/*	SimpleFileWriter.java
*	@author: jbell
*	@version: Jul 19, 2001
*/

import java.awt.event.*;
import java.io.*;
import javax.swing.*;

public class SimpleFileWriter implements ActionListener{

	JFrame frame;
	JTextArea editor;

	/**	Instantiates a SimpleFileWriter object.
	*/
	public static void main(String[] args){

		SimpleFileWriter simplefilewriter = new SimpleFileWriter();
		simplefilewriter.init();

	}

	/**	Initializes the button controls, a textarea for an editor to display or enter
	*	text, and adds the components to a frame window and displays it.
	*/
	public void init(){
		frame = new JFrame("SimpleFileWriter");
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		//button controls
		JPanel controlpanel = new JPanel();
		JButton openbutton = new JButton("Open A File");
		JButton writebutton = new JButton("Write To File");
		JButton clearbutton = new JButton("Clear");
		JButton exitbutton = new JButton("Exit");
		exitbutton.addActionListener(this);
		openbutton.addActionListener(this);
		writebutton.addActionListener(this);
		clearbutton.addActionListener(this);
		controlpanel.add(writebutton);
		controlpanel.add(openbutton);
		controlpanel.add(clearbutton);
		controlpanel.add(exitbutton);
		frame.getContentPane().add(controlpanel,"North");
		//editor
		editor = new JTextArea(30,60); //initializes a JTex Editor with width 60 and height 30 
		JScrollPane scrollpane = new JScrollPane(editor);
		frame.getContentPane().add(scrollpane,"Center");
		frame.pack();
		frame.show();
	}

	/**	Brings up a simple FileSave dialog for the user to enter a file name,
	*	and creates a file based on that name in the selected directory.
	*/
	public File getAFileForSave(){
		File file = null;
		File currentdirectory = new File(".");
		JFileChooser filechooser = new JFileChooser(currentdirectory);
		int replycode = filechooser.showSaveDialog(frame);
		if (replycode == JFileChooser.APPROVE_OPTION){
			file = filechooser.getSelectedFile();
		}
		return file;

	}

	/**	Brings up as imple file open dialog and returns the file selected by the user.
	*/
	public File getAFileToOpen(){
		File file = null;
		File currentdirectory = new File(".");
		JFileChooser filechooser = new JFileChooser(currentdirectory);
		int replycode = filechooser.showOpenDialog(frame);
		if (replycode == JFileChooser.APPROVE_OPTION){
			file = filechooser.getSelectedFile();
		}
		return file;
	}

	/**	Writes the string to the input file.
	*/
	public void writeStringToFile(File file, String s){

		try{
			FileWriter filewriter = new FileWriter(file);
			filewriter.write(s);
			filewriter.close();
		}catch (FileNotFoundException fnfe){
			System.err.println("FileNotFoundException: " + fnfe.getMessage());
		}catch (IOException ioe){
			System.err.println("IOException: " + ioe.getMessage());
		}
		

	}

	/**	Appends the contents of the input file to the text editor.
	*/
	public void writeFileToEditor(File file){

		try{
			FileReader filereader = new FileReader(file);
			BufferedReader bufferedreader = new BufferedReader(filereader);
			String lineread = "";
			while ((lineread = bufferedreader.readLine()) != null){
				println(lineread);
			}
			filereader.close();
		}catch (FileNotFoundException fnfe){
			System.err.println("FileNotFoundException: " + fnfe.getMessage());
		}catch (IOException ioe){
			System.err.println("IOException: " + ioe.getMessage());
		}

	}

	/**	Provides actions to user input.
	*/
	public void actionPerformed(ActionEvent actionevent){
		String actioncommand = actionevent.getActionCommand();
		if (actioncommand.compareTo("Exit") == 0) {
			System.exit(0);
		}else if (actioncommand.compareTo("Clear") == 0) {
			editor.setText("");
		}else if (actioncommand.compareTo("Open A File") == 0) {
			File f = getAFileToOpen();
			writeFileToEditor(f);
		}else if (actioncommand.compareTo("Write To File") == 0) {
			String s = editor.getText();
			File f = getAFileForSave();
			writeStringToFile(f,s);
			showMessage("Contents of the Text Editor saved to file " + f.getName());
		}
	}

	/**	Conveniently displays a message to the user and waits for confirmation.
	*/
	public void showMessage(String s){
		JOptionPane.showMessageDialog(null,s);
	}
	
	private void println(String s){
		editor.append(s + "\n");
		editor.setCaretPosition(editor.getText().length());
	}
}