Scrollbars in dropdownlist inside DataGrid itemEditor not working

Question

I have a DropDownList inside the itemEditor of my DataGrid. There are enough items in the DropDownList to justify scrollbars. You can see the scrollbars, and the mousewhee

Answer 1

I posted this to Adobe as a bug (SDK-27783, Flex SDK, Spark:DropDownList), which was just closed today. Alex Harui had a good workaround:

Workaround is to change renderer as follows:

<s:DropDownList id="ddl" 
 width="100%" 
 dataProvider="{myChoices}" open="ddl.skin['dropDown'].owner = this"/>

I tested this and it solves my problem. Hopefully this will help others as well.

Answer 2

I'm not sure that it's a mouseEvent that you should to trap. You can debug the framework class: DropDownController.as, put a breakpoint at the start of the systemManager_mouseDownHandler function and processFocusOut function. You can see when you clic on the dropdownlist'scrollbar that the systemManager_mouseDownHandler function doesn't call closeDropDown, closeDropDown is called by processFocusOut.

Now add a DropDownList object at the top of your application:

<s:DropDownList id="ddltop"
                    top="10"
                    left="10"
                    width="100%"
                    dataProvider="{dataList.getItemAt(0).choices}"
                    />
<mx:DataGrid id="glGrid" top="50" left="10" right="10" bottom="10"

...

and debug again with the same breakpoints. Now it's the systemManager_mouseDownHandler function that call closeDropDown.

Perhaps the reason for the closure of the dropdownlist.