Question

I have a 2D array of Enums I want to pass between two of my activities.

Currently I convert the 2D Enum array to a 2D int array, pass it to the Bundle, and on the other side convert it to a 1D Object array, then a 2D int array and finally back to my 2D Enum array.

Is there a better way to do this?

I have no problem passing single enums, after checking out Android: How to put an Enum in a Bundle?

I tried directly passing and retrieving the 2D Enum array, but I get a RuntimeException when I try to retrieve it.

Here’s my code:

Passing the 2D array to the Bundle:

    // Send the correct answer for shape arrangement
    Intent intent = new Intent(getApplicationContext(), RecallScreen.class);

    Bundle bundle = new Bundle();

    // Convert mCorrectShapesArrangement (Shapes[][]) to an int[][].
    int[][] correctShapesArrangementAsInts = new int[mCorrectShapesArrangement.length][mCorrectShapesArrangement[0].length];
    for (int i = 0; i < mCorrectShapesArrangement.length; ++i)
        for (int j = 0; j < mCorrectShapesArrangement[0].length; ++j)
            correctShapesArrangementAsInts[i][j] = mCorrectShapesArrangement[i][j].ordinal();

    // Pass int[] and int[][] to bundle.
    bundle.putSerializable("correctArrangement", correctShapesArrangementAsInts);

    intent.putExtras(bundle);

    startActivityForResult(intent, RECALL_SCREEN_RESULT_CODE);

Retrieving out of the Bundle:

    Bundle bundle = getIntent().getExtras();

    // Get the int[][] that stores mCorrectShapesArrangement (Shapes[][]).      
    Object[] tempArr = (Object[]) bundle.getSerializable("correctArrangement");
    int[][] correctShapesArrangementAsInts = new int[tempArr.length][tempArr.length];
    for (int i = 0; i < tempArr.length; ++i)
    {
        int[] row = (int[]) tempArr[i];
        for (int j = 0; j < row.length; ++j)
            correctShapesArrangementAsInts[i][j] = row[j];
    }

    // Convert both back to Shapes[][].
    mCorrectShapesArrangement = new Shapes[correctShapesArrangementAsInts.length][correctShapesArrangementAsInts[0].length];
    for (int i = 0; i < correctShapesArrangementAsInts.length; ++i)
        for (int j = 0; j < correctShapesArrangementAsInts[0].length; ++j)
            mCorrectShapesArrangement[i][j] = Shapes.values()[correctShapesArrangementAsInts[i][j]];

Thanks in advance!

Answer 1

Create a customclass which contains your 2D array on Enum(getter/setter) which implements Parcelable and then you can pass that customclass’s object through intent.

class customclass implements Parcelable { 
   public enum Foo { BAR, BAZ }

   public Foo fooValue;

   public void writeToParcel(Parcel dest, int flags) {
      dest.writeString(fooValue == null ? null : fooValue.name());
   }

   public static final Creator<customclass> CREATOR = new Creator<customclass>() {
     public customclass createFromParcel(Parcel source) {        
       customclass e = new customclass();
       String s = source.readString(); 
       if (s != null) e.fooValue = Foo.valueOf(s);
       return e;
     }
   }
 }