list.java

源码为Eclipse开源开发平台桌面开发工具SWT的源代码,

/*******************************************************************************
 * Copyright (c) 2000, 2004 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.widgets;


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 displays a list of strings and issues notificiation
 * when a string selected.  A list may be single or multi select.
 * <p>
 * <dl>
 * <dt><b>Styles:</b></dt>
 * <dd>SINGLE, MULTI</dd>
 * <dt><b>Events:</b></dt>
 * <dd>Selection, DefaultSelection</dd>
 * </dl>
 * <p>
 * Note: Only one of SINGLE and MULTI may be specified.
 * </p><p>
 * IMPORTANT: This class is <em>not</em> intended to be subclassed.
 * </p>
 */

public class List extends Scrollable {
	static final int ListProc;
	static final TCHAR ListClass = new TCHAR (0, "LISTBOX", true);
	static {
		WNDCLASS lpWndClass = new WNDCLASS ();
		OS.GetClassInfo (0, ListClass, lpWndClass);
		ListProc = 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#SINGLE
 * @see SWT#MULTI
 * @see Widget#checkSubclass
 * @see Widget#getStyle
 */
public List (Composite parent, int style) {
	super (parent, checkStyle (style));
}
/**
 * Adds the argument to the end of the receiver's list.
 *
 * @param string the new item
 *
 * @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>
 * @exception SWTError <ul>
 *    <li>ERROR_ITEM_NOT_ADDED - if the operation fails because of an operating system failure</li>
 * </ul>
 *
 * @see #add(String,int)
 */
public void add (String string) {
	checkWidget ();
	if (string == null) error (SWT.ERROR_NULL_ARGUMENT);
	TCHAR buffer = new TCHAR (getCodePage (), string, true);
	int result = OS.SendMessage (handle, OS.LB_ADDSTRING, 0, buffer);
	if (result == OS.LB_ERR) error (SWT.ERROR_ITEM_NOT_ADDED);
	if (result == OS.LB_ERRSPACE) error (SWT.ERROR_ITEM_NOT_ADDED);
	if ((style & SWT.H_SCROLL) != 0) setScrollWidth (buffer, true);
}
/**
 * Adds the argument to the receiver's list at the given
 * zero-relative index.
 * <p>
 * Note: To add an item at the end of the list, use the
 * result of calling <code>getItemCount()</code> as the
 * index or use <code>add(String)</code>.
 * </p>
 *
 * @param string the new item
 * @param index the index for the item
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the string is null</li>
 *    <li>ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the list (inclusive)</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>
 * @exception SWTError <ul>
 *    <li>ERROR_ITEM_NOT_ADDED - if the operation fails because of an operating system failure</li>
 * </ul>
 *
 * @see #add(String)
 */
public void add (String string, int index) {
	checkWidget ();
	if (string == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (index == -1) error (SWT.ERROR_INVALID_RANGE);
	TCHAR buffer = new TCHAR (getCodePage (), string, true);
	int result = OS.SendMessage (handle, OS.LB_INSERTSTRING, index, buffer);
	if (result == OS.LB_ERRSPACE) error (SWT.ERROR_ITEM_NOT_ADDED);
	if (result == OS.LB_ERR) {
		int count = OS.SendMessage (handle, OS.LB_GETCOUNT, 0, 0);
		if (0 <= index && index <= count) {
			error (SWT.ERROR_ITEM_NOT_ADDED);
		} else {
			error (SWT.ERROR_INVALID_RANGE);
		}
	}
	if ((style & SWT.H_SCROLL) != 0) setScrollWidth (buffer, true);
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when the receiver's selection changes, by sending
 * it one of the messages defined in the <code>SelectionListener</code>
 * interface.
 * <p>
 * <code>widgetSelected</code> is called when the selection changes.
 * <code>widgetDefaultSelected</code> is typically called when an item is double-clicked.
 * </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 callWindowProc (int msg, int wParam, int lParam) {
	if (handle == 0) return 0;
	return OS.CallWindowProc (ListProc, handle, msg, wParam, lParam);
}

static int checkStyle (int style) {
	return checkBits (style, SWT.SINGLE, SWT.MULTI, 0, 0, 0, 0);
}

public Point computeSize (int wHint, int hHint, boolean changed) {
	checkWidget ();
	int width = 0, height = 0;
	if (wHint == SWT.DEFAULT) {
		if ((style & SWT.H_SCROLL) != 0) {
			width = OS.SendMessage (handle, OS.LB_GETHORIZONTALEXTENT, 0, 0);
		} else {
			int count = OS.SendMessage (handle, OS.LB_GETCOUNT, 0, 0);
			int newFont, oldFont = 0;
			int hDC = OS.GetDC (handle);
			newFont = OS.SendMessage (handle, OS.WM_GETFONT, 0, 0);
			if (newFont != 0) oldFont = OS.SelectObject (hDC, newFont);
			RECT rect = new RECT ();
			int flags = OS.DT_CALCRECT | OS.DT_SINGLELINE | OS.DT_NOPREFIX;
			int cp = getCodePage ();
			TCHAR buffer = new TCHAR (cp, 64 + 1);
			for (int i=0; i<count; i++) {
				int length = OS.SendMessage (handle, OS.LB_GETTEXTLEN, i, 0);
				if (length != OS.LB_ERR) {
					if (length + 1 > buffer.length ()) {
						buffer = new TCHAR (cp, length + 1);
					}
					int result = OS.SendMessage (handle, OS.LB_GETTEXT, i, buffer);
					if (result != OS.LB_ERR) {
						OS.DrawText (hDC, buffer, length, rect, flags);
						width = Math.max (width, rect.right - rect.left);
					}
				}
			}	
			if (newFont != 0) OS.SelectObject (hDC, oldFont);
			OS.ReleaseDC (handle, hDC);
		}
	}
	if (hHint == SWT.DEFAULT) {
		int count = OS.SendMessage (handle, OS.LB_GETCOUNT, 0, 0);
		int itemHeight = OS.SendMessage (handle, OS.LB_GETITEMHEIGHT, 0, 0);
	 	height = count * itemHeight;
	}
	if (width == 0) width = DEFAULT_WIDTH;
	if (height == 0) height = DEFAULT_HEIGHT;
	if (wHint != SWT.DEFAULT) width = wHint;
	if (hHint != SWT.DEFAULT) height = hHint;
	int border = getBorderWidth ();
	width += border * 2 + 3;
	height += border * 2;
	if ((style & SWT.V_SCROLL) != 0) {
		width += OS.GetSystemMetrics (OS.SM_CXVSCROLL);
	}
	if ((style & SWT.H_SCROLL) != 0) {
		height += OS.GetSystemMetrics (OS.SM_CYHSCROLL);
	}
	return new Point (width, height);
}

int defaultBackground () {
	return OS.GetSysColor (OS.COLOR_WINDOW);
}

/**
 * Deselects the items at the given zero-relative indices in the receiver.
 * If the item at the given zero-relative index in the receiver 
 * is selected, it is deselected.  If the item at the index
 * was not selected, it remains deselected. Indices that are out
 * of range and duplicate indices are ignored.
 *
 * @param indices the array of indices for the items to deselect
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the set of indices 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 deselect (int [] indices) {
	checkWidget ();
	if (indices == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (indices.length == 0) return;
	if ((style & SWT.SINGLE) != 0) {
		int oldIndex = OS.SendMessage (handle, OS.LB_GETCURSEL, 0, 0);
		if (oldIndex == OS.LB_ERR) return;
		for (int i=0; i<indices.length; i++) {
			if (oldIndex == indices [i]) {
				OS.SendMessage (handle, OS.LB_SETCURSEL, -1, 0);
				return;
			}
		}
		return;
	}
	for (int i=0; i<indices.length; i++) {
		int index = indices [i];
		if (index != -1) {
			OS.SendMessage (handle, OS.LB_SETSEL, 0, index);
		}
	}
}

/**
 * Deselects the item at the given zero-relative index in the receiver.
 * If the item at the index was already deselected, it remains
 * deselected. Indices that are out of range are ignored.
 *
 * @param index the index of the item to deselect
 *
 * @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 deselect (int index) {
	checkWidget ();
	if (index == -1) return;
	if ((style & SWT.SINGLE) != 0) {
		int oldIndex = OS.SendMessage (handle, OS.LB_GETCURSEL, 0, 0);
		if (oldIndex == OS.LB_ERR) return;
		if (oldIndex == index) OS.SendMessage (handle, OS.LB_SETCURSEL, -1, 0);
		return;
	} 
	OS.SendMessage (handle, OS.LB_SETSEL, 0, index);
}

/**
 * Deselects the items at the given zero-relative indices in the receiver.
 * If the item at the given zero-relative index in the receiver 
 * is selected, it is deselected.  If the item at the index
 * was not selected, it remains deselected.  The range of the
 * indices is inclusive. Indices that are out of range are ignored.
 *
 * @param start the start index of the items to deselect
 * @param end the end index of the items to deselect
 *
 * @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 deselect (int start, int end) {
	checkWidget ();
	if (start > end) return;
	if ((style & SWT.SINGLE) != 0) {
		int oldIndex = OS.SendMessage (handle, OS.LB_GETCURSEL, 0, 0);
		if (oldIndex == OS.LB_ERR) return;
		if (start <= oldIndex && oldIndex <= end) {
			OS.SendMessage (handle, OS.LB_SETCURSEL, -1, 0);
		}
		return;
	}
	/*
	* Ensure that at least one item is contained in
	* the range from start to end.  Note that when
	* start = end, LB_SELITEMRANGEEX deselects the
	* item.
	*/
	int count = OS.SendMessage (handle, OS.LB_GETCOUNT, 0, 0);
	if (start < 0 && end < 0) return;
	if (start >= count && end >= count) return;
	start = Math.min (count - 1, Math.max (0, start));
	end = Math.min (count - 1, Math.max (0, end));
	OS.SendMessage (handle, OS.LB_SELITEMRANGEEX, end, start);
}

/**
 * Deselects all selected items in the receiver.
 *
 * @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 deselectAll () {
	checkWidget ();
	if ((style & SWT.SINGLE) != 0) {
		OS.SendMessage (handle, OS.LB_SETCURSEL, -1, 0);
	} else {
		OS.SendMessage (handle, OS.LB_SETSEL, 0, -1);
	}
}

/**
 * Returns the zero-relative index of the item which currently
 * has the focus in the receiver, or -1 if no item has focus.
 *
 * @return the index of the selected item
 *
 * @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 getFocusIndex () {
	checkWidget ();
	int result = OS.SendMessage (handle, OS.LB_GETCARETINDEX, 0, 0);
	if (result == 0) {
		int count = OS.SendMessage (handle, OS.LB_GETCOUNT, 0, 0);
		if (count == 0) return -1;
	}
	return result;
}

/**
 * Returns the item at the given, zero-relative index in the
 * receiver. Throws an exception if the index is out of range.
 *
 * @param index the index of the item to return
 * @return the item at the given index
 *