// -*- Mode: java; c-basic-offset: 2; -*-
// Copyright 2009-2011 Google, All Rights reserved
// Copyright 2011-2019 MIT, All rights reserved
// Released under the Apache License, Version 2.0
// http://www.apache.org/licenses/LICENSE-2.0

package com.google.appinventor.components.runtime.util;

import com.google.appinventor.components.runtime.errors.YailRuntimeError;
import org.json.JSONObject;

import java.util.List;

/**
 * Utilities for Components that display a number of options on Screen such as ListPicker,
 * Spinner, and ListView.
 */
public class ElementsUtil {

  public static YailList elementsFromString(String itemString){
    YailList items = new YailList();
    if (itemString.length() > 0) {
      items = YailList.makeList((Object[]) itemString.split(" *, *"));
    }

    return items;
  }

 /** Check a Yail list of items to verify that they are all strings and
  *
  * @param itemList
  * @param componentName
  * @return the original list
  */

  public static YailList elements(YailList itemList, String componentName){
    Object[] objects = itemList.toStringArray();
    for (int i = 0; i < objects.length; i++) {
      if (!(objects[i] instanceof String)) {
        throw new YailRuntimeError("Items passed to " + componentName + " must be Strings",
            "Error");
      }
    }
    // this is not changing itemlist.  it's just checking that the items are strings
    return itemList;
  }

  public static int selectionIndex(int index, YailList items){
    if (index <= 0 || index > items.size()) {
      return 0;
    } else {
      return index;
    }
  }

  public static String setSelectionFromIndex(int index, YailList items){
    if (index == 0 || index > items.size()) {
      return "";
    }
    // YailLists are 0-based, but we want to be 1-based.
    return items.getString(index - 1);
  }

  public static int setSelectedIndexFromValue(String value, YailList items){
    // Now, we need to change SelectionIndex to correspond to Selection.
    // If multiple Selections have the same SelectionIndex, use the first.
    // If none do, arbitrarily set the SelectionIndex to its default value
    // of 0.
    for (int i = 0; i < items.size(); i++) {
      // The comparison is case-sensitive to be consistent with yail-equal?.
      if (items.getString(i).equals(value)) {
        return i + 1;
      }
    }
    return 0;
  }

  public static String toStringEmptyIfNull(Object o) {
    String text = o.toString();
    return text == null ? "" : text;
  }
}

@@ -2426,40 +2426,8 @@
 ) %7B%0A
-    String text = o.toString();%0A
     
@@ -2433,20 +2433,17 @@
  return 
-text
+o
  == null
@@ -2454,12 +2454,20 @@
 %22 : 
-text
+o.toString()
 ;%0A  

Fix NPE in ElementsUtil (#2590)