I think there is a bug in the exporter, because the canvas has a color (which is white and _not_ transparent).

Normally you can set the color of the of the canvas (view canvas color: Color purple), but the default exporter (I assume you are exporting it via GT-inspector) is ignoring it.

There is however second exporter which you can use

~~~~~~~~~~~~~~~~~~~~~

|v fileName|

v := RTView new.

v canvas color: Color purple.

v addAll: (RTEllipse new color: Color black; size: 30; elementsOn: (1 to: 10)).

RTCircleLayout on: v elements.

fileName := UITheme builder��

fileSave: 'Enter the PNG file name'

extensions: #('png')

path: nil.

"fileName := '/tmp/test.png' asFileReference."

fileName notNil ifTrue: [��

(DCTRCanvasExporter canvas: v canvas)

format: #png;

fileName: fileName fullName;

export ].

~~~~~~~~~~~~~~~~~~~~~~~

You could also add the export code (with minor modification) to GLMRoassal2Presentation>>defaultActions but there seems to be some kind of bug that clears the content of the playground when executed from GLM, which is a big wtf, but maybe that's just my mixed up configuration.

Peter

On Mon, Apr 13, 2015 at 5:17 PM, Offray Vladimir Luna C��rdenas <offray@riseup.net> wrote:

Hi,

I have finally finished the first part of my visualization project of political discourses on Twitter. You can see the details here:

http://mutabit.com/offray/static/blog/output/posts/visualizing-politicianspolitical-discourses-on-twitter.html

(As you can see Pharo was not used to extract the data, just to scrap it, structure it and visualize it).

The politicians tag cloud look nice if the background is white, because the png background is transparent, but if you share it on Twitter, the black background makes the tag cloud invisible. I could use image editing programs to change the background from transparent to white, but I would like to know if there is a way to make that change inside Pharo/Roasal.

Thanks for all your support in making this ideas possible.

Cheers,

Offray