public void setEmptyText(CharSequence text) {
        ensureList();
        if (mStandardEmptyView == null) {
            throw new IllegalStateException("Can't be used with a custom content view");
        }
        mStandardEmptyView.setText(text);
        if (mEmptyText == null) {
            mGridView.setEmptyView(mStandardEmptyView);
        }
        mEmptyText = text;
    }
The default content for a ProgressGridFragment has a TextView that can
be shown when the grid is empty. If you would like to have it
shown, call this method to supply the text it should use.

@param text Text for empty view
@see #setEmptyText(int)
progressfragment-native/src/com/devspark/progressfragment/ProgressGridFragment.java