Model Observable

gistfile1.txt

interface ModelObservable : Observable {
    fun notifyChange()
    fun notifyPropertyChanged(fieldId: Int)
}

/**
 * A convenience class that implements an extension of the [Observable] interface and provides
 * [.notifyPropertyChanged] and [.notifyChange] methods.
 */
class ModelObservableImpl : ModelObservable {
    @Transient
    private var mCallbacks: PropertyChangeRegistry? = null

    override fun addOnPropertyChangedCallback(callback: Observable.OnPropertyChangedCallback) {
        synchronized(this) {
            if (mCallbacks == null) {
                mCallbacks = PropertyChangeRegistry()
            }
        }
        mCallbacks!!.add(callback)
    }

    override fun removeOnPropertyChangedCallback(callback: Observable.OnPropertyChangedCallback) {
        synchronized(this) {
            if (mCallbacks == null) {
                return
            }
        }
        mCallbacks!!.remove(callback)
    }

    /**
     * Notifies listeners that all properties of this instance have changed.
     */
    override fun notifyChange() {
        synchronized(this) {
            if (mCallbacks == null) {
                return
            }
        }
        mCallbacks!!.notifyCallbacks(this, 0, null)
    }

    /**
     * Notifies listeners that a specific property has changed. The getter for the property
     * that changes should be marked with [androidx.databinding.Bindable] to generate a field in
     * `BR` to be used as `fieldId`.
     *
     * @param fieldId The generated BR id for the Bindable field.
     */
    override fun notifyPropertyChanged(fieldId: Int) {
        synchronized(this) {
            if (mCallbacks == null) {
                return
            }
        }
        mCallbacks!!.notifyCallbacks(this, fieldId, null)
    }
}