bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/widgets/Button.java

/*******************************************************************************
 * Copyright (c) 2000, 2011 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.swt.widgets;


import org.eclipse.swt.internal.*;
import org.eclipse.swt.internal.win32.*;
import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.events.*;

/**
 * Instances of this class represent a selectable user interface object that
 * issues notification when pressed and released. 
 * <dl>
 * <dt><b>Styles:</b></dt>
 * <dd>ARROW, CHECK, PUSH, RADIO, TOGGLE, FLAT, WRAP</dd>
 * <dd>UP, DOWN, LEFT, RIGHT, CENTER</dd>
 * <dt><b>Events:</b></dt>
 * <dd>Selection</dd>
 * </dl>
 * <p>
 * Note: Only one of the styles ARROW, CHECK, PUSH, RADIO, and TOGGLE 
 * may be specified.
 * </p><p>
 * Note: Only one of the styles LEFT, RIGHT, and CENTER may be specified.
 * </p><p>
 * Note: Only one of the styles UP, DOWN, LEFT, and RIGHT may be specified
 * when the ARROW style is specified.
 * </p><p>
 * IMPORTANT: This class is <em>not</em> intended to be subclassed.
 * </p>
 * 
 * @see <a href="http://www.eclipse.org/swt/snippets/#button">Button snippets</a>
 * @see <a href="http://www.eclipse.org/swt/examples.php">SWT Example: ControlExample</a>
 * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
 * @noextend This class is not intended to be subclassed by clients.
 */

public class Button extends Control {
	String text = "", message = "";
	Image image, image2, disabledImage;
	ImageList imageList;
	boolean ignoreMouse, grayed;
	static final int MARGIN = 4;
	static final int CHECK_WIDTH, CHECK_HEIGHT;
	static final int ICON_WIDTH = 128, ICON_HEIGHT = 128;
	static /*final*/ boolean COMMAND_LINK = false;
	static final int /*long*/ ButtonProc;
	static final TCHAR ButtonClass = new TCHAR (0, "BUTTON", true);
	static {
		int /*long*/ hBitmap = OS.LoadBitmap (0, OS.OBM_CHECKBOXES);
		if (hBitmap == 0) {
			CHECK_WIDTH = OS.GetSystemMetrics (OS.IsWinCE ? OS.SM_CXSMICON : OS.SM_CXVSCROLL);
			CHECK_HEIGHT = OS.GetSystemMetrics (OS.IsWinCE ? OS.SM_CYSMICON : OS.SM_CYVSCROLL);
		} else {
			BITMAP bitmap = new BITMAP ();
			OS.GetObject (hBitmap, BITMAP.sizeof, bitmap);
			OS.DeleteObject (hBitmap);
			CHECK_WIDTH = bitmap.bmWidth / 4;
			CHECK_HEIGHT =  bitmap.bmHeight / 3;
		}
		WNDCLASS lpWndClass = new WNDCLASS ();
		OS.GetClassInfo (0, ButtonClass, lpWndClass);
		ButtonProc = lpWndClass.lpfnWndProc;
	}

/**
 * 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
 *
 * @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>
 *
 * @see SWT#ARROW
 * @see SWT#CHECK
 * @see SWT#PUSH
 * @see SWT#RADIO
 * @see SWT#TOGGLE
 * @see SWT#FLAT
 * @see SWT#UP
 * @see SWT#DOWN
 * @see SWT#LEFT
 * @see SWT#RIGHT
 * @see SWT#CENTER
 * @see Widget#checkSubclass
 * @see Widget#getStyle
 */
public Button (Composite parent, int style) {
	super (parent, checkStyle (style));
}

void _setImage (Image image) {
	if ((style & SWT.COMMAND) != 0) return;
	if (OS.COMCTL32_MAJOR >= 6) {
		if (imageList != null) imageList.dispose ();
		imageList = null;
		if (image != null) {
			imageList = new ImageList (style & SWT.RIGHT_TO_LEFT);
			if (OS.IsWindowEnabled (handle)) {
				imageList.add (image);
			} else {
				if (disabledImage != null) disabledImage.dispose ();
				disabledImage = new Image (display, image, SWT.IMAGE_DISABLE);
				imageList.add (disabledImage);
			}
			BUTTON_IMAGELIST buttonImageList = new BUTTON_IMAGELIST ();
			buttonImageList.himl = imageList.getHandle ();
			int oldBits = OS.GetWindowLong (handle, OS.GWL_STYLE), newBits = oldBits;
			newBits &= ~(OS.BS_LEFT | OS.BS_CENTER | OS.BS_RIGHT);
			if ((style & SWT.LEFT) != 0) newBits |= OS.BS_LEFT;
			if ((style & SWT.CENTER) != 0) newBits |= OS.BS_CENTER;
			if ((style & SWT.RIGHT) != 0) newBits |= OS.BS_RIGHT;
			if (text.length () == 0) {
				if ((style & SWT.LEFT) != 0) buttonImageList.uAlign = OS.BUTTON_IMAGELIST_ALIGN_LEFT;
				if ((style & SWT.CENTER) != 0) buttonImageList.uAlign = OS.BUTTON_IMAGELIST_ALIGN_CENTER;
				if ((style & SWT.RIGHT) != 0) buttonImageList.uAlign = OS.BUTTON_IMAGELIST_ALIGN_RIGHT;
			} else {
				buttonImageList.uAlign = OS.BUTTON_IMAGELIST_ALIGN_LEFT;
				buttonImageList.margin_left = computeLeftMargin ();
				buttonImageList.margin_right = MARGIN;
				newBits &= ~(OS.BS_CENTER | OS.BS_RIGHT);
				newBits |= OS.BS_LEFT;
			}
			if (newBits != oldBits) {
				OS.SetWindowLong (handle, OS.GWL_STYLE, newBits);
				OS.InvalidateRect (handle, null, true);
			}
			OS.SendMessage (handle, OS.BCM_SETIMAGELIST, 0, buttonImageList);
		} else {
			OS.SendMessage (handle, OS.BCM_SETIMAGELIST, 0, 0);
		}
		/*
		* Bug in Windows.  Under certain cirumstances yet to be
		* isolated, BCM_SETIMAGELIST does not redraw the control
		* when a new image is set.  The fix is to force a redraw.
		*/
		OS.InvalidateRect (handle, null, true);
	} else {
		if (image2 != null) image2.dispose ();
		image2 = null;
		int /*long*/ hImage = 0;
		int imageBits = 0, fImageType = 0;
		if (image != null) {
			switch (image.type) {
				case SWT.BITMAP: {
					Rectangle rect = image.getBounds ();
					ImageData data = image.getImageData ();
					switch (data.getTransparencyType ()) {
						case SWT.TRANSPARENCY_PIXEL: 
							if (rect.width <= ICON_WIDTH && rect.height <= ICON_HEIGHT) {
								image2 = new Image (display, data, data.getTransparencyMask ());
								hImage = image2.handle;
								imageBits = OS.BS_ICON;
								fImageType = OS.IMAGE_ICON;
								break;
							}
							//FALL THROUGH
						case SWT.TRANSPARENCY_ALPHA:
							image2 = new Image (display, rect.width, rect.height);
							GC gc = new GC (image2);
							gc.setBackground (getBackground ());
							gc.fillRectangle (rect);
							gc.drawImage (image, 0, 0);
							gc.dispose ();
							hImage = image2.handle;
							imageBits = OS.BS_BITMAP;
							fImageType = OS.IMAGE_BITMAP;
							break;
						case SWT.TRANSPARENCY_NONE:
							hImage = image.handle;
							imageBits = OS.BS_BITMAP;
							fImageType = OS.IMAGE_BITMAP;
							break;
					}
					break;
				}
				case SWT.ICON: {
					hImage = image.handle;
					imageBits = OS.BS_ICON;
					fImageType = OS.IMAGE_ICON;
					break;
				}
			}
			/*
			* Feature in Windows.  The button control mirrors its image when the
			* flag WS_EX_LAYOUTRTL is set. This behaviour is not desirable in SWT.
			* The fix is to set a mirrored version of real image in the button.
			*/
			if ((style & SWT.RIGHT_TO_LEFT) != 0) {
				if (!OS.IsWinCE && OS.WIN32_VERSION >= OS.VERSION (4, 10)) {
					Rectangle rect = image.getBounds ();
					int /*long*/ hDC = OS.GetDC (handle);
					int /*long*/ dstHdc = OS.CreateCompatibleDC (hDC);
					int /*long*/ hBitmap = OS.CreateCompatibleBitmap (hDC, rect.width, rect.height);
					int /*long*/ oldBitmap = OS.SelectObject (dstHdc, hBitmap);
					OS.SetLayout (dstHdc, OS.LAYOUT_RTL);
					if (fImageType == OS.IMAGE_BITMAP) {
						int /*long*/ srcHdc = OS.CreateCompatibleDC (hDC);
						int /*long*/ oldSrcBitmap = OS.SelectObject (srcHdc, hImage);
						OS.SetLayout (dstHdc, 0);
						OS.BitBlt (dstHdc, 0, 0, rect.width, rect.height, srcHdc, 0, 0, OS.SRCCOPY);
						OS.SelectObject (srcHdc, oldSrcBitmap);
						OS.DeleteDC (srcHdc);
					} else {
						Control control = findBackgroundControl ();
						if (control == null) control = this;
						int /*long*/ newBrush = OS.CreateSolidBrush (control.getBackgroundPixel ());
						int /*long*/ oldBrush = OS.SelectObject (dstHdc, newBrush);
						OS.PatBlt (dstHdc, 0, 0, rect.width, rect.height, OS.PATCOPY);
						OS.DrawIconEx (dstHdc, 0, 0, hImage, 0, 0, 0, 0, OS.DI_NORMAL);
						OS.SelectObject (dstHdc, oldBrush);
						OS.DeleteObject (newBrush);
					}
					OS.SelectObject (dstHdc, oldBitmap);
					OS.DeleteDC (dstHdc);
					OS.ReleaseDC (handle, hDC);
					if (image2 != null) image2.dispose ();
					image2 = Image.win32_new (display, SWT.BITMAP, hBitmap);
					imageBits = OS.BS_BITMAP;
					fImageType = OS.IMAGE_BITMAP;
					hImage = hBitmap;
				}
			}
		}
		int newBits = OS.GetWindowLong (handle, OS.GWL_STYLE), oldBits = newBits;
		newBits &= ~(OS.BS_BITMAP | OS.BS_ICON);
		newBits |= imageBits;
		if (newBits != oldBits) OS.SetWindowLong (handle, OS.GWL_STYLE, newBits);
		OS.SendMessage (handle, OS.BM_SETIMAGE, fImageType, hImage);
	}
}

void _setText (String text) {
	int oldBits = OS.GetWindowLong (handle, OS.GWL_STYLE), newBits = oldBits;
	if (OS.COMCTL32_MAJOR >= 6) {
		newBits &= ~(OS.BS_LEFT | OS.BS_CENTER | OS.BS_RIGHT);
		if ((style & SWT.LEFT) != 0) newBits |= OS.BS_LEFT;
		if ((style & SWT.CENTER) != 0) newBits |= OS.BS_CENTER;
		if ((style & SWT.RIGHT) != 0) newBits |= OS.BS_RIGHT;
		if (imageList != null) {
			BUTTON_IMAGELIST buttonImageList = new BUTTON_IMAGELIST ();
			buttonImageList.himl = imageList.getHandle ();
			if (text.length () == 0) {
				if ((style & SWT.LEFT) != 0) buttonImageList.uAlign = OS.BUTTON_IMAGELIST_ALIGN_LEFT;
				if ((style & SWT.CENTER) != 0) buttonImageList.uAlign = OS.BUTTON_IMAGELIST_ALIGN_CENTER;
				if ((style & SWT.RIGHT) != 0) buttonImageList.uAlign = OS.BUTTON_IMAGELIST_ALIGN_RIGHT;
			} else {
				buttonImageList.uAlign = OS.BUTTON_IMAGELIST_ALIGN_LEFT;
				buttonImageList.margin_left = computeLeftMargin ();
				buttonImageList.margin_right = MARGIN;
				newBits &= ~(OS.BS_CENTER | OS.BS_RIGHT);
				newBits |= OS.BS_LEFT;
			}
			OS.SendMessage (handle, OS.BCM_SETIMAGELIST, 0, buttonImageList);
		}
	} else {
		newBits &= ~(OS.BS_BITMAP | OS.BS_ICON);
	}
	if (newBits != oldBits) {
		OS.SetWindowLong (handle, OS.GWL_STYLE, newBits);
		OS.InvalidateRect (handle, null, true);
	}
	/*
	* Bug in Windows.  When a Button control is right-to-left and
	* is disabled, the first pixel of the text is clipped.  The
	* fix is to add a space to both sides of the text.
	*/
	if ((style & SWT.RIGHT_TO_LEFT) != 0) {
		if (OS.COMCTL32_MAJOR < 6 || !OS.IsAppThemed ()) {
			text = OS.IsWindowEnabled (handle) ? text : " " + text + " ";
		}
	}
	TCHAR buffer = new TCHAR (getCodePage (), text, true);
	OS.SetWindowText (handle, buffer);
}

/**
 * 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>
 * <p>
 * When the <code>SWT.RADIO</code> style bit is set, the <code>widgetSelected</code> method is
 * also called when the receiver loses selection because another item in the same radio group 
 * was selected by the user. During <code>widgetSelected</code> the application can use
 * <code>getSelection()</code> to determine the current selected state of the receiver.
 * </p>
 *
 * @param listener the listener which should be notified
 *
 * @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>
 *
 * @see SelectionListener
 * @see #removeSelectionListener
 * @see SelectionEvent
 */
public void addSelectionListener (SelectionListener listener) {
	checkWidget ();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	TypedListener typedListener = new TypedListener (listener);
	addListener (SWT.Selection,typedListener);
	addListener (SWT.DefaultSelection,typedListener);
}

int /*long*/ callWindowProc (int /*long*/ hwnd, int msg, int /*long*/ wParam, int /*long*/ lParam) {
	if (handle == 0) return 0;
	return OS.CallWindowProc (ButtonProc, hwnd, msg, wParam, lParam);
}

static int checkStyle (int style) {
	style = checkBits (style, SWT.PUSH, SWT.ARROW, SWT.CHECK, SWT.RADIO, SWT.TOGGLE, COMMAND_LINK ? SWT.COMMAND : 0);
	if ((style & (SWT.PUSH | SWT.TOGGLE)) != 0) {
		return checkBits (style, SWT.CENTER, SWT.LEFT, SWT.RIGHT, 0, 0, 0);
	}
	if ((style & (SWT.CHECK | SWT.RADIO)) != 0) {
		return checkBits (style, SWT.LEFT, SWT.RIGHT, SWT.CENTER, 0, 0, 0);
	}
	if ((style & SWT.ARROW) != 0) {
		style |= SWT.NO_FOCUS;
		return checkBits (style, SWT.UP, SWT.DOWN, SWT.LEFT, SWT.RIGHT, 0, 0);
	}
	return style;
}

void click () {
	/*
	* Feature in Windows.  BM_CLICK sends a fake WM_LBUTTONDOWN and
	* WM_LBUTTONUP in order to click the button.  This causes the
	* application to get unexpected mouse events.  The fix is to
	* ignore mouse events when they are caused by BM_CLICK.
	*/
	ignoreMouse = true;
	OS.SendMessage (handle, OS.BM_CLICK, 0, 0);
	ignoreMouse = false;
}

int computeLeftMargin () {
	if (OS.COMCTL32_MAJOR < 6) return MARGIN;
	if ((style & (SWT.PUSH | SWT.TOGGLE)) == 0) return MARGIN;
	int margin = 0;
	if (image != null && text.length () != 0) {
		Rectangle bounds = image.getBounds ();
		margin += bounds.width + MARGIN * 2;
		int /*long*/ oldFont = 0;
		int /*long*/ hDC = OS.GetDC (handle);
		int /*long*/ newFont = OS.SendMessage (handle, OS.WM_GETFONT, 0, 0);
		if (newFont != 0) oldFont = OS.SelectObject (hDC, newFont);
		TCHAR buffer = new TCHAR (getCodePage (), text, true);
		RECT rect = new RECT ();
		int flags = OS.DT_CALCRECT | OS.DT_SINGLELINE;
		OS.DrawText (hDC, buffer, -1, rect, flags);
		margin += rect.right - rect.left;
		if (newFont != 0) OS.SelectObject (hDC, oldFont);
		OS.ReleaseDC (handle, hDC);
		OS.GetClientRect (handle, rect);
		margin = Math.max (MARGIN, (rect.right - rect.left - margin) / 2);
	}
	return margin;
}

public Point computeSize (int wHint, int hHint, boolean changed) {
	checkWidget ();
	int width = 0, height = 0, border = getBorderWidth ();
	if ((style & SWT.ARROW) != 0) {
		if ((style & (SWT.UP | SWT.DOWN)) != 0) {
			width += OS.GetSystemMetrics (OS.SM_CXVSCROLL);
			height += OS.GetSystemMetrics (OS.SM_CYVSCROLL);
		} else {
			width += OS.GetSystemMetrics (OS.SM_CXHSCROLL);
			height += OS.GetSystemMetrics (OS.SM_CYHSCROLL);
		}
	} else {
		if ((style & SWT.COMMAND) != 0) {
			SIZE size = new SIZE ();
			if (wHint != SWT.DEFAULT) {
				size.cx = wHint;
				OS.SendMessage (handle, OS.BCM_GETIDEALSIZE, 0, size);
				width = size.cx;
				height = size.cy;
			} else {
				OS.SendMessage (handle, OS.BCM_GETIDEALSIZE, 0, size);
				width = size.cy;
				height = size.cy;
				size.cy = 0;
				while (size.cy != height) {
					size.cx = width++;
					size.cy = 0;
					OS.SendMessage (handle, OS.BCM_GETIDEALSIZE, 0, size);
				}
			}
		} else {
			int extra = 0;
			boolean hasImage = image != null, hasText = true;
			if (OS.COMCTL32_MAJOR < 6) {
				if ((style & SWT.PUSH) == 0) {
					int bits = OS.GetWindowLong (handle, OS.GWL_STYLE);
					hasImage = (bits & (OS.BS_BITMAP | OS.BS_ICON)) != 0;
					if (hasImage) hasText = false;
				}
			}
			if (hasImage) {
				if (image != null) {
					Rectangle rect = image.getBounds ();
					width = rect.width;
					if (hasText && text.length () != 0) {
						width += MARGIN * 2;
					}
					height = rect.height;
					extra = MARGIN * 2;
				}
			}
			if (hasText) {
				int /*long*/ oldFont = 0;
				int /*long*/ hDC = OS.GetDC (handle);
				int /*long*/ newFont = OS.SendMessage (handle, OS.WM_GETFONT, 0, 0);
				if (newFont != 0) oldFont = OS.SelectObject (hDC, newFont);
				TEXTMETRIC lptm = OS.IsUnicode ? (TEXTMETRIC) new TEXTMETRICW () : new TEXTMETRICA ();
				OS.GetTextMetrics (hDC, lptm);
				int length = text.length ();
				if (length == 0) {
					height = Math.max (height, lptm.tmHeight);
				} else {
					extra = Math.max (MARGIN * 2, lptm.tmAveCharWidth);
					TCHAR buffer = new TCHAR (getCodePage (), text, true);
					RECT rect = new RECT ();
					int flags = OS.DT_CALCRECT | OS.DT_SINGLELINE;
					if ((style & SWT.WRAP) != 0 && wHint != SWT.DEFAULT) {
						flags = OS.DT_CALCRECT | OS.DT_WORDBREAK;
						rect.right = wHint - width - 2 * border;
						if ((style & (SWT.CHECK | SWT.RADIO)) != 0) {
							rect.right -= CHECK_WIDTH + 3; 
						} else {
							rect.right -= 6;
						}
						if (OS.COMCTL32_MAJOR < 6 || !OS.IsAppThemed ()) {
							rect.right -= 2;
							if ((style & (SWT.CHECK | SWT.RADIO)) != 0) {
								rect.right -= 2;
							}
						}
					}
					OS.DrawText (hDC, buffer, -1, rect, flags);
					width += rect.right - rect.left;
					height = Math.max (height, rect.bottom - rect.top);
				}
				if (newFont != 0) OS.SelectObject (hDC, oldFont);
				OS.ReleaseDC (handle, hDC);
			}
			if ((style & (SWT.CHECK | SWT.RADIO)) != 0) {
				width += CHECK_WIDTH + extra;
				height = Math.max (height, CHECK_HEIGHT + 3);
			}
			if ((style & (SWT.PUSH | SWT.TOGGLE)) != 0) {
				width += 12;  height += 10;
			}
		}
	}
	if (wHint != SWT.DEFAULT) width = wHint;
	if (hHint != SWT.DEFAULT) height = hHint;
	width += border * 2; 
	height += border * 2;
	return new Point (width, height);
}

void createHandle () {
	/*
	* Feature in Windows.  When a button is created,
	* it clears the UI state for all controls in the
	* shell by sending WM_CHANGEUISTATE with UIS_SET,
	* UISF_HIDEACCEL and UISF_HIDEFOCUS to the parent.
	* This is undocumented and unexpected.  The fix
	* is to ignore the WM_CHANGEUISTATE, when sent
	* from CreateWindowEx().
	*/
	parent.state |= IGNORE_WM_CHANGEUISTATE;
	super.createHandle ();
	parent.state &= ~IGNORE_WM_CHANGEUISTATE;
	
	/* Set the theme background */
	if (OS.COMCTL32_MAJOR >= 6 && OS.IsAppThemed ()) {
		/* 
		* NOTE: On Vista this causes problems when the tab
		* key is pressed for push buttons so disable the
		* theme background drawing for these widgets for
		* now.
		*/
		if (!OS.IsWinCE && OS.WIN32_VERSION < OS.VERSION (6, 0)) {
			state |= THEME_BACKGROUND;
		} else {
			if ((style & (SWT.PUSH | SWT.TOGGLE)) == 0) {
				state |= THEME_BACKGROUND;
			}
		}
	}
	
	/*
	* Bug in Windows.  For some reason, the HBRUSH that
	* is returned from WM_CTRLCOLOR is misaligned when
	* the button uses it to draw.  If the brush is a solid
	* color, this does not matter.  However, if the brush
	* contains an image, the image is misaligned.  The
	* fix is to draw the background in WM_CTRLCOLOR.
	* 
	* NOTE: For comctl32.dll 6.0 with themes disabled,
	* drawing in WM_ERASEBKGND will draw on top of the
	* text of the control.
	*/
	if (OS.COMCTL32_MAJOR >= 6 && OS.IsAppThemed ()) {
		if ((style & SWT.RADIO) != 0) state |= DRAW_BACKGROUND;
	}
	
	/*
	* Feature in Windows.  Push buttons draw border around
	* the button using the default background color instead
	* of using the color provided by WM_CTRLCOLOR.  The fix
	* is to draw the background in WM_CTRLCOLOR.
	* 
	* NOTE: On Vista this causes problems when the tab key
	* is pressed for push buttons so disable the fix for now.
	*/
	if (OS.COMCTL32_MAJOR >= 6 && OS.IsAppThemed ()) {
		if (!OS.IsWinCE && OS.WIN32_VERSION < OS.VERSION (6, 0)) {
			if ((style & (SWT.PUSH | SWT.TOGGLE)) != 0) {
				state |= DRAW_BACKGROUND;
			}
		}
	}
}

int defaultBackground () {
	if ((style & (SWT.PUSH | SWT.TOGGLE)) != 0) {
		return OS.GetSysColor (OS.COLOR_BTNFACE);
	}
	return super.defaultBackground ();
}

int defaultForeground () {
	return OS.GetSysColor (OS.COLOR_BTNTEXT);
}

/*
 * Reference vsstyle.h in the Windows SDK.
 * 
 * Return the button style for the PushButton or the ToggleButton. Button styles come in various flavors: disabled, pressed, hot, default
 * and normal.
 * 
 */
int determineStateOfPushButton () {
	POINT ptCursor = new POINT ();
	RECT rectWindow = new RECT ();
	OS.GetWindowRect (handle, rectWindow);
	OS.GetCursorPos (ptCursor);
	boolean hovering = OS.PtInRect (rectWindow, ptCursor); 
	boolean captured = OS.GetCapture () == handle;

	if (!getEnabled ()) {
		return OS.PBS_DISABLED;
	}
	
	if (hovering && captured) {
		return OS.PBS_PRESSED;
	}

	if (hovering || captured) {
		return OS.PBS_HOT;
	}
	
	int /*long*/ dwCheckState = OS.SendMessage(handle, OS.BM_GETCHECK, 0, 0);
	if (dwCheckState == OS.BST_CHECKED) {
		return OS.PBS_PRESSED;
	}
	
	if (getDefault ()) {
		return OS.PBS_DEFAULTED;
	}
	
	return OS.PBS_NORMAL;
}

/*
 * Reference vsstyle.h in the Windows SDK.
 * 
 * Button states will determine which bitmap the theme will draw in the background. The visual state comes in 4 states: normal, hot, pressed or 
 * disabled. These 4 visual states are then combined with the checked/unchecked state of the button (in the case of the check box, there's
 * a 3rd checked state of indeterminate), yielding the final button state that is returned.
 * 
 */
int determineStateOfRadioOrCheck () {
	POINT ptCursor = new POINT ();
	RECT rectWindow = new RECT ();
	OS.GetWindowRect (handle, rectWindow);
	OS.GetCursorPos (ptCursor);
	boolean hovering = OS.PtInRect (rectWindow, ptCursor); 
	boolean captured = OS.GetCapture () == handle;
	int /*long*/ dwCheckState = OS.SendMessage (handle, OS.BM_GETCHECK, 0, 0);

	if (!getEnabled ()) {
		if ((style & SWT.RADIO) != 0) {
			return (dwCheckState == OS.BST_CHECKED) ? OS.RBS_CHECKEDDISABLED : OS.RBS_UNCHECKEDDISABLED;
		} else {
			return (dwCheckState == OS.BST_CHECKED) ? OS.CBS_CHECKEDDISABLED : (dwCheckState == OS.BST_UNCHECKED) ? OS.CBS_UNCHECKEDDISABLED : OS.CBS_MIXEDDISABLED;
		}
	}
	
	if (hovering && captured) {
		if ((style & SWT.RADIO) != 0) {
			return (dwCheckState == OS.BST_CHECKED) ? OS.RBS_CHECKEDPRESSED : OS.RBS_UNCHECKEDPRESSED;
		} else {
			return (dwCheckState == OS.BST_CHECKED) ? OS.CBS_CHECKEDPRESSED : (dwCheckState == OS.BST_UNCHECKED) ? OS.CBS_UNCHECKEDPRESSED : OS.CBS_MIXEDPRESSED;
		}
	}

	if (hovering || captured) {
		if ((style & SWT.RADIO) != 0) {
			return (dwCheckState == OS.BST_CHECKED) ? OS.RBS_CHECKEDHOT : OS.RBS_UNCHECKEDHOT;
		} else {
			return (dwCheckState == OS.BST_CHECKED) ? OS.CBS_CHECKEDHOT : (dwCheckState == OS.BST_UNCHECKED) ? OS.CBS_UNCHECKEDHOT : OS.CBS_MIXEDHOT;
		}
	}
	
	if ((style & SWT.RADIO) != 0) {
		return (dwCheckState == OS.BST_CHECKED) ? OS.RBS_CHECKEDNORMAL : OS.RBS_UNCHECKEDNORMAL;
	} else {
		return (dwCheckState == OS.BST_CHECKED) ? OS.CBS_CHECKEDNORMAL : (dwCheckState == OS.BST_UNCHECKED) ? OS.CBS_UNCHECKEDNORMAL : OS.CBS_MIXEDNORMAL;
	}
}

void enableWidget (boolean enabled) {
	super.enableWidget (enabled);
	/*
	* Bug in Windows.  When a button control is right-to-left and
	* is disabled, the first pixel of the text is clipped.   The
	* fix is to add a space to both sides of the text.
	*/
	if ((style & SWT.RIGHT_TO_LEFT) != 0) {
		if (OS.COMCTL32_MAJOR < 6 || !OS.IsAppThemed ()) {
			int bits = OS.GetWindowLong (handle, OS.GWL_STYLE);
			boolean hasImage = (bits & (OS.BS_BITMAP | OS.BS_ICON)) != 0;
			if (!hasImage) {
				String string = enabled ? text : " " + text + " ";
				TCHAR buffer = new TCHAR (getCodePage (), string, true);
				OS.SetWindowText (handle, buffer);
			}
		}
	}
	/*
	* Bug in Windows.  When a button has the style BS_CHECKBOX
	* or BS_RADIOBUTTON, is checked, and is displaying both an
	* image and some text, when BCM_SETIMAGELIST is used to
	* assign an image list for each of the button states, the
	* button does not draw properly.  When the user drags the
	* mouse in and out of the button, it draws using a blank
	* image.  The fix is to set the complete image list only
	* when the button is disabled.
	*/
	updateImageList ();
}

/**
 * Returns a value which describes the position of the
 * text or image in the receiver. The value will be one of
 * <code>LEFT</code>, <code>RIGHT</code> or <code>CENTER</code>
 * unless the receiver is an <code>ARROW</code> button, in 
 * which case, the alignment will indicate the direction of
 * the arrow (one of <code>LEFT</code>, <code>RIGHT</code>, 
 * <code>UP</code> or <code>DOWN</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 ();
	if ((style & SWT.ARROW) != 0) {
		if ((style & SWT.UP) != 0) return SWT.UP;
		if ((style & SWT.DOWN) != 0) return SWT.DOWN;
		if ((style & SWT.LEFT) != 0) return SWT.LEFT;
		if ((style & SWT.RIGHT) != 0) return SWT.RIGHT;
		return SWT.UP;
	}
	if ((style & SWT.LEFT) != 0) return SWT.LEFT;
	if ((style & SWT.CENTER) != 0) return SWT.CENTER;
	if ((style & SWT.RIGHT) != 0) return SWT.RIGHT;
	return SWT.LEFT;
}

boolean getBufferredPaint() {
	Shell shell = getShell ();
	if ((shell.style & SWT.TRIM_FILL) != 0 && (style & SWT.TRIM_FILL) != 0) {
		if ((style & SWT.PUSH) != 0) return true;
		if ((style & SWT.TOGGLE) != 0) return true;
		if ((style & SWT.RADIO) != 0) return true;
		if ((style & SWT.CHECK) != 0) return true;
		//what about arrow ? should be transparent with custom draw ?
	}
	return false;
}

boolean getDefault () {
	if ((style & SWT.PUSH) == 0) return false;
	int bits = OS.GetWindowLong (handle, OS.GWL_STYLE);
	return (bits & OS.BS_DEFPUSHBUTTON) != 0;
}

/**
 * Returns <code>true</code> if the receiver is grayed,
 * and false otherwise. When the widget does not have
 * the <code>CHECK</code> style, return false.
 *
 * @return the grayed state of the checkbox
 *
 * @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>
 * 
 * @since 3.4
 */
public boolean getGrayed () {
	checkWidget();
	if ((style & SWT.CHECK) == 0) return false;
	return grayed;
}

/**
 * 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 image;
}

/**
 * Returns the widget message. When the widget is created
 * with the style <code>SWT.COMMAND</code>, the message text
 * is displayed to provide further information for the user.
 * 
 * @return the widget message
 *
 * @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>
 * 
 * @since 3.3
 */
/*public*/ String getMessage () {
	checkWidget ();
	return message;
}

String getNameText () {
	return getText ();
}

/**
 * Returns <code>true</code> if the receiver is selected,
 * and false otherwise.
 * <p>
 * When the receiver is of type <code>CHECK</code> or <code>RADIO</code>,
 * it is selected when it is checked. When it is of type <code>TOGGLE</code>,
 * it is selected when it is pushed in. If the receiver is of any other type,
 * this method returns false.
 *
 * @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 ();
	if ((style & (SWT.CHECK | SWT.RADIO | SWT.TOGGLE)) == 0) return false;
	int /*long*/ flags = OS.SendMessage (handle, OS.BM_GETCHECK, 0, 0);
	return flags != OS.BST_UNCHECKED;
}

/**
 * Returns the receiver's text, which will be an empty
 * string if it has never been set or if the receiver is
 * an <code>ARROW</code> button.
 *
 * @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 ();
	if ((style & SWT.ARROW) != 0) return "";
	return text;
}

/*
 * Return the width of the bitmap that is drawn in the background for the radio or checkbox.
 */
int getThemeBitmapWidth (int /*long*/ hTheme, int iPartId, int iState) {
	BITMAP bm = new BITMAP ();
	int /*long*/ [] hBitmap = new int /*long*/ [1];
	OS.GetThemeBitmap (hTheme, iPartId, iState, 0, OS.GBF_DIRECT, hBitmap);
	OS.GetObject (hBitmap[0], BITMAP.sizeof, bm);
	return bm.bmWidth;
}

boolean isTabItem () {
	if ((style & SWT.PUSH) != 0) return isTabGroup ();
	return super.isTabItem ();
}

boolean mnemonicHit (char ch) {
	if (!setFocus ()) return false;
	/*
	* Feature in Windows.  When a radio button gets focus, 
	* it selects the button in WM_SETFOCUS.  Therefore, it
	* is not necessary to click the button or send events
	* because this has already happened in WM_SETFOCUS.
	*/
	if ((style & SWT.RADIO) == 0) click ();
	return true;
}

boolean mnemonicMatch (char key) {
	char mnemonic = findMnemonic (getText ());
	if (mnemonic == '\0') return false;
	return Character.toUpperCase (key) == Character.toUpperCase (mnemonic);
}

void releaseWidget () {
	super.releaseWidget ();
	if (imageList != null) imageList.dispose ();
	imageList = null;
	if (disabledImage != null) disabledImage.dispose ();
	disabledImage = null;
	if (image2 != null) image2.dispose ();
	image2 = null;
	text = null;
	image = null;
}

/**
 * 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
 *
 * @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>
 *
 * @see SelectionListener
 * @see #addSelectionListener
 */
public void removeSelectionListener (SelectionListener listener) {
	checkWidget ();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook (SWT.Selection, listener);
	eventTable.unhook (SWT.DefaultSelection,listener);	
}

void selectRadio () {
	/*
	* This code is intentionally commented.  When two groups
	* of radio buttons with the same parent are separated by
	* another control, the correct behavior should be that
	* the two groups act independently.  This is consistent
	* with radio tool and menu items.  The commented code
	* implements this behavior.
	*/
//	int index = 0;
//	Control [] children = parent._getChildren ();
//	while (index < children.length && children [index] != this) index++;
//	int i = index - 1;
//	while (i >= 0 && children [i].setRadioSelection (false)) --i;
//	int j = index + 1;
//	while (j < children.length && children [j].setRadioSelection (false)) j++;
//	setSelection (true);
	Control [] children = parent._getChildren ();
	for (int i=0; i<children.length; i++) {
		Control child = children [i];
		if (this != child) child.setRadioSelection (false);
	}
	setSelection (true);
}

/**
 * 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>
 * unless the receiver is an <code>ARROW</code> button, in 
 * which case, the argument indicates the direction of
 * the arrow (one of <code>LEFT</code>, <code>RIGHT</code>, 
 * <code>UP</code> or <code>DOWN</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 (int alignment) {
	checkWidget ();
	if ((style & SWT.ARROW) != 0) {
		if ((style & (SWT.UP | SWT.DOWN | SWT.LEFT | SWT.RIGHT)) == 0) return; 
		style &= ~(SWT.UP | SWT.DOWN | SWT.LEFT | SWT.RIGHT);
		style |= alignment & (SWT.UP | SWT.DOWN | SWT.LEFT | SWT.RIGHT);
		OS.InvalidateRect (handle, null, true);
		return;
	}
	if ((alignment & (SWT.LEFT | SWT.RIGHT | SWT.CENTER)) == 0) return;
	style &= ~(SWT.LEFT | SWT.RIGHT | SWT.CENTER);
	style |= alignment & (SWT.LEFT | SWT.RIGHT | SWT.CENTER);
	int oldBits = OS.GetWindowLong (handle, OS.GWL_STYLE), newBits = oldBits;
	newBits &= ~(OS.BS_LEFT | OS.BS_CENTER | OS.BS_RIGHT);
	if ((style & SWT.LEFT) != 0) newBits |= OS.BS_LEFT;
	if ((style & SWT.CENTER) != 0) newBits |= OS.BS_CENTER;
	if ((style & SWT.RIGHT) != 0) newBits |= OS.BS_RIGHT;
	if (OS.COMCTL32_MAJOR >= 6) {
		if (imageList != null) {
			BUTTON_IMAGELIST buttonImageList = new BUTTON_IMAGELIST ();
			buttonImageList.himl = imageList.getHandle ();
			if (text.length () == 0) {
				if ((style & SWT.LEFT) != 0) buttonImageList.uAlign = OS.BUTTON_IMAGELIST_ALIGN_LEFT;
				if ((style & SWT.CENTER) != 0) buttonImageList.uAlign = OS.BUTTON_IMAGELIST_ALIGN_CENTER;
				if ((style & SWT.RIGHT) != 0) buttonImageList.uAlign = OS.BUTTON_IMAGELIST_ALIGN_RIGHT;
			} else {
				buttonImageList.uAlign = OS.BUTTON_IMAGELIST_ALIGN_LEFT;
				buttonImageList.margin_left = computeLeftMargin ();
				buttonImageList.margin_right = MARGIN;
				newBits &= ~(OS.BS_CENTER | OS.BS_RIGHT);
				newBits |= OS.BS_LEFT;
			}
			OS.SendMessage (handle, OS.BCM_SETIMAGELIST, 0, buttonImageList);
		}
	}
	if (newBits != oldBits) {
		OS.SetWindowLong (handle, OS.GWL_STYLE, newBits);
		OS.InvalidateRect (handle, null, true);
	}
}

void setDefault (boolean value) {
	if ((style & SWT.PUSH) == 0) return;
	int /*long*/ hwndShell = menuShell ().handle;
	int bits = OS.GetWindowLong (handle, OS.GWL_STYLE);
	if (value) {
		bits |= OS.BS_DEFPUSHBUTTON;
		OS.SendMessage (hwndShell, OS.DM_SETDEFID, handle, 0);
	} else {
		bits &= ~OS.BS_DEFPUSHBUTTON;
		OS.SendMessage (hwndShell, OS.DM_SETDEFID, 0, 0);
	}
	OS.SendMessage (handle, OS.BM_SETSTYLE, bits, 1);
}

public boolean setFocus () {
	checkWidget ();
	/*
	* Feature in Windows.  When a radio button gets focus, 
	* it selects the button in WM_SETFOCUS.  The fix is to
	* not assign focus to an unselected radio button.
	*/
	if ((style & SWT.RADIO) != 0 && !getSelection () && display.fixFocus) return false;
	return super.setFocus ();
}

/**
 * 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 (Image image) {
	checkWidget ();
	if (image != null && image.isDisposed()) error(SWT.ERROR_INVALID_ARGUMENT);
	if ((style & SWT.ARROW) != 0) return;
	this.image = image;
	/* This code is intentionally commented */
//	if (OS.COMCTL32_MAJOR < 6) {
//		if (image == null || text.length () != 0) {
//			_setText (text);
//			return;
//		}
//	}
	_setImage (image);
}

/**
 * Sets the grayed state of the receiver.  This state change 
 * only applies if the control was created with the SWT.CHECK
 * style.
 *
 * @param grayed the new grayed 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>
 * 
 * @since 3.4
 */
public void setGrayed (boolean grayed) {
	checkWidget ();
	if ((style & SWT.CHECK) == 0) return;
	this.grayed = grayed;
	int /*long*/ flags = OS.SendMessage (handle, OS.BM_GETCHECK, 0, 0);
	if (grayed) {
		if (flags == OS.BST_CHECKED) updateSelection (OS.BST_INDETERMINATE);
	} else {
		if (flags == OS.BST_INDETERMINATE) updateSelection (OS.BST_CHECKED);
	}
}

/**
 * Sets the widget message. When the widget is created
 * with the style <code>SWT.COMMAND</code>, the message text
 * is displayed to provide further information for the user.
 * 
 * @param message the new message
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the string 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>
 * 
 * @since 3.3
 */
/*public*/ void setMessage (String message) {
	checkWidget ();
	if (message == null) error (SWT.ERROR_NULL_ARGUMENT);
	this.message = message;
	if (OS.COMCTL32_VERSION >= OS.VERSION (6, 1)) {
		if ((style & SWT.COMMAND) != 0) {
			int length = message.length ();
			char [] chars = new char [length + 1];
			message.getChars(0, length, chars, 0);
			OS.SendMessage (handle, OS.BCM_SETNOTE, 0, chars);
		}
	}
}

boolean setRadioFocus (boolean tabbing) {
	if ((style & SWT.RADIO) == 0 || !getSelection ()) return false;
	return tabbing ? setTabItemFocus () : setFocus ();
}

boolean setRadioSelection (boolean value) {
	if ((style & SWT.RADIO) == 0) return false;
	if (getSelection () != value) {
		setSelection (value);
		sendSelectionEvent (SWT.Selection);
	}
	return true;
}

boolean setSavedFocus () {
	/*
	* Feature in Windows.  When a radio button gets focus, 
	* it selects the button in WM_SETFOCUS.  If the previous
	* saved focus widget was a radio button, allowing the shell
	* to automatically restore the focus to the previous radio
	* button will unexpectedly check that button.  The fix is to
	* not assign focus to an unselected radio button.
	*/
	if ((style & SWT.RADIO) != 0 && !getSelection ()) return false;
	return super.setSavedFocus ();
}

/**
 * Sets the selection state of the receiver, if it is of type <code>CHECK</code>, 
 * <code>RADIO</code>, or <code>TOGGLE</code>.
 *
 * <p>
 * When the receiver is of type <code>CHECK</code> or <code>RADIO</code>,
 * it is selected when it is checked. When it is of type <code>TOGGLE</code>,
 * it is selected when it is pushed in.
 *
 * @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 (boolean selected) {
	checkWidget ();
	if ((style & (SWT.CHECK | SWT.RADIO | SWT.TOGGLE)) == 0) return;
	int flags = selected ? OS.BST_CHECKED : OS.BST_UNCHECKED;
	if ((style & SWT.CHECK) != 0) {
		if (selected && grayed) flags = OS.BST_INDETERMINATE;
	}
	updateSelection (flags);
}

/**
 * Sets the receiver's text.
 * <p>
 * This method sets the button label.  The label may include
 * the mnemonic character but must not contain line delimiters.
 * </p>
 * <p>
 * Mnemonics are indicated by an '&amp;' that causes the next
 * character to be the mnemonic.  When the user presses a
 * key sequence that matches the mnemonic, a selection
 * event occurs. On most platforms, the mnemonic appears
 * underlined but may be emphasized in a platform specific
 * manner.  The mnemonic indicator character '&amp;' can be
 * escaped by doubling it in the string, causing a single
 * '&amp;' to be displayed.
 * </p><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 string 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 (String string) {
	checkWidget ();
	if (string == null) error (SWT.ERROR_NULL_ARGUMENT);
	if ((style & SWT.ARROW) != 0) return;
	text = string;
	/* This code is intentionally commented */
//	if (OS.COMCTL32_MAJOR < 6) {
//		if (text.length () == 0 && image != null) {
//			_setImage (image);
//			return;
//		}
//	}
	_setText (string);
}

void updateImageList () {
	if (OS.COMCTL32_MAJOR >= 6) {
		if (imageList != null) {
			BUTTON_IMAGELIST buttonImageList = new BUTTON_IMAGELIST ();
			OS.SendMessage (handle, OS.BCM_GETIMAGELIST, 0, buttonImageList);
			if (imageList != null) imageList.dispose ();
			imageList = new ImageList (style & SWT.RIGHT_TO_LEFT);
			if (OS.IsWindowEnabled (handle)) {
				imageList.add (image);
			} else {
				if (disabledImage != null) disabledImage.dispose ();
				disabledImage = new Image (display, image, SWT.IMAGE_DISABLE);
				imageList.add (disabledImage);
			}
			buttonImageList.himl = imageList.getHandle ();
			OS.SendMessage (handle, OS.BCM_SETIMAGELIST, 0, buttonImageList);
			/*
			* Bug in Windows.  Under certain cirumstances yet to be
			* isolated, BCM_SETIMAGELIST does not redraw the control
			* when an image is set.  The fix is to force a redraw.
			*/
			OS.InvalidateRect (handle, null, true);
		}
	}	
}

void updateOrientation () {
	super.updateOrientation ();
	updateImageList ();
}

void updateSelection (int flags) {
	if (flags != OS.SendMessage (handle, OS.BM_GETCHECK, 0, 0)) {
		/*
		* Feature in Windows. When BM_SETCHECK is used
		* to set the checked state of a radio or check
		* button, it sets the WS_TABSTOP style.  This
		* is undocumented and unwanted.  The fix is
		* to save and restore the window style bits.
		*/
		int bits = OS.GetWindowLong (handle, OS.GWL_STYLE);
		if ((style & SWT.CHECK) != 0) {
			if (flags == OS.BST_INDETERMINATE) {
				bits &= ~OS.BS_CHECKBOX;
				bits |= OS.BS_3STATE;
			} else {
				bits |= OS.BS_CHECKBOX;
				bits &= ~OS.BS_3STATE;
			}
			if (bits != OS.GetWindowLong (handle, OS.GWL_STYLE)) {
				OS.SetWindowLong (handle, OS.GWL_STYLE, bits);
			}
		}
		OS.SendMessage (handle, OS.BM_SETCHECK, flags, 0);
		if (bits != OS.GetWindowLong (handle, OS.GWL_STYLE)) {
			OS.SetWindowLong (handle, OS.GWL_STYLE, bits);
		}
	}
}

int widgetStyle () {
	int bits = super.widgetStyle ();
	if ((style & SWT.FLAT) != 0) bits |= OS.BS_FLAT;
	if ((style & SWT.ARROW) != 0) return bits | OS.BS_OWNERDRAW;
	if ((style & SWT.LEFT) != 0) bits |= OS.BS_LEFT;
	if ((style & SWT.CENTER) != 0) bits |= OS.BS_CENTER;
	if ((style & SWT.RIGHT) != 0) bits |= OS.BS_RIGHT;
	if ((style & SWT.WRAP) != 0) bits |= OS.BS_MULTILINE;
	if ((style & SWT.PUSH) != 0) return bits | OS.BS_PUSHBUTTON | OS.WS_TABSTOP;
	if ((style & SWT.CHECK) != 0) return bits | OS.BS_CHECKBOX | OS.WS_TABSTOP;
	if ((style & SWT.RADIO) != 0) return bits | OS.BS_RADIOBUTTON;
	if ((style & SWT.TOGGLE) != 0) return bits | OS.BS_PUSHLIKE | OS.BS_CHECKBOX | OS.WS_TABSTOP;
	if ((style & SWT.COMMAND) != 0) return bits | OS.BS_COMMANDLINK | OS.WS_TABSTOP;
	return bits | OS.BS_PUSHBUTTON | OS.WS_TABSTOP;
}

TCHAR windowClass () {
	return ButtonClass;
}

int /*long*/ windowProc () {
	return ButtonProc;
}


LRESULT WM_ERASEBKGND (int /*long*/ wParam, int /*long*/ lParam) {
	LRESULT result = super.WM_ERASEBKGND (wParam, lParam);
	if (result != null) return result;
	/*
	* Bug in Windows.  For some reason, the HBRUSH that
	* is returned from WM_CTRLCOLOR is misaligned when
	* the button uses it to draw.  If the brush is a solid
	* color, this does not matter.  However, if the brush
	* contains an image, the image is misaligned.  The
	* fix is to draw the background in WM_ERASEBKGND.
	*/
	if (OS.COMCTL32_MAJOR < 6) {
		if ((style & (SWT.RADIO | SWT.CHECK)) != 0) {
			if (findImageControl () != null) {
				drawBackground (wParam);
				return LRESULT.ONE;
			}
		}
	}
	return result;
}

LRESULT WM_GETDLGCODE (int /*long*/ wParam, int /*long*/ lParam) {
	LRESULT result = super.WM_GETDLGCODE (wParam, lParam);
	if (result != null) return result;
	if ((style & SWT.ARROW) != 0) {
		return new LRESULT (OS.DLGC_STATIC);
	}
	return result;
}

LRESULT WM_KILLFOCUS (int /*long*/ wParam, int /*long*/ lParam) {
	LRESULT result = super.WM_KILLFOCUS (wParam, lParam);
	if ((style & SWT.PUSH) != 0 && getDefault ()) {
		menuShell ().setDefaultButton (null, false);
	}
	return result;
}

LRESULT WM_LBUTTONDOWN (int /*long*/ wParam, int /*long*/ lParam) {
	if (ignoreMouse) return null;
	return super.WM_LBUTTONDOWN (wParam, lParam);
}

LRESULT WM_LBUTTONUP (int /*long*/ wParam, int /*long*/ lParam) {
	if (ignoreMouse) return null;
	return super.WM_LBUTTONUP (wParam, lParam);
}

LRESULT WM_SETFOCUS (int /*long*/ wParam, int /*long*/ lParam) {
	/*
	* Feature in Windows. When Windows sets focus to
	* a radio button, it sets the WS_TABSTOP style.
	* This is undocumented and unwanted.  The fix is
	* to save and restore the window style bits.
	*/
	int bits = 0;
	if ((style & SWT.RADIO) != 0) {
		bits = OS.GetWindowLong (handle, OS.GWL_STYLE);
	}
	LRESULT result = super.WM_SETFOCUS (wParam, lParam);
	if ((style & SWT.RADIO) != 0) {
		OS.SetWindowLong (handle, OS.GWL_STYLE, bits);
	}
	if ((style & SWT.PUSH) != 0) {
		menuShell ().setDefaultButton (this, false);
	}
	return result;
}

LRESULT WM_SIZE (int /*long*/ wParam, int /*long*/ lParam) {
	LRESULT result = super.WM_SIZE (wParam, lParam);
	if (result != null) return result;
	if (OS.COMCTL32_MAJOR >= 6) {
		if ((style & (SWT.PUSH | SWT.TOGGLE)) != 0) {
			if (imageList != null && text.length () != 0) {
				BUTTON_IMAGELIST buttonImageList = new BUTTON_IMAGELIST ();
				OS.SendMessage (handle, OS.BCM_GETIMAGELIST, 0, buttonImageList);
				buttonImageList.uAlign = OS.BUTTON_IMAGELIST_ALIGN_LEFT;
				buttonImageList.margin_left = computeLeftMargin ();
				buttonImageList.margin_right = MARGIN;
				OS.SendMessage (handle, OS.BCM_SETIMAGELIST, 0, buttonImageList);
			}
		}
	}
	return result;
}

LRESULT WM_SYSCOLORCHANGE (int /*long*/ wParam, int /*long*/ lParam) {
	LRESULT result = super.WM_SYSCOLORCHANGE (wParam, lParam);
	if (result != null) return result;
	if (image2 != null) _setImage (image);
	return result;
}

LRESULT WM_UPDATEUISTATE (int /*long*/ wParam, int /*long*/ lParam) {
	LRESULT result = super.WM_UPDATEUISTATE (wParam, lParam);
	if (result != null) return result;
	/*
	* Feature in Windows.  When WM_UPDATEUISTATE is sent to
	* a button, it sends WM_CTLCOLORBTN to get the foreground
	* and background.  If drawing happens in WM_CTLCOLORBTN,
	* it will overwrite the contents of the control.  The
	* fix is draw the button without drawing the background
	* and avoid the button window proc.
	* 
	* NOTE:  This only happens for radio, check and toggle
	* buttons.
	*/
	if (!OS.IsWinCE && OS.WIN32_VERSION >= OS.VERSION (6, 0)) {
		if ((style & (SWT.RADIO | SWT.CHECK | SWT.TOGGLE)) != 0) {
			boolean redraw = findImageControl () != null;
			if (!redraw) {
				if ((state & THEME_BACKGROUND) != 0) {
					if (OS.COMCTL32_MAJOR >= 6 && OS.IsAppThemed ()) {
						redraw = findThemeControl () != null;
					}
				}
				if (!redraw) redraw = findBackgroundControl () != null;
			}
			if (redraw) {
				OS.InvalidateRect (handle, null, false);
				int /*long*/ code = OS.DefWindowProc (handle, OS.WM_UPDATEUISTATE, wParam, lParam);
				return new LRESULT (code);
			}
		}
	}
	/*
	* Feature in Windows.  Push and toggle buttons draw directly
	* in WM_UPDATEUISTATE rather than damaging and drawing later
	* in WM_PAINT.  This means that clients who hook WM_PAINT
	* expecting to get all the drawing will not.  The fix is to
	* redraw the control when paint events are hooked.
	*/
	if ((style & (SWT.PUSH | SWT.TOGGLE)) != 0) {
		if (hooks (SWT.Paint) || filters (SWT.Paint)) OS.InvalidateRect (handle, null, true);
	}
	return result;
}

LRESULT wmBufferedPaint (int /*long*/ hWnd, int /*long*/ wParam, int /*long*/ lParam) {
	int /*long*/ paintDC = 0;
	PAINTSTRUCT ps = new PAINTSTRUCT ();
	paintDC = OS.BeginPaint (hWnd, ps);
	
	RECT rcClient = new RECT();
	OS.GetClientRect (hWnd, rcClient);

	// setup the theme parameters
	int /*long*/ hTheme = display.hButtonTheme(); 
	int iPartId = ((style & SWT.PUSH) != 0 || (style & SWT.TOGGLE) != 0) ? OS.BP_PUSHBUTTON : ((style & SWT.RADIO) != 0) ? OS.BP_RADIOBUTTON : OS.BP_CHECKBOX;
	int iState = ((style & SWT.PUSH) != 0 || (style & SWT.TOGGLE) != 0) ? determineStateOfPushButton() : determineStateOfRadioOrCheck();

	// initialize the buffered painting device context
	BP_PAINTPARAMS params = new BP_PAINTPARAMS();
	params.cbSize = BP_PAINTPARAMS.sizeof;
	params.dwFlags = OS.BPPF_ERASE;
	int /*long*/ [] hdcBuffered = new int /*long*/ [1];
	int /*long*/ hBufferedPaint = OS.BeginBufferedPaint(paintDC, rcClient, OS.BPBF_TOPDOWNDIB, params, hdcBuffered);
	OS.PatBlt(hdcBuffered[0], 0, 0, rcClient.right, rcClient.bottom, OS.BLACKNESS);
	OS.BufferedPaintSetAlpha(hdcBuffered[0], rcClient, (byte)0x00);
	
	// the DrawThemeBackground will draw the radio button or checkbox in the middle of the button's client
	// area, and hence we need shift the painting rectangle off to the left if this is not a pushbutton
	int bitmapWidth = ((style & SWT.PUSH) != 0 || (style & SWT.TOGGLE) != 0) ? 0 : getThemeBitmapWidth(hTheme, iPartId, iState);
	int bitmapOffset = ((style & SWT.PUSH) != 0 || (style & SWT.TOGGLE) != 0) ? 0 : (rcClient.right - rcClient.left) / 2 - bitmapWidth / 2;
	RECT rcBackground = new RECT();
	rcBackground.top = rcClient.top;
	rcBackground.bottom = rcClient.bottom;
	rcBackground.left = rcClient.left - bitmapOffset;
	rcBackground.right = rcClient.right - bitmapOffset;
	
	// get the coordinates of the content rectangle and draw the background bitmap (the content rectangle is later fed into
	// DrawThemeTextEx and is also used for the focus rectangle)
	RECT rcContent = new RECT();
	OS.GetThemeBackgroundContentRect(hTheme, hdcBuffered[0], iPartId, iState, rcClient, rcContent);
	OS.DrawThemeBackground(hTheme, hdcBuffered[0], iPartId, iState, rcBackground, null);

	// setup the DTTOPTS structure for calling into DrawThemeTextEx - note how we call getThemeGlowSize()
	// to apply a glow around the text we are drawing to enhance readability of the text against a glass background
	DTTOPTS dttOpts =new DTTOPTS();
	dttOpts.dwSize = DTTOPTS.sizeof;
	dttOpts.dwFlags = OS.DTT_COMPOSITED | OS.DTT_GLOWSIZE;
	dttOpts.iGlowSize = getThemeGlowSize();
	
	// set font before drawing the text
	int /*long*/ hFont = OS.SendMessage(handle, OS.WM_GETFONT, 0, 0);
	if (hFont != 0) {
		hFont = OS.SelectObject(hdcBuffered[0], hFont);
	}

	// draw the button text in an aero/glass friendly manner
	rcContent.left += bitmapWidth; // adjust the drawing rectangle to accomodate for the bitmap in case of radio or checkbox
	int dwFlags = OS.DT_SINGLELINE | OS.DT_CENTER | OS.DT_VCENTER;
	TCHAR buffer = new TCHAR (getCodePage (), text, true);
	OS.DrawThemeTextEx(hTheme, hdcBuffered[0], iPartId, iState, buffer.chars, buffer.length()-1, dwFlags, rcContent, dttOpts);
	
	// draw the focus rectangle if needed
	if (OS.GetFocus()==handle) {
		OS.DrawFocusRect(hdcBuffered[0], rcContent);
	}

	if (hFont != 0) {
		OS.SelectObject(hdcBuffered[0], hFont);
	}
	
	OS.EndBufferedPaint(hBufferedPaint, true);
	OS.EndPaint (handle, ps);
	return LRESULT.ZERO;
}

LRESULT wmCommandChild (int /*long*/ wParam, int /*long*/ lParam) {
	int code = OS.HIWORD (wParam);
	switch (code) {
		case OS.BN_CLICKED:
		case OS.BN_DOUBLECLICKED:
			if ((style & (SWT.CHECK | SWT.TOGGLE)) != 0) {
				setSelection (!getSelection ());
			} else {
				if ((style & SWT.RADIO) != 0) {
					if ((parent.getStyle () & SWT.NO_RADIO_GROUP) != 0) {
						setSelection (!getSelection ());
					} else {
						selectRadio ();
					}
				}
			}
			sendSelectionEvent (SWT.Selection);
	}
	return super.wmCommandChild (wParam, lParam);
}

LRESULT wmColorChild (int /*long*/ wParam, int /*long*/ lParam) {
	/*
	* Bug in Windows.  For some reason, the HBRUSH that
	* is returned from WM_CTRLCOLOR is misaligned when
	* the button uses it to draw.  If the brush is a solid
	* color, this does not matter.  However, if the brush
	* contains an image, the image is misaligned.  The
	* fix is to draw the background in WM_ERASEBKGND.
	*/
	LRESULT result = super.wmColorChild (wParam, lParam);
	if (OS.COMCTL32_MAJOR < 6) {
		if ((style & (SWT.RADIO | SWT.CHECK)) != 0) {
			if (findImageControl () != null) {
				OS.SetBkMode (wParam, OS.TRANSPARENT);
				return new LRESULT (OS.GetStockObject (OS.NULL_BRUSH));
			}
		}
	}
	return result;
}

LRESULT wmDrawChild (int /*long*/ wParam, int /*long*/ lParam) {
	if ((style & SWT.ARROW) == 0) return super.wmDrawChild (wParam, lParam);
	DRAWITEMSTRUCT struct = new DRAWITEMSTRUCT ();
	OS.MoveMemory (struct, lParam, DRAWITEMSTRUCT.sizeof);
	RECT rect = new RECT ();
	OS.SetRect (rect, struct.left, struct.top, struct.right, struct.bottom);
	if (OS.COMCTL32_MAJOR >= 6 && OS.IsAppThemed ()) {
		int iStateId = OS.ABS_LEFTNORMAL;
		switch (style & (SWT.UP | SWT.DOWN | SWT.LEFT | SWT.RIGHT)) {
			case SWT.UP: iStateId = OS.ABS_UPNORMAL; break;
			case SWT.DOWN: iStateId = OS.ABS_DOWNNORMAL; break;
			case SWT.LEFT: iStateId = OS.ABS_LEFTNORMAL; break;
			case SWT.RIGHT: iStateId = OS.ABS_RIGHTNORMAL; break;
		}
		/*
		* Feature in Windows.  On Vista only, DrawThemeBackground()
		* does not mirror the drawing. The fix is switch left to right
		* and right to left.
		*/
		if (!OS.IsWinCE && OS.WIN32_VERSION >= OS.VERSION (6, 0)) {
			if ((style & SWT.MIRRORED) != 0) {
				if ((style & (SWT.LEFT | SWT.RIGHT)) != 0) {
					iStateId = iStateId == OS.ABS_RIGHTNORMAL ? OS.ABS_LEFTNORMAL : OS.ABS_RIGHTNORMAL; 
				}
			}
		}
		/*
		* NOTE: The normal, hot, pressed and disabled state is
		* computed relying on the fact that the increment between
		* the direction states is invariant (always separated by 4).
		*/
		if (!getEnabled ()) iStateId += OS.ABS_UPDISABLED - OS.ABS_UPNORMAL;
		if ((struct.itemState & OS.ODS_SELECTED) != 0) iStateId += OS.ABS_UPPRESSED - OS.ABS_UPNORMAL;
		OS.DrawThemeBackground (display.hScrollBarTheme (), struct.hDC, OS.SBP_ARROWBTN, iStateId, rect, null);
	} else {
		int uState = OS.DFCS_SCROLLLEFT;
		switch (style & (SWT.UP | SWT.DOWN | SWT.LEFT | SWT.RIGHT)) {
			case SWT.UP: uState = OS.DFCS_SCROLLUP; break;
			case SWT.DOWN: uState = OS.DFCS_SCROLLDOWN; break;
			case SWT.LEFT: uState = OS.DFCS_SCROLLLEFT; break;
			case SWT.RIGHT: uState = OS.DFCS_SCROLLRIGHT; break;
		}
		if (!getEnabled ()) uState |= OS.DFCS_INACTIVE;
		if ((style & SWT.FLAT) == SWT.FLAT) uState |= OS.DFCS_FLAT;
		if ((struct.itemState & OS.ODS_SELECTED) != 0) uState |= OS.DFCS_PUSHED;
		OS.DrawFrameControl (struct.hDC, rect, OS.DFC_SCROLL, uState);
	}
	return null;
}

}