drawBitmap nullpointerexception

Question

I'm experiencing a nullpointerexception in my android java code in the following code. This is inside AndroidGraphics.java.

public void drawPixmap(Pixmap pixmap, int x, int y) {
    canvas.drawBitmap(((AndroidPixmap)pixmap).bitmap, x, y, null);
}

AndroidPixmap.java is here:

package com.badlogic.androidgames.framework.impl;

import android.graphics.Bitmap;

import com.badlogic.androidgames.framework.Graphics.PixmapFormat;
import com.badlogic.androidgames.framework.Pixmap;

public class AndroidPixmap implements Pixmap{
    Bitmap bitmap;
    PixmapFormat format;

    public AndroidPixmap(Bitmap bitmap, PixmapFormat format){
        this.bitmap = bitmap;
        this.format = format;
    }

    @Override
    public int getWidth(){
        return bitmap.getWidth();
    }

    @Override
    public int getHeight(){
        return bitmap.getHeight();
    }

    @Override
    public PixmapFormat getFormat(){
        return format;
    }

    @Override
    public void dispose(){
        bitmap.recycle();
    }
}

Is there something wrong with the casting? Any help would be great!

EDIT: This is the pixmap class:

package com.badlogic.androidgames.framework;

import com.badlogic.androidgames.framework.Graphics.PixmapFormat;

public interface Pixmap {
    public int getWidth();

    public int getHeight();

    public PixmapFormat getFormat();

    public void dispose();
}

Answer 1

Your AndroidPixmap implements Pixmap, it is not inherited/extended from Pixmap. If you cast to Pixmap, you get the Implementation only, which I assume has bitmap=null. As you didn't add the Pixmap class to the question, it's quite hard to answer in more detail.

Answer 2

Try this:

public void drawPixmap(AndroidPixmap pixmap, int x, int y) {
    canvas.drawBitmap(pixmap.bitmap, x, y, null);
}

Alternatively if you want to keep Pixmap in the signature you can make it an abstract class and extend it instead of an interface.