Jonathan Jonathan - 4 days ago 4
Android Question

android change text color of items in spinner

I have a spinner where in certain conditions some options should not be selectable. I have the code to make items not selectable but it does not grey out text color to specify that the item is not selectable. How would I change the text color of the items in the spinner that should be disabled? Here is the code:

public class main extends Activity {

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

PatchedSpinner pSpinner = (PatchedSpinner) findViewById(R.id.spinner2);
ArrayList<String> testarray = new ArrayList<String>();
testarray.add("item0");
testarray.add("item1");
testarray.add("item2");
testarray.add("item3");

ArrayAdapter<String> spinnerAdapter = new ArrayAdapter<String>(this,
android.R.layout.simple_spinner_dropdown_item, testarray) {

@Override
public boolean isEnabled(int position) {
return position != 1;
}

public boolean areAllItemsEnabled() {
return false;
}
};
pSpinner.setAdapter(spinnerAdapter);
}


Below is the Custom Spinner Class used to create a spinner that is able to disable certain items in the spinner.

public class PatchedSpinner extends Spinner {

public PatchedSpinner(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}

public PatchedSpinner(Context context) {
super(context);
}

public PatchedSpinner(Context context, AttributeSet attrs) {
super(context, attrs);
}

@Override
public boolean performClick() {
// this line removed, we do not want to delegate the click to the spinner.
// boolean handled = super.performClick();

Context context = getContext();

final DropDownAdapter adapter = new DropDownAdapter(getAdapter());

CharSequence mPrompt = getPrompt();

AlertDialog.Builder builder = new AlertDialog.Builder(context);
if (mPrompt != null) {
builder.setTitle(mPrompt);
}
builder.setSingleChoiceItems(adapter, getSelectedItemPosition(), this).show();

return true;
}

private static class DropDownAdapter implements ListAdapter, SpinnerAdapter {
private SpinnerAdapter mAdapter;

public DropDownAdapter(SpinnerAdapter adapter) {
mAdapter = adapter;
}

public int getCount() {
return mAdapter == null ? 0 : mAdapter.getCount();
}

public Object getItem(int position) {
return mAdapter == null ? null : mAdapter.getItem(position);
}

public long getItemId(int position) {
return mAdapter == null ? -1 : mAdapter.getItemId(position);
}

public View getView(int position, View convertView, ViewGroup parent) {
return getDropDownView(position, convertView, parent);
}

public View getDropDownView(int position, View convertView,ViewGroup parent) {
if (mAdapter == null) {
return null;
}
mAdapter.getDropDownView(position, convertView, parent);
}

public boolean hasStableIds() {
return mAdapter != null && mAdapter.hasStableIds();
}

public void registerDataSetObserver(DataSetObserver observer){
if (mAdapter != null) {
mAdapter.registerDataSetObserver(observer);
}
}

public void unregisterDataSetObserver(DataSetObserver observer) {
if (mAdapter != null) {
mAdapter.unregisterDataSetObserver(observer);
}
}

// PATCHED
public boolean areAllItemsEnabled() {
if (mAdapter instanceof BaseAdapter) {
return ((BaseAdapter) mAdapter).areAllItemsEnabled();
} else {
return true;
}
}

// PATCHED
public boolean isEnabled(int position) {
if (mAdapter instanceof BaseAdapter) {
return ((BaseAdapter) mAdapter).isEnabled(position);
} else {
return true;
}
}

public int getItemViewType(int position) {
return 0;
}

public int getViewTypeCount() {
return 1;
}

public boolean isEmpty() {
return getCount() == 0;
}
}
}

Answer

I figured out that to make this work you have to override the getDropDownView when setting up the ArrayAdapter in the main activity.

public class main extends Activity {  
     @Override 
     public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);   
        setContentView(R.layout.main);  

        PatchedSpinner pSpinner = (PatchedSpinner) findViewById(R.id.spinner2); 
        ArrayList<String> testarray = new ArrayList<String>();
        testarray.add("item0");
        testarray.add("item1");
        testarray.add("item2");
        testarray.add("item3");
        ArrayAdapter<String> spinnerAdapter = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_dropdown_item, testarray) {

           @Override      
           public boolean isEnabled(int position) {
               return position != 1;                             
           }

           @Override                
           public boolean areAllItemsEnabled() {
               return false;
           }

           @Override
           public View getDropDownView(int position, View convertView, ViewGroup parent){
               View v = convertView;
               if (v == null) {
                   Context mContext = this.getContext();
                   LayoutInflater vi = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                   v = vi.inflate(R.layout.row, null);
               }

               TextView tv = (TextView) v.findViewById(R.id.spinnerTarget);
               tv.setText(testarray.get(position));

               switch (position) {
                   case 0:
                       tv.setTextColor(Color.RED);  
                       break; 
                   case 1:
                       tv.setTextColor(Color.BLUE);
                       break;
                   default:
                       tv.setTextColor(Color.BLACK);
                       break;
               }
               return v;  
           }              
        };

        pSpinner.setAdapter(spinnerAdapter); 
} 

The layout that is being inflated is a custom layout called row.xml. it is used to set the display for the dropdown view.

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/spinnerTarget"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="14pt" />
Comments