Add the ability to get the parent Activity of a View

[gahfy]

Adding the ability to get the parent Activity of a View.

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[gahfy]

I signed it!

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CLAs look good, thanks!

[gahfy]

Need #582 to be merged otherwise CI won't pass

[JakeWharton]

Why do you need this? Accessing the activity from a view is a generally discouraged pattern as it creates a bad coupling that prevents reuse.

[gahfy]

@JakeWharton Most of the time, I use it in BindingAdapters in order to put the Observer process out of the Activity to avoid boilerplate code in Activity which is often the same. For example:

/**
 * Sets a mutable visibility to the View. When the value of the LiveData changes, the visibility of
 * the View will change as well.
 * @param view the View to which to set the mutableVisibility
 * @param visibility the visibility LiveData the View should observe
 */
@BindingAdapter("mutableVisibility")
fun setMutableVisibility(view: View, visibility: MutableLiveData<Int>?) {
    val parentActivity: AppCompatActivity? = view.getParentActivity()
    if(parentActivity != null && visibility != null) {
        visibility.observe(parentActivity, Observer { value -> view.visibility = value?: View.VISIBLE})
    }
}

Then all you have to do is to set app:mutableVisibility as attribute in XML, and you don't have to care about Observers in your Kotlin Activity.

[gahfy]

Rebased on #582 as it has been merged to let CI pass

[gahfy]

Does someone understand the error of instrumented tests and how to solve it?