bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/widgets/Label.java - platform/eclipse.platform.swt - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2019 IBM Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
  * which accompanies this distribution, and is available at
  * https://www.eclipse.org/legal/epl-2.0/
  *
  * SPDX-License-Identifier: EPL-2.0
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *     Paul Pazderski - Bug 205199: setImage(null) on Label overrides text
  *******************************************************************************/
 package org.eclipse.swt.widgets;


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

 /**
  * Instances of this class represent a non-selectable
  * user interface object that displays a string or image.
  * When SEPARATOR is specified, displays a single
  * vertical or horizontal line.
  * <p>
  * Shadow styles are hints and may not be honored
  * by the platform.  To create a separator label
  * with the default shadow style for the platform,
  * do not specify a shadow style.
  * </p>
  * <dl>
  * <dt><b>Styles:</b></dt>
  * <dd>SEPARATOR, HORIZONTAL, VERTICAL</dd>
  * <dd>SHADOW_IN, SHADOW_OUT, SHADOW_NONE</dd>
  * <dd>CENTER, LEFT, RIGHT, WRAP</dd>
  * <dt><b>Events:</b></dt>
  * <dd>(none)</dd>
  * </dl>
  * <p>
  * Note: Only one of SHADOW_IN, SHADOW_OUT and SHADOW_NONE may be specified.
  * SHADOW_NONE is a HINT. Only one of HORIZONTAL and VERTICAL may be specified.
  * Only one of CENTER, LEFT and RIGHT may be specified.
  * </p><p>
  * IMPORTANT: This class is <em>not</em> intended to be subclassed.
  * </p>
  *
  * @see <a href="http://www.eclipse.org/swt/snippets/#label">Label 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 Label extends Control {
 	String text = "";
 	Image image;
 	boolean isImageMode;	// Resolves ambiguity when both image and text are set
 	static final int MARGIN = 4;
 	static final long LabelProc;
 	static final TCHAR LabelClass = new TCHAR (0, "STATIC", true);
 	static {
 		WNDCLASS lpWndClass = new WNDCLASS ();
 		OS.GetClassInfo (0, LabelClass, lpWndClass);
 		LabelProc = 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#SEPARATOR
  * @see SWT#HORIZONTAL
  * @see SWT#VERTICAL
  * @see SWT#SHADOW_IN
  * @see SWT#SHADOW_OUT
  * @see SWT#SHADOW_NONE
  * @see SWT#CENTER
  * @see SWT#LEFT
  * @see SWT#RIGHT
  * @see SWT#WRAP
  * @see Widget#checkSubclass
  * @see Widget#getStyle
  */
 public Label (Composite parent, int style) {
 	super (parent, checkStyle (style));
 }

 @Override
 long callWindowProc (long hwnd, int msg, long wParam, long lParam) {
 	if (handle == 0) return 0;
 	/*
 	* Feature in Windows 7.  When the user double clicks
 	* on the label, the text of the label is copied to the
 	* clipboard.  This is unwanted. The fix is to avoid
 	* calling the label window proc.
 	*/
 	if (OS.WIN32_VERSION >= OS.VERSION(6, 1)) {
 		switch (msg) {
 			case OS.WM_LBUTTONDBLCLK: return OS.DefWindowProc (hwnd, msg, wParam, lParam);
 		}
 	}
 	return OS.CallWindowProc (LabelProc, hwnd, msg, wParam, lParam);
 }

 static int checkStyle (int style) {
 	style |= SWT.NO_FOCUS;
 	if ((style & SWT.SEPARATOR) != 0) {
 		style = checkBits (style, SWT.VERTICAL, SWT.HORIZONTAL, 0, 0, 0, 0);
 		return checkBits (style, SWT.SHADOW_OUT, SWT.SHADOW_IN, SWT.SHADOW_NONE, 0, 0, 0);
 	}
 	return checkBits (style, SWT.LEFT, SWT.CENTER, SWT.RIGHT, 0, 0, 0);
 }

 @Override Point computeSizeInPixels (int wHint, int hHint, boolean changed) {
 	checkWidget ();
 	int width = 0, height = 0, border = getBorderWidthInPixels ();
 	if ((style & SWT.SEPARATOR) != 0) {
 		int lineWidth = OS.GetSystemMetrics (OS.SM_CXBORDER);
 		if ((style & SWT.HORIZONTAL) != 0) {
 			width = DEFAULT_WIDTH;  height = lineWidth * 2;
 		} else {
 			width = lineWidth * 2; height = DEFAULT_HEIGHT;
 		}
 		if (wHint != SWT.DEFAULT) width = wHint;
 		if (hHint != SWT.DEFAULT) height = hHint;
 		width += border * 2; height += border * 2;
 		return new Point (width, height);
 	}
 	if (isImageMode) {
 		Rectangle rect = image.getBoundsInPixels();
 		width += rect.width;
 		height += rect.height;
 	} else {
 		long hDC = OS.GetDC (handle);
 		long newFont = OS.SendMessage (handle, OS.WM_GETFONT, 0, 0);
 		long oldFont = OS.SelectObject (hDC, newFont);
 		int length = OS.GetWindowTextLength (handle);
 		if (length == 0) {
 			TEXTMETRIC tm = new TEXTMETRIC ();
 			OS.GetTextMetrics (hDC, tm);
 			height = Math.max (height, tm.tmHeight);
 		} else {
 			RECT rect = new RECT ();
 			int flags = OS.DT_CALCRECT | OS.DT_EDITCONTROL | OS.DT_EXPANDTABS;
 			if ((style & SWT.WRAP) != 0 && wHint != SWT.DEFAULT) {
 				flags |= OS.DT_WORDBREAK;
 				rect.right = Math.max (0, wHint - width);
 			}
 			char [] buffer = new char [length + 1];
 			OS.GetWindowText (handle, buffer, length + 1);
 			OS.DrawText (hDC, buffer, length, 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 (wHint != SWT.DEFAULT) width = wHint;
 	if (hHint != SWT.DEFAULT) height = hHint;
 	width += border * 2;
 	height += border * 2;
 	return new Point (width, height);
 }

 @Override
 void createHandle () {
 	super.createHandle ();
 	state |= THEME_BACKGROUND;
 }

 /**
  * 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 a <code>SEPARATOR</code> label, in
  * which case, <code>NONE</code> is returned.
  *
  * @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.SEPARATOR) != 0) return 0;
 	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;
 }

 /**
  * 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;
 }

 @Override
 String getNameText () {
 	return getText ();
 }

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

 @Override
 boolean isUseWsBorder () {
 	return super.isUseWsBorder () || ((display != null) && display.useWsBorderLabel);
 }

 @Override
 boolean mnemonicHit (char key) {
 	Control control = this;
 	while (control.parent != null) {
 		Control [] children = control.parent._getChildren ();
 		int index = 0;
 		while (index < children.length) {
 			if (children [index] == control) break;
 			index++;
 		}
 		index++;
 		if (index < children.length) {
 			if (children [index].setFocus ()) return true;
 		}
 		control = control.parent;
 	}
 	return false;
 }

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

 @Override
 void releaseWidget () {
 	super.releaseWidget ();
 	text = null;
 	image = null;
 }

 @Override
 int resolveTextDirection() {
 	return (style & SWT.SEPARATOR) != 0 ? SWT.NONE : BidiUtil.resolveTextDirection (text);
 }

 /**
  * Controls how text and images will be displayed in the receiver.
  * The argument should be one of <code>LEFT</code>, <code>RIGHT</code>
  * or <code>CENTER</code>.  If the receiver is a <code>SEPARATOR</code>
  * label, the argument is ignored and the alignment is not changed.
  *
  * @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.SEPARATOR) != 0) 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);
 	updateStyleBits();
 	OS.InvalidateRect (handle, null, true);
 }

 /**
  * Sets the receiver's image to the argument, which may be
  * null indicating that no image should be displayed.
  *
  * @param image the image to display on the receiver (may be null)
  *
  * @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 ((style & SWT.SEPARATOR) != 0) return;
 	if (image != null && image.isDisposed()) error(SWT.ERROR_INVALID_ARGUMENT);
 	this.image = image;
 	isImageMode = (image != null);
 	updateStyleBits();
 	OS.InvalidateRect (handle, null, true);
 }

 /**
  * Sets the receiver's text.
  * <p>
  * This method sets the widget label.  The label may include
  * the mnemonic character and 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, focus is assigned
  * to the control that follows the label. On most platforms,
  * the mnemonic appears underlined but may be emphasised 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: If control characters like '\n', '\t' etc. are used
  * in the string, then the behavior is platform dependent.
  * </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.SEPARATOR) != 0) return;
 	isImageMode = false;
 	updateStyleBits();
 	/*
 	* Feature in Windows.  For some reason, SetWindowText() for
 	* static controls redraws the control, even when the text has
 	* has not changed.  The fix is to check for this case and do
 	* nothing.
 	*/
 	if (string.equals (text)) return;
 	text = string;
 	string = Display.withCrLf (string);
 	TCHAR buffer = new TCHAR (getCodePage (), string, true);
 	OS.SetWindowText (handle, buffer);
 	if ((state & HAS_AUTO_DIRECTION) != 0) {
 		updateTextDirection (AUTO_TEXT_DIRECTION);
 	}
 }

 void updateStyleBits() {
 	boolean useOwnerDraw = isImageMode;

 	int oldBits = OS.GetWindowLong(handle, OS.GWL_STYLE);

 	int newBits = oldBits;
 	newBits &= ~OS.SS_OWNERDRAW;
 	newBits &= ~(OS.SS_LEFTNOWORDWRAP | OS.SS_CENTER | OS.SS_RIGHT);

 	if (useOwnerDraw) {
 		newBits |= OS.SS_OWNERDRAW;
 	} else {
 		if ((style & SWT.LEFT) != 0) {
 			if ((style & SWT.WRAP) != 0) {
 				newBits |= OS.SS_LEFT;
 			} else {
 				newBits |= OS.SS_LEFTNOWORDWRAP;
 			}
 		}
 		if ((style & SWT.CENTER) != 0) newBits |= OS.SS_CENTER;
 		if ((style & SWT.RIGHT) != 0) newBits |= OS.SS_RIGHT;
 	}

 	if (oldBits != newBits) OS.SetWindowLong (handle, OS.GWL_STYLE, newBits);
 }

 @Override
 int widgetExtStyle () {
 	int bits = super.widgetExtStyle () & ~OS.WS_EX_CLIENTEDGE;
 	if ((style & SWT.BORDER) != 0) return bits | OS.WS_EX_STATICEDGE;
 	return bits;
 }

 @Override
 int widgetStyle () {
 	int bits = super.widgetStyle () | OS.SS_NOTIFY;
 	if ((style & SWT.SEPARATOR) != 0) return bits | OS.SS_OWNERDRAW;
 	if ((style & SWT.WRAP) != 0) bits |= OS.SS_EDITCONTROL;
 	if ((style & SWT.CENTER) != 0) return bits | OS.SS_CENTER;
 	if ((style & SWT.RIGHT) != 0) return bits | OS.SS_RIGHT;
 	if ((style & SWT.WRAP) != 0) return bits | OS.SS_LEFT;
 	return bits | OS.SS_LEFTNOWORDWRAP;
 }

 @Override
 TCHAR windowClass () {
 	return LabelClass;
 }

 @Override
 long windowProc () {
 	return LabelProc;
 }

 @Override
 LRESULT WM_ERASEBKGND (long wParam, long lParam) {
 	LRESULT result = super.WM_ERASEBKGND (wParam, lParam);
 	if (result != null) return result;
 	int bits = OS.GetWindowLong (handle, OS.GWL_STYLE);
 	if ((bits & OS.SS_OWNERDRAW) == OS.SS_OWNERDRAW) {
 		return LRESULT.ONE;
 	}
 	return result;
 }

 @Override
 LRESULT WM_SIZE (long wParam, long lParam) {
 	LRESULT result = super.WM_SIZE (wParam, lParam);
 	if (isDisposed ()) return result;
 	if ((style & SWT.SEPARATOR) != 0) {
 		OS.InvalidateRect (handle, null, true);
 		return result;
 	}
 	int bits = OS.GetWindowLong (handle, OS.GWL_STYLE);
 	if ((bits & OS.SS_OWNERDRAW) == OS.SS_OWNERDRAW) {
 		OS.InvalidateRect (handle, null, true);
 		return result;
 	}
 	/*
 	* Bug in Windows.  For some reason, a label with
 	* style SS_LEFT, SS_CENTER or SS_RIGHT does not
 	* redraw the text in the new position when resized.
 	* Note that SS_LEFTNOWORDWRAP does not have the
 	* problem.  The fix is to force the redraw.
 	*/
 	if ((bits & OS.SS_LEFTNOWORDWRAP) != OS.SS_LEFTNOWORDWRAP) {
 		OS.InvalidateRect (handle, null, true);
 		return result;
 	}
 	return result;
 }

 @Override
 LRESULT WM_UPDATEUISTATE (long wParam, long lParam) {
 	LRESULT result = super.WM_UPDATEUISTATE (wParam, lParam);
 	if (result != null) return result;
 	/*
 	* Feature in Windows.  When WM_UPDATEUISTATE is sent to
 	* a static control, it sends WM_CTLCOLORSTATIC to get the
 	* foreground and background.  If any drawing happens in
 	* WM_CTLCOLORSTATIC, it overwrites the contents of the control.
 	* The fix is draw the static without drawing the background
 	* and avoid the static window proc.
 	*/
 	boolean redraw = findImageControl () != null;
 	if (!redraw) {
 		if ((state & THEME_BACKGROUND) != 0) {
 			if (OS.IsAppThemed ()) {
 				redraw = findThemeControl () != null;
 			}
 		}
 	}
 	if (redraw) {
 		OS.InvalidateRect (handle, null, false);
 		long code = OS.DefWindowProc (handle, OS.WM_UPDATEUISTATE, wParam, lParam);
 		return new LRESULT (code);
 	}
 	return result;
 }

 void wmDrawChildSeparator(DRAWITEMSTRUCT struct) {
 	if ((style & SWT.SHADOW_NONE) != 0) return;

 	RECT rect = new RECT ();
 	int lineWidth = OS.GetSystemMetrics (OS.SM_CXBORDER);
 	int flags = (style & SWT.SHADOW_IN) != 0 ? OS.EDGE_SUNKEN : OS.EDGE_ETCHED;
 	if ((style & SWT.HORIZONTAL) != 0) {
 		int bottom = struct.top + Math.max (lineWidth * 2, (struct.bottom - struct.top) / 2);
 		OS.SetRect (rect, struct.left, struct.top, struct.right, bottom);
 		OS.DrawEdge (struct.hDC, rect, flags, OS.BF_BOTTOM);
 	} else {
 		int right = struct.left + Math.max (lineWidth * 2, (struct.right - struct.left) / 2);
 		OS.SetRect (rect, struct.left, struct.top, right, struct.bottom);
 		OS.DrawEdge (struct.hDC, rect, flags, OS.BF_RIGHT);
 	}
 }

 void wmDrawChildImage(DRAWITEMSTRUCT struct) {
 	int width = struct.right - struct.left;
 	int height = struct.bottom - struct.top;
 	if (width == 0 || height == 0) return;

 	Rectangle imageRect = image.getBoundsInPixels ();

 	int x = 0;
 	if ((style & SWT.CENTER) != 0) {
 		x = Math.max (0, (width - imageRect.width) / 2);
 	} else if ((style & SWT.RIGHT) != 0) {
 		x = width - imageRect.width;
 	}

 	GCData data = new GCData();
 	data.device = display;
 	GC gc = GC.win32_new (struct.hDC, data);
 	Image image = getEnabled () ? this.image : new Image (display, this.image, SWT.IMAGE_DISABLE);
 	gc.drawImage (image, DPIUtil.autoScaleDown(x), DPIUtil.autoScaleDown(Math.max (0, (height - imageRect.height) / 2)));
 	if (image != this.image) image.dispose ();
 	gc.dispose ();
 }

 void wmDrawChildText(DRAWITEMSTRUCT struct) {
 	int width = struct.right - struct.left;
 	int height = struct.bottom - struct.top;
 	if (width == 0 || height == 0) return;

 	RECT rect = new RECT ();
 	rect.left = struct.left;
 	rect.top = struct.top;
 	rect.right = struct.right;
 	rect.bottom = struct.bottom;

 	int flags = OS.DT_EDITCONTROL | OS.DT_EXPANDTABS;
 	if ((style & SWT.LEFT) != 0)   flags |= OS.DT_LEFT;
 	if ((style & SWT.CENTER) != 0) flags |= OS.DT_CENTER;
 	if ((style & SWT.RIGHT) != 0)  flags |= OS.DT_RIGHT;
 	if ((style & SWT.WRAP) != 0)   flags |= OS.DT_WORDBREAK;

 	char [] buffer = text.toCharArray ();
 	OS.DrawText (struct.hDC, buffer, buffer.length, rect, flags);
 }

 @Override
 LRESULT wmDrawChild (long wParam, long lParam) {
 	DRAWITEMSTRUCT struct = new DRAWITEMSTRUCT ();
 	OS.MoveMemory (struct, lParam, DRAWITEMSTRUCT.sizeof);
 	drawBackground (struct.hDC);
 	if ((style & SWT.SEPARATOR) != 0)
 		wmDrawChildSeparator(struct);
 	else if (isImageMode)
 		wmDrawChildImage(struct);
 	else
 		wmDrawChildText(struct);

 	return null;
 }

 }
	/*******************************************************************************
	* Copyright (c) 2000, 2019 IBM Corporation and others.
	*
	* This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License 2.0
	* which accompanies this distribution, and is available at
	* https://www.eclipse.org/legal/epl-2.0/
	*
	* SPDX-License-Identifier: EPL-2.0
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	* Paul Pazderski - Bug 205199: setImage(null) on Label overrides text
	*******************************************************************************/
	package org.eclipse.swt.widgets;


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

	/**
	* Instances of this class represent a non-selectable
	* user interface object that displays a string or image.
	* When SEPARATOR is specified, displays a single
	* vertical or horizontal line.
	* <p>
	* Shadow styles are hints and may not be honored
	* by the platform. To create a separator label
	* with the default shadow style for the platform,
	* do not specify a shadow style.
	* </p>
	* <dl>
	* <dt><b>Styles:</b></dt>
	* <dd>SEPARATOR, HORIZONTAL, VERTICAL</dd>
	* <dd>SHADOW_IN, SHADOW_OUT, SHADOW_NONE</dd>
	* <dd>CENTER, LEFT, RIGHT, WRAP</dd>
	* <dt><b>Events:</b></dt>
	* <dd>(none)</dd>
	* </dl>
	* <p>
	* Note: Only one of SHADOW_IN, SHADOW_OUT and SHADOW_NONE may be specified.
	* SHADOW_NONE is a HINT. Only one of HORIZONTAL and VERTICAL may be specified.
	* Only one of CENTER, LEFT and RIGHT may be specified.
	* </p><p>
	* IMPORTANT: This class is <em>not</em> intended to be subclassed.
	* </p>
	*
	* @see <a href="http://www.eclipse.org/swt/snippets/#label">Label 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 Label extends Control {
	String text = "";
	Image image;
	boolean isImageMode; // Resolves ambiguity when both image and text are set
	static final int MARGIN = 4;
	static final long LabelProc;
	static final TCHAR LabelClass = new TCHAR (0, "STATIC", true);
	static {
	WNDCLASS lpWndClass = new WNDCLASS ();
	OS.GetClassInfo (0, LabelClass, lpWndClass);
	LabelProc = 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#SEPARATOR
	* @see SWT#HORIZONTAL
	* @see SWT#VERTICAL
	* @see SWT#SHADOW_IN
	* @see SWT#SHADOW_OUT
	* @see SWT#SHADOW_NONE
	* @see SWT#CENTER
	* @see SWT#LEFT
	* @see SWT#RIGHT
	* @see SWT#WRAP
	* @see Widget#checkSubclass
	* @see Widget#getStyle
	*/
	public Label (Composite parent, int style) {
	super (parent, checkStyle (style));
	}

	@Override
	long callWindowProc (long hwnd, int msg, long wParam, long lParam) {
	if (handle == 0) return 0;
	/*
	* Feature in Windows 7. When the user double clicks
	* on the label, the text of the label is copied to the
	* clipboard. This is unwanted. The fix is to avoid
	* calling the label window proc.
	*/
	if (OS.WIN32_VERSION >= OS.VERSION(6, 1)) {
	switch (msg) {
	case OS.WM_LBUTTONDBLCLK: return OS.DefWindowProc (hwnd, msg, wParam, lParam);
	}
	}
	return OS.CallWindowProc (LabelProc, hwnd, msg, wParam, lParam);
	}

	static int checkStyle (int style) {
	style \|= SWT.NO_FOCUS;
	if ((style & SWT.SEPARATOR) != 0) {
	style = checkBits (style, SWT.VERTICAL, SWT.HORIZONTAL, 0, 0, 0, 0);
	return checkBits (style, SWT.SHADOW_OUT, SWT.SHADOW_IN, SWT.SHADOW_NONE, 0, 0, 0);
	}
	return checkBits (style, SWT.LEFT, SWT.CENTER, SWT.RIGHT, 0, 0, 0);
	}

	@Override Point computeSizeInPixels (int wHint, int hHint, boolean changed) {
	checkWidget ();
	int width = 0, height = 0, border = getBorderWidthInPixels ();
	if ((style & SWT.SEPARATOR) != 0) {
	int lineWidth = OS.GetSystemMetrics (OS.SM_CXBORDER);
	if ((style & SWT.HORIZONTAL) != 0) {
	width = DEFAULT_WIDTH; height = lineWidth * 2;
	} else {
	width = lineWidth * 2; height = DEFAULT_HEIGHT;
	}
	if (wHint != SWT.DEFAULT) width = wHint;
	if (hHint != SWT.DEFAULT) height = hHint;
	width += border * 2; height += border * 2;
	return new Point (width, height);
	}
	if (isImageMode) {
	Rectangle rect = image.getBoundsInPixels();
	width += rect.width;
	height += rect.height;
	} else {
	long hDC = OS.GetDC (handle);
	long newFont = OS.SendMessage (handle, OS.WM_GETFONT, 0, 0);
	long oldFont = OS.SelectObject (hDC, newFont);
	int length = OS.GetWindowTextLength (handle);
	if (length == 0) {
	TEXTMETRIC tm = new TEXTMETRIC ();
	OS.GetTextMetrics (hDC, tm);
	height = Math.max (height, tm.tmHeight);
	} else {
	RECT rect = new RECT ();
	int flags = OS.DT_CALCRECT \| OS.DT_EDITCONTROL \| OS.DT_EXPANDTABS;
	if ((style & SWT.WRAP) != 0 && wHint != SWT.DEFAULT) {
	flags \|= OS.DT_WORDBREAK;
	rect.right = Math.max (0, wHint - width);
	}
	char [] buffer = new char [length + 1];
	OS.GetWindowText (handle, buffer, length + 1);
	OS.DrawText (hDC, buffer, length, 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 (wHint != SWT.DEFAULT) width = wHint;
	if (hHint != SWT.DEFAULT) height = hHint;
	width += border * 2;
	height += border * 2;
	return new Point (width, height);
	}

	@Override
	void createHandle () {
	super.createHandle ();
	state \|= THEME_BACKGROUND;
	}

	/**
	* 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 a <code>SEPARATOR</code> label, in
	* which case, <code>NONE</code> is returned.
	*
	* @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.SEPARATOR) != 0) return 0;
	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;
	}

	/**
	* 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;
	}

	@Override
	String getNameText () {
	return getText ();
	}

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

	@Override
	boolean isUseWsBorder () {
	return super.isUseWsBorder () \|\| ((display != null) && display.useWsBorderLabel);
	}

	@Override
	boolean mnemonicHit (char key) {
	Control control = this;
	while (control.parent != null) {
	Control [] children = control.parent._getChildren ();
	int index = 0;
	while (index < children.length) {
	if (children [index] == control) break;
	index++;
	}
	index++;
	if (index < children.length) {
	if (children [index].setFocus ()) return true;
	}
	control = control.parent;
	}
	return false;
	}

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

	@Override
	void releaseWidget () {
	super.releaseWidget ();
	text = null;
	image = null;
	}

	@Override
	int resolveTextDirection() {
	return (style & SWT.SEPARATOR) != 0 ? SWT.NONE : BidiUtil.resolveTextDirection (text);
	}

	/**
	* Controls how text and images will be displayed in the receiver.
	* The argument should be one of <code>LEFT</code>, <code>RIGHT</code>
	* or <code>CENTER</code>. If the receiver is a <code>SEPARATOR</code>
	* label, the argument is ignored and the alignment is not changed.
	*
	* @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.SEPARATOR) != 0) 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);
	updateStyleBits();
	OS.InvalidateRect (handle, null, true);
	}

	/**
	* Sets the receiver's image to the argument, which may be
	* null indicating that no image should be displayed.
	*
	* @param image the image to display on the receiver (may be null)
	*
	* @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 ((style & SWT.SEPARATOR) != 0) return;
	if (image != null && image.isDisposed()) error(SWT.ERROR_INVALID_ARGUMENT);
	this.image = image;
	isImageMode = (image != null);
	updateStyleBits();
	OS.InvalidateRect (handle, null, true);
	}

	/**
	* Sets the receiver's text.
	* <p>
	* This method sets the widget label. The label may include
	* the mnemonic character and line delimiters.
	* </p>
	* <p>
	* Mnemonics are indicated by an '&' that causes the next
	* character to be the mnemonic. When the user presses a
	* key sequence that matches the mnemonic, focus is assigned
	* to the control that follows the label. On most platforms,
	* the mnemonic appears underlined but may be emphasised in a
	* platform specific manner. The mnemonic indicator character
	* '&' can be escaped by doubling it in the string, causing
	* a single '&' to be displayed.
	* </p>
	* <p>
	* Note: If control characters like '\n', '\t' etc. are used
	* in the string, then the behavior is platform dependent.
	* </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.SEPARATOR) != 0) return;
	isImageMode = false;
	updateStyleBits();
	/*
	* Feature in Windows. For some reason, SetWindowText() for
	* static controls redraws the control, even when the text has
	* has not changed. The fix is to check for this case and do
	* nothing.
	*/
	if (string.equals (text)) return;
	text = string;
	string = Display.withCrLf (string);
	TCHAR buffer = new TCHAR (getCodePage (), string, true);
	OS.SetWindowText (handle, buffer);
	if ((state & HAS_AUTO_DIRECTION) != 0) {
	updateTextDirection (AUTO_TEXT_DIRECTION);
	}
	}

	void updateStyleBits() {
	boolean useOwnerDraw = isImageMode;

	int oldBits = OS.GetWindowLong(handle, OS.GWL_STYLE);

	int newBits = oldBits;
	newBits &= ~OS.SS_OWNERDRAW;
	newBits &= ~(OS.SS_LEFTNOWORDWRAP \| OS.SS_CENTER \| OS.SS_RIGHT);

	if (useOwnerDraw) {
	newBits \|= OS.SS_OWNERDRAW;
	} else {
	if ((style & SWT.LEFT) != 0) {
	if ((style & SWT.WRAP) != 0) {
	newBits \|= OS.SS_LEFT;
	} else {
	newBits \|= OS.SS_LEFTNOWORDWRAP;
	}
	}
	if ((style & SWT.CENTER) != 0) newBits \|= OS.SS_CENTER;
	if ((style & SWT.RIGHT) != 0) newBits \|= OS.SS_RIGHT;
	}

	if (oldBits != newBits) OS.SetWindowLong (handle, OS.GWL_STYLE, newBits);
	}

	@Override
	int widgetExtStyle () {
	int bits = super.widgetExtStyle () & ~OS.WS_EX_CLIENTEDGE;
	if ((style & SWT.BORDER) != 0) return bits \| OS.WS_EX_STATICEDGE;
	return bits;
	}

	@Override
	int widgetStyle () {
	int bits = super.widgetStyle () \| OS.SS_NOTIFY;
	if ((style & SWT.SEPARATOR) != 0) return bits \| OS.SS_OWNERDRAW;
	if ((style & SWT.WRAP) != 0) bits \|= OS.SS_EDITCONTROL;
	if ((style & SWT.CENTER) != 0) return bits \| OS.SS_CENTER;
	if ((style & SWT.RIGHT) != 0) return bits \| OS.SS_RIGHT;
	if ((style & SWT.WRAP) != 0) return bits \| OS.SS_LEFT;
	return bits \| OS.SS_LEFTNOWORDWRAP;
	}

	@Override
	TCHAR windowClass () {
	return LabelClass;
	}

	@Override
	long windowProc () {
	return LabelProc;
	}

	@Override
	LRESULT WM_ERASEBKGND (long wParam, long lParam) {
	LRESULT result = super.WM_ERASEBKGND (wParam, lParam);
	if (result != null) return result;
	int bits = OS.GetWindowLong (handle, OS.GWL_STYLE);
	if ((bits & OS.SS_OWNERDRAW) == OS.SS_OWNERDRAW) {
	return LRESULT.ONE;
	}
	return result;
	}

	@Override
	LRESULT WM_SIZE (long wParam, long lParam) {
	LRESULT result = super.WM_SIZE (wParam, lParam);
	if (isDisposed ()) return result;
	if ((style & SWT.SEPARATOR) != 0) {
	OS.InvalidateRect (handle, null, true);
	return result;
	}
	int bits = OS.GetWindowLong (handle, OS.GWL_STYLE);
	if ((bits & OS.SS_OWNERDRAW) == OS.SS_OWNERDRAW) {
	OS.InvalidateRect (handle, null, true);
	return result;
	}
	/*
	* Bug in Windows. For some reason, a label with
	* style SS_LEFT, SS_CENTER or SS_RIGHT does not
	* redraw the text in the new position when resized.
	* Note that SS_LEFTNOWORDWRAP does not have the
	* problem. The fix is to force the redraw.
	*/
	if ((bits & OS.SS_LEFTNOWORDWRAP) != OS.SS_LEFTNOWORDWRAP) {
	OS.InvalidateRect (handle, null, true);
	return result;
	}
	return result;
	}

	@Override
	LRESULT WM_UPDATEUISTATE (long wParam, long lParam) {
	LRESULT result = super.WM_UPDATEUISTATE (wParam, lParam);
	if (result != null) return result;
	/*
	* Feature in Windows. When WM_UPDATEUISTATE is sent to
	* a static control, it sends WM_CTLCOLORSTATIC to get the
	* foreground and background. If any drawing happens in
	* WM_CTLCOLORSTATIC, it overwrites the contents of the control.
	* The fix is draw the static without drawing the background
	* and avoid the static window proc.
	*/
	boolean redraw = findImageControl () != null;
	if (!redraw) {
	if ((state & THEME_BACKGROUND) != 0) {
	if (OS.IsAppThemed ()) {
	redraw = findThemeControl () != null;
	}
	}
	}
	if (redraw) {
	OS.InvalidateRect (handle, null, false);
	long code = OS.DefWindowProc (handle, OS.WM_UPDATEUISTATE, wParam, lParam);
	return new LRESULT (code);
	}
	return result;
	}

	void wmDrawChildSeparator(DRAWITEMSTRUCT struct) {
	if ((style & SWT.SHADOW_NONE) != 0) return;

	RECT rect = new RECT ();
	int lineWidth = OS.GetSystemMetrics (OS.SM_CXBORDER);
	int flags = (style & SWT.SHADOW_IN) != 0 ? OS.EDGE_SUNKEN : OS.EDGE_ETCHED;
	if ((style & SWT.HORIZONTAL) != 0) {
	int bottom = struct.top + Math.max (lineWidth * 2, (struct.bottom - struct.top) / 2);
	OS.SetRect (rect, struct.left, struct.top, struct.right, bottom);
	OS.DrawEdge (struct.hDC, rect, flags, OS.BF_BOTTOM);
	} else {
	int right = struct.left + Math.max (lineWidth * 2, (struct.right - struct.left) / 2);
	OS.SetRect (rect, struct.left, struct.top, right, struct.bottom);
	OS.DrawEdge (struct.hDC, rect, flags, OS.BF_RIGHT);
	}
	}

	void wmDrawChildImage(DRAWITEMSTRUCT struct) {
	int width = struct.right - struct.left;
	int height = struct.bottom - struct.top;
	if (width == 0 \|\| height == 0) return;

	Rectangle imageRect = image.getBoundsInPixels ();

	int x = 0;
	if ((style & SWT.CENTER) != 0) {
	x = Math.max (0, (width - imageRect.width) / 2);
	} else if ((style & SWT.RIGHT) != 0) {
	x = width - imageRect.width;
	}

	GCData data = new GCData();
	data.device = display;
	GC gc = GC.win32_new (struct.hDC, data);
	Image image = getEnabled () ? this.image : new Image (display, this.image, SWT.IMAGE_DISABLE);
	gc.drawImage (image, DPIUtil.autoScaleDown(x), DPIUtil.autoScaleDown(Math.max (0, (height - imageRect.height) / 2)));
	if (image != this.image) image.dispose ();
	gc.dispose ();
	}

	void wmDrawChildText(DRAWITEMSTRUCT struct) {
	int width = struct.right - struct.left;
	int height = struct.bottom - struct.top;
	if (width == 0 \|\| height == 0) return;

	RECT rect = new RECT ();
	rect.left = struct.left;
	rect.top = struct.top;
	rect.right = struct.right;
	rect.bottom = struct.bottom;

	int flags = OS.DT_EDITCONTROL \| OS.DT_EXPANDTABS;
	if ((style & SWT.LEFT) != 0) flags \|= OS.DT_LEFT;
	if ((style & SWT.CENTER) != 0) flags \|= OS.DT_CENTER;
	if ((style & SWT.RIGHT) != 0) flags \|= OS.DT_RIGHT;
	if ((style & SWT.WRAP) != 0) flags \|= OS.DT_WORDBREAK;

	char [] buffer = text.toCharArray ();
	OS.DrawText (struct.hDC, buffer, buffer.length, rect, flags);
	}

	@Override
	LRESULT wmDrawChild (long wParam, long lParam) {
	DRAWITEMSTRUCT struct = new DRAWITEMSTRUCT ();
	OS.MoveMemory (struct, lParam, DRAWITEMSTRUCT.sizeof);
	drawBackground (struct.hDC);
	if ((style & SWT.SEPARATOR) != 0)
	wmDrawChildSeparator(struct);
	else if (isImageMode)
	wmDrawChildImage(struct);
	else
	wmDrawChildText(struct);

	return null;
	}

	}