package org.eclipse.swt.widgets;

/*
 * (c) Copyright IBM Corp. 2000, 2001.
 * All Rights Reserved
 */

import org.eclipse.swt.internal.*;
import org.eclipse.swt.internal.photon.*;
import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;

/**
 * Instances of this class provide an etched border
 * with an optional title.
 * <p>
 * Shadow styles are hints and may not be honoured
 * by the platform.  To create a group with the
 * default shadow style for the platform, do not
 * specify a shadow style.
 * <dl>
 * <dt><b>Styles:</b></dt>
 * <dd>SHADOW_ETCHED_IN, SHADOW_ETCHED_OUT, SHADOW_IN, SHADOW_OUT, SHADOW_NONE</dd>
 * <dt><b>Events:</b></dt>
 * <dd>(none)</dd>
 * </dl>
 * <p>
 * IMPORTANT: This class is <em>not</em> intended to be subclassed.
 * </p>
 */
public class Group extends Composite {

/**
 * 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
 * for all SWT widget classes should include a comment which
 * describes the style constants which are applicable to the class.
 * </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
 * @see Widget#checkSubclass
 * @see Widget#getStyle
 */
public Group (Composite parent, int style) {
	super (parent, checkStyle (style));
}

static int checkStyle (int style) {
	/*
	* Even though it is legal to create this widget
	* with scroll bars, they serve no useful purpose
	* because they do not automatically scroll the
	* widget's client area.  The fix is to clear
	* the SWT style.
	*/
	return style & ~(SWT.H_SCROLL | SWT.V_SCROLL);
}

public Point computeSize (int wHint, int hHint, boolean changed) {
	checkWidget();
	Point titleSize = getTitleSize();
	Point size;
	if (layout != null) {
		size = layout.computeSize (this, wHint, hHint, changed);
	} else {
		size = minimumSize ();
	}
	int width = size.x;  int height = size.y;
	if (width == 0) width = DEFAULT_WIDTH;
	if (height == 0) height = DEFAULT_HEIGHT;
	if (wHint != SWT.DEFAULT) width = wHint;
	if (hHint != SWT.DEFAULT) height = hHint;
	Rectangle trim = computeTrim (0, 0, width, height);
	width = Math.max (trim.width, titleSize.x + 6);
	height = trim.height + titleSize.y;
	return new Point (width, height);
}

protected void checkSubclass () {
	if (!isValidSubclass ()) error (SWT.ERROR_INVALID_SUBCLASS);
}

void createHandle (int index) {
	state |= HANDLE;
	Display display = getDisplay ();
	int clazz = display.PtPane;
	int parentHandle = parent.handle;
	int [] args = {
		OS.Pt_ARG_RESIZE_FLAGS, 0, OS.Pt_RESIZE_XY_BITS,
	};
	handle = OS.PtCreateWidget (clazz, parentHandle, args.length / 3, args);
	if (handle == 0) error (SWT.ERROR_NO_HANDLES);
}

/**
 * Returns the receiver's text, which is the string that the
 * is used as the <em>title</em>. If the text has not previously
 * been set, returns an empty string.
 *
 * @return the 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();
	int [] args = {OS.Pt_ARG_TITLE, 0, 0};
	OS.PtGetResources (handle, args.length / 3, args);
	if (args [1] == 0) return "";
	int length = OS.strlen (args [1]);
	byte [] buffer = new byte [length];
	OS.memmove (buffer, args [1], length);
	char [] unicode = Converter.mbcsToWcs (null, buffer);
	return new String (unicode);
}

Point getTitleSize() {
	int width = 0, height = 0;
	int [] args = {
		OS.Pt_ARG_TITLE, 0, 0,
		OS.Pt_ARG_TITLE_FONT, 0, 0,
		OS.Pt_ARG_CONTAINER_FLAGS, 0, 0,
	};
	OS.PtGetResources (handle, args.length / 3, args);
	if ((OS.Pt_ARG_CONTAINER_FLAGS & OS.Pt_SHOW_TITLE) != 0) {
		PhRect_t rect = new PhRect_t();
		if (args [1] != 0) {
			int length = OS.strlen (args [1]);
			OS.PfExtentText(rect, null, args [4], args [1], length);
		}
		int inset = 4;
		width = inset + rect.lr_x - rect.ul_x + 1;
		height = inset + rect.lr_y - rect.ul_y + 1;
	}
	return new Point(width, height);
}

int processPaint (int damage) {
	OS.PtSuperClassDraw (OS.PtPane (), handle, damage);
	sendPaintEvent (damage);
	return OS.Pt_CONTINUE;
}

/**
 * Sets the receiver's text, which is the string that will
 * be displayed as the receiver's <em>title</em>, to the argument,
 * which may not be null. 
 *
 * @param text the new text
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public void setText (String string) {	
	checkWidget();
	if (string == null) error (SWT.ERROR_NULL_ARGUMENT);
	int flags = OS.Pt_SHOW_TITLE | OS.Pt_ETCH_TITLE_AREA | OS.Pt_GRADIENT_TITLE_AREA;
	byte [] buffer = Converter.wcsToMbcs (null, string, true);
	int ptr = OS.malloc (buffer.length);
	OS.memmove (ptr, buffer, buffer.length);
	int [] args = {
		OS.Pt_ARG_TITLE, ptr, 0,
		OS.Pt_ARG_CONTAINER_FLAGS, string.length () == 0 ? 0 : flags, flags,
	};
	OS.PtSetResources (handle, args.length / 3, args);
	OS.free (ptr);
}

}