Ok, I built it and looks promising, but it isn't saving or loading any layout (you said you implemented that, so where did you hid it?).
The second problem is the toolbars are a bit bigger than the space assigned for them when icons are 32x32, and smaller when 16x16. In the first case it's painting a few extra pixels, in the second case it isn't painting all pixels (the ones at the bottom), and, also for 16x16, the space for the toolbar is larger than needed.
I suppose those are wxAUI problems, right?
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