Kotlin 简化多回调函数

这里只是简单的例子,并没有实际意义,可以通过这个方法改造Android的TextWatcher ViewPager以及网络回调等各种多回调

    "123".setXListener(object :XListener{
        override fun onStart(name: String, time: String) {

        }

        override fun onProgress(progress: Int) {

        }

        override fun onEnd(path: String, time: Int) {

        }

    })

    "123".setXlistenerHelpter {
        OnStart { name, time ->

        }

        OnProgress {progress ->

        }

        OnEnd { path, time ->

        }
    }

源码

interface XListener {
    fun onStart(name: String, time: String)
    fun onProgress(progress: Int)
    fun onEnd(path: String, time: Int)
}

class XListenerHelper : XListener {

    private var tmpStart: ((String, String) -> Unit)? = null
    private var tmpProgress: ((Int) -> Unit)? = null
    private var tmpEnd: ((String, Int) -> Unit)? = null

    override fun onStart(name: String, time: String) {
        tmpStart?.invoke(name, time)
    }

    fun OnStart(start: (name: String, time: String) -> Unit) {
        tmpStart = start
    }

    override fun onProgress(progress: Int) {
        tmpProgress?.invoke(progress)
    }

    fun OnProgress(progress: (progress: Int) -> Unit) {
        tmpProgress = progress
    }

    override fun onEnd(path: String, time: Int) {
        tmpEnd?.invoke(path, time)
    }

    fun OnEnd(end: (path: String, time: Int) -> Unit) {
        tmpEnd = end
    }

}

fun String.setXListener(listener: XListener) {

}

fun String.setXlistenerHelpter(listener: (XListenerHelper.() -> Unit)) {
    setXListener(XListenerHelper().apply { listener })
}