import java.awt.*;
import java.io.*;

// Notes Text editor
// Contains 
// 1. TextArea
// 2. Open/Save Dialogs
// 3. Menus and MenuBar
// All of which are private to this class
public class Notes extends Frame
{
	private	TextArea t;

	private FileDialog openDialog;
	private FileDialog saveDialog;

	private MenuBar mbar;

	// The constructor where we initialize data
	public Notes()
	{
		super("Notes Editor");

		// For non-Win95 systems, try "Helvetica" or "TimesRoman"
		// for the font name
		Font f = new Font("TimesRoman", Font.PLAIN, 12);
		setFont(f);
		setBackground(Color.gray);

		// Move the code out of the contructor into other methods 
		InitializeMenus();
		InitializeTextArea();
		InitializeToolBars();

		openDialog = new FileDialog(this, "Open File...", FileDialog.LOAD);
		saveDialog = new FileDialog(this, "Save File...", FileDialog.SAVE);

		setMenuBar(mbar);
		resize(300,200);
		pack();
		show();
	}

	// Reads from a file, throws an IOException if an error occured
	public void read(String s) throws IOException
	{
		String line;
		int i =0;
		FileInputStream in = null;
		BufferedInputStream bis = null;
		DataInputStream dataIn = null;

		try
		{
			in = new FileInputStream(s);
			bis = new BufferedInputStream(in);
			dataIn = new DataInputStream(bis);
		}
		catch(Throwable e)
		{
			System.out.println("Error in opening file");
			return;
		}

		try
		{
			while ((line = dataIn.readLine()) != null)
			{
				t.insertText(line, i);
				i++;
			}
			in.close();
		}
		catch(IOException e) 
		{
			System.out.println("Error in reading file");
			throw e;
		}
	}

	// Writes to a file
	public void write(String s) throws IOException
	{
		FileOutputStream out = null;
		BufferedOutputStream bos = null;
		DataOutputStream dataOut = null;

		try
		{
			out = new FileOutputStream(s);
			bos = new BufferedOutputStream(out);
			dataOut = new DataOutputStream(bos);

		}
		catch (Throwable e)
		{
			System.out.println("Error in opening file");
			return;
		}

		try
		{
			dataOut.writeChars(t.getText());
			out.close();
		}
		catch(IOException e) 
		{
		 	System.out.println("Error in writing to file");
			throw e; 
		}
	}

	// Creates the menus and attaches it to the MenuBar
	private void InitializeMenus()
	{
		mbar = new MenuBar();
		Menu m = new Menu("File");
		m.add(new MenuItem("New"));
		m.add(new MenuItem("Open"));
		m.add(new MenuItem("Save"));
		m.add(new MenuItem("Save As"));
		m.addSeparator();
		m.add(new MenuItem("Quit"));
		mbar.add(m);

		m = new Menu("Help");
		m.add(new MenuItem("Help!!!!"));
		m.addSeparator();
		m.add(new MenuItem("About..."));
		mbar.add(m);
	}

	// Creates the TextArea
	private void InitializeTextArea()
	{
		t = new TextArea("This is a TextArea", 24, 80);
		t.setEditable(true);
		add("Center", t);
	}

	// Creates the Toolbars
	private void InitializeToolBars()
	{
	}

	// Handle events that have occurred
	public boolean handleEvent(Event evt)
	{
		switch(evt.id)
		{
			System.out.println(evt.target.toString());
			case Event.WINDOW_DESTROY:
			{
				System.out.println("Exiting...");
				System.exit(0);
				return true;
			}
			// This can be handled
			case Event.ACTION_EVENT:
			{
				String label = evt.arg.toString();

				if(evt.target instanceof MenuItem)
				{
					// or "Open".equals(label)
					// or evt.arg.equals("Open")
					if (label.equals("Open"))
					{
						String filename;
						openDialog.show();
						// getFile() throws an exception
						// So wee need to catch it if there is an error
						try
						{
							filename = openDialog.getFile();
							read(filename);
						}
						catch(IOException e)
						{
							System.out.println("File not found");
							return true;
						}
						return true;
					}
					else if (label.equals("Save As"))
					{
						String filename;
						try
						{
							filename = saveDialog.getFile();
	                  write(filename);
						}
						catch(IOException e)
						{
							System.out.println("File not found");
							return true;
						}
						saveDialog.show();
						return true;
					}
					else if(label.equals("Quit"))
					{
						System.exit(0);
					}
					else if(label.equals("About..."))
					{
						AboutDialog ab = new AboutDialog(this);
						ab.show();
						return true;
					}
				}
			}
			default:
				return false;
		}
	}

	// Where execution begins in a stand-alone executable
	public static void main(String args[])
	{
		new Notes();
	}
}

// Sub-class(i.e child/descendant) of Dialog, put is NOT public
// because only one public class can reside in a file and that
// class is the name of the file
class AboutDialog extends Dialog
{
	// Class is specific to "Notes", because it takes a parameter to
	// to it. Can be made generic, by asking for a Frame instead
	public AboutDialog(Notes parent)
	{
		super(parent, "About Dialog", true);
		Panel p = new Panel();
		p.add(new Button("OK"));
		add("South", p);
		resize(300,200);
	}
	// Same as the above. Except lets try something different
/*
	public boolean handleEvent(Event evt)
	{
		switch(evt.id)
		{
			case Event.ACTION_EVENT:
			{
				if("OK".equals(evt.arg))
				{
					dispose();
					return true;
				}
			}
			default:
				return false;
		}
	}
*/
	// No different from the above handler
	public boolean action(Event evt, Object arg)
	{
		if("Ok".equals(arg))
		{
			dispose();
			return true;
		}
		return false;
	}
}