Working on a mobile project I needed to create a renderer for a list, so I choose to look at the IconItemRenderer which extends the LabelItemRenderer. These have been optimised for mobile use so it seemed a reasonable place to start. On the whole they seem like good classes to use, but if you’ve ever worked with the Datagrid/DataGridBase in the past you will probably know about the white square which comes about from the hardcoded #FFFFFF values inside the DataGridBase!
Well the IconItemRenderer and LabelItemRenderer have a similar issue. So lets just say you create a list and you wish to skin the list exactly how you like or use it in a tile layout or something other than vertical then you will find some lines above and below your renderers which look out of place. You can’t get rid of them no matter what property styles you set.
The fix is pretty straight forward but why does there have to be some hardcoded values in something that is meant to be very versatile?
So inside the LabelItemRenderer around lines 881 you will see the following. It uses these values to draw separators whether you like it or not.
// separators are a highlight on the top and shadow on the bottom topSeparatorColor = 0xFFFFFF; topSeparatorAlpha = .3; bottomSeparatorColor = 0x000000; bottomSeparatorAlpha = .3;
So the quickest way of dealing with this is to override the drawBackground function in your own class which is created in LabelItemRenderer. This doesn’t get called from IconItemRenderer so you can quite simple copy the entire function and just remove the separator chunk and do not call super from your function which overrides the drawBackground.
Better still would be to change the hard coded values to styles from a CSS file.
var topSeparatorColor : uint = getStyle( 'topSeparatorColor' ); var topSeparatorAlpha : Number = getStyle( 'topSeparatorAlpha' ); topSeparatorAlpha = isNaN( topSeparatorAlpha ) ? 1 : topSeparatorAlpha;
If you’re setting a Number just remember to check for NaN’s in case you haven’t set a style, uints default to 0 anyway.