Flutter 调用以及返回的封装, 防止重复返回, 有锁版, 防止多线程重复返回的可能

ReplyHandler.kt

import android.os.Handler
import android.os.Looper
import io.flutter.plugin.common.MethodCall
import io.flutter.plugin.common.MethodChannel
import java.util.concurrent.locks.ReentrantLock
import kotlin.concurrent.withLock

/// create 2019-11-27 by cai
class ReplyHandler(val call: MethodCall, private val result: MethodChannel.Result?) {
  
  companion object {
    val handler = Handler(Looper.getMainLooper())
  }
  
  private var isReply = false
  
  private val lock = ReentrantLock()
  
  fun success(any: Any?) {
    run {
      result?.success(any)
    }
  }
  
  fun error(code: String, detail: String? = null, error: Any? = null) {
    run {
      result?.error(code, detail, error)
    }
  }
  
  fun notImplemented() {
    run {
      result?.notImplemented()
    }
  }
  
  private inline fun run(crossinline runnable: () -> Unit) {
    lock.withLock {
      if (isReply) {
        return
      }
      isReply = true
      handler.post {
        runnable()
      }
    }
  }
}