NSLineBreakByTruncatingTail在NSTextView中设置为段落样式时滚动文本

Question

我有一个NSTextView，应该是固定大小的。当文本到达指定帧的底线和右边缘时，我需要设置NSLineBreakByTruncatingTail以向用户显示椭圆形符号并禁用进一步输入。 当我通过在textStorage NSTextView上设置段落样式时，文本向上滚动，我只看到最后一行带有椭圆形符号。我的问题是如何在更改NSTextView时阻止lineBreakMode滚动？

谢谢， 纳瓦

编辑:(添加截图）之前：

后：

现在这是执行此操作的代码：

- (void)textDidChange:(NSNotification *)notification
{
    NSString *text = [textView string];

    CGFloat width, height;
    NSRect  newFrame = self.frame;

    width = round([text widthForHeight:newFrame.size.height font:textView.font]);

    height = round([text heightForWidth:newFrame.size.width font:textView.font]);
    if (height > newFrame.size.height && width > newFrame.size.width) {
        NSTextContainer *textContainer = textView.textContainer;
        [textContainer setWidthTracksTextView:NO];
        [textContainer setHeightTracksTextView:NO];
        [textView setHorizontallyResizable:NO];
        [textView setVerticallyResizable:NO];
        [textView setAutoresizingMask:NSViewNotSizable];
        [textView setLineBreakMode:NSLineBreakByTruncatingTail];
    } 
}

函数widthForHeight和heightForWidth是第三方添加的，但效果很好。问题出在我设置NSLineBreakByTruncatingTail时发生的突然滚动。 这是设置换行模式的功能（也是第三方加入 - 来自一个不错的开发人员（不记得他的名字））：

- (void)setLineBreakMode:(NSLineBreakMode)lineBreakMode {
    NSDictionary* curAttributes = [[self textStorage] attributesAtIndex:0
                                                              effectiveRange:NULL];

    NSParagraphStyle *currentStyle = [curAttributes objectForKey:NSParagraphStyleAttributeName];

    if (currentStyle.lineBreakMode != lineBreakMode) {

        NSMutableParagraphStyle* paragraphStyle = [[NSParagraphStyle defaultParagraphStyle] mutableCopy] ;
        [paragraphStyle setLineBreakMode:lineBreakMode] ;       
        NSMutableDictionary* attributes = [[[self textStorage] attributesAtIndex:0
                                                                  effectiveRange:NULL] mutableCopy] ;

        [attributes setObject:paragraphStyle
                       forKey:NSParagraphStyleAttributeName] ;
        [paragraphStyle release] ;
        NSAttributedString* attributedString = [[NSAttributedString alloc] initWithString:[self string]
                                                                               attributes:attributes] ;
        [attributes release] ;
        [[self textStorage] setAttributedString:attributedString] ;
        [attributedString release] ;

    }
}