REFRESH - line 5409 & 5442 : call ensureCellIsVisible(caretRowIndex, -1) that calls in turn validateNow(); So if I change that to newCaretRowIndexChanged=true; invalidateProperties(); I will have to do it for the whole method, and call the actual updateCaretForDataProviderChange in commitProperties. But then ensureCellIsVisible(caretRowIndex, -1) does not need to call validateNow() anymore , or we lose all the benefits of deferring. But it's a public method. Two options: 1) duplicate ensureCellsVisible as ensureCellsVisibleDeffered , that does not call validateNow() 2) [Preferred] add an optional parameter ensureCellIsVisible(rowIndex:int = -1, columnIndex:int = -1, validateNow: Boolean = true):void In the second option, I change the API, but don't break the existing calls. What do you think? Maurice -----Message d'origine----- De : Alex Harui [mailto:aha...@adobe.com] Envoyé : vendredi 11 octobre 2013 16:44 À : dev@flex.apache.org Objet : Re: Need help on https://issues.apache.org/jira/browse/FLEX-33813 (DataGrid goes blank) Hi Maurice, Thanks for digging into this. ValidateNow() can fix a lot of things, but it can also cause inefficiencies if the things it validates were going to get invalidated shortly after. I don't know if that is the case or not here. If it were me (and it isn't) I would change the collectionChangeHandler to set a flag and call updateCaretForDataProviderChange in updateDisplayList. InvalidateDisplayList is called in the collectionChangeHandler, and in theory, stuff like contentHeight should be resolved by the time you get to updateDisplayList. Last night I checked in a fix for another similar DG issue in a similar way by deferring work to measure(). -Alex On 10/11/13 6:55 AM, "Maurice Amsellem" <maurice.amsel...@systar.com> wrote: >Hi, I would like your help on a fix for > >https://issues.apache.org/jira/browse/FLEX-33813 (DataGrid goes blank >when scrolled and content is reset) > >I managed to spot where the issue is: > >Grid.as >line 850: >const gridViewLayout:GridViewLayout = centerGridView.gridViewLayout; >const gridMaxVSP:Number = contentHeight - height; const >centerContentHeight:Number = >Math.ceil(gridViewLayout.gridDimensionsView.getContentHeight()); > const centerMaxVSP:Number = centerContentHeight - >centerGridView.height; const vsp:Number = (centerMaxVSP / gridMaxVSP) * >value; centerGridView.verticalScrollPosition = vsp; > >=> contentHeight is NaN so all computations fails and >verticalScrollPosiiton is set to NaN, which clears all the renderers >(goes blank) > >My assumption is that the Grid is not ready yet, so it's missing a >validateNow() somewhere(). > >Call chain: >Grid.dataProvider_collectionChangeHandler(event:CollectionEvent) >=> Grid.updateCaretForDataProviderChange(event:CollectionEvent):void > >In Grid.updateCaretForDataProviderChange(): [line 5356], when managing >RESET event in line 5448, if the caret is not found (which is the case, >since all data is new), we call directly verticalScrollPosition = 0; > >=> I added validateNow() before the call, and it's fixed. > >Do you validate ? > >Maurice > > >Maurice Amsellem >SYSTAR R&D - BusinessBridgeFX >
