ColumnExtenderCursor

ColumnExtenderCursor.java

package com.example.app.myapplication;

import android.database.Cursor;
import android.database.CursorWrapper;

public class ColumnExtenderCursor extends CursorWrapper {

    private final String[] columnNames;

    public ColumnExtenderCursor(Cursor cursor, String... newColumns) {
        super(cursor);
        String[] oldColumnNames = cursor.getColumnNames();
        int oldColumnCount = cursor.getColumnCount();
        columnNames = new String[oldColumnCount + newColumns.length];
        System.arraycopy(oldColumnNames, 0, columnNames, 0, oldColumnNames.length);
        System.arraycopy(newColumns, 0, columnNames, oldColumnCount, newColumns.length);
    }

    @Override
    public int getColumnCount() {
        return columnNames.length;
    }

    @Override
    public int getColumnIndex(String columnName) {
        for (int i = 0; i < columnNames.length; i++) {
            if (columnNames[i].equals(columnName)) {
                return i;
            }
        }
        return -1;
    }

    @Override
    public int getColumnIndexOrThrow(String columnName) throws IllegalArgumentException {
        int idx = getColumnIndex(columnName);
        if (idx >= 0) {
            return idx;
        }
        throw new IllegalArgumentException("column '" + columnName + "' does not exist");
    }

    @Override
    public String getColumnName(int columnIndex) {
        return columnNames[columnIndex];
    }

    @Override
    public String[] getColumnNames() {
        return columnNames;
    }
}