package awt;

import java.awt.*;
import java.awt.event.*;

 This class has two possible uses:
  MODAL: when you call getResult(), blocks all other user input until a
 	choice is made; then returns this choice.
  NON-MODAL: shows itself when you call getResult(). In this case,
 	getResult() always returns null. The dialog window will close
 	automatically when the user picks a button. If you want to do
 	something when that happens, use the result of addButton()
  	to add an ActionListener.
  @author Geert Vernaeve
 
public class SimpleDialog extends Dialog implements ActionListener
{
	private Panel buttonPanel;
	private Panel textPanel;
	private String result = null;
	// Frame and cursor to restore
	private Frame fr;
	private Cursor oldCursor;
	private Exception exc;

	public SimpleDialog(Component comp,String title,boolean modal) {
		super(getFrame(comp),title,modal);
		fr = getFrame(comp);
		Cursor oldCursor = fr.getCursor();
		fr.setCursor(Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR));
		buttonPanel = new Panel(new FlowLayout());
		buttonPanel.setBackground(Color.lightGray);
		add("South",buttonPanel);
		textPanel = new Panel(new GridLayout(0,1));
		add("Center",textPanel);
	}

	
 Show an exception
	  You cannot add more buttons since it is shown immediately! 
	public SimpleDialog(Component comp,String title,Exception ex,boolean modal) {
		this(comp,title,modal);
		addText(ex.getLocalizedMessage());
		addButton("Debug info ...");
		addButton("Bummer!");
		exc = ex;
		getResult();
	}

	
 Show a one-line message and one button
	  You cannot add more buttons since it is shown immediately! 
	public SimpleDialog(Component comp,String title,String message,String buttontxt,boolean modal) {
		this(comp,title,modal);
		addText(message);
		addButton(buttontxt);
		getResult();
	}

	public Button addButton(String text) {
		Button b = new Button(text);
		b.addActionListener(this);
		buttonPanel.add(b);
		return b;
	}

	
 Add a custom component 
	public Component addComp(Component comp) {
		return buttonPanel.add(comp);
	}

	public void addText(String text) {
		int idx;
		while ( (idx = text.indexOf('\n'))  >=  0) {
			textPanel.add(new Label(text.substring(0,idx)));
			text = text.substring(idx+1);
		}
		textPanel.add(new Label(text,Label.CENTER));
	}

	public void actionPerformed(ActionEvent e) {
		result = e.getActionCommand();
		dispose();
		if (exc == null) return;
		// Exception dialog
		if (result.equals("Bummer!")) return;
		// PENDING: naar een PrintStream of PrintWriter sturen
		// en dan tonen in een venster
		System.out.println(exc.getClass().getName());
		exc.printStackTrace();
		new SimpleDialog(this,"Debug","Debug dumped to stdout","OK",false);
	}

	
 Helper function 
	public static Frame getFrame(Component comp) {
		while (!(comp instanceof Frame) && comp!=null)
			comp = comp.getParent();
		return (Frame)comp;
	}

	
 If the dialog is modal: Wait until the user has made a choice.
	  Then return result.
	  If the dialog is not modal: return result or null if the user
	 	hasn't chosen any button yet.
	  Warning: only call this method once, then buffer the resulting string.
	  Calling this method twice causes the dialog to pop up twice ... 
	public String getResult() {
		if (getGraphics() == null) {
			pack();
			try {
				Point pt = fr.getLocationOnScreen();
				Dimension siz = fr.getSize();
				Dimension thisSiz = getSize();
				int locx = pt.x+(siz.width-thisSiz.width)/2;
				if (locx < 0) locx = 0;
				int locy = pt.y+(siz.height-thisSiz.height)/2;
				if (locy < 0) locy = 0;
				setLocation(locx,locy);
			} catch (IllegalComponentStateException exc) {
				// If fr not visible, the getLocationOnScreen()
				// throws this exception
			}
			show();
		}
		fr.setCursor(oldCursor==null ? Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR) : oldCursor);
		return result;
	}
}