org.mihalis.opal/src/main/java/org/mihalis/opal/flatButton/FlatButton.java - osbp/org.eclipse.osbp.fork.mihalis.opal.imageSelector.osgi - Git at Google

 /*******************************************************************************
  * Copyright (c) 2011 Laurent CARON
  * 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:
  *     Laurent CARON (laurent.caron at gmail dot com) - initial API and implementation
  *******************************************************************************/
 package org.mihalis.opal.flatButton;

 import java.util.ArrayList;
 import java.util.List;

 import org.eclipse.swt.SWT;
 import org.eclipse.swt.SWTException;
 import org.eclipse.swt.events.PaintEvent;
 import org.eclipse.swt.events.PaintListener;
 import org.eclipse.swt.events.SelectionEvent;
 import org.eclipse.swt.events.SelectionListener;
 import org.eclipse.swt.graphics.Color;
 import org.eclipse.swt.graphics.GC;
 import org.eclipse.swt.graphics.Image;
 import org.eclipse.swt.graphics.Point;
 import org.eclipse.swt.graphics.Rectangle;
 import org.eclipse.swt.widgets.Canvas;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Event;
 import org.eclipse.swt.widgets.Listener;
 import org.mihalis.opal.utils.SWTGraphicUtil;

 /**
  * Instances of this class represent a flat button.
  * <dl>
  * <dt><b>Styles:</b></dt>
  * <dd>UP, DOWN, LEFT, RIGHT, CENTER</dd>
  * <dt><b>Events:</b></dt>
  * <dd>Selection</dd>
  * </dl>
  * <p>
  * Note: Only one of the styles LEFT, RIGHT, and CENTER may be specified.
  * </p>
  *
  */
 public class FlatButton extends Canvas {

 	/** The Constant DEFAULT_PADDING. */
 	private static final int DEFAULT_PADDING = 5;

 	/** The image. */
 	private Image image;

 	/** The text. */
 	private String text;

 	/** The selection. */
 	private boolean selection;

 	/** The alignment. */
 	private int alignment;

 	/** The listeners. */
 	private final List<SelectionListener> listeners;

 	/** The mouse in. */
 	private boolean mouseIn;

 	/** The background color. */
 	private Color backgroundColor;

 	/** The selected color. */
 	private Color selectedColor;

 	/** The selected text color. */
 	private Color selectedTextColor;

 	/** The mouse over color. */
 	private Color mouseOverColor;

 	/**
 	 * Constructs a new instance of this class given its parent and a style
 	 * value describing its behavior and appearance.
 	 * <p>
 	 * The style value is either one of the style constants defined in class
 	 * <code>SWT</code> which is applicable to instances of this class, or must
 	 * be built by <em>bitwise OR</em>'ing together (that is, using the
 	 * <code>int</code> "|" operator) two or more of those <code>SWT</code>
 	 * style constants. The class description lists the style constants that are
 	 * applicable to the class. Style bits are also inherited from superclasses.
 	 * </p>
 	 *
 	 * @param parent a composite control which will be the parent of the new
 	 *            instance (cannot be null)
 	 * @param style the style of control to construct
 	 * @see SWT#DOWN
 	 * @see SWT#LEFT
 	 * @see SWT#RIGHT
 	 * @see SWT#CENTER
 	 * @exception IllegalArgumentException <ul>
 	 *                <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
 	 *                </ul>
 	 * @exception SWTException <ul>
 	 *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
 	 *                thread that created the parent</li>
 	 *                <li>ERROR_INVALID_SUBCLASS - if this class is not an
 	 *                allowed subclass</li>
 	 *                </ul>
 	 */
 	public FlatButton(final Composite parent, final int style) {
 		super(parent, style);
 		this.listeners = new ArrayList<SelectionListener>();
 		buildAlignmentFromStyle(style);
 		addListeners();
 		initializeDefaultColors();
 	}

 	/**
 	 * Builds the alignment from style.
 	 *
 	 * @param style the style
 	 */
 	private void buildAlignmentFromStyle(final int style) {
 		if ((style & SWT.LEFT) == SWT.LEFT) {
 			this.alignment = SWT.LEFT;
 		} else if ((style & SWT.RIGHT) == SWT.RIGHT) {
 			this.alignment = SWT.RIGHT;
 		} else {
 			this.alignment = SWT.CENTER;

 		}
 	}

 	/**
 	 * Adds the listeners.
 	 */
 	private void addListeners() {
 		addPaintListener(new PaintListener() {
 			@Override
 			public void paintControl(final PaintEvent e) {
 				FlatButton.this.paintControl(e);
 			}
 		});

 		addListener(SWT.MouseEnter, new Listener() {
 			@Override
 			public void handleEvent(final Event event) {
 				FlatButton.this.mouseIn = true;
 				redraw();
 			}
 		});

 		addListener(SWT.MouseExit, new Listener() {
 			@Override
 			public void handleEvent(final Event event) {
 				FlatButton.this.mouseIn = false;
 				redraw();
 			}
 		});

 		addListener(SWT.MouseUp, new Listener() {
 			@Override
 			public void handleEvent(final Event event) {
 				boolean doIt = true;
 				FlatButton.this.selection = !FlatButton.this.selection;
 				for (final SelectionListener listener : FlatButton.this.listeners) {
 					final SelectionEvent sEvent = new SelectionEvent(event);
 					listener.widgetSelected(sEvent);
 					doIt = doIt && sEvent.doit;
 				}
 				if (!doIt) {
 					FlatButton.this.selection = !FlatButton.this.selection;
 				}
 			}

 		});
 	}

 	/**
 	 * Initialize default colors.
 	 */
 	private void initializeDefaultColors() {
 		this.backgroundColor = getDisplay().getSystemColor(SWT.COLOR_WHITE);
 		this.selectedColor = new Color(getDisplay(), 0, 112, 192);
 		this.selectedTextColor = getDisplay().getSystemColor(SWT.COLOR_WHITE);
 		this.mouseOverColor = new Color(getDisplay(), 235, 234, 226);

 		SWTGraphicUtil.addDisposer(this, this.selectedColor);
 		SWTGraphicUtil.addDisposer(this, this.mouseOverColor);
 		SWTGraphicUtil.addDisposer(this, this.image);
 	}

 	/**
 	 * Paint control.
 	 *
 	 * @param e the e
 	 */
 	private void paintControl(final PaintEvent e) {
 		final GC gc = e.gc;
 		drawBackground(gc);
 		if (this.image != null) {
 			drawImage(gc);
 		}
 		if (this.text != null) {
 			drawText(gc);
 		}
 	}

 	/**
 	 * Draw background.
 	 *
 	 * @param gc the gc
 	 */
 	private void drawBackground(final GC gc) {
 		Color color;
 		if (this.selection) {
 			color = this.selectedColor;
 		} else if (this.mouseIn) {
 			color = this.mouseOverColor;
 		} else {
 			color = this.backgroundColor;
 		}
 		gc.setBackground(color);
 		gc.fillRectangle(getClientArea());

 	}

 	/**
 	 * Draw image.
 	 *
 	 * @param gc the gc
 	 */
 	private void drawImage(final GC gc) {
 		final Rectangle rect = getClientArea();
 		final Point imageSize = new Point(this.image.getBounds().width, this.image.getBounds().height);

 		int x;
 		if (this.alignment == SWT.LEFT) {
 			x = DEFAULT_PADDING;
 		} else if (this.alignment == SWT.RIGHT) {
 			x = rect.width - imageSize.x - DEFAULT_PADDING;
 		} else {
 			x = (rect.width - imageSize.x) / 2;
 		}
 		gc.drawImage(this.image, x, DEFAULT_PADDING);
 	}

 	/**
 	 * Draw text.
 	 *
 	 * @param gc the gc
 	 */
 	private void drawText(final GC gc) {
 		final Rectangle rect = getClientArea();

 		if (this.selection) {
 			gc.setForeground(this.selectedTextColor);
 		} else {
 			gc.setForeground(getForeground());
 		}

 		gc.setFont(getFont());
 		final Point textSize = gc.stringExtent(this.text);
 		int x, y;

 		if (this.alignment == SWT.LEFT) {
 			x = DEFAULT_PADDING;
 		} else if (this.alignment == SWT.RIGHT) {
 			x = rect.width - textSize.x - DEFAULT_PADDING;
 		} else {
 			x = (rect.width - textSize.x) / 2;
 		}
 		if (this.image == null) {
 			y = DEFAULT_PADDING;
 		} else {
 			y = 2 * DEFAULT_PADDING + this.image.getBounds().height;
 		}
 		gc.drawString(this.text, x, y, true);
 	}

 	/**
 	 * Adds the listener to the collection of listeners who will be notified
 	 * when the control is selected by the user, by sending it one of the
 	 * messages defined in the <code>SelectionListener</code> interface.
 	 * <p>
 	 * <code>widgetSelected</code> is called when the control is selected by the
 	 * user. <code>widgetDefaultSelected</code> is not called.
 	 * </p>
 	 *
 	 * @param listener the listener which should be notified
 	 * @see SelectionListener
 	 * @see #removeSelectionListener
 	 * @see SelectionEvent
 	 * @exception IllegalArgumentException <ul>
 	 *                <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
 	 *                </ul>
 	 * @exception SWTException <ul>
 	 *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
 	 *                disposed</li>
 	 *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
 	 *                thread that created the receiver</li>
 	 *                </ul>
 	 */
 	public void addSelectionListener(final SelectionListener listener) {
 		checkWidget();
 		this.listeners.add(listener);
 	}

 	/**
 	 * Compute size.
 	 *
 	 * @param wHint the w hint
 	 * @param hHint the h hint
 	 * @param changed the changed
 	 * @return the point
 	 * @see org.eclipse.swt.widgets.Composite#computeSize(int, int, boolean)
 	 */
 	@Override
 	public Point computeSize(final int wHint, final int hHint, final boolean changed) {
 		int width = 2 * DEFAULT_PADDING, height = 3 * DEFAULT_PADDING;
 		if (this.image != null) {
 			final Rectangle bounds = this.image.getBounds();
 			width += bounds.width;
 			height += bounds.height;
 		}

 		if (this.text != null) {
 			final GC gc = new GC(this);
 			final Point extent = gc.stringExtent(this.text);
 			gc.dispose();
 			width = Math.max(width, extent.x + 2 * DEFAULT_PADDING);
 			height = height + extent.y;
 		}

 		return new Point(Math.max(width, wHint), Math.max(height, hHint));
 	}

 	/**
 	 * Returns a value which describes the position of the text in the receiver.
 	 * The value will be one of <code>LEFT</code>, <code>RIGHT</code> or
 	 * <code>CENTER</code>.
 	 *
 	 * @return the alignment
 	 *
 	 * @exception SWTException <ul>
 	 *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
 	 *                disposed</li>
 	 *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
 	 *                thread that created the receiver</li>
 	 *                </ul>
 	 */
 	public int getAlignment() {
 		checkWidget();
 		return this.alignment;
 	}

 	/**
 	 * Returns a value which describes the default background color.
 	 *
 	 * @return the default background color
 	 * @exception SWTException <ul>
 	 *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
 	 *                disposed</li>
 	 *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
 	 *                thread that created the receiver</li>
 	 *                </ul>
 	 */
 	public Color getBackgroundColor() {
 		checkWidget();
 		return this.backgroundColor;
 	}

 	/**
 	 * Returns the receiver's image if it has one, or null if it does not.
 	 *
 	 * @return the receiver's image
 	 *
 	 * @exception SWTException <ul>
 	 *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
 	 *                disposed</li>
 	 *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
 	 *                thread that created the receiver</li>
 	 *                </ul>
 	 */
 	public Image getImage() {
 		checkWidget();
 		return this.image;
 	}

 	/**
 	 * Returns a value which describes the color when the mouse is over the
 	 * button.
 	 *
 	 * @return the color when the mouse is over the button
 	 * @exception SWTException <ul>
 	 *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
 	 *                disposed</li>
 	 *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
 	 *                thread that created the receiver</li>
 	 *                </ul>
 	 */
 	public Color getMouseOverColor() {
 		checkWidget();
 		return this.mouseOverColor;
 	}

 	/**
 	 * Returns a value which describes the color when the button is selected.
 	 *
 	 * @return the color when the button is selected
 	 * @exception SWTException <ul>
 	 *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
 	 *                disposed</li>
 	 *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
 	 *                thread that created the receiver</li>
 	 *                </ul>
 	 */
 	public Color getSelectedColor() {
 		checkWidget();
 		return this.selectedColor;
 	}

 	/**
 	 * Returns a value which describes the color of the text when the button is
 	 * selected.
 	 *
 	 * @return the color of the text when the button is selected
 	 * @exception SWTException <ul>
 	 *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
 	 *                disposed</li>
 	 *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
 	 *                thread that created the receiver</li>
 	 *                </ul>
 	 */

 	public Color getSelectedTextColor() {
 		return this.selectedTextColor;
 	}

 	/**
 	 * Returns <code>true</code> if the receiver is selected, and false
 	 * otherwise.
 	 * <p>
 	 *
 	 * @return the selection state
 	 *
 	 * @exception SWTException <ul>
 	 *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
 	 *                disposed</li> <li>ERROR_THREAD_INVALID_ACCESS - if not
 	 *                called from the thread that created the receiver</li>
 	 *                </ul>
 	 */
 	public boolean getSelection() {
 		checkWidget();
 		return this.selection;
 	}

 	/**
 	 * Returns the receiver's text.
 	 *
 	 * @return the receiver's text
 	 *
 	 * @exception SWTException <ul>
 	 *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 	 *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
 	 *                thread that created the receiver</li>
 	 *                </ul>
 	 */
 	public String getText() {
 		checkWidget();
 		return this.text;
 	}

 	/**
 	 * Removes the listener from the collection of listeners who will be
 	 * notified when the control is selected by the user.
 	 *
 	 * @param listener the listener which should no longer be notified
 	 * @see SelectionListener
 	 * @see #addSelectionListener
 	 * @exception IllegalArgumentException <ul>
 	 *                <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
 	 *                </ul>
 	 * @exception SWTException <ul>
 	 *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
 	 *                disposed</li>
 	 *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
 	 *                thread that created the receiver</li>
 	 *                </ul>
 	 */
 	public void removeSelectionListener(final SelectionListener listener) {
 		checkWidget();
 		this.listeners.remove(listener);
 	}

 	/**
 	 * Controls how text, images and arrows will be displayed in the receiver.
 	 * The argument should be one of <code>LEFT</code>, <code>RIGHT</code> or
 	 * <code>CENTER</code>.
 	 *
 	 * @param alignment the new alignment
 	 *
 	 * @exception SWTException <ul>
 	 *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
 	 *                disposed</li>
 	 *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
 	 *                thread that created the receiver</li>
 	 *                </ul>
 	 */
 	public void setAlignment(final int alignment) {
 		checkWidget();
 		if ((alignment & (SWT.LEFT | SWT.RIGHT | SWT.CENTER)) == 0) {
 			return;
 		}
 		this.alignment = alignment;
 		redraw();
 	}

 	/**
 	 * Sets the receiver's background color to the color specified by the
 	 * argument.
 	 *
 	 * @param backgroundColor the new background color
 	 * @exception IllegalArgumentException <ul>
 	 *                <li>ERROR_INVALID_ARGUMENT - if the argument has been
 	 *                disposed</li>
 	 *                </ul>
 	 * @exception SWTException <ul>
 	 *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
 	 *                disposed</li>
 	 *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
 	 *                thread that created the receiver</li>
 	 *                </ul>
 	 */
 	public void setBackgroundColor(final Color backgroundColor) {
 		checkWidget();
 		this.backgroundColor = backgroundColor;
 	}

 	/**
 	 * Sets the receiver's image to the argument, which may be <code>null</code>
 	 * indicating that no image should be displayed.
 	 * <p>
 	 * Note that a Button can display an image and text simultaneously on
 	 * Windows (starting with XP), GTK+ and OSX. On other platforms, a Button
 	 * that has an image and text set into it will display the image or text
 	 * that was set most recently.
 	 * </p>
 	 *
 	 * @param image the image to display on the receiver (may be
 	 *            <code>null</code>)
 	 *
 	 * @exception IllegalArgumentException <ul>
 	 *                <li>ERROR_INVALID_ARGUMENT - if the image has been disposed</li>
 	 *                </ul>
 	 * @exception SWTException <ul>
 	 *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 	 *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
 	 *                thread that created the receiver</li>
 	 *                </ul>
 	 */
 	public void setImage(final Image image) {
 		checkWidget();
 		this.image = image;
 		redraw();
 	}

 	/**
 	 * Sets the receiver's color when the mouse if over the button.
 	 *
 	 * @param mouseOverColor the new mouse over color
 	 * @exception IllegalArgumentException <ul>
 	 *                <li>ERROR_INVALID_ARGUMENT - if the argument has been
 	 *                disposed</li>
 	 *                </ul>
 	 * @exception SWTException <ul>
 	 *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
 	 *                disposed</li>
 	 *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
 	 *                thread that created the receiver</li>
 	 *                </ul>
 	 */
 	public void setMouseOverColor(final Color mouseOverColor) {
 		checkWidget();
 		this.mouseOverColor = mouseOverColor;
 	}

 	/**
 	 * Sets the receiver's color when the button is selected.
 	 *
 	 * @param selectedColor the new selected color
 	 * @exception IllegalArgumentException <ul>
 	 *                <li>ERROR_INVALID_ARGUMENT - if the argument has been
 	 *                disposed</li>
 	 *                </ul>
 	 * @exception SWTException <ul>
 	 *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
 	 *                disposed</li>
 	 *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
 	 *                thread that created the receiver</li>
 	 *                </ul>
 	 */
 	public void setSelectedColor(final Color selectedColor) {
 		checkWidget();
 		this.selectedColor = selectedColor;
 	}

 	/**
 	 * Sets the receiver's text color when the button is selected.
 	 *
 	 * @param selectedTextColor the new selected text color
 	 * @exception IllegalArgumentException <ul>
 	 *                <li>ERROR_INVALID_ARGUMENT - if the argument has been
 	 *                disposed</li>
 	 *                </ul>
 	 * @exception SWTException <ul>
 	 *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
 	 *                disposed</li>
 	 *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
 	 *                thread that created the receiver</li>
 	 *                </ul>
 	 */
 	public void setSelectedTextColor(final Color selectedTextColor) {
 		this.selectedTextColor = selectedTextColor;
 	}

 	/**
 	 * Sets the selection state of the receiver.
 	 *
 	 * @param selected the new selection state
 	 *
 	 * @exception SWTException <ul>
 	 *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 	 *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
 	 *                thread that created the receiver</li>
 	 *                </ul>
 	 */
 	public void setSelection(final boolean selected) {
 		checkWidget();
 		this.selection = selected;
 		redraw();
 	}

 	/**
 	 * Sets the receiver's text.
 	 *
 	 * @param text the new text
 	 * @exception IllegalArgumentException <ul>
 	 *                <li>ERROR_NULL_ARGUMENT - if the text is null</li>
 	 *                </ul>
 	 * @exception SWTException <ul>
 	 *                <li>ERROR_WIDGET_DISPOSED - if the receiver has been
 	 *                disposed</li>
 	 *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
 	 *                thread that created the receiver</li>
 	 *                </ul>
 	 */
 	public void setText(final String text) {
 		checkWidget();
 		this.text = text;
 		redraw();
 	}

 }
	/*******************************************************************************
	* Copyright (c) 2011 Laurent CARON
	* 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:
	* Laurent CARON (laurent.caron at gmail dot com) - initial API and implementation
	*******************************************************************************/
	package org.mihalis.opal.flatButton;

	import java.util.ArrayList;
	import java.util.List;

	import org.eclipse.swt.SWT;
	import org.eclipse.swt.SWTException;
	import org.eclipse.swt.events.PaintEvent;
	import org.eclipse.swt.events.PaintListener;
	import org.eclipse.swt.events.SelectionEvent;
	import org.eclipse.swt.events.SelectionListener;
	import org.eclipse.swt.graphics.Color;
	import org.eclipse.swt.graphics.GC;
	import org.eclipse.swt.graphics.Image;
	import org.eclipse.swt.graphics.Point;
	import org.eclipse.swt.graphics.Rectangle;
	import org.eclipse.swt.widgets.Canvas;
	import org.eclipse.swt.widgets.Composite;
	import org.eclipse.swt.widgets.Event;
	import org.eclipse.swt.widgets.Listener;
	import org.mihalis.opal.utils.SWTGraphicUtil;

	/**
	* Instances of this class represent a flat button.
	* <dl>
	* <dt><b>Styles:</b></dt>
	* <dd>UP, DOWN, LEFT, RIGHT, CENTER</dd>
	* <dt><b>Events:</b></dt>
	* <dd>Selection</dd>
	* </dl>
	* <p>
	* Note: Only one of the styles LEFT, RIGHT, and CENTER may be specified.
	* </p>
	*
	*/
	public class FlatButton extends Canvas {

	/** The Constant DEFAULT_PADDING. */
	private static final int DEFAULT_PADDING = 5;

	/** The image. */
	private Image image;

	/** The text. */
	private String text;

	/** The selection. */
	private boolean selection;

	/** The alignment. */
	private int alignment;

	/** The listeners. */
	private final List<SelectionListener> listeners;

	/** The mouse in. */
	private boolean mouseIn;

	/** The background color. */
	private Color backgroundColor;

	/** The selected color. */
	private Color selectedColor;

	/** The selected text color. */
	private Color selectedTextColor;

	/** The mouse over color. */
	private Color mouseOverColor;

	/**
	* Constructs a new instance of this class given its parent and a style
	* value describing its behavior and appearance.
	* <p>
	* The style value is either one of the style constants defined in class
	* <code>SWT</code> which is applicable to instances of this class, or must
	* be built by <em>bitwise OR</em>'ing together (that is, using the
	* <code>int</code> "\|" operator) two or more of those <code>SWT</code>
	* style constants. The class description lists the style constants that are
	* applicable to the class. Style bits are also inherited from superclasses.
	* </p>
	*
	* @param parent a composite control which will be the parent of the new
	* instance (cannot be null)
	* @param style the style of control to construct
	* @see SWT#DOWN
	* @see SWT#LEFT
	* @see SWT#RIGHT
	* @see SWT#CENTER
	* @exception IllegalArgumentException <ul>
	* <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
	* </ul>
	* @exception SWTException <ul>
	* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
	* thread that created the parent</li>
	* <li>ERROR_INVALID_SUBCLASS - if this class is not an
	* allowed subclass</li>
	* </ul>
	*/
	public FlatButton(final Composite parent, final int style) {
	super(parent, style);
	this.listeners = new ArrayList<SelectionListener>();
	buildAlignmentFromStyle(style);
	addListeners();
	initializeDefaultColors();
	}

	/**
	* Builds the alignment from style.
	*
	* @param style the style
	*/
	private void buildAlignmentFromStyle(final int style) {
	if ((style & SWT.LEFT) == SWT.LEFT) {
	this.alignment = SWT.LEFT;
	} else if ((style & SWT.RIGHT) == SWT.RIGHT) {
	this.alignment = SWT.RIGHT;
	} else {
	this.alignment = SWT.CENTER;

	}
	}

	/**
	* Adds the listeners.
	*/
	private void addListeners() {
	addPaintListener(new PaintListener() {
	@Override
	public void paintControl(final PaintEvent e) {
	FlatButton.this.paintControl(e);
	}
	});

	addListener(SWT.MouseEnter, new Listener() {
	@Override
	public void handleEvent(final Event event) {
	FlatButton.this.mouseIn = true;
	redraw();
	}
	});

	addListener(SWT.MouseExit, new Listener() {
	@Override
	public void handleEvent(final Event event) {
	FlatButton.this.mouseIn = false;
	redraw();
	}
	});

	addListener(SWT.MouseUp, new Listener() {
	@Override
	public void handleEvent(final Event event) {
	boolean doIt = true;
	FlatButton.this.selection = !FlatButton.this.selection;
	for (final SelectionListener listener : FlatButton.this.listeners) {
	final SelectionEvent sEvent = new SelectionEvent(event);
	listener.widgetSelected(sEvent);
	doIt = doIt && sEvent.doit;
	}
	if (!doIt) {
	FlatButton.this.selection = !FlatButton.this.selection;
	}
	}

	});
	}

	/**
	* Initialize default colors.
	*/
	private void initializeDefaultColors() {
	this.backgroundColor = getDisplay().getSystemColor(SWT.COLOR_WHITE);
	this.selectedColor = new Color(getDisplay(), 0, 112, 192);
	this.selectedTextColor = getDisplay().getSystemColor(SWT.COLOR_WHITE);
	this.mouseOverColor = new Color(getDisplay(), 235, 234, 226);

	SWTGraphicUtil.addDisposer(this, this.selectedColor);
	SWTGraphicUtil.addDisposer(this, this.mouseOverColor);
	SWTGraphicUtil.addDisposer(this, this.image);
	}

	/**
	* Paint control.
	*
	* @param e the e
	*/
	private void paintControl(final PaintEvent e) {
	final GC gc = e.gc;
	drawBackground(gc);
	if (this.image != null) {
	drawImage(gc);
	}
	if (this.text != null) {
	drawText(gc);
	}
	}

	/**
	* Draw background.
	*
	* @param gc the gc
	*/
	private void drawBackground(final GC gc) {
	Color color;
	if (this.selection) {
	color = this.selectedColor;
	} else if (this.mouseIn) {
	color = this.mouseOverColor;
	} else {
	color = this.backgroundColor;
	}
	gc.setBackground(color);
	gc.fillRectangle(getClientArea());

	}

	/**
	* Draw image.
	*
	* @param gc the gc
	*/
	private void drawImage(final GC gc) {
	final Rectangle rect = getClientArea();
	final Point imageSize = new Point(this.image.getBounds().width, this.image.getBounds().height);

	int x;
	if (this.alignment == SWT.LEFT) {
	x = DEFAULT_PADDING;
	} else if (this.alignment == SWT.RIGHT) {
	x = rect.width - imageSize.x - DEFAULT_PADDING;
	} else {
	x = (rect.width - imageSize.x) / 2;
	}
	gc.drawImage(this.image, x, DEFAULT_PADDING);
	}

	/**
	* Draw text.
	*
	* @param gc the gc
	*/
	private void drawText(final GC gc) {
	final Rectangle rect = getClientArea();

	if (this.selection) {
	gc.setForeground(this.selectedTextColor);
	} else {
	gc.setForeground(getForeground());
	}

	gc.setFont(getFont());
	final Point textSize = gc.stringExtent(this.text);
	int x, y;

	if (this.alignment == SWT.LEFT) {
	x = DEFAULT_PADDING;
	} else if (this.alignment == SWT.RIGHT) {
	x = rect.width - textSize.x - DEFAULT_PADDING;
	} else {
	x = (rect.width - textSize.x) / 2;
	}
	if (this.image == null) {
	y = DEFAULT_PADDING;
	} else {
	y = 2 * DEFAULT_PADDING + this.image.getBounds().height;
	}
	gc.drawString(this.text, x, y, true);
	}

	/**
	* Adds the listener to the collection of listeners who will be notified
	* when the control is selected by the user, by sending it one of the
	* messages defined in the <code>SelectionListener</code> interface.
	* <p>
	* <code>widgetSelected</code> is called when the control is selected by the
	* user. <code>widgetDefaultSelected</code> is not called.
	* </p>
	*
	* @param listener the listener which should be notified
	* @see SelectionListener
	* @see #removeSelectionListener
	* @see SelectionEvent
	* @exception IllegalArgumentException <ul>
	* <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
	* </ul>
	* @exception SWTException <ul>
	* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
	* disposed</li>
	* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
	* thread that created the receiver</li>
	* </ul>
	*/
	public void addSelectionListener(final SelectionListener listener) {
	checkWidget();
	this.listeners.add(listener);
	}

	/**
	* Compute size.
	*
	* @param wHint the w hint
	* @param hHint the h hint
	* @param changed the changed
	* @return the point
	* @see org.eclipse.swt.widgets.Composite#computeSize(int, int, boolean)
	*/
	@Override
	public Point computeSize(final int wHint, final int hHint, final boolean changed) {
	int width = 2 * DEFAULT_PADDING, height = 3 * DEFAULT_PADDING;
	if (this.image != null) {
	final Rectangle bounds = this.image.getBounds();
	width += bounds.width;
	height += bounds.height;
	}

	if (this.text != null) {
	final GC gc = new GC(this);
	final Point extent = gc.stringExtent(this.text);
	gc.dispose();
	width = Math.max(width, extent.x + 2 * DEFAULT_PADDING);
	height = height + extent.y;
	}

	return new Point(Math.max(width, wHint), Math.max(height, hHint));
	}

	/**
	* Returns a value which describes the position of the text in the receiver.
	* The value will be one of <code>LEFT</code>, <code>RIGHT</code> or
	* <code>CENTER</code>.
	*
	* @return the alignment
	*
	* @exception SWTException <ul>
	* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
	* disposed</li>
	* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
	* thread that created the receiver</li>
	* </ul>
	*/
	public int getAlignment() {
	checkWidget();
	return this.alignment;
	}

	/**
	* Returns a value which describes the default background color.
	*
	* @return the default background color
	* @exception SWTException <ul>
	* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
	* disposed</li>
	* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
	* thread that created the receiver</li>
	* </ul>
	*/
	public Color getBackgroundColor() {
	checkWidget();
	return this.backgroundColor;
	}

	/**
	* Returns the receiver's image if it has one, or null if it does not.
	*
	* @return the receiver's image
	*
	* @exception SWTException <ul>
	* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
	* disposed</li>
	* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
	* thread that created the receiver</li>
	* </ul>
	*/
	public Image getImage() {
	checkWidget();
	return this.image;
	}

	/**
	* Returns a value which describes the color when the mouse is over the
	* button.
	*
	* @return the color when the mouse is over the button
	* @exception SWTException <ul>
	* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
	* disposed</li>
	* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
	* thread that created the receiver</li>
	* </ul>
	*/
	public Color getMouseOverColor() {
	checkWidget();
	return this.mouseOverColor;
	}

	/**
	* Returns a value which describes the color when the button is selected.
	*
	* @return the color when the button is selected
	* @exception SWTException <ul>
	* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
	* disposed</li>
	* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
	* thread that created the receiver</li>
	* </ul>
	*/
	public Color getSelectedColor() {
	checkWidget();
	return this.selectedColor;
	}

	/**
	* Returns a value which describes the color of the text when the button is
	* selected.
	*
	* @return the color of the text when the button is selected
	* @exception SWTException <ul>
	* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
	* disposed</li>
	* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
	* thread that created the receiver</li>
	* </ul>
	*/

	public Color getSelectedTextColor() {
	return this.selectedTextColor;
	}

	/**
	* Returns <code>true</code> if the receiver is selected, and false
	* otherwise.
	* <p>
	*
	* @return the selection state
	*
	* @exception SWTException <ul>
	* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
	* disposed</li> <li>ERROR_THREAD_INVALID_ACCESS - if not
	* called from the thread that created the receiver</li>
	* </ul>
	*/
	public boolean getSelection() {
	checkWidget();
	return this.selection;
	}

	/**
	* Returns the receiver's text.
	*
	* @return the receiver's text
	*
	* @exception SWTException <ul>
	* <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
	* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
	* thread that created the receiver</li>
	* </ul>
	*/
	public String getText() {
	checkWidget();
	return this.text;
	}

	/**
	* Removes the listener from the collection of listeners who will be
	* notified when the control is selected by the user.
	*
	* @param listener the listener which should no longer be notified
	* @see SelectionListener
	* @see #addSelectionListener
	* @exception IllegalArgumentException <ul>
	* <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
	* </ul>
	* @exception SWTException <ul>
	* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
	* disposed</li>
	* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
	* thread that created the receiver</li>
	* </ul>
	*/
	public void removeSelectionListener(final SelectionListener listener) {
	checkWidget();
	this.listeners.remove(listener);
	}

	/**
	* Controls how text, images and arrows will be displayed in the receiver.
	* The argument should be one of <code>LEFT</code>, <code>RIGHT</code> or
	* <code>CENTER</code>.
	*
	* @param alignment the new alignment
	*
	* @exception SWTException <ul>
	* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
	* disposed</li>
	* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
	* thread that created the receiver</li>
	* </ul>
	*/
	public void setAlignment(final int alignment) {
	checkWidget();
	if ((alignment & (SWT.LEFT \| SWT.RIGHT \| SWT.CENTER)) == 0) {
	return;
	}
	this.alignment = alignment;
	redraw();
	}

	/**
	* Sets the receiver's background color to the color specified by the
	* argument.
	*
	* @param backgroundColor the new background color
	* @exception IllegalArgumentException <ul>
	* <li>ERROR_INVALID_ARGUMENT - if the argument has been
	* disposed</li>
	* </ul>
	* @exception SWTException <ul>
	* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
	* disposed</li>
	* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
	* thread that created the receiver</li>
	* </ul>
	*/
	public void setBackgroundColor(final Color backgroundColor) {
	checkWidget();
	this.backgroundColor = backgroundColor;
	}

	/**
	* Sets the receiver's image to the argument, which may be <code>null</code>
	* indicating that no image should be displayed.
	* <p>
	* Note that a Button can display an image and text simultaneously on
	* Windows (starting with XP), GTK+ and OSX. On other platforms, a Button
	* that has an image and text set into it will display the image or text
	* that was set most recently.
	* </p>
	*
	* @param image the image to display on the receiver (may be
	* <code>null</code>)
	*
	* @exception IllegalArgumentException <ul>
	* <li>ERROR_INVALID_ARGUMENT - if the image has been disposed</li>
	* </ul>
	* @exception SWTException <ul>
	* <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
	* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
	* thread that created the receiver</li>
	* </ul>
	*/
	public void setImage(final Image image) {
	checkWidget();
	this.image = image;
	redraw();
	}

	/**
	* Sets the receiver's color when the mouse if over the button.
	*
	* @param mouseOverColor the new mouse over color
	* @exception IllegalArgumentException <ul>
	* <li>ERROR_INVALID_ARGUMENT - if the argument has been
	* disposed</li>
	* </ul>
	* @exception SWTException <ul>
	* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
	* disposed</li>
	* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
	* thread that created the receiver</li>
	* </ul>
	*/
	public void setMouseOverColor(final Color mouseOverColor) {
	checkWidget();
	this.mouseOverColor = mouseOverColor;
	}

	/**
	* Sets the receiver's color when the button is selected.
	*
	* @param selectedColor the new selected color
	* @exception IllegalArgumentException <ul>
	* <li>ERROR_INVALID_ARGUMENT - if the argument has been
	* disposed</li>
	* </ul>
	* @exception SWTException <ul>
	* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
	* disposed</li>
	* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
	* thread that created the receiver</li>
	* </ul>
	*/
	public void setSelectedColor(final Color selectedColor) {
	checkWidget();
	this.selectedColor = selectedColor;
	}

	/**
	* Sets the receiver's text color when the button is selected.
	*
	* @param selectedTextColor the new selected text color
	* @exception IllegalArgumentException <ul>
	* <li>ERROR_INVALID_ARGUMENT - if the argument has been
	* disposed</li>
	* </ul>
	* @exception SWTException <ul>
	* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
	* disposed</li>
	* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
	* thread that created the receiver</li>
	* </ul>
	*/
	public void setSelectedTextColor(final Color selectedTextColor) {
	this.selectedTextColor = selectedTextColor;
	}

	/**
	* Sets the selection state of the receiver.
	*
	* @param selected the new selection state
	*
	* @exception SWTException <ul>
	* <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
	* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
	* thread that created the receiver</li>
	* </ul>
	*/
	public void setSelection(final boolean selected) {
	checkWidget();
	this.selection = selected;
	redraw();
	}

	/**
	* Sets the receiver's text.
	*
	* @param text the new text
	* @exception IllegalArgumentException <ul>
	* <li>ERROR_NULL_ARGUMENT - if the text is null</li>
	* </ul>
	* @exception SWTException <ul>
	* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
	* disposed</li>
	* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
	* thread that created the receiver</li>
	* </ul>
	*/
	public void setText(final String text) {
	checkWidget();
	this.text = text;
	redraw();
	}

	}