Initialising List array for use in a custom Editor

Question

I am having trouble initialising something before it gets used in a custom Editor.

I have a component attached to a game object, ResourceGenerator:

 public class ResourceGenerator : MonoBehaviour {
     
     //..some irrelevant public stuff here..
 
     public List<string>[] resourceSpawnTimes; // This is what i intend to modify in a custom editor
 
     void Awake() // I've also tried OnEnable
     {        
             // MatchInfo is another component in another game object
         MatchInfo info = (MatchInfo)GameObject.Find ("MatchInfo").GetComponent<MatchInfo>();
             // Array size defined by variables set in editor for the MatchInfo object
         resourceSpawnTimes = new List<string>[(int) (info.matchTimeSeconds / info.timeBetweenDropsSeconds)];
     }

     //..More irrelevant stuff..
 }

The List[] resourceSpawnTimes is what I want a custom editor interface for, so I've written ResourceSpawnTiming (It's not neccessary to read through it all but I wanted to include something reasonably complete just in case):

 [CustomEditor(typeof(ResourceGenerator))]
 public class ResourceSpawnTiming : Editor {
 
     MatchInfo info;
     int minutes;
     ResourceGenerator gen;
 
     ser List<string>[] resourceSpawnTimes;
 
     void OnEnable()
     {
         info = (MatchInfo)GameObject.Find("MatchInfo").GetComponent<MatchInfo>();
         gen = (ResourceGenerator)target;
     }
 
 
     public override void OnInspectorGUI()
     {
         DrawDefaultInspector ();
         minutes = (int)(info.matchTimeSeconds / info.timeBetweenDropsSeconds);
         for(int i = 0; i < minutes; i++)
         {
             GUILayout.Label("Minutes into match: " + i + " - " + (i+1));
             // Display check boxes for all the wood resources
             foreach(string s in Resource.WoodResourceNames)
             {
 
                 bool currentlyEnabled = GetCurrentValue(i,s);
                 SetCurrentValue( i, s, currentlyEnabled,
                                 EditorGUILayout.Toggle(s, currentlyEnabled));
 
             }
 
         }
     }
 
     private bool GetCurrentValue(int minute, string resourceName)
     {
         // Check if resourceName is in the list for that minute
         foreach(string s in gen.resourceSpawnTimes[minute]) // This is where resourceSpawnTimes turns out to still be null
         {
             if(s == resourceName)
                 return true; // resource currently enabled
         }
         return false; // resource not 
     }

     private void SetCurrentValue(int minute, string resourceName, bool currentlyEnabled, bool enable)
     {
          //..Some stuff left out for brevity..
         }
 }

My problem is when I try to loop over resourceSpawnTimes in ResourceSpawnTiming's GetCurrentValue(..) method. The gen object is not null but it's List[] resourceSpawnTimes is! As illustrated by this screenshot:

alt text

Having tested I now know that Awake(), where resourceSpawnTimes should be intialised, in the ResourceGenerator is not called before OnInspectorGUI() in ResourceSpawnTimes, but I can't figure out anyway to initialise it earlier! I also tried OnEnable() but that didn't work either.. I believe the issue is somewhat complicated by the fact I need to know what has been entered into the editor interface for MatchInfo before deciding on a size..

Been experimenting without any luck for hours, help much appreciated!

Answer 1

Best Answer

Answer by Azrapse · Jan 16, 2014 at 05:42 PM

The problem is that you are initializing the array of lists, but not the lists themselves, so when you access an element of the array it is null.

Try initializing it like this:

 var arraySize = (int) (info.matchTimeSeconds / info.timeBetweenDropsSeconds);
 resourceSpawnTimes = new List<string>[arraySize];
 for(int i=0; i<arraySize; i++)
 {
   resourceSpawnTimes[i] = new List<string>();
 }

Or if you want a single, more elegant instruction, add using System.Linq; at the begining and initialize it like this:

 resourceSpawnTimes = Enumerable.Range(1, arraySize)
   .Select(i=>new List<string>())
   .ToArray();

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MrsZorx · Jan 16, 2014 at 08:19 PM 0

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Thanks! I also found that I had to move the initialisation into a function i could call from onInspectorGUI() if the array was still null. Oh and I made the gen object Dirty although i'm not sure if that was necessary.

Initialising List array for use in a custom Editor

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