[FLEX-21996] ComboBox valueCommit event dispatches twice when it should dispatch just once

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: Adobe Flex SDK 3.4 (Release)
• Component/s: Events, mx: ComboBox
• Environment: Affected OS(s): All OS Platforms; Affected OS(s): All OS Platforms; Browser: Firefox 3.x; Language Found: English
• Assignee: Unassigned
• Reporter: Adobe JIRA
• Created: 12/Nov/09 15:49
• Updated: 13/Nov/09 07:14

Description

Steps to reproduce:
1. Create a ComboBox and set the valueCommit listener to trigger a task (an easy example is to trace a word).
2. Add a dataprovider with a a couple objects
3. Run your program and select an object from the ComboBox (thus triggering the valueCommit event on said ComboBox).

Actual Results:
The valueCommit event gets triggered twice in a row.

Expected Results:
The valueCommit event gets triggered once.

Workaround (if any):
There are several ways you can work around this issue. An easy one would to be to store a boolean variable inside your class and trigger it on and off based on whether it was the 2nd occurence of the event.

Example:
Here's an example of it happening with the debugger thread stack.

1st event:

Main Thread (Suspended)
com.onevision.view.components.reports::ReportsWindow/filterJobs
com.onevision.view.components.reports::ReportsWindow/__filterActionComboBox_valueCommit
flash.events::EventDispatcher/dispatchEventFunction [no source]
flash.events::EventDispatcher/dispatchEvent [no source]
mx.core::UIComponent/dispatchEvent
mx.controls::ComboBase/set selectedIndex
mx.controls::ComboBox/set selectedIndex
mx.controls::ComboBox/dropdown_changeHandler
flash.events::EventDispatcher/dispatchEventFunction [no source]
flash.events::EventDispatcher/dispatchEvent [no source]
mx.core::UIComponent/dispatchEvent
mx.controls.listClasses::ListBase/mouseUpHandler
mx.controls::List/mouseUpHandler

2nd event:

Main Thread (Suspended)
com.onevision.view.components.reports::ReportsWindow/filterJobs
com.onevision.view.components.reports::ReportsWindow/__filterActionComboBox_valueCommit
flash.events::EventDispatcher/dispatchEventFunction [no source]
flash.events::EventDispatcher/dispatchEvent [no source]
mx.core::UIComponent/dispatchEvent
mx.controls::ComboBase/textInput_valueCommitHandler
flash.events::EventDispatcher/dispatchEventFunction [no source]
flash.events::EventDispatcher/dispatchEvent [no source]
mx.core::UIComponent/dispatchEvent
mx.controls::TextInput/set text
mx.controls::ComboBox/set selectedIndex
mx.controls::ComboBox/dropdown_changeHandler
flash.events::EventDispatcher/dispatchEventFunction [no source]
flash.events::EventDispatcher/dispatchEvent [no source]
mx.core::UIComponent/dispatchEvent

So it looks like it is getting triggered by a mouseUpEvent (or keyDownHandler depending on whether you're using the mouse or the keyboard to interact with the ComboBox) when it's not supposed to, since it is already being dispatched by the dropdown_changeHandler.