content: // ===============================================================================
  // Authors: AFRL/RQQD
  // Organization: Air Force Research Laboratory, Aerospace Systems Directorate, Power and Control Division
  // 
  // Copyright (c) 2017 Government of the United State of America, as represented by
  // the Secretary of the Air Force.  No copyright is claimed in the United States under
  // Title 17, U.S. Code.  All Other Rights Reserved.
  // ===============================================================================
  
  /*
   * GRAL: GRAphing Library for Java(R)
   *
   * (C) Copyright 2009-2013 Erich Seifert <dev[at]erichseifert.de>,
   * Michael Seifert <mseifert[at]error-reports.org>
   *
   * This file is part of GRAL.
   *
   * GRAL is free software: you can redistribute it and/or modify
   * it under the terms of the GNU Lesser General Public License as published by
   * the Free Software Foundation, either version 3 of the License, or
   * (at your option) any later version.
   *
   * GRAL 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.
   *
   * You should have received a copy of the GNU Lesser General Public License
   * along with GRAL.  If not, see <http://www.gnu.org/licenses/>.
   */
  package de.erichseifert.gral.plots.points;
  
  import java.awt.Font;
  import java.awt.Shape;
  import java.awt.geom.AffineTransform;
  import java.awt.geom.Rectangle2D;
  import java.text.Format;
  import java.text.NumberFormat;
  
  import de.erichseifert.gral.data.Row;
  import de.erichseifert.gral.util.GraphicsUtils;
  
  /**
   * Class that provides {@code Drawable}s, which display specified data
   * values as labels.
   */
  public class LabelPointRenderer extends DefaultPointRenderer2D {
  	/** Version id for serialization. */
  	private static final long serialVersionUID = -2612520977245369774L;
  
  	/** Index of the column for the label content. */
  	private int column;
  	/** Format for the label content. */
  	private Format format;
  	/** Font for the label content. */
  	private Font font;
  	/** Horizontal alignment of the label content. */
  	private double alignmentX;
  	/** Vertical alignment of the label content. */
  	private double alignmentY;
  
  	/**
  	 * Initializes a new renderer.
  	 */
  	public LabelPointRenderer() {
  		column = 1;
  		format = NumberFormat.getInstance();
  		font = Font.decode(null);
  		alignmentX = 0.5;
  		alignmentY = 0.5;
  	}
  
  	/**
  	 * Returns the index of the column which is used for the label.
  	 * @return Index of the column which is used for the label.
  	 */
  	public int getColumn() {
  		return column;
  	}
  
  	/**
  	 * Sets the index of the column which will be used for the label.
  	 * @param column Index of the column which will be used for the label.
  	 */
  	public void setColumn(int column) {
  		this.column = column;
  	}
  
  	/**
  	 * Returns the format which specifies how the labels are displayed.
  	 * @return {@code Format} instance which specifies how the labels are
  	 * displayed.
  	 */
  	public Format getFormat() {
  		return format;
  	}
  
  	/**
  	 * Sets the format which specifies how the labels will be displayed.
  	 * @param format {@code Format} instance which specifies how the labels will
  	 * be displayed.
  	 */
  	public void setFormat(Format format) {
  		this.format = format;
  	}
  
  	/**
  	 * Returns the font of this label.
  	 * @return Font of this label.
  	 */
  	public Font getFont() {
  		return font;
  	}
  
  	/**
  	 * Sets font of this label.
  	 * @param font Font of this label.
  	 */
  	public void setFont(Font font) {
  		this.font = font;
  	}
  
  	/**
  	 * Returns the horizontal alignment relative to the data point.
  	 * 0 means left, 1 means right.
  	 * @return Horizontal alignment relative to the data point.
  	 */
  	public double getAlignmentX() {
  		return alignmentX;
  	}
  
  	/**
  	 * Sets the horizontal alignment relative to the data point.
  	 * 0 means left, 1 means right.
  	 * @param alignmentX Horizontal alignment relative to the data point.
  	 */
  	public void setAlignmentX(double alignmentX) {
  		this.alignmentX = alignmentX;
  	}
  
  	/**
  	 * Returns the vertical alignment relative to the data point.
  	 * 0 means top, 1 means bottom.
  	 * @return Vertical alignment relative to the data point.
  	 */
  	public double getAlignmentY() {
  		return alignmentY;
  	}
  
  	/**
  	 * Sets the vertical alignment relative to the data point.
  	 * 0 means top, 1 means bottom.
  	 * @param alignmentY Vertical alignment relative to the data point.
  	 */
  	public void setAlignmentY(double alignmentY) {
  		this.alignmentY = alignmentY;
  	}
  
  	@Override
  	public Shape getPointShape(PointData data) {
  		Row row = data.row;
  		int colLabel = getColumn();
  		if (colLabel >= row.size()) {
  			return null;
  		}
  
  		Comparable<?> labelValue = row.get(colLabel);
  		if (labelValue == null) {
  			return null;
  		}
  
  		Format format = getFormat();
  		Font font = getFont();
  		String text = format.format(labelValue);
  		double alignment = getAlignmentX();
  		Shape shape = GraphicsUtils.getOutline(text, font, 0f, alignment);
  
  		double alignX = getAlignmentX();
  		double alignY = getAlignmentY();
  		Rectangle2D bounds = shape.getBounds2D();
  		AffineTransform tx = AffineTransform.getTranslateInstance(
  			-alignX*bounds.getWidth(), alignY*bounds.getHeight());
  		shape = tx.createTransformedShape(shape);
  
  		return shape;
  	}
  }
  