wpf listbox/listview : grouped by header, but if only one item exists, only show the header?

Basically I have the following setup:

public class Sections
{
    public String Heading { get; set; }

 开发者_如何学编程   public String SectionTitle { get; set; }

    public ICollection<MyTask> Tasks { get; set; }
}

Right now I can do the following (Group all items by header and show their tasks under them):

• Heading1
  • Section1
    1. DoX (Clickable)
    2. DoY (Clickable)
  • Section2
    1. DoFoo (Clickable)
    2. DoBar (Clickable)
• Heading2
  • SectionX
    1. DoSomething (Clickable)
  • SectionY
    1. DoSomethingElse (Clickable)
• Heading3
  • SpecialSection
    1. AccessSpecialSection (Clickable)

What I'm trying to achieve is to condense this list down:

• Heading1
  • Section1
    1. DoX
    2. DoY
  • Section2
    1. DoFoo
    2. DoBar
• Heading2
  • SectionX (DoSomething is hidden within this - Now SectionX is Clickable)
  • SectionY (DoSomethingElse is hidden within this - Now SectionY is Clickable)
• Heading3 (SpecialSection / AccessSpecialSection is hidden within this - Now Heading3 is Clickable)

Not sure if there is an easy way to do this?

• IF ONE SECTION exists in the Heading AND ONE TASK exists in the Section => Heading gets the command binding
• IF ONE SECTION exists in the Heading AND 2+ TASKS exist in the Section => Show Heading / Hide Section and the TASKS get the command binding
• IF 2+ SECTIONS exist in the Heading and ONE TASK exists in the Section => Show Heading / Show Section / Hide the TASK and give the Section the command binding
• IF 2+ SECTIONS exist in the Heading and 2+ TASKS exist in the Section => Show all and proceed as normal (TASKS get the command binding).