tools.aqua.bgw.observable.properties.ReadonlyProperty.kt Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of bgw-core Show documentation

A framework for board game applications.

There is a newer version: 0.5

/*
 *    Copyright 2021 The BoardGameWork Authors
 *    SPDX-License-Identifier: Apache-2.0
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */

@file:Suppress("unused")

package tools.aqua.bgw.observable.properties

import tools.aqua.bgw.observable.ValueObservable

/**
 * Property baseclass providing observable fields.
 *
 * @constructor Creates a [ReadonlyProperty] with given initial value.
 *
 * @param initialValue Initial value of this property.
 */
open class ReadonlyProperty(initialValue: T) : ValueObservable() {
	
	/**
	 * Value of this property.
	 */
	private var boxedValue: T = initialValue
	
	/**
	 * Value of this property.
	 */
	open var value: T
		get() = boxedValue
		internal set(value) {
			val savedValue = boxedValue
			if (boxedValue != value) {
				boxedValue = value
				notifyChange(savedValue, value)
			}
		}
	
	/**
	 * Overrides [value] of this property without notifying public listeners.
	 *
	 * Only notifies GUI listener.
	 */
	internal open fun setSilent(value: T) {
		val savedValue = boxedValue
		if (boxedValue != value) {
			boxedValue = value
			notifyGUIListener(savedValue, value)
		}
	}
	
	/**
	 * Notifies all listeners with current value.
	 */
	fun notifyUnchanged(): Unit = notifyChange(boxedValue, boxedValue)
}