/* AlgAnimFrame.java */

import java.awt.*;
import java.applet.*;
import java.io.*;
import java.net.*;

/**
 * The <code>AlgAnimFrame</code> class is a top-level window with a title
 * and border. The layout used is GridBagLayout.
 * <p>
 * This extended frame class holds a set references to the panel/frame objects
 * used in the algorithm animation.
 * @see Frame
 */
public class AlgAnimFrame extends Frame {
    private AlgAnimApp parentApp;
    private URL sourceURL;
    private String algname;
    private AlgThread alg = null;
    private int delay = 200;
    private DrawingPanel drawingPanel;
    private TextFrame tf;
    private ComPanel cpanel;
    private boolean step = false, stepWait = false;

    // control panel
    private MenuItem quitItem;
    private Button runItem, stopItem, stepItem, skipItem;
    private CheckboxMenuItem enableAnim, disableAnim; 
    private CheckboxMenuItem[] dataChoice, delayChoice;
    private Menu dataMenu, delayMenu;
    private int dataSelected = 0;
    private boolean noAnim = false;

    /**
     * Creates and shows the frame consists of a drawing panel, commentary
     * panel and control panel. The text frame is now displayed on a separate
     * window.
     * @param parentApp The applet which results in the creation of this frame
     * @param sourceURL The URL of the source code to be displayed on the text
     * frame
     * @see URL
     */
    public AlgAnimFrame(AlgAnimApp parentApp, URL sourceURL) {
        this.parentApp = parentApp;
        this.sourceURL = sourceURL;
        this.algname = parentApp.getParameter("algname");

        setTitle(algname);
	move(0, 0);
        alg = new AlgThread(this);

        setLayout( new BorderLayout() );

	ControlPanel cp = new ControlPanel(this, algname);
	add("North", cp);
	runItem = cp.getRunButton();
	stopItem = cp.getStopButton();
	stepItem = cp.getStepButton();
	skipItem = cp.getSkipButton();

	drawingPanel = new DrawingPanel();
        add("Center", drawingPanel);

        /* Source panel */
        tf = new TextFrame( sourceURL );
	
        /* Commentary panel */
        cpanel = new ComPanel( algname, 1 );
        add( "South", cpanel );
 
        // generate initial data set
        alg.generateData();

	setMenuBar(createMenuBar());

        pack();
        validate();
        show();
	//if (tf.getTextPanel().getNumLines() > 0)
	    //tf.toFront();
    } // init()

    private MenuBar createMenuBar() {
	MenuBar mb = new MenuBar();

	mb.setFont(new Font("Helvetica", Font.PLAIN, 14));
	dataMenu = new Menu("Select");
	mb.add(dataMenu);
	dataChoice = new CheckboxMenuItem[alg.dataSets.length];
	for (int i = 0; i < alg.dataSets.length; i++) {
	    dataChoice[i] = new CheckboxMenuItem(alg.dataSets[i]);
	    dataMenu.add(dataChoice[i]);
	}
	if (alg.dataSets.length > 0)
	    dataChoice[0].setState(true);
	dataMenu.addSeparator();
	quitItem = new MenuItem("Quit");
	dataMenu.add(quitItem);

	/*
	Menu algMenu = new Menu("Algorithm", true);
	mb.add(algMenu);
	runItem = new MenuItem("Run " + algname);
	stopItem = new MenuItem("Stop " + algname);
	stepItem = new MenuItem("Next Step...");
	skipItem = new MenuItem("Skip...");
	algMenu.add(runItem);
	algMenu.add(stopItem);
	algMenu.add(stepItem);
	algMenu.add(skipItem);
	*/

	Menu animMenu = new Menu("Animation");
	mb.add(animMenu);
	enableAnim = new CheckboxMenuItem("Enable");
	enableAnim.setState(true);
	disableAnim = new CheckboxMenuItem("Disable");
	animMenu.add(enableAnim);
	animMenu.add(disableAnim);
	animMenu.addSeparator();
	delayMenu = new Menu("Delay");
	animMenu.add(delayMenu);
	delayChoice = new CheckboxMenuItem[5];
	for (int i = 0; i < 5; i++) {
	    delayChoice[i] = 
		new CheckboxMenuItem(""+((i+1)*200)+"msec");
	    delayMenu.add(delayChoice[i]);
	}
	delayChoice[0].setState(true);

	Menu viewMenu = new Menu("View");
	mb.add(viewMenu);
	MenuItem srcCode = new MenuItem("Source Code");
	if (tf.getTextPanel().getNumLines() < 1)
	    srcCode.disable();
	viewMenu.add(new MenuItem("Source Code"));
	//viewMenu.add(new MenuItem("Commentary Panel"));

	Menu helpMenu = new Menu("About");
	mb.setHelpMenu(helpMenu);
	helpMenu.add(new MenuItem("Credits"));
	helpMenu.add(new MenuItem("Copyrights"));

	return mb;
    } // createMenuBar()

    /**
     * Returns the preferred size of the frame. By default, it is set
     * to 850x700. It can be modified based on the specific application.
     * @return the dimension of the frame
     */
    public Dimension preferredSize() {
        return new Dimension(850,700);
    }

    /**
     * Event handler of the frame. The main purpose of this method is to
     * perform the cleanup statements upon receival of the WINDOW_DESTROY
     * event message.
     */
    public boolean handleEvent(Event event) {
        if (event.id == Event.WINDOW_DESTROY) {
            if (alg != null) {
              alg.drawingPanel = null;
              if (alg.isAlive())
                alg.stop();
            }
            parentApp.start_button.enable();
	    tf.dispose();
            dispose();
        } 
        return super.handleEvent(event);
    }

    /**
     * Action handler for the buttons and choice buttons in the control
     * panel.
     * @param e Event invoked
     * @param arg Object that invokes the event
     */
    public boolean action(Event e, Object arg) {
        Object target = e.target;
 
        if (target == runItem) {
            skipItem.enable();
            setSkip(false);
            setText(0, "Running algorithm continuously...");
            startAlg();
            return true;
        } else if (target == stopItem) {
            setText(0, "Stop button pressed...");
            setStep(false);
            if (getAlg().isAlive())
                getAlg().stop();
            finishAlg();
            return true;
        } else if (target == stepItem) {
            setText(0, "Executing next step...");
            setSkip(false);
            skipItem.enable();
            setStep(true);
            if (!getAlg().isAlive())
                startAlg();
            return true;
        } else if (target == skipItem) {
            startAlg();
            setText(0, "Skipping to the next phase...");
            setSkip(true);
            skipItem.disable();
            return true;
        } else if (target == quitItem) {
            getApplet().start_button.enable();
            if (getAlg() != null && getAlg().isAlive())
                getAlg().stop();
            getTextFrame().dispose();
            dispose();
        } else if (target instanceof CheckboxMenuItem) {
	    Menu parent = (Menu)((MenuItem)target).getParent();
	    if (parent == dataMenu) {
	        for (int i = 0; i < dataChoice.length; i++) {
		    if (target == dataChoice[i]) {
		        dataSelected = i;
			dataChoice[i].setState(true);
		    } else
			dataChoice[i].setState(false);
	        }
	    } else if (parent == delayMenu) {
		for (int i = 0; i < delayChoice.length; i++) {
		    if (target == delayChoice[i]) {
			setDelay((i+1)*200);
			getAlg().setDelay(getDelay());
                	setText(0, "Animation delay now set to " + 
					getDelay()
                        		+ " msec...");
			delayChoice[i].setState(true);
		    } else
			delayChoice[i].setState(false);
		}
	    } else { // parent is Animation.. -> enable/disable anim
		if (target == enableAnim) {
		    disableAnim.setState(!enableAnim.getState());
		    noAnim = false;
		    drawingPanel.setNoAnim(noAnim);
		} else if (target == disableAnim) {
		    enableAnim.setState(!disableAnim.getState());
		    noAnim = true;
		    drawingPanel.setNoAnim(noAnim);
		}
	    }
        } else {
	    if (target instanceof MenuItem) {
		String text = ((MenuItem)target).getLabel();
		if (text.trim().equals("Source Code")) {
		    tf.show();
		    tf.toFront();
		} else if (text.trim().equals("Credits")) {
		   setText(0, "Author: Woi L Ang   Supervised by: John Morris");
		} else if (text.trim().equals("Copyrights")) {
		   setText(0, "Copyright (c) 1998 The Department of Electrical and Electronic Engineering. University of Western Australia");
		}
	    }
	}
        return false;
    } // action()


    /**
     * Sets the text string to be displayed on a specific text field on the
     * commentary panel return from <code>getComPanel</code>.
     * @see AlgAnimFrame#getComPanel
     * @param n The text field to display the string. First is <b>0</b>.
     * @param s The string to be displayed.
     */
    public void setText( int n, String s ) {
        cpanel.setText( n, s );
    }
 
    /**
     * Highlights the specified line of the source code on the text panel.
     * If the line is beyond the scroll pane, it will be scrolled to the
     * center of the window.
     * @param n The line to be highlighted.
     */
    public void Highlight( int n ) {
	if (tf.getTextPanel().getNumLines() < 1) return;
	if (!((Component)tf).isShowing()) return;
        tf.getTextPanel().Highlight(n);
	int numLineVisible = 
	    tf.getTextPanel().size().height/tf.getTextPanel().getLineSpace();
	
	if ( (n < (tf.getTextPanel().getStart() + 2)) || 
		(n > (tf.getTextPanel().getStart() + numLineVisible - 2))) {
	    int max = tf.getVertScrollbar().getMaximum();
	    int min = tf.getVertScrollbar().getMinimum();
	    int startLine = n - numLineVisible/2;
	    if (startLine > 0) {
	    	tf.getTextPanel().setStart(startLine);
	    	tf.getVertScrollbar().setValue(startLine * (max - min) / 
			tf.getTextPanel().getNumLines());
	    } else {
	    	tf.getTextPanel().setStart(0);
	    	tf.getVertScrollbar().setValue(0);
	    }
	}
	try {
	    Thread.sleep(delay/4);
	} catch (InterruptedException e) {}
    }

    /**
     * Restore the drawing panel at the end of the animation or during
     * initialization.
     */
    public void restoreDrawingPanel() {
        alg.restoreDrawingPanel();
    }

    /**
     * Start the animation algorithm if the <b>run</b> or <b>step</b>
     * button is pressed.
     */
    public void startAlg() {
	if (alg.isAlive() && !stepWait) {
	    alg.stop();
	    alg = new AlgThread(this);
	    alg.start();
	} else if (alg.isAlive() && stepWait) {
	    //alg.resume();
	    step = !step;
	    stepWait = false;
	} else { // alg.isAlive() == false
	    alg = new AlgThread(this);
	    alg.start();
	}
	if (!stepWait) {
	    runItem.disable();
	    dataMenu.disable();
	    stopItem.enable();
	    stepItem.enable();
	}
    }

    /**
     * This method is invoked at the end of the animation or when
     * the <b>stop</b> button is pressed. It restores the buttons
     * status on the control panel.
     */
    public void finishAlg() {
	stopItem.disable();
	runItem.enable();
	dataMenu.enable();
	stepItem.enable(); step = false;
        alg.restoreDrawingPanel();
    }
    
    /**
     * This method is called when the <b>step</b> execution mode is used.
     * It is normally added to the line where the execution will wait
     * for the <b>step</b> button to be pressed.
     */
    public void waitStep() {
	if (step) {
	    setText(0, "Click NEXT STEP...");
	    stepItem.enable();
	    repaint();
	    step = false; stepWait = true;
	    while (!step) {
		try {
		    Thread.sleep(100);
		} catch (InterruptedException e) {}
	    }
	    if (!stepWait)
		step = false;
	}
    }

    /**
     * This method is called when the <b>skip</b> execution mode is used.
     * It is normally added to the line where the execution will wait
     * after the <b>skip</b> button to be pressed.
     */
    public void waitSkip() {
	alg.waitSkip();
    }

    /**
     * Sets the attribute which indicate if the <b>skip</b> execution
     * mode is current.
     */
    public void setSkip(boolean skip) {
	drawingPanel.setSkip(skip);
    }
    
    /**
     * Sets the attribute which indicate if the <b>step</b> execution
     * mode is current.
     */
    public void setStep(boolean step) {
	//setText(2, "Stepping through the next line(s)...");
	this.step = step;
	stepItem.disable();
	runItem.enable();
	dataMenu.enable();
	if (step) {
	    stepItem.disable();
	    stepWait = true;
	} else 
	    stepWait = false;
    }

    /**
     * Returns the reference to the AlgThread which contains the details and
     * execution sequences of the algorithm.
     * @see AlgThread
     */
    public AlgThread getAlg() {
	return alg;
    }

    /**
     * Set the delay for highlighting text.
     */
    public void setDelay(int delay) {
	this.delay = delay;
    }

    /**
     * Get the delay for highlighting text.
     */
    public int getDelay() {
	return delay;
    }

    /**
     * @return Returns the applet which contains the button to start up
     * 		this window.
     */
    public AlgAnimApp getApplet() {
	return parentApp;
    }

    /**
     * Returns an instance of the drawing panel which is cast to its super class
     * <code>Panel</code>.
     */
    public DrawingPanel getDrawingPanel() {
	return drawingPanel;
    }

    /**
     * Sets the drawing panel which is cast to its super class
     * <code>Panel</code>. This instance is used to set the GridBagConstraint
     * of the layout manager.
     * @see DrawingPanel
     */
    public void setDrawingPanel(DrawingPanel panel) {
	this.drawingPanel = panel;
    }

    /**
     * Returns an instance of the <code>TextFrame</code> used to set the layout
     * constraints and highlight certain lines of the source code.
     * @see TextFrame
     */
    public TextFrame getTextFrame() {
	return tf;
    }

    /**
     * @return Commentary panel, in which each text field within can be set to
     * display text string from this class.
     * @see ComPanel
     */
    public ComPanel getComPanel() {
	return cpanel;
    }

    /**
     * @return The choice of the data selected.
     */
    public int getDataChoice() {
	return dataSelected;
    }

    /**
     * @return The skip button.
     */
    public Button getSkipItem() {
	return skipItem;
    }

    /**
     * @return The run button.
     */
    public Button getRunItem() {
	return runItem;
    }

    /**
     * @return The stop button.
     */
    public Button getStopItem() {
	return stopItem;
    }

    /**
     * @return True is the animation is kept to a minimum for the animated
     * algorithm; false otherwise.
     */
    public boolean isNoAnim() {
	return noAnim;
    }
} // class AlgAnimApp