When should I hide preview?

Question

My application looks like this:

The user may select an item from the list and a preview of this item will be displayed:

The user can also use filtering to reduce the number of displayed items. The problem is, if the user enters such a filter, that currently selected item is no longer visible, it's preview remains on screen:

So I've decided that the preview should be hidden in this case, but I'm not sure when to do it. I have two options:

1. Hide the preview immediately after the filter box is shown.
2. Hide preview only when currently selected item is no longer visible due to applied filter.

I personally favor the 1st option, because I believe if the user wants to filter items, it is likely that he is no longer interested in the current item.

Answer 1

You can see the solution on Gmail when you turn on vertical split view.

When you click to some label and all you see all mails with this mail. Then you click on the top of mail body on cross near label name. Message on the left dissapeared but preview is still show, because any other mail was selected.

Let's back to your application. I can see some clues on preview how to filter items to find what I want. For example dates, keywords, etc.

So my answer is: show preview until you select another item or you remove it.

Answer 2

Option 2 will be best option

Move the filters on top of the list. Show results below it. Keep the preview below the list. Hide the preview when, currently selected item is no longer in the list due to applied filter.

Case Study : Lets consider root folder as books, and book1, book2, etc. are results, and the filter is price. User select book1, to get the preview,Now user wants to filter books below price 100, he gets list of 2, Most probably he will check both previews.Even if checking the 2nd, he will likely wants to come back to check 1st preview again. It will be better to keep the preview as long as the selected item is in the list.