Android GridView Reversing After Handling Orientation Change

Question

EDIT: This problem may be related to http://stackoverflow.com/questions/3121153/baseadapter-causing-listview-to-go-out-of-order-when-scrolled

---

My main application screen uses a GridView to display a grid of icons. Each icon has an image, name, and Intent. I have the Activity set to handle orientation changes so I can change the background. The onCreate method sets up the GridView with 3 test icons that don't do anything and a preferences icon which opens a PreferencesActivity:

super.onCreate(savedInstanceState);
setContentView(R.layout.main);

GridView gv = (GridView) findViewById(R.id.main_grid);
if (getResources().getConfiguration().orientation ==
        Configuration.ORIENTATION_LANDSCAPE)
    gv.setBackgroundResource(R.drawable.main_bg_horiz);
else
    gv.setBackgroundResource(R.drawable.main_bg);

ArrayList<Icon> icons = new ArrayList<Icon>();
icons.add(new Icon("Test 1", R.drawable.test1, null));
icons.add(new Icon("Test 2", R.drawable.test2, null));
icons.add(new Icon("Test 3", R.drawable.test3, null));
icons.add(new Icon("Preferences", R.drawable.perferences, new Intent(this,
        AlertPreferences.class)));
IconAdapter ia = new IconAdapter(icons);
gv.setAdapter(ia);
gv.setOnItemClickListener(new OnItemClickListener() {
    @Override
    public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3){
        Intent i = ((IconAdapter)arg0.getAdapter()).getItem(arg2).getIntent();
        if (i != null)
            HomeActivity.this.startActivity(i);
    }
});

And the onConfigurationChanged is very simple:

super.onConfigurationChanged(newConfig);    
GridView gv = (GridView) findViewById(R.id.main_grid);

if (newConfig.orientation == Configuration.ORIENTATION_LANDSCAPE)
    gv.setBackgroundResource(R.drawable.main_bg_horiz);
else
    gv.setBackgroundResource(R.drawable.main_bg);

The background changes just fine but the code introduces a new problem with the GridView. Whatever orientation I start the application in it works just fine. However, when I change orientation, the order of the icons in the GridView reverses. And when I rotate the screen back to the orientation it started in, everything goes back to normal. What's going on here?

Answer 1

Try to separate the logic where you are setting up the user interface:

GridView gv;

public void onCreate(Bundle savedInstanceState){
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    configureYourUIHere();    
}

public void configureYourUIHere(){
    gv = (GridView) findViewById(R.id.main_grid);
    if (getResources().getConfiguration().orientation ==
            Configuration.ORIENTATION_LANDSCAPE)
        gv.setBackgroundResource(R.drawable.main_bg_horiz);
    else
        gv.setBackgroundResource(R.drawable.main_bg);

    ArrayList<Icon> icons = new ArrayList<Icon>();
    icons.add(new Icon("Test 1", R.drawable.test1, null));
    icons.add(new Icon("Test 2", R.drawable.test2, null));
    icons.add(new Icon("Test 3", R.drawable.test3, null));
    icons.add(new Icon("Preferences", R.drawable.perferences, new Intent(this,
            AlertPreferences.class)));
    IconAdapter ia = new IconAdapter(icons);
    gv.setAdapter(ia);
    gv.setOnItemClickListener(new OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3){
            Intent i = ((IconAdapter)arg0.getAdapter()).getItem(arg2).getIntent();
            if (i != null)
                HomeActivity.this.startActivity(i);
        }
    });
}

public void onConfigurationChanged(Configuration newConfig){
    super.onConfigurationChanged(newConfig);    
    configureYourUIHere();
}

Answer 2

It was in fact a problem with the custom Adapter. The problem and solution are both here http://stackoverflow.com/questions/3121153/baseadapter-causing-listview-to-go-out-of-order-when-scrolled