Guidelines for object selection with a contextual menu

Question

I've always thought that a contextual click (aka right-click) on an object should select the object if it's not already selected while bringing up a contextual menu. But lately I've noticed a variation of that behavior from both Apple and Microsoft. Instead of changing the selection, there is a secondary selection that only applies to the contextual menu.

Here is an example with Mac OS 10.10's Finder:

The blue fill on Dictionary shows the selection prior to the right-click. The blue outline on Calendar shows the temporary selection for the contextual action.

And here's an example from Microsoft Outlook 2013:

The gray fill shows the previous selection and the dotted outline shows the temporary selection.

I can see the appeal of this behavior since it allows you to apply an action to an object without losing the current selection, but I can't find any documentation about it. Other apps I sampled still have the single selection model, including Windows 7 File Explorer and Visual Studio 2015.

I can find reference to the select-object-on-context-click in the Windows 7 UX Guidelines:

Single right click: Selects the object and displays its context menu.

But I haven't found any guidelines for the newer secondary selection feature.

Question: Are there UX guidelines that discuss the use of a secondary selection for contextual menus?

Answer 1

I'd also take a look in mobile guidelines (aka Android & iOS Human interface guidelines). Since "long press" contextual gesture does exactly what you describe - context menu opens, but no action is hit - this as well might be the "cause" for the change. It also applies to hyperlink usage on mobile devices: Long press -> Copy URL, but link is not activated.

Maybe it is an inheritance of the mobile age? Just a guess. Will look that up in the mobile guidelines as well.

Interesting question.