SizableLabel.java

/*
 * Author:  Chris Seguin
 *
 * This software has been developed under the copyleft
 * rules of the GNU General Public License.  Please
 * consult the GNU General Public License for more
 * details about use and distribution of this software.
 */
package org.acm.seguin.uml.line;

import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.image.BufferedImage;

import javax.swing.JLabel;

/**
 *  Creates a label that can be resized by setting it's scaling factor.
 *
 *@author    Chris Seguin
 */
public class SizableLabel extends ScalablePanel {
	private boolean bufferCreated = false;
	private Image scaledImage;
	private Color foreground;
	private Color background;
	private Font font;
	private int height = 200;
	private int width = 25;
	private String text;
	private int align;
	private int ascent;

	private static Font defaultFont = null;
	private static Color defaultColor = null;


	/**
	 *  Constructor for the SizableLabel object
	 */
	public SizableLabel() {
		this(" ");
	}


	/**
	 *  Constructor for the SizableLabel object
	 *
	 *@param  init  Description of Parameter
	 */
	public SizableLabel(String init) {
		if (defaultFont == null) {
			SizableLabel.init();
		}

		font = defaultFont;
		foreground = defaultColor;

		setText(init);
		setSize(getPreferredSize());

		setDoubleBuffered(false);
	}


	/**
	 *  Sets the Foreground attribute of the SizableLabel object
	 *
	 *@param  value  The new Foreground value
	 */
	public void setSLForeground(Color value) {
		foreground = value;
		bufferCreated = false;
	}


	/**
	 *  Sets the Font attribute of the SizableLabel object
	 *
	 *@param  value  The new Font value
	 */
	public void setSLFont(Font value) {
		font = value;
		setSize(getPreferredSize());
	}


	/**
	 *  Sets the Text attribute of the SizableLabel object
	 *
	 *@param  value  The new Text value
	 */
	public void setText(String value) {
		if ((value == null) || (value == "")) {
			text = " ";
		}
		else {
			text = value;
		}
		bufferCreated = false;
		setSize(getPreferredSize());
	}


	/**
	 *  Sets the HorizontalAlignment attribute of the SizableLabel object
	 *
	 *@param  value  The new HorizontalAlignment value
	 */
	public void setSLHorizontalAlignment(int value) {
		align = value;
	}


	/**
	 *  Gets the Text attribute of the SizableLabel object
	 *
	 *@return    The Text value
	 */
	public String getText() {
		return text;
	}


	/**
	 *  Gets the PreferredSize attribute of the SizableLabel object
	 *
	 *@return    The PreferredSize value
	 */
	public Dimension getPreferredSize() {
		determineSize();

		Dimension dim = new Dimension();
		dim.width = scaleInteger(width);
		dim.height = scaleInteger(height);

		bufferCreated = false;

		return dim;
	}


	/**
	 *  Paints the sizable label
	 *
	 *@param  g  the graphics area to print in
	 */
	public void paint(Graphics g) {
		print(g, 0, 0);
	}


	/**
	 *  Prints the label at the proper location
	 *
	 *@param  g  the graphics object
	 *@param  x  the x coordinate
	 *@param  y  the y coordinate
	 */
	public void print(Graphics g, int x, int y) {
		if (!bufferCreated || !getParentBackground().equals(background)) {
			createBuffer();
		}
		Dimension dim = getSize();
		//g.setColor(background);
		//g.fillRect(x, y, dim.width, dim.height);
		if (align == JLabel.LEFT) {
			g.drawImage(scaledImage, x, y, this);
		}
		else if (align == JLabel.RIGHT) {
			int deltax = (int) (dim.width - scaleInteger(width));
			g.drawImage(scaledImage, x + deltax, y, this);
		}
		else if (align == JLabel.CENTER) {
			int deltax = (int) ((dim.width - scaleInteger(width)) * 0.5);
			g.drawImage(scaledImage, x + deltax, y, this);
		}
	}


	/**
	 *  Scales the image
	 *
	 *@param  value  the amount to scale
	 */
	public void scale(double value) {
		if (Math.abs(getScale() - value) > 0.001) {
			super.scale(value);
			bufferCreated = false;
		}
	}


	/**
	 *  Gets the ParentBackground attribute of the SizableLabel object
	 *
	 *@return    The ParentBackground value
	 */
	private Color getParentBackground() {
		Component parent = getParent();
		if (parent == null) {
			return Color.gray;
		}
		else {
			return parent.getBackground();
		}
	}


	/**
	 *  Creates the buffer from which to draw the resized text
	 */
	private void createBuffer() {
		bufferCreated = true;
		determineSize();
		Dimension dim = new Dimension(width, height);

		int tempWidth = Math.max(1, scaleInteger(width + 10));
		int tempHeight = Math.max(1, scaleInteger(height + 10));
		scaledImage = new BufferedImage(
				tempWidth,
				tempHeight,
				BufferedImage.TYPE_INT_RGB);
		Graphics2D g = (Graphics2D) scaledImage.getGraphics();
		g.scale(getScale(), getScale());

		//  Fill in the background
		background = getParentBackground();
		g.setColor(background);
		g.fillRect(0, 0, dim.width + 10, dim.height + 10);

		//  Draw the text
		g.setColor(foreground);
		g.setFont(font);
		g.drawString(text, 0, ascent);
	}


	/**
	 *  Description of the Method
	 */
	private void determineSize() {
		TextInfo ti = LabelSizeComputation.get().compute(text, font);

		height = ti.height;
		width = ti.width;
		ascent = ti.ascent;
	}


	/**
	 *  Prints some debug information about this label
	 */
	private void debug() {
		System.out.println("Label:  " + text);
		System.out.println("    Scale:  " + getScale());
		System.out.println("    Height:  " + height);
		System.out.println("    Width:   " + width);
		System.out.println("    Align:   " + align);
		System.out.println("    Color:   " + foreground);
		System.out.println("    Shape:   " + getBounds());
	}


	/**
	 *  Initializes the static font and color
	 */
	private static synchronized void init() {
		if (defaultFont == null) {
			defaultFont = new Font("Serif", Font.PLAIN, 12);
			defaultColor = new Color(0, 80, 180);
		}
	}
}