Hello.

I need to know what logic does P.P. use to move slide elements (shapes) on theme change.
I have created a "template" PPTX with a master slide and some layouts and I use it with Aspose to generate a new PPTX.
Most of the layouts I created do not correspond to an existing layout predefined in P.P., meaning that I have slides with 6 charts and a table and other unusual configurations.
As far as I saw, one factor affecting the application of a layout defined in a theme (on theme change) is the current layout name of the slide. I mean, in order for a slide using a layout of mine to follow the element positions of a layout defined in the new theme, my layout should use the same name to the theme's layout.
What I haven't figured out yet, is how it decides which shape to move and based on which placeholder (especially when the number of shapes in the two slides do not match).

I you can enlighten me on this issue it would be great. Otherwise, at least help me with this (which is my main problem):

I have a custom layout defined in a master slide (no content match to any predefined P.P. layout) and I need to make sure that when the user changes the theme, some specific elements of the slide do not move. I have a problem with this because, despite the fact that I use a custom name for my layout and a custom name for my placeholder, somehow, some (but not all) of the predefined themes change the position of that shape.

Thanks in advance,
Kostas