package net.lacolaco.smileessence.util

import net.lacolaco.smileessence.entity.RBinding

import java.util.*

abstract class UIObservable {
    private val observers = WeakHashMap<Any, (EnumSet<RBinding>) -> Unit>()

    fun addObserver(weakKey: Any, observer: (EnumSet<RBinding>) -> Unit) {
        synchronized(this) {
            observers.put(weakKey, observer)
        }
    }

    fun removeObserver(weakKey: Any) {
        synchronized(this) {
            observers.remove(weakKey)
        }
    }

    protected fun notifyChange(flag: RBinding) {
        notifyChange(EnumSet.of(flag))
    }

    protected fun notifyChange(flags: EnumSet<RBinding>) {
        val obs = ArrayList<(EnumSet<RBinding>) -> Unit>()
        synchronized(this) {
            obs.addAll(observers.values)
        }

        UIHandler().post {
            for (observer in obs) {
                observer(flags)
            }
        }
    }
}