On 14 Mar 2013, at 8:35, commits at source.squeak.org wrote:

> A new version of Graphics was added to project The Inbox:
> http://source.squeak.org/inbox/Graphics-cbc.203.mcz
> 
> ==================== Summary ====================
> 
> Name: Graphics-cbc.203
> Author: cbc
> Time: 13 March 2013, 4:14:19.182 pm
> UUID: e843098f-81e9-c944-bc06-8b15a3d44f23
> Ancestors: Graphics-nice.202
> 
> Added Form>>writePNGfileNamed: (along the lines of Form>>writeBMPfileNamed:)
> 
> =============== Diff against Graphics-nice.202 ===============
> 
> Item was added:
> + ----- Method: Form>>writePNGfileNamed: (in category 'fileIn/Out') -----
> + writePNGfileNamed: fName  "Display writePNGfileNamed: 'display.png'"
> +    PNGReadWriter putForm: self onFileNamed: fName!

Given that Form and PNGReadWriter are in the same package, I'd be happy to see this in trunk.

frank