list.java

源码为Eclipse开源开发平台桌面开发工具SWT的源代码,

 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the list minus 1 (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_CANNOT_GET_ITEM - if the operation fails because of an operating system failure</li>
 * </ul>
 */
public String getItem (int index) {
	checkWidget ();
	int length = OS.SendMessage (handle, OS.LB_GETTEXTLEN, index, 0);
	if (length != OS.LB_ERR) {
		TCHAR buffer = new TCHAR (getCodePage (), length + 1);
		int result = OS.SendMessage (handle, OS.LB_GETTEXT, index, buffer);
		if (result != OS.LB_ERR) return buffer.toString (0, length);
	}
	int count = OS.SendMessage (handle, OS.LB_GETCOUNT, 0, 0);
	if (0 <= index && index < count) {
		error (SWT.ERROR_CANNOT_GET_ITEM);
	} else {
		error (SWT.ERROR_INVALID_RANGE);
	}
	return null;
}

/**
 * Returns the number of items contained in the receiver.
 *
 * @return the number of items
 *
 * @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_CANNOT_GET_COUNT - if the operation fails because of an operating system failure</li>
 * </ul>
 */
public int getItemCount () {
	checkWidget ();
	int result = OS.SendMessage (handle, OS.LB_GETCOUNT, 0, 0);
	if (result == OS.LB_ERR) error (SWT.ERROR_CANNOT_GET_COUNT);
	return result;
}

/**
 * Returns the height of the area which would be used to
 * display <em>one</em> of the items in the tree.
 *
 * @return the height of one 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>
 * @exception SWTError <ul>
 *    <li>ERROR_CANNOT_GET_ITEM_HEIGHT - if the operation fails because of an operating system failure</li>
 * </ul>
 */
public int getItemHeight () {
	checkWidget ();
	int result = OS.SendMessage (handle, OS.LB_GETITEMHEIGHT, 0, 0);
	if (result == OS.LB_ERR) error (SWT.ERROR_CANNOT_GET_ITEM_HEIGHT);
	return result;
}

/**
 * Returns an array of <code>String</code>s which are the items
 * in the receiver. 
 * <p>
 * Note: This is not the actual structure used by the receiver
 * to maintain its list of items, so modifying the array will
 * not affect the receiver. 
 * </p>
 *
 * @return the items in the receiver's list
 *
 * @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_CANNOT_GET_ITEM - if the operation fails because of an operating system failure while getting an item</li>
 *    <li>ERROR_CANNOT_GET_COUNT - if the operation fails because of an operating system failure while getting the item count</li>
 * </ul>
 */
public String [] getItems () {
	checkWidget ();
	int count = getItemCount ();
	String [] result = new String [count];
	for (int i=0; i<count; i++) result [i] = getItem (i);
	return result;
}

/**
 * Returns an array of <code>String</code>s that are currently
 * selected in the receiver. An empty array indicates that no
 * items are selected.
 * <p>
 * Note: This is not the actual structure used by the receiver
 * to maintain its selection, so modifying the array will
 * not affect the receiver. 
 * </p>
 * @return an array representing the selection
 *
 * @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_CANNOT_GET_SELECTION - if the operation fails because of an operating system failure while getting the selection</li>
 *    <li>ERROR_CANNOT_GET_ITEM - if the operation fails because of an operating system failure while getting an item</li>
 * </ul>
 */
public String [] getSelection () {
	checkWidget ();
	int [] indices = getSelectionIndices ();
	String [] result = new String [indices.length];
	for (int i=0; i<indices.length; i++) {
		result [i] = getItem (indices [i]);
	}
	return result;
}

/**
 * Returns the number of selected items contained in the receiver.
 *
 * @return the number of selected items
 *
 * @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_CANNOT_GET_COUNT - if the operation fails because of an operating system failure</li>
 * </ul>
 */
public int getSelectionCount () {
	checkWidget ();
	if ((style & SWT.SINGLE) != 0) {
		int result = OS.SendMessage (handle, OS.LB_GETCURSEL, 0, 0);
		if (result == OS.LB_ERR) return 0;
		return 1;
	}
	int result = OS.SendMessage (handle, OS.LB_GETSELCOUNT, 0, 0);
	if (result == OS.LB_ERR) error (SWT.ERROR_CANNOT_GET_COUNT);
	return result;
}

/**
 * Returns the zero-relative index of the item which is currently
 * selected in the receiver, or -1 if no item is selected.
 *
 * @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>
 * @exception SWTError <ul>
 *    <li>ERROR_CANNOT_GET_SELECTION - if the operation fails because of an operating system failure</li>
 * </ul>
 */
public int getSelectionIndex () {
	checkWidget ();
	if ((style & SWT.SINGLE) != 0) {
		return OS.SendMessage (handle, OS.LB_GETCURSEL, 0, 0);
	}
	int count = OS.SendMessage (handle, OS.LB_GETSELCOUNT, 0, 0);
	if (count == OS.LB_ERR) error (SWT.ERROR_CANNOT_GET_SELECTION);
	if (count == 0) return -1;
	int index = OS.SendMessage (handle, OS.LB_GETCARETINDEX, 0, 0);
	int result = OS.SendMessage (handle, OS.LB_GETSEL, index, 0);
	if (result == OS.LB_ERR) error (SWT.ERROR_CANNOT_GET_SELECTION);
	if (result != 0) return index;
	int [] buffer = new int [1];
	result = OS.SendMessage (handle, OS.LB_GETSELITEMS, 1, buffer);
	if (result != 1) error (SWT.ERROR_CANNOT_GET_SELECTION);
	return buffer [0];
}

/**
 * Returns the zero-relative indices of the items which are currently
 * selected in the receiver.  The array is empty if no items are selected.
 * <p>
 * Note: This is not the actual structure used by the receiver
 * to maintain its selection, so modifying the array will
 * not affect the receiver. 
 * </p>
 * @return the array of indices of the selected items
 *
 * @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_CANNOT_GET_SELECTION - if the operation fails because of an operating system failure</li>
 * </ul>
 */
public int [] getSelectionIndices () {
	checkWidget ();
	if ((style & SWT.SINGLE) != 0) {
		int result = OS.SendMessage (handle, OS.LB_GETCURSEL, 0, 0);
		if (result == OS.LB_ERR) return new int [0];
		return new int [] {result};
	}
	int length = OS.SendMessage (handle, OS.LB_GETSELCOUNT, 0, 0);
	if (length == OS.LB_ERR) error (SWT.ERROR_CANNOT_GET_SELECTION);
	int [] indices = new int [length];
	int result = OS.SendMessage (handle, OS.LB_GETSELITEMS, length, indices);
	if (result != length) error (SWT.ERROR_CANNOT_GET_SELECTION);
	return indices;
}

/**
 * Returns the zero-relative index of the item which is currently
 * at the top of the receiver. This index can change when items are
 * scrolled or new items are added or removed.
 *
 * @return the index of the top 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 getTopIndex () {
	checkWidget ();
	return OS.SendMessage (handle, OS.LB_GETTOPINDEX, 0, 0);
}

/**
 * Gets the index of an item.
 * <p>
 * The list is searched starting at 0 until an
 * item is found that is equal to the search item.
 * If no item is found, -1 is returned.  Indexing
 * is zero based.
 *
 * @param string the search item
 * @return the index of the 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>
 */
public int indexOf (String string) {
	return indexOf (string, 0);
}

/**
 * Searches the receiver's list starting at the given, 
 * zero-relative index until an item is found that is equal
 * to the argument, and returns the index of that item. If
 * no item is found or the starting index is out of range,
 * returns -1.
 *
 * @param string the search item
 * @param start the zero-relative index at which to start the search
 * @return the index of the 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_CANNOT_GET_COUNT - if the operation fails because of an operating system failure while getting the item count</li>
 *    <li>ERROR_CANNOT_GET_ITEM - if the operation fails because of an operating system failure while getting an item</li>
 * </ul>
 */
public int indexOf (String string, int start) {
	checkWidget ();
	if (string == null) error (SWT.ERROR_NULL_ARGUMENT);
	
	/*
	* Bug in Windows.  For some reason, LB_FINDSTRINGEXACT
	* will not find empty strings even though it is legal
	* to insert an empty string into a list.  The fix is
	* to search the list, an item at a time.
	*/
	if (string.length () == 0) {
		int count = getItemCount ();
		for (int i=start; i<count; i++) {
			if (string.equals (getItem (i))) return i;
		}
		return -1;
	}

	/* Use LB_FINDSTRINGEXACT to search for the item */
	int count = OS.SendMessage (handle, OS.LB_GETCOUNT, 0, 0);
	if (!(0 <= start && start < count)) return -1;
	int index = start - 1, last;
	TCHAR buffer = new TCHAR (getCodePage (), string, true);
	do {
		index = OS.SendMessage (handle, OS.LB_FINDSTRINGEXACT, last = index, buffer);
		if (index == OS.LB_ERR || index <= last) return -1;
	} while (!string.equals (getItem (index)));
	return index;
}

/**
 * Returns <code>true</code> if the item is selected,
 * and <code>false</code> otherwise.  Indices out of
 * range are ignored.
 *
 * @param index the index of the item
 * @return the visibility state of the item at the index
 *
 * @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 isSelected (int index) {
	checkWidget ();
	int result = OS.SendMessage (handle, OS.LB_GETSEL, index, 0);
	return (result != 0) && (result != OS.LB_ERR);
}

/**
 * Removes the items from the receiver at the given
 * zero-relative indices.
 *
 * @param indices the array of indices of the items
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the list minus 1 (inclusive)</li>
 *    <li>ERROR_NULL_ARGUMENT - if the indices array 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_REMOVED - if the operation fails because of an operating system failure</li>
 * </ul>
 */
public void remove (int [] indices) {
	checkWidget ();
	if (indices == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (indices.length == 0) return;
	int [] newIndices = new int [indices.length];
	System.arraycopy (indices, 0, newIndices, 0, indices.length);
	sort (newIndices);
	int start = newIndices [newIndices.length - 1], end = newIndices [0];
	int count = OS.SendMessage (handle, OS.LB_GETCOUNT, 0, 0);
	if (!(0 <= start && start <= end && end < count)) {
		error (SWT.ERROR_INVALID_RANGE);
	}
	int topIndex = OS.SendMessage (handle, OS.LB_GETTOPINDEX, 0, 0);
	RECT rect = null;
	int hDC = 0, oldFont = 0, newFont = 0, newWidth = 0;
	if ((style & SWT.H_SCROLL) != 0) {
		rect = new RECT ();
		hDC = OS.GetDC (handle);
		newFont = OS.SendMessage (handle, OS.WM_GETFONT, 0, 0);
		if (newFont != 0) oldFont = OS.SelectObject (hDC, newFont);
	}
	int cp = getCodePage ();
	int i = 0, topCount = 0, last = -1;
	while (i < newIndices.length) {
		int index = newIndices [i];
		if (index != last) {
			TCHAR buffer = null;
			if ((style & SWT.H_SCROLL) != 0) {
				int length = OS.SendMessage (handle, OS.LB_GETTEXTLEN, index, 0);
				if (length == OS.LB_ERR) break;
				buffer = new TCHAR (cp, length + 1);
				int result = OS.SendMessage (handle, OS.LB_GETTEXT, index, buffer);
				if (result == OS.LB_ERR) break;
			}
			int result = OS.SendMessage (handle, OS.LB_DELETESTRING, index, 0);
			if (result == OS.LB_ERR) break;
			if ((style & SWT.H_SCROLL) != 0) {
				int flags = OS.DT_CALCRECT | OS.DT_SINGLELINE | OS.DT_NOPREFIX;
				OS.DrawText (hDC, buffer, -1, rect, flags);
				newWidth = Math.max (newWidth, rect.right - rect.left);
			}
			if (index < topIndex) topCount++;
			last = index;
		}
		i++;
	}
	if ((style & SWT.H_SCROLL) != 0) {
		if (newFont != 0) OS.SelectObject (hDC, oldFont);
		OS.ReleaseDC (handle, hDC);