/*
 * @(#)ProgressMonitor.java	1.24 01/02/09
 *
 * Copyright 1997-2001 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * This software is the proprietary information of Sun Microsystems, Inc.  
 * Use is subject to license terms.
 * 
 */



package javax.swing;



import java.io.*;
import java.awt.BorderLayout;
import java.awt.Frame;
import java.awt.Component;
import java.awt.Container;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;



/** A class to monitor the progress of some operation. If it looks
 * like the operation will take a while, a progress dialog will be popped up.
 * When the ProgressMonitor is created it is given a numeric range and a
 * descriptive string. As the operation progresses, call the setProgress method
 * to indicate how far along the [min,max] range the operation is.
 * Initially, there is no ProgressDialog. After the first millisToDecideToPopup
 * milliseconds (default 500) the progress monitor will predict how long
 * the operation will take.  If it is longer than millisToPopup (default 2000,
 * 2 seconds) a ProgressDialog will be popped up.
 * <p>
 * From time to time, when the Dialog box is visible, the progress bar will
 * be updated when setProgress is called.  setProgress won't always update
 * the progress bar, it will only be done if the amount of progress is
 * visibly significant.
 *
 * <p>
 * 
 * For further documentation and examples see
 * <a
 href="http://java.sun.com/docs/books/tutorial/uiswing/components/progress.html">How to Monitor Progress</a>,
 * a section in <em>The Java Tutorial.</em>
 *
 * @see ProgressMonitorInputStream
 * @author James Gosling
 * @version 1.24 02/09/01
 */
public class ProgressMonitor extends Object
{
    private ProgressMonitor root;
    private JDialog         dialog;
    private JOptionPane     pane;
    private JProgressBar    myBar;
    private JLabel          noteLabel;
    private Component       parentComponent;
    private String          note;
    private Object[]        cancelOption = null;
    private Object          message;
    private long            T0;
    private int             millisToDecideToPopup = 500;
    private int             millisToPopup = 2000;
    private int             min;
    private int             max;
    private int             v;
    private int             lastDisp;
    private int             reportDelta;


    /**
     * Constructs a graphic object that shows progress, typically by filling
     * in a rectangular bar as the process nears completion.
     *
     * @param parentComponent the parent component for the dialog box
     * @param message a descriptive message that will be shown
     *        to the user to indicate what operation is being monitored.
     *        This does not change as the operation progresses.
     *        See the message parameters to methods in
     *        {@link JOptionPane#message}
     *        for the range of values.
     * @param note a short note describing the state of the
     *        operation.  As the operation progresses, you can call
     *        setNote to change the note displayed.  This is used,
     *        for example, in operations that iterate through a
     *        list of files to show the name of the file being processes.
     *        If note is initially null, there will be no note line
     *        in the dialog box and setNote will be ineffective
     * @param min the lower bound of the range
     * @param max the upper bound of the range
     * @see JDialog
     * @see JOptionPane
     */
    public ProgressMonitor(Component parentComponent,
                           Object message,
                           String note,
                           int min,
                           int max) {
        this(parentComponent, message, note, min, max, null);
    }


    private ProgressMonitor(Component parentComponent,
                            Object message,
                            String note,
                            int min,
                            int max,
                            ProgressMonitor group) {
        this.min = min;
        this.max = max;
        this.parentComponent = parentComponent;

        cancelOption = new Object[1];
        cancelOption[0] = UIManager.getString("OptionPane.cancelButtonText");

        reportDelta = (max - min) / 100;
        if (reportDelta < 1) reportDelta = 1;
        v = min;
        this.message = message;
        this.note = note;
        if (group != null) {
            root = (group.root != null) ? group.root : group;
            T0 = root.T0;
            dialog = root.dialog;
        }
        else {
            T0 = System.currentTimeMillis();
        }
    }


    private class ProgressOptionPane extends JOptionPane
    {
        ProgressOptionPane(Object messageList) {
            super(messageList,
                  JOptionPane.INFORMATION_MESSAGE,
                  JOptionPane.DEFAULT_OPTION,
                  null,
                  ProgressMonitor.this.cancelOption,
                  null);
        }


        public int getMaxCharactersPerLineCount() {
            return 60;
        }


        // Equivalent to JOptionPane.createDialog,
        // but create a modeless dialog.
        // This is necessary because the Solaris implementation doesn't
        // support Dialog.setModal yet.
        public JDialog createDialog(Component parentComponent, String title) {
            Frame frame = JOptionPane.getFrameForComponent(parentComponent);
            final JDialog dialog = new JDialog(frame, title, false);
            Container contentPane = dialog.getContentPane();

            contentPane.setLayout(new BorderLayout());
            contentPane.add(this, BorderLayout.CENTER);
            dialog.pack();
            dialog.setLocationRelativeTo(parentComponent);
            dialog.addWindowListener(new WindowAdapter() {
                boolean gotFocus = false;

                public void windowClosing(WindowEvent we) {
                    setValue(null);
                }

                public void windowActivated(WindowEvent we) {
                    // Once window gets focus, set initial focus
                    if (!gotFocus) {
                        selectInitialValue();
                        gotFocus = true;
                    }
                }
            });

            addPropertyChangeListener(new PropertyChangeListener() {
                public void propertyChange(PropertyChangeEvent event) {
                    if(dialog.isVisible() && 
                       event.getSource() == ProgressOptionPane.this &&
                       (event.getPropertyName().equals(VALUE_PROPERTY) ||
                        event.getPropertyName().equals(INPUT_VALUE_PROPERTY))){
                        dialog.setVisible(false);
                        dialog.dispose();
                    }
                }
            });
            return dialog;
        }
    }


    /** 
     * Indicate the progress of the operation being monitored.
     * If the specified value is >= the maximum, the progress
     * monitor is closed. 
     * @param nv an int specifying the current value, between the
     *        maximum and minimum specified for this component
     * @see #setMinimum
     * @see #setMaximum
     * @see #close
     */
    public void setProgress(int nv) {
        v = nv;
        if (nv >= max) {
            close();
        }
        else if (nv >= lastDisp + reportDelta) {
            lastDisp = nv;
            if (myBar != null) {
                myBar.setValue(nv);
            }
            else {
                long T = System.currentTimeMillis();
                long dT = (int)(T-T0);
                if (dT >= millisToDecideToPopup) {
                    int predictedCompletionTime;
                    if (nv > min) {
                        predictedCompletionTime = (int)((long)dT *
                                                        (max - min) /
                                                        (nv - min));
                    }
                    else {
                        predictedCompletionTime = millisToPopup;
                    }
                    if (predictedCompletionTime >= millisToPopup) {
                        myBar = new JProgressBar();
                        myBar.setMinimum(min);
                        myBar.setMaximum(max);
                        myBar.setValue(nv);
                        if (note != null) noteLabel = new JLabel(note);
                        pane = new ProgressOptionPane(new Object[] {message,
                                                                    noteLabel,
                                                                    myBar});
                        dialog = pane.createDialog(parentComponent,
                            UIManager.getString(
                                "ProgressMonitor.progressText"));
                        dialog.show();
                    }
                }
            }
        }
    }


    /** 
     * Indicate that the operation is complete.  This happens automatically
     * when the value set by setProgress is >= max, but it may be called
     * earlier if the operation ends early.
     */
    public void close() {
        if (dialog != null) {
            dialog.setVisible(false);
            dialog.dispose();
            dialog = null;
            pane = null;
            myBar = null;
        }
    }


    /**
     * Returns the minimum value -- the lower end of the progress value.
     *
     * @return an int representing the minimum value
     * @see #setMinimum
     */
    public int getMinimum() {
        return min;
    }


    /**
     * Specifies the minimum value.
     *
     * @param m  an int specifying the minimum value
     * @see #getMinimum
     */
    public void setMinimum(int m) {
        min = m;
    }


    /**
     * Returns the maximum value -- the higher end of the progress value.
     *
     * @return an int representing the maximum value
     * @see #setMaximum
     */
    public int getMaximum() {
        return max;
    }


    /**
     * Specifies the maximum value.
     *
     * @param m  an int specifying the maximum value
     * @see #getMaximum
     */
    public void setMaximum(int m) {
        max = m;
    }


    /** 
     * Returns true if the user hits the Cancel button in the progress dialog.
     */
    public boolean isCanceled() {
        if (pane == null) return false;
        Object v = pane.getValue();
        return ((v != null) &&
                (cancelOption.length == 1) &&
                (v.equals(cancelOption[0])));
    }


    /**
     * Specifies the amount of time to wait before deciding whether or
     * not to popup a progress monitor.
     *
     * @param millisToDecideToPopup  an int specifying the time to wait,
     *        in milliseconds
     * @see #getMillisToDecideToPopup
     */
    public void setMillisToDecideToPopup(int millisToDecideToPopup) {
        this.millisToDecideToPopup = millisToDecideToPopup;
    }


    /**
     * Returns the amount of time this object waits before deciding whether
     * or not to popup a progress monitor.
     *
     * @param millisToDecideToPopup  an int specifying waiting time,
     *        in milliseconds
     * @see #setMillisToDecideToPopup
     */
    public int getMillisToDecideToPopup() {
        return millisToDecideToPopup;
    }


    /**
     * Specifies the amount of time it will take for the popup to appear.
     * (If the predicted time remaining is less than this time, the popup
     * won't be displayed.)
     *
     * @param millisToPopup  an int specifying the time in milliseconds
     * @see #getMillisToPopup
     */
    public void setMillisToPopup(int millisToPopup) {
        this.millisToPopup = millisToPopup;
    }


    /**
     * Returns the amount of time it will take for the popup to appear.
     *
     * @param millisToPopup  an int specifying the time in milliseconds
     * @see #setMillisToPopup
     */
    public int getMillisToPopup() {
        return millisToPopup;
    }


    /**
     * Specifies the additional note that is displayed along with the
     * progress message. Used, for example, to show which file the
     * is currently being copied during a multiple-file copy.
     *
     * @param note  a String specifying the note to display
     * @see #getNote
     */
    public void setNote(String note) {
        this.note = note;
        if (noteLabel != null) {
            noteLabel.setText(note);
        }
    }


    /**
     * Specifies the additional note that is displayed along with the
     * progress message.
     *
     * @return a String specifying the note to display
     * @see #setNote
     */
    public String getNote() {
        return note;
    }
}