list.java

源码为Eclipse开源开发平台桌面开发工具SWT的源代码,

/**
 * Sets the text of the item in the receiver's list at the given
 * zero-relative index to the string argument. This is equivalent
 * to <code>remove</code>'ing the old item at the index, and then
 * <code>add</code>'ing the new item at that index.
 *
 * @param index the index for the item
 * @param string the new text for the item
 *
 * @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 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_REMOVED - if the remove operation fails because of an operating system failure</li>
 *    <li>ERROR_ITEM_NOT_ADDED - if the add operation fails because of an operating system failure</li>
 * </ul>
 */
public void setItem (int index, String string) {
	checkWidget ();
	if (string == null) error (SWT.ERROR_NULL_ARGUMENT);
	int topIndex = getTopIndex ();
	boolean isSelected = isSelected (index);
	remove (index);
	add (string, index);
	if (isSelected) select (index, false);
	setTopIndex (topIndex);
}

/**
 * Sets the receiver's items to be the given array of items.
 *
 * @param items the array of items
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the items 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_ADDED - if the operation fails because of an operating system failure</li>
 * </ul>
 */
public void setItems (String [] items) {
	checkWidget ();
	if (items == null) error (SWT.ERROR_NULL_ARGUMENT);
	int oldProc = OS.GetWindowLong (handle, OS.GWL_WNDPROC);
	OS.SetWindowLong (handle, OS.GWL_WNDPROC, ListProc);
	boolean redraw = drawCount == 0 && OS.IsWindowVisible (handle);
	if (redraw) {
		OS.SendMessage (handle, OS.WM_SETREDRAW, 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);
		OS.SendMessage (handle, OS.LB_SETHORIZONTALEXTENT, 0, 0);
	}
	int length = items.length;
	OS.SendMessage (handle, OS.LB_RESETCONTENT, 0, 0);
	OS.SendMessage (handle, OS.LB_INITSTORAGE, length, length * 32);
	int index = 0;
	int cp = getCodePage ();
	while (index < length) {
		String string = items [index];
		if (string == null) break;
		TCHAR buffer = new TCHAR (cp, string, true);
		int result = OS.SendMessage (handle, OS.LB_ADDSTRING, 0, buffer);
		if (result == OS.LB_ERR || result == OS.LB_ERRSPACE) break;
		if ((style & SWT.H_SCROLL) != 0) {
			int flags = OS.DT_CALCRECT | OS.DT_SINGLELINE | OS.DT_NOPREFIX;
			OS.DrawText (hDC, buffer, buffer.length (), rect, flags);
			newWidth = Math.max (newWidth, rect.right - rect.left);
		}
		index++;
	}
	if ((style & SWT.H_SCROLL) != 0) {
		if (newFont != 0) OS.SelectObject (hDC, oldFont);
		OS.ReleaseDC (handle, hDC);
		OS.SendMessage (handle, OS.LB_SETHORIZONTALEXTENT, newWidth + 3, 0);
	}
	if (redraw) {
		OS.SendMessage (handle, OS.WM_SETREDRAW, 1, 0);
		/*
		* This code is intentionally commented.  The window proc
		* for the list box implements WM_SETREDRAW to invalidate
		* and erase the widget.  This is undocumented behavior.
		* The commented code below shows what is actually happening
		* and reminds us that we are relying on this undocumented
		* behavior.
		*/
//		int flags = OS.RDW_ERASE | OS.RDW_FRAME | OS.RDW_INVALIDATE;
//		OS.RedrawWindow (handle, null, 0, flags);
	}
	OS.SetWindowLong (handle, OS.GWL_WNDPROC, oldProc);
	if (index < items.length) error (SWT.ERROR_ITEM_NOT_ADDED);
}

void setScrollWidth () {
	int newWidth = 0;
	RECT rect = new RECT ();
	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);
	int cp = getCodePage ();
	int count = OS.SendMessage (handle, OS.LB_GETCOUNT, 0, 0);
	int flags = OS.DT_CALCRECT | OS.DT_SINGLELINE | OS.DT_NOPREFIX;
	for (int i=0; i<count; i++) {
		int length = OS.SendMessage (handle, OS.LB_GETTEXTLEN, i, 0);
		if (length != OS.LB_ERR) {
			TCHAR 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, -1, rect, flags);
				newWidth = Math.max (newWidth, rect.right - rect.left);
			}
		}
	}
	if (newFont != 0) OS.SelectObject (hDC, oldFont);
	OS.ReleaseDC (handle, hDC);
	OS.SendMessage (handle, OS.LB_SETHORIZONTALEXTENT, newWidth + 3, 0);
}

void setScrollWidth (TCHAR buffer, boolean grow) {
	RECT rect = new RECT ();
	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);
	int flags = OS.DT_CALCRECT | OS.DT_SINGLELINE | OS.DT_NOPREFIX;
	OS.DrawText (hDC, buffer, -1, rect, flags);
	if (newFont != 0) OS.SelectObject (hDC, oldFont);
	OS.ReleaseDC (handle, hDC);
	setScrollWidth (rect.right - rect.left, grow);
}

void setScrollWidth (int newWidth, boolean grow) {
	int width = OS.SendMessage (handle, OS.LB_GETHORIZONTALEXTENT, 0, 0);
	if (grow) {
		if (newWidth <= width) return;
		OS.SendMessage (handle, OS.LB_SETHORIZONTALEXTENT, newWidth + 3, 0);
	} else {
		if (newWidth < width) return;
		setScrollWidth ();
	}
}

/**
 * Selects the items at the given zero-relative indices in the receiver.
 * The current selection is cleared before the new items are selected.
 * <p>
 * Indices that are out of range and duplicate indices are ignored.
 * If the receiver is single-select and multiple indices are specified,
 * then all indices are ignored.
 *
 * @param indices the indices of the items to select
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the array 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>
 *
 * @see List#deselectAll()
 * @see List#select(int[])
 */
public void setSelection(int [] indices) {
	checkWidget ();
	if (indices == null) error (SWT.ERROR_NULL_ARGUMENT);
	deselectAll ();
	int length = indices.length;
	if (length == 0 || ((style & SWT.SINGLE) != 0 && length > 1)) return;
	select (indices, true);
	if ((style & SWT.MULTI) != 0) {
		int focusIndex = indices [0];
		if (focusIndex >= 0) setFocusIndex (focusIndex);
	}
}

/**
 * Sets the receiver's selection to be the given array of items.
 * The current selection is cleared before the new items are selected.
 * <p>
 * Items that are not in the receiver are ignored.
 * If the receiver is single-select and multiple items are specified,
 * then all items are ignored.
 *
 * @param items the array of items
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the array of items 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 List#deselectAll()
 * @see List#select(int[])
 * @see List#setSelection(int[])
 */
public void setSelection (String [] items) {
	checkWidget ();
	if (items == null) error (SWT.ERROR_NULL_ARGUMENT);
	deselectAll ();
	int length = items.length;
	if (length == 0 || ((style & SWT.SINGLE) != 0 && length > 1)) return;
	int focusIndex = -1;
	for (int i=length-1; i>=0; --i) {
		String string = items [i];
		int index = 0;
		if (string != null) {
			int localFocus = -1;
			while ((index = indexOf (string, index)) != -1) {
				if (localFocus == -1) localFocus = index;
				select (index, false);
				if ((style & SWT.SINGLE) != 0 && isSelected (index)) {
					showSelection ();
					return;
				}
				index++;
			}
			if (localFocus != -1) focusIndex = localFocus;
		}
	}
	if ((style & SWT.MULTI) != 0) {
		if (focusIndex >= 0) setFocusIndex (focusIndex);
	}
}

/**
 * Selects the item at the given zero-relative index in the receiver. 
 * If the item at the index was already selected, it remains selected.
 * The current selected is first cleared, then the new items are selected.
 * Indices that are out of range are ignored.
 *
 * @param index the index of the item to select
 *
 * @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 List#deselectAll()
 * @see List#select(int)
 */
public void setSelection (int index) {
	checkWidget ();
	if ((style & SWT.MULTI) != 0) deselectAll ();
	select (index, true);
	if ((style & SWT.MULTI) != 0) {
		if (index >= 0) setFocusIndex (index);
	}
}

/**
 * Selects the items in the range specified by the given zero-relative
 * indices in the receiver. The range of indices is inclusive.
 * The current selection is cleared before the new items are selected.
 * <p>
 * Indices that are out of range are ignored and no items will be selected
 * if start is greater than end.
 * If the receiver is single-select and there is more than one item in the
 * given range, then all indices are ignored.
 *
 * @param start the start index of the items to select
 * @param end the end index of the items to select
 *
 * @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 List#deselectAll()
 * @see List#select(int,int)
 */
public void setSelection (int start, int end) {
	checkWidget ();
	deselectAll ();
	if (end < 0 || start > end || ((style & SWT.SINGLE) != 0 && start != end)) return;
	int count = OS.SendMessage (handle, OS.LB_GETCOUNT, 0, 0);
	if (count == 0 || start >= count) return;
	start = Math.max (0, start);
	end = Math.min (end, count - 1);
	if ((style & SWT.SINGLE) != 0) {
		select (start, true);
	} else {
		select (start, end, true);
		setFocusIndex (start);
	}
}

/**
 * Sets 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 and removed.
 *
 * @param index 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 void setTopIndex (int index) {
	checkWidget ();
	int result = OS.SendMessage (handle, OS.LB_SETTOPINDEX, index, 0);
	if (result == OS.LB_ERR) {
		int count = OS.SendMessage (handle, OS.LB_GETCOUNT, 0, 0);
		index = Math.min (count - 1, Math.max (0, index));
		OS.SendMessage (handle, OS.LB_SETTOPINDEX, index, 0);
	}
}

/**
 * Shows the selection.  If the selection is already showing in the receiver,
 * this method simply returns.  Otherwise, the items are scrolled until
 * the selection is visible.
 *
 * @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 showSelection () {
	checkWidget ();
	int index;
	if ((style & SWT.SINGLE) != 0) {
		index = OS.SendMessage (handle, OS.LB_GETCURSEL, 0, 0);
	} else {
		int [] indices = new int [1];
		int result = OS.SendMessage (handle, OS.LB_GETSELITEMS, 1, indices);
		index = indices [0];
		if (result != 1) index = -1;
	}
	if (index == -1) return;
	int count = OS.SendMessage (handle, OS.LB_GETCOUNT, 0, 0);
	if (count == 0) return;
	int height = OS.SendMessage (handle, OS.LB_GETITEMHEIGHT, 0, 0);
	forceResize ();
	RECT rect = new RECT ();
	OS.GetClientRect (handle, rect);
	int topIndex = OS.SendMessage (handle, OS.LB_GETTOPINDEX, 0, 0);
	int visibleCount = Math.max (rect.bottom / height, 1);
	int bottomIndex = Math.min (topIndex + visibleCount + 1, count - 1);
	if ((topIndex <= index) && (index <= bottomIndex)) return;
	int newTop = Math.min (Math.max (index - (visibleCount / 2), 0), count - 1);
	OS.SendMessage (handle, OS.LB_SETTOPINDEX, newTop, 0);
}

int widgetStyle () {
	int bits = super.widgetStyle () | OS.LBS_NOTIFY | OS.LBS_NOINTEGRALHEIGHT;
	if ((style & SWT.SINGLE) != 0) return bits;
	if ((style & SWT.MULTI) != 0) {
		if ((style & SWT.SIMPLE) != 0) return bits | OS.LBS_MULTIPLESEL;
		return bits | OS.LBS_EXTENDEDSEL;
	}
	return bits;
}

TCHAR windowClass () {
	return ListClass;
}

int windowProc () {
	return ListProc;
}

LRESULT wmCommandChild (int wParam, int lParam) {
	int code = wParam >> 16;
	switch (code) {
		case OS.LBN_SELCHANGE:
			postEvent (SWT.Selection);
			break;
		case OS.LBN_DBLCLK:
			postEvent (SWT.DefaultSelection);
			break;
	}
	return super.wmCommandChild (wParam, lParam);
}



}