controller.java

来自「演示win32的socket 通讯 八皇后的改进算法 并发Concurren」· Java 代码 · 共 55 行

package concurrency.cruise;

class Controller {
  final static int INACTIVE = 0; // cruise controller states
  final static int ACTIVE   = 1;
  final static int CRUISING = 2;
  final static int STANDBY  = 3;
  private int controlState  = INACTIVE; //initial state
  private SpeedControl sc;
  private boolean isfixed;

  Controller(CarSpeed cs, CruiseDisplay disp, boolean b)
    {sc=new SpeedControl(cs,disp); isfixed=b;}

  synchronized void brake(){
    if (controlState==CRUISING )
      {sc.disableControl(); controlState=STANDBY; }
  }

  synchronized void accelerator(){
    if (controlState==CRUISING )
      {sc.disableControl(); controlState=STANDBY; }
  }

  synchronized void engineOff(){
    if(controlState!=INACTIVE) {
      if (isfixed && controlState==CRUISING) sc.disableControl(); //bugfix
      controlState=INACTIVE;
    }
  }

  synchronized void engineOn(){
    if(controlState==INACTIVE)
      {sc.clearSpeed(); controlState=ACTIVE;}
  }

  synchronized void on(){
    if(controlState!=INACTIVE){
      sc.recordSpeed(); sc.enableControl();
      controlState=CRUISING;
    }
  }

  synchronized void off(){
    if(controlState==CRUISING )
      {sc.disableControl(); controlState=STANDBY;}
  }

  synchronized void resume(){
    if(controlState==STANDBY)
     {sc.enableControl(); controlState=CRUISING;}
  }
}