bundles/org.eclipse.draw2d/src/org/eclipse/draw2d/ButtonModel.java

/*******************************************************************************
 * Copyright (c) 2000, 2010 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.draw2d;

import java.util.Iterator;
import java.util.Timer;
import java.util.TimerTask;

//import org.eclipse.draw2d.internal.Timer;

/**
 * A model for buttons containing several properties, including enabled,
 * pressed, selected, rollover enabled and mouseover.
 */
public class ButtonModel {

	/** Enabled property */
	public static final String ENABLED_PROPERTY = "enabled"; //$NON-NLS-1$
	/** Pressed property */
	public static final String PRESSED_PROPERTY = "pressed"; //$NON-NLS-1$
	/** Selected property */
	public static final String SELECTED_PROPERTY = "selected"; //$NON-NLS-1$
	/** Rollover Enabled property */
	public static final String ROLLOVER_ENABLED_PROPERTY = "rollover enabled"; //$NON-NLS-1$
	/** Mouseover property */
	public static final String MOUSEOVER_PROPERTY = "mouseover"; //$NON-NLS-1$

	/** Armed property */
	public static final String ARMED_PROPERTY = "armed"; //$NON-NLS-1$

	/** Flag for armed button state */
	protected static final int ARMED_FLAG = 1;
	/** Flag for pressed button state */
	protected static final int PRESSED_FLAG = 2;
	/** Flag for mouseOver state */
	protected static final int MOUSEOVER_FLAG = 4;
	/** Flag for selected button state */
	protected static final int SELECTED_FLAG = 8;
	/** Flag for enablement button state */
	protected static final int ENABLED_FLAG = 16;
	/** Flag for rollover enablement button state */
	protected static final int ROLLOVER_ENABLED_FLAG = 32;
	/** Flag that can be used by subclasses to define more states */
	protected static final int MAX_FLAG = ROLLOVER_ENABLED_FLAG;

	private int state = ENABLED_FLAG;
	private Object data;

	/**
	 * Action performed events are not fired until the mouse button is released.
	 */
	public static final int DEFAULT_FIRING_BEHAVIOR = 0;

	/**
	 * Action performed events fire repeatedly until the mouse button is
	 * released.
	 */
	public static final int REPEAT_FIRING_BEHAVIOR = 1;

	/**
	 * The name of the action associated with this button.
	 */
	protected String actionName;

	/**
	 * The ButtonGroup this button belongs to (if any).
	 */
	protected ButtonGroup group = null;

	private EventListenerList listeners = new EventListenerList();

	/**
	 * Listens to button state transitions and fires action performed events
	 * based on the desired behavior ({@link #DEFAULT_FIRING_BEHAVIOR} or
	 * {@link #REPEAT_FIRING_BEHAVIOR}).
	 */
	protected ButtonStateTransitionListener firingBehavior;
	{
		installFiringBehavior();
	}

	/**
	 * Registers the given listener as an ActionListener.
	 * 
	 * @param listener
	 *            The ActionListener to add
	 * @since 2.0
	 */
	public void addActionListener(ActionListener listener) {
		if (listener == null)
			throw new IllegalArgumentException();
		listeners.addListener(ActionListener.class, listener);
	}

	/**
	 * Registers the given listener as a ChangeListener.
	 * 
	 * @param listener
	 *            The ChangeListener to add
	 * @since 2.0
	 */
	public void addChangeListener(ChangeListener listener) {
		if (listener == null)
			throw new IllegalArgumentException();
		listeners.addListener(ChangeListener.class, listener);
	}

	/**
	 * Registers the given listener as a ButtonStateTransitionListener.
	 * 
	 * @param listener
	 *            The ButtonStateTransitionListener to add
	 * @since 2.0
	 */
	public void addStateTransitionListener(
			ButtonStateTransitionListener listener) {
		if (listener == null)
			throw new IllegalArgumentException();
		listeners.addListener(ButtonStateTransitionListener.class, listener);
	}

	/**
	 * Notifies any ActionListeners on this ButtonModel that an action has been
	 * performed.
	 * 
	 * @since 2.0
	 */
	protected void fireActionPerformed() {
		Iterator iter = listeners.getListeners(ActionListener.class);
		ActionEvent action = new ActionEvent(this);
		while (iter.hasNext())
			((ActionListener) iter.next()).actionPerformed(action);
	}

	/**
	 * Notifies any listening ButtonStateTransitionListener that the pressed
	 * state of this button has been cancelled.
	 * 
	 * @since 2.0
	 */
	protected void fireCanceled() {
		Iterator iter = listeners
				.getListeners(ButtonStateTransitionListener.class);
		while (iter.hasNext())
			((ButtonStateTransitionListener) iter.next()).canceled();
	}

	/**
	 * Notifies any listening ButtonStateTransitionListener that this button has
	 * been pressed.
	 * 
	 * @since 2.0
	 */
	protected void firePressed() {
		Iterator iter = listeners
				.getListeners(ButtonStateTransitionListener.class);
		while (iter.hasNext())
			((ButtonStateTransitionListener) iter.next()).pressed();
	}

	/**
	 * Notifies any listening ButtonStateTransitionListener that this button has
	 * been released.
	 * 
	 * @since 2.0
	 */
	protected void fireReleased() {
		Iterator iter = listeners
				.getListeners(ButtonStateTransitionListener.class);
		while (iter.hasNext())
			((ButtonStateTransitionListener) iter.next()).released();
	}

	/**
	 * Notifies any listening ButtonStateTransitionListeners that this button
	 * has resumed activity.
	 * 
	 * @since 2.0
	 */
	protected void fireResume() {
		Iterator iter = listeners
				.getListeners(ButtonStateTransitionListener.class);
		while (iter.hasNext())
			((ButtonStateTransitionListener) iter.next()).resume();
	}

	/**
	 * Notifies any listening ChangeListeners that this button's state has
	 * changed.
	 * 
	 * @param property
	 *            The name of the property that changed
	 * @since 2.0
	 */
	protected void fireStateChanged(String property) {
		Iterator iter = listeners.getListeners(ChangeListener.class);
		ChangeEvent change = new ChangeEvent(this, property);
		while (iter.hasNext())
			((ChangeListener) iter.next()).handleStateChanged(change);
	}

	/**
	 * Notifies any listening ButtonStateTransitionListeners that this button
	 * has suspended activity.
	 * 
	 * @since 2.0
	 */
	protected void fireSuspend() {
		Iterator iter = listeners
				.getListeners(ButtonStateTransitionListener.class);
		while (iter.hasNext())
			((ButtonStateTransitionListener) iter.next()).suspend();
	}

	boolean getFlag(int which) {
		return (state & which) != 0;
	}

	/**
	 * Returns the group to which this model belongs.
	 * 
	 * @return The ButtonGroup to which this model belongs
	 * @since 2.0
	 */
	public ButtonGroup getGroup() {
		return group;
	}

	/**
	 * Returns an object representing user data.
	 * 
	 * @return User data
	 * @since 2.0
	 */
	public Object getUserData() {
		return data;
	}

	/**
	 * Sets the firing behavior for this button.
	 * 
	 * @since 2.0
	 */
	protected void installFiringBehavior() {
		setFiringBehavior(DEFAULT_FIRING_BEHAVIOR);
	}

	/**
	 * Returns <code>true</code> if this button is armed. If a button is armed,
	 * it will fire an ActionPerformed when released.
	 * 
	 * @return <code>true</code> if this button is armed
	 * @since 2.0
	 */
	public boolean isArmed() {
		return (state & ARMED_FLAG) != 0;
	}

	/**
	 * Returns <code>true</code> if this button is enabled.
	 * 
	 * @return <code>true</code> if this button is enabled
	 * @since 2.0
	 */
	public boolean isEnabled() {
		return (state & ENABLED_FLAG) != 0;
	}

	/**
	 * Returns <code>true</code> if the mouse is over this button.
	 * 
	 * @return <code>true</code> if the mouse is over this button
	 * @since 2.0
	 */
	public boolean isMouseOver() {
		return (state & MOUSEOVER_FLAG) != 0;
	}

	/**
	 * Returns <code>true</code> if this button is pressed.
	 * 
	 * @return <code>true</code> if this button is pressed
	 * @since 2.0
	 */
	public boolean isPressed() {
		return (state & PRESSED_FLAG) != 0;
	}

	/**
	 * Returns the selection state of this model. If this model belongs to any
	 * group, the group is queried for selection state, else the flags are used.
	 * 
	 * @return <code>true</code> if this button is selected
	 * @since 2.0
	 */
	public boolean isSelected() {
		if (group == null) {
			return (state & SELECTED_FLAG) != 0;
		} else {
			return group.isSelected(this);
		}
	}

	/**
	 * Removes the given ActionListener.
	 * 
	 * @param listener
	 *            The ActionListener to remove
	 * @since 2.0
	 */
	public void removeActionListener(ActionListener listener) {
		listeners.removeListener(ActionListener.class, listener);
	}

	/**
	 * Removes the given ChangeListener.
	 * 
	 * @param listener
	 *            The ChangeListener to remove
	 * @since 2.0
	 */
	public void removeChangeListener(ChangeListener listener) {
		listeners.removeListener(ChangeListener.class, listener);
	}

	/**
	 * Removes the given ButtonStateTransitionListener.
	 * 
	 * @param listener
	 *            The ButtonStateTransitionListener to remove
	 * @since 2.0
	 */
	public void removeStateTransitionListener(
			ButtonStateTransitionListener listener) {
		listeners.removeListener(ButtonStateTransitionListener.class, listener);
	}

	/**
	 * Sets this button to be armed. If a button is armed, it will fire an
	 * ActionPerformed when released.
	 * 
	 * @param value
	 *            The armed state
	 * @since 2.0
	 */
	public void setArmed(boolean value) {
		if (isArmed() == value)
			return;
		if (!isEnabled())
			return;
		setFlag(ARMED_FLAG, value);
		fireStateChanged(ARMED_PROPERTY);
	}

	/**
	 * Sets this button to be enabled.
	 * 
	 * @param value
	 *            The enabled state
	 * @since 2.0
	 */
	public void setEnabled(boolean value) {
		if (isEnabled() == value)
			return;
		if (!value) {
			setMouseOver(false);
			setArmed(false);
			setPressed(false);
		}
		setFlag(ENABLED_FLAG, value);
		fireStateChanged(ENABLED_PROPERTY);
	}

	/**
	 * Sets the firing behavior for this button.
	 * {@link #DEFAULT_FIRING_BEHAVIOR} is the default behavior, where action
	 * performed events are not fired until the mouse button is released.
	 * {@link #REPEAT_FIRING_BEHAVIOR} causes action performed events to fire
	 * repeatedly until the mouse button is released.
	 * 
	 * @param type
	 *            The firing behavior type
	 * @since 2.0
	 * 
	 */
	public void setFiringBehavior(int type) {
		if (firingBehavior != null)
			removeStateTransitionListener(firingBehavior);
		switch (type) {
		case REPEAT_FIRING_BEHAVIOR:
			firingBehavior = new RepeatFiringBehavior();
			break;
		default:
			firingBehavior = new DefaultFiringBehavior();
		}
		addStateTransitionListener(firingBehavior);
	}

	void setFlag(int flag, boolean value) {
		if (value)
			state |= flag;
		else
			state &= ~flag;
	}

	/**
	 * Sets the ButtonGroup to which this model belongs to. Adds this model as a
	 * listener to the group.
	 * 
	 * @param bg
	 *            The group to which this model belongs.
	 * @since 2.0
	 */
	public void setGroup(ButtonGroup bg) {
		if (group == bg)
			return;
		if (group != null)
			group.remove(this);
		group = bg;
		if (group != null)
			group.add(this);
	}

	/**
	 * Sets the mouseover property of this button.
	 * 
	 * @param value
	 *            The value the mouseover property will be set to
	 * @since 2.0
	 */
	public void setMouseOver(boolean value) {
		if (isMouseOver() == value)
			return;
		if (isPressed())
			if (value)
				fireResume();
			else
				fireSuspend();
		setFlag(MOUSEOVER_FLAG, value);
		fireStateChanged(MOUSEOVER_PROPERTY);
	}

	/**
	 * Sets the pressed property of this button.
	 * 
	 * @param value
	 *            The value the pressed property will be set to
	 * @since 2.0
	 */
	public void setPressed(boolean value) {
		if (isPressed() == value)
			return;
		setFlag(PRESSED_FLAG, value);
		if (value)
			firePressed();
		else {
			if (isArmed())
				fireReleased();
			else
				fireCanceled();
		}
		fireStateChanged(PRESSED_PROPERTY);
	}

	/**
	 * Sets this button to be selected.
	 * 
	 * @param value
	 *            The value the selected property will be set to
	 * @since 2.0
	 */
	public void setSelected(boolean value) {
		if (group == null) {
			if (isSelected() == value)
				return;
		} else {
			group.setSelected(this, value);
			if (getFlag(SELECTED_FLAG) == isSelected())
				return;
		}
		setFlag(SELECTED_FLAG, value);
		fireStateChanged(SELECTED_PROPERTY);
	}

	/**
	 * Sets user data.
	 * 
	 * @param data
	 *            The user data
	 * @since 2.0
	 */
	public void setUserData(Object data) {
		this.data = data;
	}

	class DefaultFiringBehavior extends ButtonStateTransitionListener {
		public void released() {
			fireActionPerformed();
		}
	}

	class RepeatFiringBehavior extends ButtonStateTransitionListener {
		protected static final int INITIAL_DELAY = 250, STEP_DELAY = 40;

		protected int stepDelay = INITIAL_DELAY, initialDelay = STEP_DELAY;

		protected Timer timer;

		public void pressed() {
			fireActionPerformed();
			if (!isEnabled())
				return;

			timer = new Timer();
			TimerTask runAction = new Task(timer);

			timer.scheduleAtFixedRate(runAction, INITIAL_DELAY, STEP_DELAY);
		}

		public void canceled() {
			suspend();
		}

		public void released() {
			suspend();
		}

		public void resume() {
			timer = new Timer();

			TimerTask runAction = new Task(timer);

			timer.scheduleAtFixedRate(runAction, STEP_DELAY, STEP_DELAY);
		}

		public void suspend() {
			if (timer == null)
				return;
			timer.cancel();
			timer = null;
		}
	}

	class Task extends TimerTask {

		private Timer timer;

		public Task(Timer timer) {
			this.timer = timer;
		}

		public void run() {
			org.eclipse.swt.widgets.Display.getDefault().syncExec(
					new Runnable() {
						public void run() {
							if (!isEnabled())
								timer.cancel();
							fireActionPerformed();
						}
					});
		}
	}

}