/*
 * @(#)DrawApplet.java
 *
 * Project:		JHotdraw - a GUI framework for technical drawings
 *				http://www.jhotdraw.org
 *				http://jhotdraw.sourceforge.net
 * Copyright:	© by the original author(s) and all contributors
 * License:		Lesser GNU Public License (LGPL)
 *				http://www.opensource.org/licenses/lgpl-license.html
 */

package CH.ifa.draw.applet;

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import java.io.*;
import java.net.*;
import CH.ifa.draw.framework.*;
import CH.ifa.draw.standard.*;
import CH.ifa.draw.figures.*;
import CH.ifa.draw.util.*;

/**
 * DrawApplication defines a standard presentation for
 * a drawing editor that is run as an applet. The presentation is
 * customized in subclasses.<p>
 * Supported applet parameters: <br>
 * <i>DRAWINGS</i>: a blank separated list of drawing names that is
 *           shown in the drawings choice.
 *
 * @version <$CURRENT_VERSION$>
 */
public class DrawApplet
		extends JApplet
		implements DrawingEditor, PaletteListener, VersionRequester {

	private transient Drawing         fDrawing;
	private transient Tool            fTool;

	private transient DrawingView     fView;
	private transient ToolButton      fDefaultToolButton;
	private transient ToolButton      fSelectedToolButton;

	private transient boolean         fSimpleUpdate;
	private transient JButton          fUpdateButton;

	private transient JComboBox          fFrameColor;
	private transient JComboBox          fFillColor;
	private transient JComboBox          fTextColor;
	private transient JComboBox          fArrowChoice;
	private transient JComboBox          fFontChoice;

	private transient Thread          fSleeper;
	private transient 			UndoManager myUndoManager;

	static String                     fgUntitled = "untitled";

	private static final String       fgDrawPath = "/CH/ifa/draw/";
	public static final String        IMAGES = fgDrawPath+"images/";

	/**
	 * Initializes the applet and creates its contents.
	 */
	public void init() {
		getVersionControlStrategy().assertCompatibleVersion();
		setUndoManager(new UndoManager());

		getContentPane().setLayout(new BorderLayout());

		fView = createDrawingView();

		JPanel attributes = createAttributesPanel();
		createAttributeChoices(attributes);
		getContentPane().add("North", attributes);

		JPanel toolPanel = createToolPalette();
		createTools(toolPanel);
		getContentPane().add("West", toolPanel);

		getContentPane().add("Center", (Component)view());
		JPanel buttonPalette = createButtonPanel();
		createButtons(buttonPalette);
		getContentPane().add("South", buttonPalette);

		initDrawing();
		// JFC should have its own internal double buffering...
		//setBufferedDisplayUpdate();
		setupAttributes();
	}

	public void addViewChangeListener(ViewChangeListener vsl) {
	}

	public void removeViewChangeListener(ViewChangeListener vsl) {
	}

	/*
	 * Gets the iconkit to be used in the applet.
	 */

	 /**** not sure whether this will still be needed on 1.1 enabled browsers
	 protected Iconkit iconkit() {
		if (fIconkit == null) {

			startSleeper();
			loadAllImages(this); // blocks until images loaded
			stopSleeper();
		}
		return fIconkit;
	} */

	/**
	 * Creates the attributes panel.
	 */
	protected JPanel createAttributesPanel() {
		JPanel panel = new JPanel();
		panel.setLayout(new PaletteLayout(2, new Point(2,2), false));
		return panel;
	}

	/**
	 * Creates the attribute choices. Override to add additional
	 * choices.
	 */
	protected void createAttributeChoices(JPanel panel) {
		panel.add(new JLabel("Fill"));
		fFillColor = createColorChoice(FigureAttributeConstant.FILL_COLOR.getName());
		panel.add(fFillColor);

		panel.add(new JLabel("Text"));
		fTextColor = createColorChoice(FigureAttributeConstant.TEXT_COLOR.getName());
		panel.add(fTextColor);

		panel.add(new JLabel("Pen"));
		fFrameColor = createColorChoice(FigureAttributeConstant.FRAME_COLOR.getName());
		panel.add(fFrameColor);

		panel.add(new JLabel("Arrow"));
		CommandChoice choice = new CommandChoice();
		fArrowChoice = choice;
		String arrowModeStr = FigureAttributeConstant.ARROW_MODE.getName();
		choice.addItem(new ChangeAttributeCommand("none",     arrowModeStr, new Integer(PolyLineFigure.ARROW_TIP_NONE),  this));
		choice.addItem(new ChangeAttributeCommand("at Start", arrowModeStr, new Integer(PolyLineFigure.ARROW_TIP_START), this));
		choice.addItem(new ChangeAttributeCommand("at End",   arrowModeStr, new Integer(PolyLineFigure.ARROW_TIP_END),   this));
		choice.addItem(new ChangeAttributeCommand("at Both",  arrowModeStr, new Integer(PolyLineFigure.ARROW_TIP_BOTH),  this));
		panel.add(fArrowChoice);

		panel.add(new JLabel("Font"));
		fFontChoice = createFontChoice();
		panel.add(fFontChoice);
	}

	/**
	 * Creates the color choice for the given attribute.
	 */
	protected JComboBox createColorChoice(String attribute) {
		CommandChoice choice = new CommandChoice();
		for (int i = 0; i < ColorMap.size(); i++)
			choice.addItem(
				new ChangeAttributeCommand(
					ColorMap.name(i),
					attribute,
					ColorMap.color(i),
					this
				)
			);
		return choice;
	}

	/**
	 * Creates the font choice. The choice is filled with
	 * all the fonts supported by the toolkit.
	 */
	protected JComboBox createFontChoice() {
		CommandChoice choice = new CommandChoice();
		String fonts[] = Toolkit.getDefaultToolkit().getFontList();
		for (int i = 0; i < fonts.length; i++) {
			choice.addItem(new ChangeAttributeCommand(fonts[i], FigureAttributeConstant.FONT_NAME.getName(), fonts[i],  this));
		}
		return choice;
	}

	/**
	 * Creates the buttons panel.
	 */
	protected JPanel createButtonPanel() {
		JPanel panel = new JPanel();
		panel.setLayout(new PaletteLayout(2, new Point(2,2), false));
		return panel;
	}

	/**
	 * Creates the buttons shown in the buttons panel. Override to
	 * add additional buttons.
	 * @param panel the buttons panel.
	 */
	protected void createButtons(JPanel panel) {
		panel.add(new Filler(24,20));

		JComboBox drawingChoice = new JComboBox();
		drawingChoice.addItem(fgUntitled);

		String param = getParameter("DRAWINGS");
		if (param == null) {
			param = "";
		}
		StringTokenizer st = new StringTokenizer(param);
		while (st.hasMoreTokens()) {
			drawingChoice.addItem(st.nextToken());
		}
		// offer choice only if more than one
		if (drawingChoice.getItemCount() > 1) {
			panel.add(drawingChoice);
		}
		else {
			panel.add(new JLabel(fgUntitled));
		}

		drawingChoice.addItemListener(
			new ItemListener() {
				public void itemStateChanged(ItemEvent e) {
					if (e.getStateChange() == ItemEvent.SELECTED) {
						loadDrawing((String)e.getItem());
					}
				}
			}
		);

		panel.add(new Filler(6,20));

		JButton button;
		button = new CommandButton(new DeleteCommand("Delete", this));
		panel.add(button);

		button = new CommandButton(new DuplicateCommand("Duplicate", this));
		panel.add(button);

		button = new CommandButton(new GroupCommand("Group", this));
		panel.add(button);

		button = new CommandButton(new UngroupCommand("Ungroup", this));
		panel.add(button);

		button = new JButton("Help");
		button.addActionListener(
			new ActionListener() {
				public void actionPerformed(ActionEvent event) {
					showHelp();
				}
			}
		);
		panel.add(button);

		fUpdateButton = new JButton("Simple Update");
		fUpdateButton.addActionListener(
			new ActionListener() {
				public void actionPerformed(ActionEvent event) {
					if (fSimpleUpdate) {
						setBufferedDisplayUpdate();
					}
					else {
						setSimpleDisplayUpdate();
					}
				}
			}
		);

		// panel.add(fUpdateButton); // not shown currently
	}

	/**
	 * Creates the tools palette.
	 */
	protected JPanel createToolPalette() {
		JPanel palette = new JPanel();
		palette.setLayout(new PaletteLayout(2,new Point(2,2)));
		return palette;
	}

	/**
	 * Creates the tools. By default only the selection tool is added.
	 * Override this method to add additional tools.
	 * Call the inherited method to include the selection tool.
	 * @param palette the palette where the tools are added.
	 */
	protected void createTools(JPanel palette) {
		Tool tool = createSelectionTool();

		fDefaultToolButton = createToolButton(IMAGES + "SEL", "Selection Tool", tool);
		palette.add(fDefaultToolButton);
	}

	/**
	 * Creates the selection tool used in this editor. Override to use
	 * a custom selection tool.
	 */
	protected Tool createSelectionTool() {
		return new SelectionTool(this);
	}

	/**
	 * Creates a tool button with the given image, tool, and text
	 */
	protected ToolButton createToolButton(String iconName, String toolName, Tool tool) {
		return new ToolButton(this, iconName, toolName, tool);
	}

	/**
	 * Creates the drawing used in this application.
	 * You need to override this method to use a Drawing
	 * subclass in your application. By default a standard
	 * Drawing is returned.
	 */
	protected Drawing createDrawing() {
		return new StandardDrawing();
	}

	/**
	 * Creates the drawing view used in this application.
	 * You need to override this method to use a DrawingView
	 * subclass in your application. By default a standard
	 * DrawingView is returned.
	 */
	protected DrawingView createDrawingView() {
		return new StandardDrawingView(this, 410, 370);
	}

	/**
	 * Handles a user selection in the palette.
	 * @see PaletteListener
	 */
	public void paletteUserSelected(PaletteButton button) {
		ToolButton toolButton = (ToolButton) button;
		setTool(toolButton.tool(), toolButton.name());
		setSelected(toolButton);
	}

	/**
	 * Handles when the mouse enters or leaves a palette button.
	 * @see PaletteListener
	 */
	public void paletteUserOver(PaletteButton button, boolean inside) {
		if (inside) {
			showStatus(((ToolButton) button).name());
		}
		else if (fSelectedToolButton != null) {
			showStatus(fSelectedToolButton.name());
		}
	}

	/**
	 * Gets the current drawing.
	 * @see DrawingEditor
	 */
	public Drawing drawing() {
		return fDrawing;
	}

	/**
	 * Gets the current tool.
	 * @see DrawingEditor
	 */
	public Tool tool() {
		return fTool;
	}

	/**
	 * Gets the current drawing view.
	 * @see DrawingEditor
	 */
	public DrawingView view() {
		return fView;
	}

	public DrawingView[] views() {
		return new DrawingView[] { view() } ;
	}

	/**
	 * Sets the default tool of the editor.
	 * @see DrawingEditor
	 */
	public void toolDone() {
		setTool(fDefaultToolButton.tool(), fDefaultToolButton.name());
		setSelected(fDefaultToolButton);
	}

	/**
	 * Handles a change of the current selection. Updates all
	 * menu items that are selection sensitive.
	 * @see DrawingEditor
	 */
	public void figureSelectionChanged(DrawingView view) {
		setupAttributes();
	}

	public void viewSelectionChanged(DrawingView oldView, DrawingView newView) {
	}

	private void initDrawing() {
		fDrawing = createDrawing();
		view().setDrawing(fDrawing);
		toolDone();
	}

	private void setTool(Tool t, String name) {
		if (fTool != null) {
			fTool.deactivate();
		}
		fTool = t;
		if (fTool != null) {
			showStatus(name);
			fTool.activate();
		}
	}

	private void setSelected(ToolButton button) {
		if (fSelectedToolButton != null) {
			fSelectedToolButton.reset();
		}
		fSelectedToolButton = button;
		if (fSelectedToolButton != null) {
			fSelectedToolButton.select();
		}
	}

	protected void loadDrawing(String param) {
		if (param == fgUntitled) {
			fDrawing.release();
			initDrawing();
			return;
		}

		String filename = getParameter(param);
		if (filename != null) {
			readDrawing(filename);
		}
	}

	private void readDrawing(String filename) {
		toolDone();
		String type = guessType(filename);
		if (type.equals("storable")) {
			readFromStorableInput(filename);
		}
		else if (type.equals("serialized")) {
			readFromObjectInput(filename);
		}
		else {
			showStatus("Unknown file type");
		}
	}

	private void readFromStorableInput(String filename) {
		try {
			URL url = new URL(getCodeBase(), filename);
			InputStream stream = url.openStream();
			StorableInput input = new StorableInput(stream);
			fDrawing.release();

			fDrawing = (Drawing)input.readStorable();
			view().setDrawing(fDrawing);
		}
		catch (IOException e) {
			initDrawing();
			showStatus("Error:" + e);
		}
	}

	private void readFromObjectInput(String filename) {
		try {
			URL url = new URL(getCodeBase(), filename);
			InputStream stream = url.openStream();
			ObjectInput input = new ObjectInputStream(stream);
			fDrawing.release();
			fDrawing = (Drawing)input.readObject();
			view().setDrawing(fDrawing);
		}
		catch (IOException e) {
			initDrawing();
			showStatus("Error: " + e);
		}
		catch (ClassNotFoundException e) {
			initDrawing();
			showStatus("Class not found: " + e);
		}
	}

	private String guessType(String file) {
		if (file.endsWith(".draw")) {
			return "storable";
		}
		if (file.endsWith(".ser")) {
			return "serialized";
		}
		return "unknown";
	}

	private void setupAttributes() {
		Color   frameColor = (Color)   AttributeFigure.getDefaultAttribute(FigureAttributeConstant.FRAME_COLOR);
		Color   fillColor  = (Color)   AttributeFigure.getDefaultAttribute(FigureAttributeConstant.FILL_COLOR);
		Color   textColor  = (Color)   AttributeFigure.getDefaultAttribute(FigureAttributeConstant.TEXT_COLOR);
		Integer arrowMode  = (Integer) AttributeFigure.getDefaultAttribute(FigureAttributeConstant.ARROW_MODE);
		String  fontName   = (String)  AttributeFigure.getDefaultAttribute(FigureAttributeConstant.FONT_NAME);

		FigureEnumeration fe = view().selection();
		while (fe.hasNextFigure()) {
			Figure f = fe.nextFigure();
			frameColor = (Color) f.getAttribute(FigureAttributeConstant.FRAME_COLOR);
			fillColor  = (Color) f.getAttribute(FigureAttributeConstant.FILL_COLOR);
			textColor  = (Color) f.getAttribute(FigureAttributeConstant.TEXT_COLOR);
			arrowMode  = (Integer) f.getAttribute(FigureAttributeConstant.ARROW_MODE);
			fontName   = (String) f.getAttribute(FigureAttributeConstant.FONT_NAME);
		}

		fFrameColor.setSelectedIndex(ColorMap.colorIndex(frameColor));
		fFillColor.setSelectedIndex(ColorMap.colorIndex(fillColor));
		//fTextColor.select(ColorMap.colorIndex(textColor));
		if (arrowMode != null) {
			fArrowChoice.setSelectedIndex(arrowMode.intValue());
		}
		if (fontName != null) {
			fFontChoice.setSelectedItem(fontName);
		}
	}

	protected void setSimpleDisplayUpdate() {
		view().setDisplayUpdate(new SimpleUpdateStrategy());
		fUpdateButton.setText("Simple Update");
		fSimpleUpdate = true;
	}

	protected void setBufferedDisplayUpdate() {
		view().setDisplayUpdate(new BufferedUpdateStrategy());
		fUpdateButton.setText("Buffered Update");
		fSimpleUpdate = false;
	}

	/**
	 * Shows a help page for the applet. The URL of the help
	 * page is derived as follows: codeBase+appletClassname+Help.html"
	 */
	protected void showHelp() {
		try {
			String appletPath = getClass().getName().replace('.', '/');
			URL url = new URL(getCodeBase(), appletPath + "Help.html");
			getAppletContext().showDocument(url, "Help");
		}
		catch (IOException e) {
			showStatus("Help file not found");
		}

	}

	protected void setUndoManager(UndoManager newUndoManager) {
		myUndoManager = newUndoManager;
	}

	public UndoManager getUndoManager() {
		return myUndoManager;
	}

	protected VersionControlStrategy getVersionControlStrategy() {
		return new StandardVersionControlStrategy(this);
	}

	/**
	 * Subclasses should override this method to specify to which versions of
	 * JHotDraw they are compatible. A string array is returned so it is possible
	 * to specify several version numbers of JHotDraw to which the application
	 * is compatible with.
	 *
	 * @return all versions number of JHotDraw the application is compatible with.
	 */
	public String[] getRequiredVersions() {
		String[] requiredVersions = new String[1];
		// return the version of the package we are in
		requiredVersions[0] = VersionManagement.getPackageVersion(DrawApplet.class.getPackage());
		return requiredVersions;
	}

	/**
	 * *** netscape browser work around ***
	 */
	private void startSleeper() {
		if (fSleeper == null) {
			fSleeper = new SleeperThread(this);
		}
		fSleeper.start();
	}

	private void stopSleeper() {
		if (fSleeper != null) {
			fSleeper.stop();
		}
	}
}


class SleeperThread extends Thread {

	JApplet  fApplet;

	SleeperThread(JApplet applet) {
		fApplet = applet;
	}

	public void run() {
		try {
			for (;;) {
				fApplet.showStatus("loading icons...");
				sleep(50);
			}
		}
		catch (InterruptedException e) {
			return;
		}
	}

}