VariableBoundColorBox.java

package variableEditorComponents;

import java.awt.Color;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.util.Observable;
import java.util.Observer;

import javax.swing.BorderFactory;
import javax.swing.JColorChooser;
import javax.swing.JPanel;
import javax.swing.border.BevelBorder;

import valueTypes.ColorValue;
import variableEditorUI.VariableEditorUIUpdateThread;
import variables.Variable;
import expressionConsole.ExpressionConsoleModel;

/**
 * A panel to edit a color which is bound to a Variable. When the user picks a
 * new color by clicking on it, the content of the Variable is updated with the
 * new color. When the Variable is changed from another source, the state of the
 * box is updated with the new contents of the Variable.
 * 
 * @author Curran Kelleher
 * 
 */
public class VariableBoundColorBox extends JPanel implements Observer,
		VariableEditorComponent, MouseListener {
	private static final long serialVersionUID = -7777499408692975081L;

	/**
	 * The Variable to which this VariableBoundColorBox is bound.
	 */
	Variable variable;

	/**
	 * The Value that is currently being displayed. This is checked against the
	 * actual value of the Variable periodically to decide whether or not to
	 * update the display. This String is parseable into the actual value. It is
	 * generated by the method Value.toParseableString()
	 */
	String displayedValue = "";

	/**
	 * Construct a VariableBoundColorBox which is bound to the specified
	 * Variable.
	 * 
	 * @param variable
	 *            the variable to edit
	 */
	public VariableBoundColorBox(Variable variable) {
		// set the variable reference
		this.variable = variable;

		// get notifications every second.
		VariableEditorUIUpdateThread.getInstance().addObserver(this);

		// initialize the Color box
		updateWithCurrentVariableValue();

		// set up the action listener
		addMouseListener(this);
	}

	/**
	 * Updates the content of the Color box to reflect the current value of the
	 * variable.
	 * 
	 */
	public void updateWithCurrentVariableValue() {
		setBackground(ColorValue.extractColor(variable.evaluate()));
		displayedValue = variable.evaluate().toParseableString();
	}

	/**
	 * Get the update from the VariableEditorUIUpdateThread
	 */
	public void update(Observable o, Object arg) {
		if (o == VariableEditorUIUpdateThread.getInstance())
			// if this component is no longer usable, remove it as an Observer.
			if (!isDisplayable())
				VariableEditorUIUpdateThread.getInstance().deleteObserver(this);
			else if (!variable.evaluate().toParseableString().equals(
					displayedValue))
				updateWithCurrentVariableValue();
	}

	/**
	 * This method doesn't do anything.
	 */
	public void bindToVariableEditorComponent(
			VariableEditorComponent componentToUpdate) {
	}

	public void mouseClicked(MouseEvent e) {

	}

	public void mousePressed(MouseEvent e) {
		setBorder(BorderFactory.createBevelBorder(BevelBorder.LOWERED));
	}

	public void mouseReleased(MouseEvent e) {
		if (contains(e.getPoint())) {
			setBorder(BorderFactory.createBevelBorder(BevelBorder.RAISED));

			Color color = JColorChooser.showDialog(this, "Choose Color",
					getBackground());

			if (color != null) {
				ExpressionConsoleModel.getInstance().enterExpression(
						variable.toString() + " = "
								+ new ColorValue(color).toParseableString());
				// refresh the Color
				updateWithCurrentVariableValue();
			}
		}
	}

	public void mouseEntered(MouseEvent e) {
		setBorder(BorderFactory.createBevelBorder(BevelBorder.RAISED));
	}

	public void mouseExited(MouseEvent e) {
		setBorder(null);
	}
}