Add opener controls to cell groups to make them easier to open and close.

For a Selected Cell...

Select the cell that you want to add a group opener to

Select the group header cell that you want to add an opener to:

  • You cannot add an opener to a cell that is not the head of a group.

Open the Option Inspector

Choose Format Option Inspector... () to open the Option Inspector:

Find the ShowGroupOpener option

Choose by category in the View menu and type ShowGroupOpener in the search field:

Set the value of ShowGroupOpener to True

Click the ShowGroupOpener checkbox to set its value to True. Openers are added to the selected cells:

For All Cells of a Given Style...

Open the stylesheet

To add openers to all cells of a given stylefor example, Section cellschoose Format Edit Stylesheet...:

Choose the style you want to add openers to

In the stylesheet that opens, choose the style you want to add openers to. The style is added to the stylesheet:

Open the Option Inspector

Choose Format Option Inspector to open the Option Inspector:

Find the ShowGroupOpener option

Choose View by category and type ShowGroupOpener in the search field:

Set the value of ShowGroupOpener to True

Click the ShowGroupOpener checkbox to set its value to True:

You will not see an opener on the Section cell in the stylesheet, because it is not the header cell of a group. But all Section cells in the stylesheets notebook that are heads of groups will acquire openers:

Programmatically for All Cells in a Notebook...

Add group openers to all group header cells in a notebook:

Notes

A cells group opener will not show if the group has no contents.