RotatedLabel.java

/*
 * The general modelling and simulation framework JAMES II.
 * Copyright by the University of Rostock.
 * 
 * LICENCE: JAMESLIC
 */
package edu.oregonstate.cartography.gui;

import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;

import javax.swing.Icon;
import javax.swing.JFrame;
import javax.swing.JLabel;

/**
 * A label, that can be rotated by 90 degrees either left or right. Thus the
 * reading direction is either horizontal (the default), up or down.
 * 
 * @author Johannes Rössel
 */
public class RotatedLabel extends JLabel {

  /** Serialisation ID. */
  private static final long serialVersionUID = -5589305224172247331L;

  /** Represents the direction of a rotated label. */
  public enum Direction {
    /** Normal horizontal direction. */
    HORIZONTAL,
    /** Vertical, upwards (for left-to-right languages). */
    VERTICAL_UP,
    /** Vertical, downwards (for left-to-right languages). */
    VERTICAL_DOWN
  }

  /** The text direction. */
  private Direction direction;

  {
    // it's better to set this here as default for all constructors since they
    // only call the super constructors.
    setDirection(Direction.VERTICAL_UP);
  }

  /**
   * A flag indicating whether {link #getSize()} and such methods need to return
   * a rotated dimension.
   */
  private boolean needsRotate;

  /**
   * Initialises a new instance of the {@link RotatedLabel} class using default
   * values.
   */
  public RotatedLabel() {
    super();
  }

  /**
   * Initialises a new instance of the {@link RotatedLabel} class using the
   * specified icon and horizontal alignment.
   * 
   * @param image
   *          The icon to use for this label.
   * @param horizontalAlignment
   *          The horizontal alignment of the text.
   */
  public RotatedLabel(Icon image, int horizontalAlignment) {
    super(image, horizontalAlignment);
  }

  /**
   * Initialises a new instance of the {@link RotatedLabel} class using the
   * specified icon.
   * 
   * @param image
   *          The icon to use for this label.
   */
  public RotatedLabel(Icon image) {
    super(image);
  }

  /**
   * Initialises a new instance of the {@link RotatedLabel} class using the
   * specified text, icon and horizontal alignment.
   * 
   * @param text
   *          The text to display.
   * @param icon
   *          The icon to use for this label.
   * @param horizontalAlignment
   *          The horizontal alignment of the text.
   */
  public RotatedLabel(String text, Icon icon, int horizontalAlignment) {
    super(text, icon, horizontalAlignment);
  }

  /**
   * Initialises a new instance of the {@link RotatedLabel} class using the
   * specified text and horizontal alignment.
   * 
   * @param text
   *          The text to display.
   * @param horizontalAlignment
   *          The horizontal alignment of the text.
   */
  public RotatedLabel(String text, int horizontalAlignment) {
    super(text, horizontalAlignment);
  }

  /**
   * Initialises a new instance of the {@link RotatedLabel} class using the
   * specified text.
   * 
   * @param text
   *          The text to display.
   */
  public RotatedLabel(String text) {
    super(text);
  }

  /**
   * Gets the text direction of this {@link RotatedLabel}.
   * 
   * @return The current text direction.
   */
  public Direction getDirection() {
    return direction;
  }

  /**
   * Sets the text direction of this {@link RotatedLabel}.
   * 
   * @param direction
   *          The new direction.
   */
  public void setDirection(Direction direction) {
    this.direction = direction;
  }

  /*
   * (non-Javadoc)
   * 
   * @see javax.swing.JComponent#getPreferredSize()
   */
  @Override
  public Dimension getPreferredSize() {
    Dimension preferredSize = super.getPreferredSize();

    // swap size for vertical alignments
    switch (getDirection()) {
    case VERTICAL_UP: // NOTE: fall-through
    case VERTICAL_DOWN:
      return new Dimension(preferredSize.height, preferredSize.width);
    default:
      return preferredSize;
    }
  }

  /*
   * (non-Javadoc)
   * 
   * @see java.awt.Component#getSize()
   */
  @Override
  public Dimension getSize() {
    if (!needsRotate) {
      return super.getSize();
    }

    Dimension size = super.getSize();

    switch (getDirection()) {
    case VERTICAL_DOWN:
    case VERTICAL_UP:
      return new Dimension(size.height, size.width);
    default:
      return super.getSize();
    }
  }

  /*
   * (non-Javadoc)
   * 
   * @see javax.swing.JComponent#getHeight()
   */
  @Override
  public int getHeight() {
    return getSize().height;
  }

  /*
   * (non-Javadoc)
   * 
   * @see javax.swing.JComponent#getWidth()
   */
  @Override
  public int getWidth() {
    return getSize().width;
  }

  /*
   * (non-Javadoc)
   * 
   * @see javax.swing.JComponent#paintComponent(java.awt.Graphics)
   */
  @Override
  protected void paintComponent(Graphics g) {
    Graphics2D gr = (Graphics2D) g.create();

    switch (getDirection()) {
    case VERTICAL_UP:
      gr.translate(0, getSize().getHeight());
      gr.transform(AffineTransform.getQuadrantRotateInstance(-1));
      break;
    case VERTICAL_DOWN:
      gr.transform(AffineTransform.getQuadrantRotateInstance(1));
      gr.translate(0, -getSize().getWidth());
      break;
    default:
    }

    needsRotate = true;
    super.paintComponent(gr);
    needsRotate = false;
  }

  /**
   * Test method.
   * 
   * @param args
   *          command line arguments.
   */
  public static void main(String[] args) {
    JFrame f = new JFrame("Test");
    f.setLayout(new FlowLayout());
    RotatedLabel rl = new RotatedLabel("BLAHBLAH");
    rl.setBackground(Color.ORANGE);
    rl.setOpaque(true);
    rl.setDirection(Direction.VERTICAL_DOWN);
    f.add(rl);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.pack();
    f.setVisible(true);
  }

}