A TextBox template now contains only 1 named part, PART_ContentHost, that buries the text element and selection element to where it is no longer customizable. Our previous versions of this template had many more named parts and allowed us to explicitly define the selection border element.
We want our selection to be underneath the text (just like in Blend). This was previously possible. When upgrading to WPF 4 these templates broke, and we can no longer do this. The only thing we can do is set what the selection brush is, but not how the selection border looks. For example, in Blend the selection is underneath the text and has a border thickness.
Did WPF lose styling functionality, or am I missing something? Is there a way to enable "old" templates that use the previous list of named parts?