/*
Wotonomy: OpenStep design patterns for pure Java applications.
Copyright (C) 2000 Intersect Software Corporation

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see http://www.gnu.org
*/

package net.wotonomy.ui.swing;

import java.awt.Component;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import java.net.URL;
import java.text.Format;
import java.text.ParseException;
import java.util.Enumeration;
import java.util.Iterator;

import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JOptionPane;
import javax.swing.JTextArea;
import javax.swing.LookAndFeel;
import javax.swing.Timer;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
import javax.swing.text.Document;
import javax.swing.text.JTextComponent;

import net.wotonomy.foundation.NSArray;
import net.wotonomy.foundation.NSSelector;
import net.wotonomy.foundation.internal.ValueConverter;
import net.wotonomy.foundation.internal.WotonomyException;
import net.wotonomy.ui.EOAssociation;
import net.wotonomy.ui.EODisplayGroup;

/**
 * TimedTextAssociation works like TextAssociation, but instead of using a
 * delayed event to update the model, it uses a timer so that the model is only
 * updated if the user pauses typing for some short interval. This is useful
 * when the update and/or re-read of the model is a costly operation. Bindings
 * are:
 * <ul>
 * <li>value: a property convertable to/from a string</li>
 * <li>editable: a boolean property that determines whether the user can edit
 * the text in the field</li>
 * <li>enabled: a boolean property that determines whether the user can select
 * the text in the field</li>
 * <li>label: a boolean property that determines whether field should appear as
 * a read-only, selectable label</li>
 * <li>icon: a property that returns a Swing icon, for use with JLabels and
 * other components with setIcon() methods. If bound to a static string, the
 * string will be used to load an image resource from the selected object's
 * class.</li>
 * </ul>
 *
 * @author michael@mpowers.net
 * @author $Author: cgruber $
 * @version $Revision: 904 $
 */
public class TimedTextAssociation extends EOAssociation implements FocusListener, ActionListener, DocumentListener {
	// TODO: need to refactor this so that it can subclass text association.
	// This implementation is basically a branch from the v1.20 TextAssociation.

	static final NSArray aspects = new NSArray(
			new Object[] { ValueAspect, EnabledAspect, EditableAspect, LabelAspect, IconAspect });
	static final NSArray aspectSignatures = new NSArray(new Object[] { AttributeToOneAspectSignature,
			AttributeToOneAspectSignature, AttributeToOneAspectSignature, AttributeToOneAspectSignature });
	static final NSArray objectKeysTaken = new NSArray(new Object[] { "text", "enabled", "editable" });

	private final static NSSelector getText = new NSSelector("getText");
	private final static NSSelector setText = new NSSelector("setText", new Class[] { String.class });
	private final static NSSelector getDocument = new NSSelector("getDocument");
	private final static NSSelector setIcon = new NSSelector("setIcon", new Class[] { Icon.class });
	private final static NSSelector addActionListener = new NSSelector("addActionListener",
			new Class[] { ActionListener.class });
	private final static NSSelector removeActionListener = new NSSelector("removeActionListener",
			new Class[] { ActionListener.class });
	private final static NSSelector addFocusListener = new NSSelector("addFocusListener",
			new Class[] { FocusListener.class });
	private final static NSSelector removeFocusListener = new NSSelector("removeFocusListener",
			new Class[] { FocusListener.class });

	// null handling
	protected boolean wasNull;
	protected static final String EMPTY_STRING = "";

	// dirty handling
	protected boolean needsUpdate;
	protected boolean hasDocument;
	protected boolean isListening;

	// formatting
	protected Format format;

	// cache the value aspect
	private EODisplayGroup valueDisplayGroup;
	private String valueKey;

	// coalescing document events
	protected boolean autoUpdating;
	protected int interval = 400; // adjust as needed
	protected Timer keyTimer;

	// NOTE: a new key timer is created for each use and
	// is disposed when the timer is stopped.
	// Swing's Timer class is kept in a static list of timers
	// and each retains a strong reference to their listeners.
	// This caused a memory leak as associations typically
	// refer to their controlled component which is referred
	// to by its parents and so on until no application window
	// will ever get garbage collected. yikes.

	/**
	 * Constructor specifying the object to be controlled by this association. Does
	 * not establish connection.
	 */
	public TimedTextAssociation(Object anObject) {
		super(anObject);
		wasNull = false;
		needsUpdate = false;
		hasDocument = false;
		isListening = true;
		valueDisplayGroup = null;
		valueKey = null;

		autoUpdating = true;
		keyTimer = null;
	}

	/**
	 * Returns a List of aspect signatures whose contents correspond with the
	 * aspects list. Each element is a string whose characters represent a
	 * capability of the corresponding aspect.
	 * <ul>
	 * <li>"A" attribute: the aspect can be bound to an attribute.</li>
	 * <li>"1" to-one: the aspect can be bound to a property that returns a single
	 * object.</li>
	 * <li>"M" to-one: the aspect can be bound to a property that returns multiple
	 * objects.</li>
	 * </ul>
	 * An empty signature "" means that the aspect can bind without needing a key.
	 * This implementation returns "A1M" for each element in the aspects array.
	 */
	public static NSArray aspectSignatures() {
		return aspectSignatures;
	}

	/**
	 * Returns a List that describes the aspects supported by this class. Each
	 * element in the list is the string name of the aspect. This implementation
	 * returns an empty list.
	 */
	public static NSArray aspects() {
		return aspects;
	}

	/**
	 * Returns a List of EOAssociation subclasses that, for the objects that are
	 * usable for this association, are less suitable than this association.
	 */
	public static NSArray associationClassesSuperseded() {
		return new NSArray();
	}

	/**
	 * Returns whether this class can control the specified object.
	 */
	public static boolean isUsableWithObject(Object anObject) {
		return setText.implementedByObject(anObject);
	}

	/**
	 * Returns a List of properties of the controlled object that are controlled by
	 * this class. For example, "stringValue", or "selected".
	 */
	public static NSArray objectKeysTaken() {
		return objectKeysTaken;
	}

	/**
	 * Returns the aspect that is considered primary or default. This is typically
	 * "value" or somesuch.
	 */
	public static String primaryAspect() {
		return ValueAspect;
	}

	/**
	 * Returns whether this association can bind to the specified display group on
	 * the specified key for the specified aspect.
	 */
	public boolean canBindAspect(String anAspect, EODisplayGroup aDisplayGroup, String aKey) {
		return (aspects.containsObject(anAspect));
	}

	/**
	 * Binds the specified aspect of this association to the specified key on the
	 * specified display group.
	 */
	public void bindAspect(String anAspect, EODisplayGroup aDisplayGroup, String aKey) {
		if (ValueAspect.equals(anAspect)) {
			valueDisplayGroup = aDisplayGroup;
			valueKey = aKey;
		}
		super.bindAspect(anAspect, aDisplayGroup, aKey);
	}

	/**
	 * Establishes a connection between this association and the controlled object.
	 * This implementation attempts to add this class as an ActionListener and as a
	 * FocusListener to the specified object.
	 */
	public void establishConnection() {
		Object component = object();
		try {
			if (addActionListener.implementedByObject(component)) {
				addActionListener.invoke(component, this);
			}
			if (addFocusListener.implementedByObject(component)) {
				addFocusListener.invoke(component, this);
			}
			hasDocument = false;
			if (getDocument.implementedByObject(component)) {
				Object document = getDocument.invoke(component);
				if (document instanceof Document) {
					((Document) document).addDocumentListener(this);
					hasDocument = true;
				}
			}
		} catch (Exception exc) {
			throw new WotonomyException("Error while establishing connection", exc);
		}

		super.establishConnection();

		// forces update from bindings
		subjectChanged();
	}

	/**
	 * Breaks the connection between this association and its object. Override to
	 * stop listening for events from the object.
	 */
	public void breakConnection() {
		Object component = object();
		try {
			if (removeActionListener.implementedByObject(component)) {
				removeActionListener.invoke(component, this);
			}
			if (removeFocusListener.implementedByObject(component)) {
				removeFocusListener.invoke(component, this);
			}
			if (getDocument.implementedByObject(component)) {
				Object document = getDocument.invoke(component);
				if (document instanceof Document) {
					((Document) document).removeDocumentListener(this);
				}
			}
		} catch (Exception exc) {
			throw new WotonomyException("Error while breaking connection", exc);
		}
		super.breakConnection();
	}

	/**
	 * Called when either the selection or the contents of an associated display
	 * group have changed.
	 */
	public void subjectChanged() {
		Object component = object();
		EODisplayGroup displayGroup;
		String key;
		Object value;

		// value aspect
		displayGroup = valueDisplayGroup;
		if (displayGroup != null) {
			if (component instanceof Component) {
				((Component) component).setEnabled(displayGroup.enabledToSetSelectedObjectValueForKey(valueKey));
			}

			key = valueKey;

			if (displayGroup.selectedObjects().size() > 1) {
				// if there're more than one object selected, set
				// the value to blank for all of them.
				Object previousValue;

				Iterator indexIterator = displayGroup.selectionIndexes().iterator();

				// get value for the first selected object.
				int initialIndex = ((Integer) indexIterator.next()).intValue();
				previousValue = displayGroup.valueForObjectAtIndex(initialIndex, key);
				value = null;

				// go through the rest of the selected objects, compare each
				// value with the previous one. continue comparing if two
				// values are equal, break the while loop if they're different.
				// the final value will be the common value of all selected objects
				// if there is one, or be blank if there is not.
				while (indexIterator.hasNext()) {
					int index = ((Integer) indexIterator.next()).intValue();
					Object currentValue = displayGroup.valueForObjectAtIndex(index, key);
					if (currentValue != null && !currentValue.equals(previousValue)) {
						value = null;
						break;
					} else {
						// currentValue is the same as the previous one
						value = currentValue;
					}

				} // end while

			} else {

				// if there's only one object selected.
				value = displayGroup.selectedObjectValueForKey(key);
			} // end checking the size of selected objects in displayGroup

			// convert value to string
			if (value == null) {
				wasNull = true;
				value = EMPTY_STRING;
			} else {
				wasNull = false;
				if (format() != null) {
					try {
						value = format().format(value);
					} catch (IllegalArgumentException exc) {
						value = value.toString();
					}
				}
			}

			try {
				if (!value.toString().equals(getText.invoke(component))) {
					// No need to listen for any events that might get fired
					// while setting the text since we are the one setting it.
					boolean wasListening = isListening;
					isListening = false;

					// setText is an expensive operation
					setText.invoke(component, value.toString());

					isListening = wasListening;
					needsUpdate = false;
				}
			} catch (Exception exc) {
				throw new WotonomyException("Error while updating component connection", exc);
			}
		}

		// icon aspect
		displayGroup = displayGroupForAspect(IconAspect);
		key = displayGroupKeyForAspect(IconAspect);
		if (key != null) {
			if (displayGroup != null) {
				value = displayGroup.selectedObjectValueForKey(key);
			} else {
				// treat bound key without display group
				// as a resource to be loaded from the selected class.
				value = null;
				Object o = displayGroup.selectedObject();
				if (o != null) {
					URL url = o.getClass().getResource(key);
					if (url != null) {
						value = new ImageIcon(url);
					}
				}
			}

			try {
				setIcon.invoke(component, value);
			} catch (Exception exc) {
				throw new WotonomyException("Error while updating component connection", exc);
			}
		}

		// enabled aspect
		displayGroup = displayGroupForAspect(EnabledAspect);
		key = displayGroupKeyForAspect(EnabledAspect);
		if ((key != null) && (component instanceof Component)) {
			if (displayGroup != null) {
				value = displayGroup.selectedObjectValueForKey(key);
			} else {
				// treat bound key without display group as a value
				value = key;
			}
			Boolean converted = null;
			if (value != null) {
				converted = (Boolean) ValueConverter.convertObjectToClass(value, Boolean.class);
			}
			if (converted == null)
				converted = Boolean.FALSE;
			if (((Component) component).isEnabled() != converted.booleanValue()) {
				((Component) component).setEnabled(converted.booleanValue());
			}
		}

		// editable aspect
		displayGroup = displayGroupForAspect(EditableAspect);
		key = displayGroupKeyForAspect(EditableAspect);
		if ((key != null) && (component instanceof JTextComponent)) {
			if (displayGroup != null) {
				value = displayGroup.selectedObjectValueForKey(key);
			} else {
				// treat bound key without display group as a value
				value = key;
			}
			Boolean converted = (Boolean) ValueConverter.convertObjectToClass(value, Boolean.class);

			if (converted != null) {
				if (converted.booleanValue() != ((JTextComponent) component).isEditable()) {
					((JTextComponent) component).setEditable(converted.booleanValue());
				}
			}
		}

		// label aspect
		displayGroup = displayGroupForAspect(LabelAspect);
		key = displayGroupKeyForAspect(LabelAspect);

		if ((key != null) && (component instanceof JTextComponent)) {
			if (displayGroup != null) {
				value = displayGroup.selectedObjectValueForKey(key);
			} else {
				// treat bound key without display group as a value
				value = key;
			}
			Boolean converted = (Boolean) ValueConverter.convertObjectToClass(value, Boolean.class);

			if (converted != null) {
				if (converted.booleanValue()) {
					if (component instanceof JTextComponent) {
						if (component instanceof JTextArea) {
							areaToLabel((JTextArea) component);
						} else {
							fieldToLabel((JTextComponent) component);
						}
					}
				} else {
					if (component instanceof JTextComponent) {
						if (component instanceof JTextArea) {
							labelToArea((JTextArea) component);
						} else {
							labelToField((JTextComponent) component);
						}
					}
				}
			}
		}

	}

	private void fieldToLabel(JTextComponent aTextField) {
		// turn on wrapping and disable editing and highlighting

		aTextField.setEditable(false);
		aTextField.setOpaque(false);

		// Set the border, colors and font to that of a label

		LookAndFeel.installBorder(aTextField, "Label.border");

		LookAndFeel.installColorsAndFont(aTextField, "Label.background", "Label.foreground", "Label.font");
	}

	private void labelToField(JTextComponent aTextField) {
		// turn on wrapping and disable editing and highlighting

		aTextField.setEditable(true);
		aTextField.setOpaque(true);

		// Set the border, colors and font to that of a label

		LookAndFeel.installBorder(aTextField, "TextField.border");

		LookAndFeel.installColorsAndFont(aTextField, "TextField.background", "TextField.foreground", "TextField.font");
	}

	private void areaToLabel(JTextArea aTextArea) {
		// turn on wrapping and disable editing and highlighting

		aTextArea.setLineWrap(true);
		aTextArea.setWrapStyleWord(true);
		aTextArea.setEditable(false);

		// Set the text area's border, colors and font to
		// that of a label

		LookAndFeel.installBorder(aTextArea, "Label.border");

		LookAndFeel.installColorsAndFont(aTextArea, "Label.background", "Label.foreground", "Label.font");

	}

	private void labelToArea(JTextArea aTextArea) {
		// turn on wrapping and disable editing and highlighting

		aTextArea.setEditable(true);

		// Set the border, colors and font to that of a label

		LookAndFeel.installBorder(aTextArea, "TextArea.border");

		LookAndFeel.installColorsAndFont(aTextArea, "TextArea.background", "TextArea.foreground", "TextArea.font");
	}

	/**
	 * Forces this association to cause the object to stop editing and validate the
	 * user's input.
	 * 
	 * @return false if there were problems validating, or true to continue.
	 */
	public boolean endEditing() {
		if (keyTimer != null) {
			keyTimer.stop();
			keyTimer.removeActionListener(this);
			keyTimer = null;
		}
		return writeValueToDisplayGroup();
	}

	/**
	 * Writes the value currently in the component to the selected object in the
	 * display group bound to the value aspect.
	 * 
	 * @return false if there were problems validating, or true to continue.
	 */
	protected boolean writeValueToDisplayGroup() {
		boolean returnValue = true;
		if (hasDocument && !needsUpdate)
			return true;

		EODisplayGroup displayGroup = valueDisplayGroup;
		if (displayGroup != null) {
			String key = valueKey;
			Object component = object();
			Object value = null;
			try {
				// if ( getText.implementedByObject( component ) )
				// {
				value = getText.invoke(component);
				// }
			} catch (Exception exc) {
				throw new WotonomyException("Error updating display group", exc);
			}

			if ((wasNull) && (EMPTY_STRING.equals(value))) {
				value = null;
			} else if (format() != null) {
				try {
					value = format().parseObject(value.toString());
				} catch (ParseException exc) {
					String message = exc.getMessage();
					// "That format was not recognized.";
					if (displayGroup.associationFailedToValidateValue(this, value.toString(), key, exc, message)) {
						boolean wasListening = isListening;
						isListening = false;
						JOptionPane.showMessageDialog((Component) component, message);
						isListening = wasListening;
					}
					needsUpdate = false;
					return false;
				}
			}

			needsUpdate = false;

			// only update if the value is different from the one in the display group
			Object existingValue = displayGroup.selectedObjectValueForKey(key);
			if (displayGroup.selectedObjects().size() == 1) {
				if (existingValue == value)
					return true;
				if ((existingValue != null) && (existingValue.equals(value)))
					return true;
				if ((value != null) && (value.equals(existingValue)))
					return true;
			}

			// we might lose focus if display group displays a validation message
			boolean wasListening = isListening;
			isListening = false;

			Iterator selectedIterator = displayGroup.selectionIndexes().iterator();
			while (selectedIterator.hasNext()) {
				int index = ((Integer) selectedIterator.next()).intValue();

				if (displayGroup.setValueForObjectAtIndex(value, index, key)) {
					isListening = wasListening;
					needsUpdate = false;
				} else {
					isListening = wasListening;
					needsUpdate = false;
					returnValue = false;
				}
			}

		}
		return returnValue;
	}

	/**
	 * Sets the Format that is used to convert values from the display group to and
	 * from text that is displayed in the component. Having a formatter disables
	 * auto-updating.
	 */
	public void setFormat(Format aFormat) {
		format = aFormat;
	}

	/**
	 * Gets the Format that is used to convert values from the display group to and
	 * from text that is displayed in the component.
	 */
	public Format format() {
		return format;
	}

	// interface ActionListener

	/**
	 * Updates object on action performed.
	 */
	public void actionPerformed(ActionEvent evt) {
		if (keyTimer != null) {
			keyTimer.stop();
			keyTimer.removeActionListener(this);
			keyTimer = null;
		}
		if (!isListening)
			return;
		if (needsUpdate) {
			writeValueToDisplayGroup();
		}
	}

	// interface FocusListener

	/**
	 * Notifies of beginning of edit.
	 */
	public void focusGained(FocusEvent evt) {
		if (!isListening)
			return;
		Object o;
		EODisplayGroup displayGroup;
		Enumeration e = aspects().objectEnumerator();
		while (e.hasMoreElements()) {
			displayGroup = displayGroupForAspect(e.nextElement().toString());
			if (displayGroup != null) {
				displayGroup.associationDidBeginEditing(this);
			}
		}
	}

	/**
	 * Updates object on focus lost and notifies of end of edit.
	 */
	public void focusLost(FocusEvent evt) {
		if (!isListening)
			return;
		if (endEditing()) {
			Object o;
			EODisplayGroup displayGroup;
			Enumeration e = aspects().objectEnumerator();
			while (e.hasMoreElements()) {
				displayGroup = displayGroupForAspect(e.nextElement().toString());
				if (displayGroup != null) {
					displayGroup.associationDidEndEditing(this);
				}
			}
		} else {
			// probably should notify of a validation error here,
		}
	}

	/**
	 * Returns whether the data model is updated for every change in the controlled
	 * component. If false, the data is only updated on focus lost or the enter key.
	 * Default is true.
	 */
	public boolean isAutoUpdating() {
		if (format() != null)
			return false;
		return autoUpdating;
	}

	/**
	 * Sets whether the data model is updated for every change in the controlled
	 * component.
	 */
	public void setAutoUpdating(boolean isAutoUpdating) {
		autoUpdating = isAutoUpdating;
	}

	/**
	 * Triggers the key timer to start.
	 */
	protected void queueUpdate() {
		if (isAutoUpdating()) {
			if (keyTimer == null) {
				keyTimer = new Timer(interval, this);
			}
			keyTimer.restart();
		}
	}

	// interface DocumentListener

	public void insertUpdate(DocumentEvent e) {
		if (!isListening)
			return;
		needsUpdate = true;
		queueUpdate();
	}

	public void removeUpdate(DocumentEvent e) {
		if (!isListening)
			return;
		needsUpdate = true;
		queueUpdate();
	}

	public void changedUpdate(DocumentEvent e) {
		if (!isListening)
			return;
		needsUpdate = true;
		queueUpdate();
	}

}

/*
 * $Log$ Revision 1.2 2006/02/18 23:19:05 cgruber Update imports and maven
 * dependencies.
 *
 * Revision 1.1 2006/02/16 13:22:22 cgruber Check in all sources in
 * eclipse-friendly maven-enabled packages.
 *
 * Revision 1.3 2004/01/28 18:34:57 mpowers Better handling for enabling. Now
 * respecting enabledToSetSelectedObjectValueForKey from display group.
 *
 * Revision 1.2 2003/08/06 23:07:52 chochos general code cleanup (mostly,
 * removing unused imports)
 *
 * Revision 1.1 2001/12/20 18:57:24 mpowers (Re-)Contributing
 * TimedTextAssociation. Just like TA, except uses timers.
 *
 * Revision 1.20 2001/10/26 19:58:06 mpowers Better handling for non-string
 * types. We were testing with equals with the new value against the existing
 * value in the component. Now we convert the new value to a string before
 * comparing. Fixes case for properties of non-String types, like StringBuffer.
 *
 * Revision 1.19 2001/09/30 21:57:14 mpowers Timers were not getting cleaned up
 * if breakConnection was called before the timer got a chance to fire.
 *
 * Revision 1.18 2001/08/22 15:42:26 mpowers Added support for JTextComponent
 * label-izing.
 *
 * Revision 1.17 2001/07/30 16:32:55 mpowers Implemented support for
 * bulk-editing. Detail associations will now apply changes to all selected
 * objects.
 *
 * Revision 1.16 2001/07/17 19:53:37 mpowers Made some private fields protected
 * for benefit of subclassers.
 *
 * Revision 1.15 2001/06/30 14:59:36 mpowers LabelAspect now sets the text
 * field's opaque setting.
 *
 * Revision 1.14 2001/06/29 14:54:08 mpowers Another fix for timers - timers
 * were definitely causing a memory leak.
 *
 * Revision 1.13 2001/06/26 21:37:19 mpowers Fixed a null pointer in the new key
 * timer scheme.
 *
 * Revision 1.12 2001/06/25 14:46:03 mpowers Fixed a memory leak involving the
 * use of timers.
 *
 * Revision 1.11 2001/06/01 19:14:59 mpowers Text association's enabled aspect
 * is now more discriminating.
 *
 * Revision 1.10 2001/05/18 21:07:24 mpowers Changed the way we handle failure
 * to update object value.
 *
 * Revision 1.9 2001/03/13 21:39:58 mpowers Improved validation handling.
 *
 * Revision 1.8 2001/03/12 12:49:10 mpowers Improved validation handling. Having
 * a formatter disables auto-updating.
 *
 * Revision 1.7 2001/03/09 22:08:13 mpowers Now handling any objects that have a
 * valid Document. No longer checking enabled before updating the enabled state.
 *
 * Revision 1.6 2001/03/07 19:57:32 mpowers Fixed paste error in IconAspect.
 *
 * Revision 1.4 2001/02/17 16:52:05 mpowers Changes in imports to support
 * building with jdk1.1 collections.
 *
 * Revision 1.3 2001/01/31 19:12:33 mpowers Implemented auto-updating in
 * TextComponent.
 *
 * Revision 1.2 2001/01/10 15:53:58 mpowers Preventing a null pointer exception
 * if getText were to return null, which doesn't happen for JTextFields but
 * might happen for other objects.
 *
 * Revision 1.1.1.1 2000/12/21 15:49:08 mpowers Contributing wotonomy.
 *
 * Revision 1.13 2000/12/20 16:25:41 michael Added log to all files.
 *
 *
 */