<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />

import android.content.Context;
import android.graphics.PixelFormat;
import android.graphics.Point;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.WindowManager;
import android.widget.ImageView;
import android.widget.Toast;

import com.android.view.FloatMessagePopleDialog;

/**
 * Created by liupanpan on 2017/3/16.
 */

public class FloatMessagerMainWindow {
 private Context context;
 private View view;
 private WindowManager.LayoutParams mParams = null;
 private WindowManager windowManager = null;
 private static FloatMessagerMainWindow floatMessagerMainWindow;

 public FloatMessagerMainWindow(Context context, View view) {
  this.context = context;
  this.view = view;
  showWindow(context);
 }

 public static FloatMessagerMainWindow getFloatMessagerMainWindow(Context context, View view) {
  if (floatMessagerMainWindow == null) {
   synchronized (FloatMessagerMainWindow.class) {
    if (floatMessagerMainWindow == null) {
     floatMessagerMainWindow = new FloatMessagerMainWindow(context, view);
    }
   }
  }
  return floatMessagerMainWindow;
 }

 private void showWindow(final Context context) {
//  if (!isWindowDismiss) {
//   Log.e(TAG, "view is already added here");
//   return;
//  }
//  isWindowDismiss = false;
  if (windowManager == null) {
   windowManager = (WindowManager) context.getApplicationContext().getSystemService(Context.WINDOW_SERVICE);
  }

  Point size = new Point();
  windowManager.getDefaultDisplay().getSize(size);
  int screenWidth = size.x;
  int screenHeight = size.y;

  mParams = new WindowManager.LayoutParams();
  mParams.packageName = context.getPackageName();
  mParams.width = WindowManager.LayoutParams.WRAP_CONTENT;
  mParams.height = WindowManager.LayoutParams.WRAP_CONTENT;
  mParams.flags = WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL
    | WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE | WindowManager.LayoutParams.FLAG_LAYOUT_INSET_DECOR
    | WindowManager.LayoutParams.FLAG_LAYOUT_IN_SCREEN;
  mParams.type = WindowManager.LayoutParams.TYPE_SYSTEM_ERROR;
//  mParams.softInputMode = WindowManager.LayoutParams.SOFT_INPUT_ADJUST_RESIZE |
//    WindowManager.LayoutParams.SOFT_INPUT_STATE_HIDDEN;
  mParams.format = PixelFormat.RGBA_8888;
  mParams.gravity = Gravity.LEFT | Gravity.TOP;
  mParams.x = screenWidth - dp2px(context, 450);
  mParams.y = screenHeight - dp2px(context, 550);


  ImageView imageView = new ImageView(context);
  imageView.setImageResource(R.mipmap.icon_tab_item_message_pressed);
  imageView.setOnClickListener(new View.OnClickListener() {
   @Override
   public void onClick(View v) {
    Toast.makeText(context, "image=========", Toast.LENGTH_SHORT).show();
    View view = LayoutInflater.from(context).inflate(R.layout.float_pople_room_layout, null);
    FloatMessagePopleDialog.getInstance(context, R.style.webviewTheme).setContextView(view);
   }
  });
//  floatView = new AVCallFloatView(context);
//  floatView.setParams(mParams);
//  floatView.setIsShowing(true);
  windowManager.addView(imageView, mParams);
 }

 private int dp2px(Context context, float dp) {
  final float scale = context.getResources().getDisplayMetrics().density;
  return (int) (dp * scale + 0.1f);
 }
}

FloatMessagerMainWindow.getFloatMessagerMainWindow(context, null);