/*!
* This program is free software; you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software
* Foundation.
*
* You should have received a copy of the GNU Lesser General Public License along with this
* program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
* or from the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU Lesser General Public License for more details.
*
* Copyright (c) 2002-2013 Pentaho Corporation..  All rights reserved.
*/

package org.pentaho.reporting.libraries.designtime.swing;

import javax.swing.*;
import javax.swing.border.LineBorder;
import java.awt.*;
import java.lang.reflect.Constructor;

/**
 * This editor can handle all objects that have a single argument String constructor.
 *
 * @author Thomas Morgner
 */
public class GenericCellEditor extends DefaultCellEditor {
  private transient Constructor constructor;
  private transient Object value;
  private Class fallbackType;
  private boolean allowEmptyString;

  public GenericCellEditor( final Class fallbackType ) {
    this( fallbackType, false );
  }

  public GenericCellEditor( final Class fallbackType,
                            final boolean allowEmptyString ) {
    super( new JTextField() );
    this.fallbackType = fallbackType;
    this.allowEmptyString = allowEmptyString;
    getComponent().setName( "Table.editor" );
  }

  public boolean stopCellEditing() {
    final String s = (String) super.getCellEditorValue();
    if ( allowEmptyString == false && "".equals( s ) ) {
      return super.stopCellEditing();
    }
    if ( constructor == null ) {
      return super.stopCellEditing();
    }

    try {
      value = constructor.newInstance( new Object[] { s } );
    } catch ( final Exception e ) {
      // ignore the exception
      final JComponent editorComponent = (JComponent) getComponent();
      editorComponent.setBorder( new LineBorder( Color.red ) );
      return false;
    }
    return super.stopCellEditing();
  }

  public Component getTableCellEditorComponent( final JTable table,
                                                final Object value,
                                                final boolean isSelected,
                                                final int row,
                                                final int column ) {
    this.value = null;
    final JComponent editorComponent = (JComponent) getComponent();
    editorComponent.setBorder( new LineBorder( Color.black ) );

    Class type = table.getColumnClass( column );
    // Since our obligation is to produce a value which is
    // assignable for the required fallbackType it is OK to use the
    // String constructor for columns which are declared
    // to contain Objects. A String is an Object.
    if ( type == Object.class ) {
      type = this.fallbackType;
    }

    constructor = lookupConstructor( type );
    if ( constructor == null ) {
      constructor = lookupConstructor( this.fallbackType );
    }
    return super.getTableCellEditorComponent( table, value, isSelected, row, column );
  }

  private Constructor lookupConstructor( final Class type ) {

    try {
      return type.getConstructor( new Class[] { String.class } );
    } catch ( final Exception e ) {
      // ignore exception
      return null;
    }
  }

  public Object getCellEditorValue() {
    return value;
  }
}