LiveData observer useful for unit testing

LICENSE

Copyright 2019 Alessandro Diaferia

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

OneTimeObserver.kt

import androidx.lifecycle.Lifecycle
import androidx.lifecycle.LifecycleOwner
import androidx.lifecycle.LifecycleRegistry
import androidx.lifecycle.Observer

/**
 * Observer implementation that owns its lifecycle and achieves a one-time only observation
 * by marking it as destroyed once the onChange handler is executed.
 *
 * @param handler the handler to execute on change.
 */
class OneTimeObserver<T>(private val handler: (T) -> Unit) : Observer<T>, LifecycleOwner {
    private val lifecycle = LifecycleRegistry(this)
    init {
        lifecycle.handleLifecycleEvent(Lifecycle.Event.ON_RESUME)
    }

    override fun getLifecycle(): Lifecycle = lifecycle

    override fun onChanged(t: T) {
        handler(t)
        lifecycle.handleLifecycleEvent(Lifecycle.Event.ON_DESTROY)
    }
}

Hi - love to use this, but I don't see a license anywhere. Can you add a comment on how you'd like to license this?

Hi - love to use this, but I don't see a license anywhere. Can you add a comment on how you'd like to license this?

@javadude There you go, enjoy 🙂

Thanks much!

Thank you for this :)