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

/*******************************************************************************
 * Copyright (c) 2000, 2009 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.photon.*;
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</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 = "";
	Image image;
	boolean grayed;

/**
 * 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));
}

static int checkStyle (int style) {
	style = checkBits (style, SWT.PUSH, SWT.ARROW, SWT.CHECK, SWT.RADIO, SWT.TOGGLE, 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;
}

/**
 * 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);
}

void click () {
	click (handle);
}

public Point computeSize (int wHint, int hHint, boolean changed) {
	checkWidget();
	int border = getBorderWidth ();
	int width = border * 2, height = border * 2;
	if ((style & SWT.ARROW) != 0) {
		if (wHint != SWT.DEFAULT) width += wHint;
		else width = 17;
		if (hHint != SWT.DEFAULT) height += hHint;
		else height = 17;
		return new Point (width, height);
	}
	PhDim_t dim = new PhDim_t();
	if (!OS.PtWidgetIsRealized (handle)) OS.PtExtentWidget (handle);
	OS.PtWidgetPreferredSize(handle, dim);
	width = dim.w; height = dim.h;
	if (wHint != SWT.DEFAULT || hHint != SWT.DEFAULT) {
		int [] args = {
			OS.Pt_ARG_MARGIN_LEFT, 0, 0,	// 1
			OS.Pt_ARG_MARGIN_RIGHT, 0, 0,	// 4
			OS.Pt_ARG_MARGIN_TOP, 0, 0,		// 7
			OS.Pt_ARG_MARGIN_BOTTOM, 0, 0,	// 10
//			OS.Pt_ARG_MARGIN_WIDTH, 0, 0,	// 13
//			OS.Pt_ARG_MARGIN_HEIGHT, 0, 0,	// 16
		};
		OS.PtGetResources (handle, args.length / 3, args);
		PhArea_t area = new PhArea_t ();
		area.size_w = (short) wHint;
		area.size_h = (short) hHint;

		/*
		* This code is intentionally commented. Bug compatible with Windows.
		*/
//		PhRect_t rect = new PhRect_t ();
//		rect.lr_x = (short) (wHint - 1);
//		rect.lr_y = (short) (hHint - 1);
//		OS.PtSetAreaFromWidgetCanvas (handle, rect, area);
		if (wHint != SWT.DEFAULT) {
			width = area.size_w + /*(args [13] * 2)*/ + args [1] + args [4];
		}
		if (hHint != SWT.DEFAULT) {
			height = area.size_h + /*(args [16] * 2)*/ + args [7] + args [10];
		}
	}
	return new Point (width, height);
}

void createHandle (int index) {
	state |= HANDLE;
	int parentHandle = parent.parentingHandle ();
		
	/* ARROW button */
	if ((style & SWT.ARROW) != 0) {
		int [] args = {
			OS.Pt_ARG_FLAGS, 0, OS.Pt_GETS_FOCUS,
			OS.Pt_ARG_BASIC_FLAGS, OS.Pt_HORIZONTAL_GRADIENT, OS.Pt_STATIC_GRADIENT | OS.Pt_HORIZONTAL_GRADIENT,
			OS.Pt_ARG_RESIZE_FLAGS, 0, OS.Pt_RESIZE_XY_BITS,
		};
		handle = OS.PtCreateWidget (display.PtButton, parentHandle, args.length / 3, args);
		if (handle == 0) error (SWT.ERROR_NO_HANDLES);
		return;
	}

	/* Compute alignment */
	int alignment = OS.Pt_LEFT;
	if ((style & SWT.CENTER) != 0) alignment = OS.Pt_CENTER;
	if ((style & SWT.RIGHT) != 0) alignment = OS.Pt_RIGHT;
	
	/* CHECK or RADIO button */
	if ((style & (SWT.CHECK | SWT.RADIO)) != 0) {
		int [] args = {
			OS.Pt_ARG_HORIZONTAL_ALIGNMENT, alignment, 0,
			OS.Pt_ARG_INDICATOR_TYPE, (style & SWT.CHECK) != 0 ? OS.Pt_N_OF_MANY : OS.Pt_ONE_OF_MANY, 0,
			OS.Pt_ARG_FILL_COLOR, display.WIDGET_BACKGROUND, 0,
			OS.Pt_ARG_RESIZE_FLAGS, 0, OS.Pt_RESIZE_XY_BITS,
		};	

		handle = OS.PtCreateWidget (display.PtToggleButton, parentHandle, args.length / 3, args);
		if (handle == 0) error (SWT.ERROR_NO_HANDLES);
		return;
	}
	
	/* PUSH or TOGGLE button */
	int [] args = {
		OS.Pt_ARG_FLAGS, (style & SWT.TOGGLE) != 0 ? OS.Pt_TOGGLE : 0, OS.Pt_TOGGLE,
		OS.Pt_ARG_HORIZONTAL_ALIGNMENT, alignment, 0,
		OS.Pt_ARG_RESIZE_FLAGS, 0, OS.Pt_RESIZE_XY_BITS,
	};
	handle = OS.PtCreateWidget (display.PtButton, parentHandle, args.length / 3, args);
	if (handle == 0) error (SWT.ERROR_NO_HANDLES);
}

void drawWidget (int widget, int damage) {
	super.drawWidget (widget, damage);
	if ((style & SWT.ARROW) != 0) {
		PhRect_t rect = new PhRect_t ();
		OS.PtCalcCanvas (handle, rect);
		int flags = 0;
		if ((style & SWT.RIGHT) != 0) flags = 2;
		if ((style & SWT.LEFT) != 0) flags = 1;
		if ((style & SWT.DOWN) != 0) flags = 8;
		if ((style & SWT.UP) != 0) flags = 4;
		OS.PgDrawArrow (rect, (short)0, 0x000000, flags);
	}
}

/**
 * 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 getDefault () {
	if ((style & SWT.PUSH) == 0) return false;
	int [] args = {OS.Pt_ARG_BEVEL_CONTRAST, 0, 0};
	OS.PtGetResources (handle, args.length / 3, args);
	return args [1] == 100;
}

/**
 * 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 <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;
	return (OS.PtWidgetFlags (handle) & OS.Pt_SET) != 0;
}

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
 * 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;
}

void hookEvents () {
	super.hookEvents ();
	int windowProc = display.windowProc;
	OS.PtAddCallback (handle, OS.Pt_CB_ACTIVATE, windowProc, OS.Pt_CB_ACTIVATE);
}

int hotkeyProc (int widget, int data, int info) {
	if (setFocus ()) click ();
	return OS.Pt_CONTINUE;
}

int Pt_CB_ACTIVATE (int widget, int info) {
	if ((style & SWT.RADIO) != 0) {
		if ((parent.getStyle () & SWT.NO_RADIO_GROUP) == 0) {
			selectRadio ();
		}
	}
	postEvent (SWT.Selection);
	return OS.Pt_CONTINUE;
}

int Pt_CB_GOT_FOCUS (int widget, int info) {
	int result = super.Pt_CB_GOT_FOCUS (widget, info);
	// widget could be disposed at this point
	if (handle == 0) return result;
	if ((style & SWT.PUSH) == 0) return result;
	getShell ().setDefaultButton (this, false);
	return result;
}

int Pt_CB_LOST_FOCUS (int widget, int info) {
	int result = super.Pt_CB_LOST_FOCUS (widget, info);
	// widget could be disposed at this point
	if (handle == 0) return result;
	if ((style & SWT.PUSH) == 0) return result;
	if (getDefault ()) {
		getShell ().setDefaultButton (null, false);
	}
	return result;
}

void releaseWidget () {
	super.releaseWidget ();
	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.PtDamageWidget (handle);
		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 align = OS.Pt_LEFT;
	if ((style & SWT.CENTER) != 0) align = OS.Pt_CENTER;
	if ((style & SWT.RIGHT) != 0) align = OS.Pt_RIGHT;
	OS.PtSetResource (handle, OS.Pt_ARG_HORIZONTAL_ALIGNMENT, align, 0);
}

void setDefault (boolean value) {
	if ((style & SWT.PUSH) == 0) return;
	if (getShell ().parent == null) return;
	OS.PtSetResource (handle, OS.Pt_ARG_BEVEL_CONTRAST, value ? 100 : 20, 0);
}

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

/**
 * 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;
	OS.PtSetResource (handle, OS.Pt_ARG_FLAGS, selected ? OS.Pt_SET : 0, OS.Pt_SET);
}

/**
 * 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;
}

/**
 * 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 ((style & SWT.ARROW) != 0) return;
	this.image = image;
	int imageHandle = 0;
	if (image != null) {
		if (image.isDisposed()) error(SWT.ERROR_INVALID_ARGUMENT);
		imageHandle = copyPhImage (image.handle);
	}
	int [] args = {
		OS.Pt_ARG_LABEL_IMAGE, imageHandle, 0,
		OS.Pt_ARG_LABEL_TYPE, OS.Pt_IMAGE, 0
	};
	OS.PtSetResources (handle, args.length / 3, args);
	if (imageHandle != 0) OS.free (imageHandle);
}

/**
 * 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;
	char [] text = new char [string.length ()];
	string.getChars (0, text.length, text, 0);
	char mnemonic = fixMnemonic (text);
	byte [] buffer = Converter.wcsToMbcs (null, text, true);
	int ptr1 = OS.malloc (buffer.length);
	OS.memmove (ptr1, buffer, buffer.length);
	int ptr2 = 0;
	if (mnemonic != 0) {
		byte [] buffer2 = Converter.wcsToMbcs (null, new char []{mnemonic}, true);
		ptr2 = OS.malloc (buffer2.length);
		OS.memmove (ptr2, buffer2, buffer2.length);
	}
	replaceMnemonic (mnemonic, true, true);
	int [] args = {
		OS.Pt_ARG_TEXT_STRING, ptr1, 0,
		OS.Pt_ARG_LABEL_TYPE, OS.Pt_Z_STRING, 0,
		OS.Pt_ARG_ACCEL_KEY, ptr2, 0,
	};
	OS.PtSetResources (handle, args.length / 3, args);
	OS.free (ptr1);
	OS.free (ptr2);
}

int traversalCode (int key_sym, PhKeyEvent_t ke) {
	int code = super.traversalCode (key_sym, ke);
	if ((style & SWT.RADIO) != 0) code |= SWT.TRAVERSE_ARROW_NEXT | SWT.TRAVERSE_ARROW_PREVIOUS;
	return code;
}

int widgetClass () {
	if ((style & (SWT.CHECK | SWT.RADIO)) != 0) return OS.PtToggleButton ();
	return OS.PtButton ();
}

}