package org.vaadin.hene.expandingtextarea;
   
   import java.io.Serializable;
   import java.lang.reflect.Method;
   
   import org.vaadin.hene.expandingtextarea.widgetset.client.ui.ExpandingTextAreaServerRpc;
   
   import com.vaadin.v7.data.Property;
   import com.vaadin.server.PaintException;
  import com.vaadin.server.PaintTarget;
  import com.vaadin.v7.ui.TextArea;
  import com.vaadin.util.ReflectTools;
  
  
  /**
   * An extended version of {@link TextArea} that adapts its height to the
   * textual content.
   *
   * @author Henri Kerola / Vaadin
   */
  @SuppressWarnings("serial")
  public class ExpandingTextArea extends TextArea {
  
  	private static final Method ROWS_CHANGE_METHOD = ReflectTools.findMethod(
  			RowsChangeListener.class, "rowsChange", RowsChangeEvent.class);
  
  	private int rows = 2;
  	private Integer maxRows = null;
  	
  	private ExpandingTextAreaServerRpclient/ui/ExpandingTextAreaServerRpc.html#ExpandingTextAreaServerRpc">ExpandingTextAreaServerRpc rpc = new ExpandingTextAreaServerRpc() {
  		public void setRows(int rows) {
  			ExpandingTextArea.this.rows = rows;
  			fireRowsChangeEvent();
  		}
  	};
  
  	/**
  	 * Constructs an empty <code>ExpandingTextArea</code> with no caption.
  	 */
  	public ExpandingTextArea() {
  		registerRpc(rpc);
  		setRows(2);
  		setValue("");
  	}
  
  	/**
  	 * Constructs an empty <code>ExpandingTextArea</code> with given caption.
  	 * 
  	 * @param caption
  	 *            the caption <code>String</code> for the editor.
  	 */
  	public ExpandingTextArea(String caption) {
  		registerRpc(rpc);
  		setRows(2);
  		setCaption(caption);
  	}
  
  	/**
  	 * Constructs a new <code>ExpandingTextArea</code> that's bound to the
  	 * specified <code>Property</code> and has no caption.
  	 * 
  	 * @param dataSource
  	 *            the Property to be edited with this editor.
  	 */
  	public ExpandingTextArea(Property dataSource) {
  		registerRpc(rpc);
  		setRows(2);
  		setPropertyDataSource(dataSource);
  	}
  
  	/**
  	 * Constructs a new <code>ExpandingTextArea</code> that's bound to the
  	 * specified <code>Property</code> and has the given caption
  	 * <code>String</code>.
  	 * 
  	 * @param caption
  	 *            the caption <code>String</code> for the editor.
  	 * @param dataSource
  	 *            the Property to be edited with this editor.
  	 */
  	public ExpandingTextArea(String caption, Property dataSource) {
  		this(dataSource);
  		setCaption(caption);
  	}
  
  	/**
  	 * Constructs a new <code>ExpandingTextArea</code> with the given caption
  	 * and initial text contents. The editor constructed this way will not be
  	 * bound to a Property unless
  	 * {@link com.vaadin.data.Property.Viewer#setPropertyDataSource(Property)}
  	 * is called to bind it.
  	 * 
  	 * @param caption
  	 *            the caption <code>String</code> for the editor.
  	 * @param value
  	 *            the initial text content of the editor.
  	 */
  	public ExpandingTextArea(String caption, String value) {
  		registerRpc(rpc);
 		setRows(2);
 		setValue(value);
 		setCaption(caption);
 	}
 
 	@Override
 	public void paintContent(PaintTarget target) throws PaintException {
 		target.addVariable(this, "rows", getRows());
 		if (maxRows != null) {
 			target.addAttribute("maxRows", maxRows);
 		}
 		super.paintContent(target);
 	}
 
 	@Override
 	public void setRows(int rows) {
 		if (rows < 2) {
 			throw new IllegalArgumentException("rows must be >= 2");
 		}
 		if (this.rows != rows) {
 			this.rows = rows;
 			super.setRows(rows);
 			fireRowsChangeEvent();
 		}
 	}
 
 	@Override
 	public int getRows() {
 		return rows;
 	}
 
 	@Override
 	public void setHeight(float height, Unit unit) {
 		if (height == -1) {
 			super.setHeight(height, unit);
 		} else {
 			throw new IllegalArgumentException(
 					"ExpandingTextArea supports only undefined height");
 		}
 	}
 
 	/**
 	 * Sets the maximum allowed number of rows that the {@link ExpandingTextArea} will grow to,
 	 * default is null that means that there is no limit for growing.
 	 *
 	 * Please note that max rows doesn't work very well with IE8.
 	 *
 	 * @param maxRows null or >= 2.
 	 */
 	public void setMaxRows(Integer maxRows) {
 		if (maxRows != null && maxRows < 2) {
 			throw new IllegalArgumentException("maxRows must be >= 2");
 		}
 		if ((this.maxRows == null && maxRows != null)
 				|| !this.maxRows.equals(maxRows)) {
 			this.maxRows = maxRows;
 			requestRepaint();
 		}
 	}
 
 	/**
 	 * Returns the maximum allowed number of rows that the {@link ExpandingTextArea} will grow to,
 	 * default is null that means that there is no limit for growing.
 	 *
 	 * Please note that max rows doesn't work very well with IE8.
 	 */
 	public int getMaxRows() {
 		return maxRows;
 	}
 
 	/**
 	 * Adds a {@link RowsChangeListener} to the component.
 	 */
 	public void addRowsChangeListener(RowsChangeListener listener) {
 		addListener(RowsChangeEvent.class, listener, ROWS_CHANGE_METHOD);
 	}
 
 	/**
 	 * Removes a {@link RowsChangeListener} from the component.
 	 */
 	public void removeRowsChangeListener(RowsChangeListener listener) {
 		removeListener(RowsChangeEvent.class, listener, ROWS_CHANGE_METHOD);
 	}
 
 	private void fireRowsChangeEvent() {
 		fireEvent(new RowsChangeEvent(this));
 	}
 
 	public class RowsChangeEvent extends Event {
 
 		public RowsChangeEvent(ExpandingTextArea source) {
 			super(source);
 		}
 
 		public ExpandingTextArea getExpandingTextArea() {
 			return (ExpandingTextArea) getSource();
 		}
 
 		public int getRows() {
 			return getExpandingTextArea().getRows();
 		}
 	}
 
 	/**
 	 * Listener for row count changes. When text in {@link ExpandingTextArea}
 	 * is modified (by user or programmatically) and the modification affects
 	 * to row count, then possible {@link RowsChangeListener} added to the
 	 * component are called.
 	 *
 	 * Please note, that for a disabled {@link ExpandingTextArea} listeners
 	 * won't be called. This is because Vaadin doesn't allow a disabled
 	 * component to call a RPC from client to server.
 	 */
 	public interface RowsChangeListener extends Serializable {
 
 		void rowsChange(RowsChangeEvent event);
 	}
 
 }