import javax.swing.*;
import javax.swing.event.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import java.util.*;

/**
 * Class RectDrawingListener extends Java's MouseInputAdpater to provide
 * handlers for three mouse events: mouse pressed, mouse dragged, and mouse
 * released.  The comments for the event-handling methods describe in
 * detail what each method does to allow the user to draw rectangles.
 *                                                                      <p>
 * The general drawing strategy is to add and remove rectangles from the
 * canvas shapeList as the mouse is being dragged, repainting the canvas at
 * each addition.  Since repainting is done efficiently by Java, this
 * technique is visually OK even if the canvas shapeList contains a large
 * number of other rectangles to be drawn.
 */
public class TextDrawingListener extends MouseInputAdapter
        implements ActionListener {

    private DrawingCanvas canvas;
    private WorkSpace workSpace;
    /** The starting x-axis position for drawing a shape */
    private int startX;

    /** The starting y-axis position for drawing a shape */
    private int startY;

    /** Quadrant-I normalized value of startY */
    private int nStartY;

    /** True if the user is moving the mouse. */
    private boolean moving = false;

    /** Text field for entering text.  It's non-null or null value inicidates,
     * respectively, whether typing is in progress. */
    JTextField textField;


    /**
     * Construct this with the given canvas and workspace.
     */
    public TextDrawingListener(DrawingCanvas canvas, WorkSpace workSpace) {
        this.canvas = canvas;
        this.workSpace = workSpace;
    }

    /**
     * The press event does it all in this listener.  If the text field is
     * null, create it and display it at the x/y click location.  If the text
     * field is non-null, and the click happens outside the text field, call
     * createTextShape to finish things off.
     */
    public void mousePressed(MouseEvent e) {
        Shape selection = workSpace.getSelection();
        if (selection != null) {
            selection.selected = false;
        }

	if (textField == null) {
	    int ch = canvas.getHeight();
	    startX = e.getX();
	    startY = e.getY();
	    nStartY = ch - startY;
	}

        if (textField == null) {
	    /*
	     * Turn off any previously selected text
	     *
	    workSpace.setSelection(null);
	     *
	     * OK, so this is not working as expected.
	     */
	    textField = new JTextField(40);
	    textField.addActionListener(this);
	    canvas.add(textField);
	    textField.setBounds(e.getX(), e.getY(), 40*8, 20);
	    textField.grabFocus();
	    canvas.revalidate();
	}
	else {
	    createTextShape();
	    mousePressed(e);	// this'll keep putting up text fields;
				// its behavior is seemingly a bit volatile at
				// this point, and rather beyond 102
				// expectations; however, let's leave it in
	}
    }

    /**
     * Per the JTextField documentation, pressing the enter (aka, return) key
     * in a JTextField triggers an ActionEvent.  In our case, we want to
     * finalize the text entry by calling this.createTextShape().
     */
    public void actionPerformed(ActionEvent e) {
	createTextShape();
    }

    /**
     * When the user is done typing, get the text field string, remove the text
     * field, and add the string-valued Text shape to the workspace.
     */
    private void createTextShape() {
	Point p = textField.getLocation();
	String s = textField.getText();
	int ch = canvas.getHeight();

	String value = textField.getText();
	canvas.remove(textField);
	textField = null;

	int x_fudge = 6;
	int y_fudge = 1;
	int width = (int) canvas.getFont().getStringBounds(
	    s, canvas.getGraphics2D().getFontRenderContext()).getWidth();
	int height = (int) canvas.getFont().getStringBounds(
	    s, canvas.getGraphics2D().getFontRenderContext()).getHeight();
	Text text = new Text(s, width, height,
	    startX + x_fudge, startY + y_fudge, Color.BLACK, false);

	workSpace.add(text);
	workSpace.setSelection(text);
        text.selected = true;
	moving = false;
	canvas.grabFocus();
        canvas.repaint();
    }

    /**
     * Do nothing.
     */
    public void mouseDragged(MouseEvent e) {
    }

    /**
     * Do nothing.
     */
    public void mouseReleased(MouseEvent e) {
    }

}