Justice Bauer Justice Bauer - 14 days ago 3
Android Question

How do I preserve the state of a selected spinner/dropdown item on orientation change?

I am using a spinner dropdown in my code , in which I have 4 to 5 dynamically populated values, say if I have "apples" set to default and I select "oranges" from the dropdown and rotate my screen to landscape from portrait, it goes back to default "apples" along with the view associated with it.How do I save the state such that when I select "oranges" and rotate to landscape, it populates the selected value/remains in the same selected state and keeps the view intact/populates the view that was selected in the portrait mode corresponding to the selected value. Here's the adapter code I use for the same:

public class MarketsSpinnerAdapter extends CustomRowAdapter<AdapterRow> {


private List<AdapterRow> mRenderList;

public MarketsSpinnerAdapter(final Context context, final List<AdapterRow> renderList) {
super(context);


mRenderList = new ArrayList<AdapterRow>();
mRenderList.addAll(renderList);
}

@Override
protected void setEntries(final List<AdapterRow> renderList) {
mRenderList = renderList;
}

@Override
protected List<AdapterRow> getEntries() {
return mRenderList;
}

@Override
public View getDropDownView(final int position, final View convertView, final ViewGroup parent) {
return getEntries().get(position).getDropDownView(mContext, convertView);
}

}


Corresponding usage in the respective fragment:

private void populateCategoryRows(final Cursor cursor) {
mCategories.clear();
mAllCategories.clear();
cursor.moveToPosition(-1);
Map<String, String> categoryParentNames = new HashMap<String, String>();

int selectedPosition = 0;
String previousHeader = "";
String previousAllHeader = "";

while (cursor.moveToNext()) {
final int categoryLevel = cursor.getInt(cursor.getColumnIndex(MarketsCategory.Columns.LEVEL));
final String categoryName = cursor.getString(cursor.getColumnIndex(MarketsCategory.Columns.NAME));
final String categoryDisplayName = cursor.getString(cursor.getColumnIndex(MarketsCategory.Columns.DISPLAY_NAME));

if (categoryLevel == 1) {
categoryParentNames.put(categoryName, categoryDisplayName);
}
}

cursor.moveToPosition(-1);
while (cursor.moveToNext()) {
final int categoryLevel = cursor.getInt(cursor.getColumnIndex(MarketsCategory.Columns.LEVEL));
final boolean categoryIsDefault = cursor.getInt(cursor.getColumnIndex(MarketsCategory.Columns.IS_DEFAULT)) == 1;
final boolean categoryIsSelected = cursor.getInt(cursor.getColumnIndex(MarketsCategory.Columns.IS_SELECTED)) == 1;
final String categoryParent = cursor.getString(cursor.getColumnIndex(MarketsCategory.Columns.PARENT));
final String categoryName = cursor.getString(cursor.getColumnIndex(MarketsCategory.Columns.NAME));
final String categoryDisplayName = cursor.getString(cursor.getColumnIndex(MarketsCategory.Columns.DISPLAY_NAME));


if (categoryLevel == 2 ) {
String categoryParentDisplayName = categoryParentNames.get(categoryParent);
if (!categoryParent.equals(previousHeader)) {
if (categoryIsSelected) {

mCategories.add(new CategoryHeader(categoryParentDisplayName));
previousHeader = categoryParent;
}
}

if (!categoryParent.equals(previousAllHeader)) {
mAllCategories.add(new CategoryHeader(categoryParentDisplayName));
previousAllHeader = categoryParent;
}

if (categoryIsSelected) {
mCategories.add(new SpinnerMarketCategoryRow(categoryName, categoryDisplayName, categoryParent));
}
mAllCategories.add(new MarketsCategoryCheckableRow(categoryName, categoryDisplayName, categoryIsSelected, categoryIsDefault));

if(categoryIsDefault){
selectedPosition = mCategories.size()-1;
}
}
}

mSpinnerAdapter = new MarketsSpinnerAdapter(Application.getAppContext(), mCategories);
headerView.setSpinnerAdapter(mSpinnerAdapter);
headerView.setSpinnerSelectedItemPosition(selectedPosition);
}
if (selectedItem instanceof SpinnerMarketCategoryRow) {
selectedCategory = (SpinnerMarketCategoryRow) mSpinnerAdapter.getItem(position);
} else {
if (mSpinnerAdapter.getCount() - 1 >= position + 1) {
selectedCategory = (SpinnerMarketCategoryRow) mSpinnerAdapter.getItem(position + 1);
} else {
selectedCategory = (SpinnerMarketCategoryRow) mSpinnerAdapter.getItem(position - 1);
}
}

final MarketsFragment parentFragment = (MarketsFragment) getParentFragment();
parentFragment.onCategorySelected(selectedCategory.getCategoryName(), selectedCategory.getCategoryParentName());
}
@Override
public void showResults(final Uri uri) {
LayoutUtils.showResults(getView(), headerView.getSpinnerId());
headerView.setVisibility(View.VISIBLE);
}

@Override
public void showNoResults(final Uri uri) {
final MarketsFragment parentFragment = (MarketsFragment) getParentFragment();
parentFragment.hideSpinner();
//LayoutUtils.showNoResult(getView(), headerView.getSpinnerId());
}

@Override
public void onDismiss(DialogInterface dialog) {
headerView.setSelected(false);
}
@Override
public void onNothingSelected(IcsAdapterView<?> parent) {
}


Any ideas?

Thanks!

Answer

You can do this like...

@Override
protected void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    outState.putInt("yourSpinner", yourSpinner.getSelectedItemPosition());
    // do this for each or your Spinner
    // You might consider using Bundle.putStringArray() instead
}

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    // initialize all your visual fields        
    if (savedInstanceState != null) {
        yourSpinner.setSelection(savedInstanceState.getInt("yourSpinner", 0));
        // do this for each of your text views
    }
}

Hope this helps