Get parent Activity from View

[minsik-ai]

I find this immensely useful when using MVVM pattern.

fun View.getActivity(): Activity? {
    var context = context
    while (context is ContextWrapper) {
        if (context is Activity) {
            return context
        }
        context = context.baseContext
    }
    return null
}

Please let me know what you think of it. Thanks.

[JakeWharton]

I don't think we want to violate the scoping of views with this. Would we also have one for Dialog? What about views added directly to WindowManager that have neither an Activity or Dialog? The need to reach outside of your view into the enclosing container should be rare and I'm not sure we want to encourage it at this level.

[jaredsburrows]

@trent-dev Are you getting this from the Android code base? Such as MediaRouteButton: https://android.googlesource.com/platform/frameworks/base/+/master/core/java/android/app/MediaRouteButton.java#163?

[minsik-ai]

@jaredsburrows Yes. I found it from somewhere similar to code you linked.

[hameno]

We have the following extension in our code:

fun Context.getActivityContext(): Activity = when (this) {
    is Activity -> this
    is ContextWrapper -> this.baseContext.getActivityContext()
    else -> throw IllegalArgumentException("Not an activity context")
}

I'm not super happy with the IllegalArgumentException but in our case it should never happen.

[JakeWharton]

That is needlessly recursive. I still remain unconvinced we should be promoting this.

…

On Fri, Mar 2, 2018 at 1:06 PM Philip Schiffer ***@***.***> wrote: We have the following extension in our code: fun Context.getActivityContext(): Activity = when (this) { is Activity -> this is ContextWrapper -> this.baseContext.getActivityContext() else -> throw IllegalArgumentException("Not an activity context") } I'm not super happy with the IllegalArgumentException but in our case it should never happen. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#363 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAEEEdA9cBZlU8j8n6J-MVY8k2md8r5vks5taYoFgaJpZM4SUure> .

[hameno]

@JakeWharton Good point, a "tailrec" should fix that, right? I also get your point, it is not always safe to use.

[JakeWharton]

It might! Worth a try.

…

On Fri, Mar 2, 2018 at 1:11 PM Philip Schiffer ***@***.***> wrote: @JakeWharton <https://github.com/jakewharton> Good point, a "tailrec" should fix that, right? I also get your point, it is not always safe to use. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#363 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAEEEVGSdSGLPrqclkjSccURiVwPiEgAks5taYtcgaJpZM4SUure> .

[JakeWharton]

Going to close this because we don't want to recommend this as a general pattern. You should very rarely need to do this, but if you do it's fine to keep the code in your codebase only.

[jaredsburrows]

@JakeWharton We should make a note to deprecate then remove methods in AOSP.

[JakeWharton]

They're not public.

…

On Fri, Mar 2, 2018 at 1:43 PM Jared Burrows ***@***.***> wrote: @JakeWharton <https://github.com/jakewharton> We should make a note to deprecate then remove methods in AOSP. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#363 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAEEEW7i9K-zFd6Y3Vlmil41cxa0YcLSks5taZK8gaJpZM4SUure> .

[jaredsburrows]

@JakeWharton Good.