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Issue 1: When I try to save PAGE within Visio Document (.vsdx) file to .vdx(Vsio Drawing Xml Format) fill formats of shapes as well as Text within shapes is not getting displayed in correct way.
We managed to replicate the problem of not preserving the style of the shapes (fill formats). We have logged this problem under ticket id DIAGRAMJAVA-50242 in our bug tracking system. Your post has also been linked to this issue. We'll let you know once a significant progress has been made in this regard. We're sorry for the inconvenience caused.
In reference of the mingled characters of the shape text, please set the font scale of the Char element before saving it in the VDX file format. Sample code: shape.getChars().get(0).getFontScale().setValue(1);
Issue 2: if I try to save page within visio diagram to .vsx blank document with master shapes added is getting created.
Please note, the VSX is an XML stencil format. It holds masters of the shapes. Microsoft Office Visio 2013 no longer supports the VSX format. Could you please elaborate a bit more about the use case and why you need to save it in the VSX format?
Please let us know in case of any confusion or questions.