[FLEX-26031] Single pixel scrolls can cause firstIndexInView to be incorrect

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: Adobe Flex SDK Previous
• Component/s: Spark: Layout
• Environment: Affected OS(s): All OS Platforms; Affected OS(s): All OS Platforms; Language Found: English
• Assignee: Adobe JIRA
• Reporter: Adobe JIRA
• Created: 23/Nov/10 15:47
• Updated: 09/Mar/11 11:20
• Resolved: 07/Dec/10 11:04

Description

Steps to reproduce:
1. Compile and run this application:

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark" width="700">

<fx:Script>
<![CDATA[
private function showInView1():void

{ output.text += hLayout.firstIndexInView + ' expecting 0; ' output.text += hLayout.lastIndexInView + ' expecting 10; ' }

private function showInView2():void

{ output.text += hLayout.firstIndexInView + ' expecting 1; ' output.text += hLayout.lastIndexInView + ' expecting 10; ' }

]]
>
</fx:Script>

<s:controlBarContent>
<s:Button label="set hsp to 23" click="group1.horizontalScrollPosition = 23" />
<s:Button label="assert in view" click="showInView1()" />
<s:Button label="set hsp to 24" click="group1.horizontalScrollPosition = 24" />
<s:Button label="assert in view" click="showInView2()" />
</s:controlBarContent>

<s:Label id="output" />

<s:DataGroup id="group1" width="300" height="100" y="50" clipAndEnableScrolling="true">
<s:itemRenderer>
<fx:Component>
<s:ItemRenderer width="24" height="100">
<s:states>
<s:State name="normal"/>
<s:State name="hovered"/>
<s:State name="selected"/>
</s:states>
<s:Rect top="0" left="0" right="0" bottom="0">
<s:fill>
<s:SolidColor color="0xA8C6EE" color.hovered="0xCEDBEF" color.selected="0xCCCCCC" />
</s:fill>
</s:Rect>
<s:Label id="lbl" text="

{data.myItemIndex}

" top="1" left="1" />
</s:ItemRenderer>
</fx:Component>
</s:itemRenderer>
<s:layout>
<s:HorizontalLayout id="hLayout" useVirtualLayout="true" />
</s:layout>
<s:dataProvider>
<s:ArrayList>
<fx:Object myItemIndex="0" />
<fx:Object myItemIndex="1" />
<fx:Object myItemIndex="2" />
<fx:Object myItemIndex="3" />
<fx:Object myItemIndex="4" />
<fx:Object myItemIndex="5" />
<fx:Object myItemIndex="6" />
<fx:Object myItemIndex="7" />
<fx:Object myItemIndex="8" />
<fx:Object myItemIndex="9" />
<fx:Object myItemIndex="10" />
<fx:Object myItemIndex="11" />
</s:ArrayList>
</s:dataProvider>
</s:DataGroup>

</s:Application>

2. Click "set hsp to 23"
3. Click "assert in view"
4. Click "set hsp to 24"
5. Click "assert in view"

Actual Results:

0 expecting 0; 10 expecting 10; 0 expecting 1; 10 expecting 10

Expected Results:

0 expecting 0; 10 expecting 10; 1 expecting 1; 10 expecting 10

Workaround (if any):