How to define layout in PopupWindow from xml file when PopupWindow method is called from separate class

You can try to use DialogFragment .

From the API docs, a snippet that displays a dialog floating on top of an activity window. This snippet contains a Dialog object that is displayed appropriately based on the state of the snippet. Controlling the dialog (deciding when to show, hide, dismiss it) should be done through the API here and not with direct calls to the dialog.

Implementations must override this class and implement onCreateView (LayoutInflater, ViewGroup, Bundle) to provide the contents of the dialog. Alternatively, they can override onCreateDialog (Bundle) to create a fully custom dialog like AlertDialog with their own content.

1.Create your own popup layout.

2.Creating a custom dialog fragment.

3. Create an interface for clicking a button.

4.Set it to your fragment.

1. Create your own popup layout.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >

<TextView
    android:id="@+id/app_title"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="14dp"
    android:text="TITLE"
    android:textAppearance="?android:attr/textAppearanceMedium" />

<TextView
    android:id="@+id/popupMsg"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignStart="@+id/app_title"
    android:layout_below="@+id/app_title"
    android:layout_marginTop="30dp"
    android:text="Content" />

<Button
    android:id="@+id/navBtn"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/popupMsg"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="22dp"
    android:text="OK" />

 </RelativeLayout>

      

        
        
        
      

    

... 2. Create your own dialog box fragment.

import android.app.Dialog;

import android.app.DialogFragment;

.....

public class CustomAlert extends DialogFragment {

public OnSubmitListener mListener;
Context context;
String Title = "";
String content = "";

public CustomAlert (Context context, String title, String message) {
    this.context = context;
    this.Title = title;
    this.content = message;

  }

  @Override
  public Dialog onCreateDialog(Bundle savedInstanceState) {
    final Dialog dialog = new Dialog(getActivity());
    dialog.getWindow().requestFeature(Window.FEATURE_NO_TITLE);
    dialog.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
            WindowManager.LayoutParams.FLAG_FULLSCREEN);
    dialog.setContentView(R.layout.popup_layout);
    Window window = dialog.getWindow();
    window.setLayout(ViewGroup.LayoutParams.MATCH_PARENT,
            ViewGroup.LayoutParams.WRAP_CONTENT);
    dialog.getWindow().setBackgroundDrawable(
            new ColorDrawable(Color.TRANSPARENT));
    dialog.show();
    TextView title = (TextView) dialog.findViewById(R.id.app_title);
    TextView msg = (TextView) dialog.findViewById(R.id.popupMsg);
    Button btn = (Button) dialog.findViewById(R.id.navBtn);
    title.setText(Title);
    msg.setText(content);
    btn.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            mListener.setOnAlert(content);
            dismiss();
        }
    });
    return dialog;
  }
  }

      

        
        
        
      

    

3. Create an interface for clicking a button.

public interface OnSubmitListener{

  void setOnAlert(String arg);

 }

      

        
        
        
      

    

4.Place it on your piece.

  public class Tab3Fragment extends Fragment implements OnClickListener, OnSubmitListener{
  Button btnPopup;

  @Override
  public View onCreateView(LayoutInflater inflater, ViewGroup containerGroup, Bundle     savedInstanceState) {   

     View v = inflater.inflate(R.layout.tab3_fragment, containerGroup, false);   
     btnPopup = (Button)v.findViewById(R.id.btnPopupxml);

     return v;
   }
    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        btnPopup.setOnClickListener(getActivity());
  }
   @Override
   public void onClick(View v) {
    ShowDialog("Title", "Sample content");
   }


  private void ShowDialog(String title, String msg) {
    CustomAlert fragment1 = new CustomAlert (
            getActivity(), title, msg);
    fragment1.mListener = this;
    fragment1.show(getFragmentManager(), "");
  }

    @Override
    public void setOnAlert(String arg) {
        Toast.makeText(getActivity(),
                "Button Clicked:"+arg,
                Toast.LENGTH_LONG).show();
    }

}

      

        
        
        
      

    

5.Happy coding .....