This is a Layout demo app

👉 Step 1:

Create a Linear layout with 2 buttons.

Add some string values:

<resources>
    <string name="app_name">LayoutDemo</string>
    <string name="btn_popup">PopUp</string>
    <string name="btn_alert">AlertDialog</string>
</resources>

Activity main:

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

    <Button
        android:id="@+id/btnPopUp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/btn_popup" />

    <Button
        android:id="@+id/btnAlertDialog"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/btn_alert" />
</LinearLayout>

👉 Step 2:

Create onClick on UI:

android:onClick="onClick"

Use onClick in MainActivity.java:

public void onClick(View view){
    switch (view.getId()) {
        case R.id.btnPopUp:
                showPopUp(view);
                break;
            case R.id.btnAlertDialog:
                showAlertDialog("This is the alert dialog message");
                break;
        }
    }

Create the methods:

private void showPopUp(View view){
    LayoutInflater layoutInflater = (LayoutInflater) getBaseContext().getSystemService(LAYOUT_INFLATER_SERVICE);
        //final View popUpView = layoutInflater.inflate(R.id.popUpTest, null);

    }

    private void showAlertDialog(String msg){
        
        }

👉 Step 3:

Create the popuptest.XML in layout resource:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:background="@android:color/holo_blue_dark">

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/btn_inside_popup"
        android:layout_gravity="center_horizontal"/>

    <RatingBar
        android:id="@+id/ratingBar"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"/>

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/tv_inside_popup"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:layout_gravity="center_horizontal"/>
</LinearLayout>

👉 Step 4:

In MainActivity.java write the showPopUp method:

private void showPopUp(View view){
    LayoutInflater layoutInflater = (LayoutInflater) getBaseContext().getSystemService(LAYOUT_INFLATER_SERVICE);
        final View popUpView = layoutInflater.inflate(R.layout.popuptest, null);
        final PopupWindow popupWindow = new PopupWindow(popUpView, ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);

        Button button = (Button) popUpView.findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                popupWindow.dismiss();
            }
        });

        popupWindow.showAsDropDown(view, 50, 50);
    }

👉 Step 5:

Lets write the showAlertDialog method:

 private void showAlertDialog(String msg){
        AlertDialog.Builder alertBuilder = new AlertDialog.Builder(this);
        alertBuilder.setTitle(getResources().getString(R.string.alert_dlg_title));
        alertBuilder.setMessage(msg);
        alertBuilder.setNeutralButton(getResources().getString(R.string.alert_neutral_btn_text),
                new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        Toast.makeText(MainActivity.this, getResources().getString(R.string.alert_toast_msg), Toast.LENGTH_LONG).show();
                    }
                });
        alertBuilder.show();
    }

add some strings to strings.xml:

<resources>
    <string name="app_name">LayoutDemo</string>
    <string name="btn_popup">PopUp</string>
    <string name="btn_alert">AlertDialog</string>
    <string name="btn_inside_popup">New button</string>
    <string name="tv_inside_popup">Large text</string>
    <string name="alert_dlg_msg">This is a message from alert dialog</string>
    <string name="alert_dlg_title">Title of alert dialog</string>
    <string name="alert_neutral_btn_text">Ok</string>
    <string name="alert_toast_msg">You hit the OK button from alert dialog...</string>
</resources>

That's all, try it!