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Android fragment with real lifecycle
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import android.os.Bundle | |
import androidx.annotation.LayoutRes | |
import androidx.fragment.app.Fragment | |
open class BaseFragment(@LayoutRes contentLayoutId: Int) : Fragment(contentLayoutId) { | |
protected lateinit var runId: String | |
private set | |
private var instanceStateSaved: Boolean = false | |
override fun onCreate(savedInstanceState: Bundle?) { | |
super.onCreate(savedInstanceState) | |
savedInstanceState?.getString(FIRST_RUN_ID)?.let { restoredId -> | |
runId = restoredId | |
} ?: run { | |
runId = "${javaClass.simpleName}[${hashCode()}]" | |
onFirstCreate() | |
} | |
} | |
protected open fun onFirstCreate() {} | |
override fun onStart() { | |
super.onStart() | |
instanceStateSaved = false | |
} | |
override fun onResume() { | |
super.onResume() | |
instanceStateSaved = false | |
} | |
override fun onSaveInstanceState(outState: Bundle) { | |
super.onSaveInstanceState(outState) | |
outState.putString(FIRST_RUN_ID, runId) | |
instanceStateSaved = true | |
} | |
override fun onDestroy() { | |
super.onDestroy() | |
if (isRealDestroy()) onFinalDestroy() | |
} | |
protected open fun onFinalDestroy() {} | |
// This is android, baby! | |
private fun isRealRemoving(): Boolean = | |
(isRemoving && !instanceStateSaved) || // Because isRemoving == true for fragment in backstack on screen rotation | |
((parentFragment as? BaseFragment)?.isRealRemoving() ?: false) | |
// It will be valid only for 'onDestroy()' method | |
private fun isRealDestroy(): Boolean = | |
when { | |
activity?.isChangingConfigurations == true -> false | |
activity?.isFinishing == true -> true | |
else -> isRealRemoving() | |
} | |
open fun onBackPressed() {} | |
companion object { | |
private const val FIRST_RUN_ID = "state_first_run_id" | |
} | |
} |
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