package com.spreadst.floatwindow;
 import android.app.Service;
 import android.content.Context;
 import android.content.Intent;
 import android.graphics.PixelFormat;
 import android.os.IBinder;
 import android.util.Log;
 import android.view.Gravity;
 import android.view.LayoutInflater;
 import android.view.MotionEvent;
 import android.view.View;
 import android.view.WindowManager;

 public class FloatWindowService extends Service {

  private static final TAG = "FloatWindowService";

  private WindowManager mWindowManager;
  private WindowManager.LayoutParams mLayoutParams;
  private LayoutInflater mLayoutInflater;
  private View mFloatView;
  private int mCurrentX;
  private int mCurrentY;
  private static int mFloatViewWidth = 50;
  private static int mFloatViewHeight = 80;
  @Override
  public void onCreate() {
    // TODO Auto-generated method stub
    super.onCreate();
    //初始化WindowManager對(duì)象和LayoutInflater對(duì)象
    mWindowManager = (WindowManager) getApplicationContext().getSystemService(Context.WINDOW_SERVICE);
    mLayoutInflater = LayoutInflater.from(this);
  }
  @Override
  public void onStart(Intent intent, int startId) {
    // TODO Auto-generated method stub
    super.onStart(intent, startId);
    Log.i(TAG, "onStart()");
    createView();
  }
  private void createView() {
    // TODO Auto-generated method stub
    //加載布局文件
    mFloatView = mLayoutInflater.inflate(R.layout.main, null);
    //為View設(shè)置監(jiān)聽，以便處理用戶的點(diǎn)擊和拖動(dòng)
    mFloatView.setOnTouchListener(new OnFloatViewTouchListener());
    /*為View設(shè)置參數(shù)*/
    mLayoutParams = new WindowManager.LayoutParams();
    //設(shè)置View默認(rèn)的擺放位置
    mLayoutParams.gravity = Gravity.LEFT | Gravity.TOP;
    //設(shè)置window type
    mLayoutParams.type = WindowManager.LayoutParams.TYPE_PHONE;
    //設(shè)置背景為透明
    mLayoutParams.format = PixelFormat.RGBA_8888;
    //注意該屬性的設(shè)置很重要，F(xiàn)LAG_NOT_FOCUSABLE使浮動(dòng)窗口不獲取焦點(diǎn),若不設(shè)置該屬性，屏幕的其它位置點(diǎn)擊無效，應(yīng)為它們無法獲取焦點(diǎn)
    mLayoutParams.flags = WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE;
    //設(shè)置視圖的顯示位置，通過WindowManager更新視圖的位置其實(shí)就是改變(x,y)的值
    mCurrentX = mLayoutParams.x = 50;
    mCurrentY = mLayoutParams.y = 50;
    //設(shè)置視圖的寬、高
    mLayoutParams.width = 100;
    mLayoutParams.height = 100;
    //將視圖添加到Window中
    mWindowManager.addView(mFloatView, mLayoutParams);
  }
  /*由于直接startService(),因此該方法沒用*/
  @Override
  public IBinder onBind(Intent intent) {
    // TODO Auto-generated method stub
    return null;
  }
  /*該方法用來更新視圖的位置，其實(shí)就是改變(LayoutParams.x,LayoutParams.y)的值*/
  private void updateFloatView() {
    mLayoutParams.x = mCurrentX;
    mLayoutParams.y = mCurrentY;
    mWindowManager.updateViewLayout(mFloatView, mLayoutParams);
  }
  /*處理視圖的拖動(dòng)，這里只對(duì)Move事件做了處理，用戶也可以對(duì)點(diǎn)擊事件做處理，例如：點(diǎn)擊浮動(dòng)窗口時(shí)，啟動(dòng)應(yīng)用的主Activity*/
  private class OnFloatViewTouchListener implements View.OnTouchListener {
    @Override
    public boolean onTouch(View v, MotionEvent event) {
      // TODO Auto-generated method stub
      Log.i(TAG, "mCurrentX: " + mCurrentX + ",mCurrentY: "
          + mCurrentY + ",mFloatViewWidth: " + mFloatViewWidth
          + ",mFloatViewHeight: " + mFloatViewHeight);
      /*
       * getRawX(),getRawY()這兩個(gè)方法很重要。通常情況下，我們使用的是getX(),getY()來獲得事件的觸發(fā)點(diǎn)坐標(biāo)，
       * 但getX(),getY()獲得的是事件觸發(fā)點(diǎn)相對(duì)與視圖左上角的坐標(biāo)；而getRawX(),getRawY()獲得的是事件觸發(fā)點(diǎn)
       * 相對(duì)與屏幕左上角的坐標(biāo)。由于LayoutParams中的x,y是相對(duì)與屏幕的，所以需要使用getRawX(),getRawY()。
       */
      mCurrentX = (int) event.getRawX() - mFloatViewWidth;
      mCurrentY = (int) event.getRawY() - mFloatViewHeight;
      int action = event.getAction();
      switch (action) {
      case MotionEvent.ACTION_DOWN:
        break;
      case MotionEvent.ACTION_MOVE:
        updateFloatView();
        break;
      case MotionEvent.ACTION_UP:
        break;
      }
      return true;
    }
  }
 }

private String getTopActivity(Context context) {
   //獲取ActivityManager對(duì)象
   ActivityManager manager = (ActivityManager)getSystemService(ACTIVITY_SERVICE) ;
   /*
   * 拿到當(dāng)前正在運(yùn)行的Task列表，該列表按照最近使用的時(shí)間順序排列，其中的參數(shù)表示需要返回的最大列表項(xiàng)數(shù)目。
   * 這里我們只需要拿到處于onResume狀態(tài)的Activity所在的Task。
   */
   List<RunningTaskInfo> runningTaskInfos = manager.getRunningTasks(1) ;
   if(runningTaskInfos != null) {
     //拿到該task中的棧頂Activity
     return (runningTaskInfos.get(0).topActivity).toString() ;
   } else {
     return null;
   }
 }