I am following one of Mark Murphy's tutorials about a Selection Grid. I have tried just copy/paste (after typing it out) to check I wasn't making any errors but I still get the "cell" word in red. the imports are all as they should be.
Here is the code. 
The problem is in the line `g.setAdapter(new ArrayAdapter<String>(this, R.layout.cell, items));`

I tried adding compile lines into the build.gradle dependencies. didn't help.

```
public class GridDemo extends Activity implements AdapterView.OnItemClickListener {
    private TextView selection;
    private static final String[] items={"lorem", "ipsum", "dolor",
            "sit", "amet",
            "consectetuer", "adipiscing", "elit", "morbi", "vel",
            "ligula", "vitae", "arcu", "aliquet", "mollis",
            "etiam", "vel", "erat", "placerat", "ante",
            "porttitor", "sodales", "pellentesque", "augue", "purus"};
    @Override
    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);
        setContentView(R.layout.main);
        selection=(TextView)findViewById(R.id.selection);
        GridView g=(GridView) findViewById(R.id.grid);
        g.setAdapter(new ArrayAdapter<String>(this, R.layout.cell, items));
        g.setOnItemClickListener(this);
    }
    @Override
    public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
        selection.setText(items[position]);
    }
}

```