Ribbon UI - The property name "ypadd" is not working in notebookbar.ui file...

Hi, all.

I want to customize the ribbon UI supported from the LibreOffice 5.3 experimental version.
First, I want to customize the ribbon ui in swriter.
I found out I have to make some changes on notebookbar.ui file located in the following folder :

What I wanted to make changes is to make the “Home” tab wider on ribbon ui, so I added the following line in the above notebookbar.ui file.
After adding this line, I restarted the swriter.exe in instdir folder, but nothing changed. What’s wrong?
So now I wonder if vcl can’t parse this property name…

Who can resolve this issue?
Please help me !!! It’s kinda urgent task!!!

And I don’t even know how the .ui file is used and rendered in libreoffice code structure …
In a word, I want to know the mechanism how the .ui and .xml files are used to configure GUI …

Look forward to hearing from somebody!!!

Thanks. Yoshitoshi.

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