如何从滚动时水平调整所含NSTextView顶部停止NSScrollView？

Question

我有一个NSTextView，我想显示水平滚动条。继互联网上的一些线索，我大部分的工作，但我有垂直滚动条的问题。

我所做的是找到最长行的宽度（在与所述给定字体的像素），然后我调整NSTextContainer和NSTextView适当。通过这种方式，水平滚动条代表整个宽度的和滚动到将滚动到文本的最长行的末尾的权利。

做这项工作后，我发现我的NSScrollView会显示和隐藏垂直滚动条，因为我打字。我已经通过调整大小之前autohidesScrollers设置为NO，然后后来是“固定”这一问题。但是，仍然存在另一个问题，即，为I型，垂直滚动条的拇指的跳转到滚动条的顶部，回到正确的地方，因为我打字。 I型“A” <空格>，它跳转到顶部，我按<空间>再次，并将其跳回到适当的位置。

任何想法？

下面是一些示例代码：

- (CGFloat)longestLineOfText
{
    CGFloat longestLineOfText = 0.0;

    NSRange lineRange;

    NSString* theScriptText = [myTextView string];

    NSDictionary* attributesDict = [NSDictionary dictionaryWithObject:scriptFont forKey:NSFontAttributeName]; //scriptFont is a instance variable

    NSUInteger characterIndex = 0;
    NSUInteger stringLength = [theScriptText length];

    while (characterIndex < stringLength) {
        lineRange = [theScriptText lineRangeForRange:NSMakeRange(characterIndex, 0)];

        NSSize lineSize = [[theScriptText substringWithRange:lineRange] sizeWithAttributes:attributesDict];
        longestLineOfText = max(longestLineOfText, lineSize.width);

        characterIndex = NSMaxRange(lineRange);
    }

    return longestLineOfText;

}

// ----------------------------------------------------------------------------

- (void)updateMyTextViewWidth
{
    static CGFloat previousLongestLineOfText = 0.0;

    CGFloat currentLongestLineOfText = [self longestLineOfText];
    if (currentLongestLineOfText != previousLongestLineOfText) {
        BOOL shouldStopBlinkingScrollBar = (previousLongestLineOfText < currentLongestLineOfText);
        previousLongestLineOfText = currentLongestLineOfText;

        NSTextContainer* container = [myTextView textContainer];
        NSScrollView* scrollView = [myTextView enclosingScrollView];
        if (shouldStopBlinkingScrollBar) {
            [scrollView setAutohidesScrollers:NO];
        }

        CGFloat padding = [container lineFragmentPadding];

        NSSize size = [container containerSize];
        size.width = currentLongestLineOfText + padding * 2;
        [container setContainerSize:size];

        NSRect frame = [myTextView frame];
        frame.size.width = currentLongestLineOfText + padding * 2;
        [myTextView setFrame:frame];

        if (shouldStopBlinkingScrollBar) {
            [scrollView setAutohidesScrollers:YES];
        }
    }   
}

Answer 1

感谢罗斯·卡特的帖子上可可开发列表，我解决了这个问题。

一个。你必须设置你的文本视图，支持水平滚动：

- (void)awakeFromNib {
    [myTextView setHorizontallyResizable:YES];
    NSSize tcSize = [[myTextView textContainer] containerSize];
    tcSize.width = FLT_MAX;
    [[myTextView textContainer] setContainerSize:tcSize];
    [[myTextView textContainer] setWidthTracksTextView:NO];
}

B中。你必须更新文本视图的宽度，因为它改变了，否则所述水平滚动条未正确更新：

- (void)textDidChange:(NSNotification *)notification
{
    [self updateTextViewWidth];
}

- (CGFloat)longestLineOfText
{
    CGFloat longestLineOfText = 0.0;

    NSLayoutManager* layoutManager = [myTextView layoutManager];

    NSRange lineRange;
    NSUInteger glyphIndex = 0;
    NSUInteger glyphCount = [layoutManager numberOfGlyphs];
    while (glyphIndex < glyphCount) {

        NSRect lineRect = [layoutManager lineFragmentUsedRectForGlyphAtIndex:glyphIndex
                                                              effectiveRange:&lineRange
                                                     withoutAdditionalLayout:YES];

        longestLineOfText = max(longestLineOfText, lineRect.size.width);

        glyphIndex = NSMaxRange(lineRange);
    }

    return longestLineOfText;

}

// ----------------------------------------------------------------------------

- (void)updateTextViewWidth
{
    static CGFloat previousLongestLineOfText = 0.0;

    CGFloat currentLongestLineOfText = [self longestLineOfText];
    if (currentLongestLineOfText != previousLongestLineOfText) {
        previousLongestLineOfText = currentLongestLineOfText;

        NSTextContainer* container = [myTextView textContainer];
        CGFloat padding = [container lineFragmentPadding];

        NSRect frame = [myTextView frame];
        frame.size.width = currentLongestLineOfText + padding * 2;
        [myTextView setFrame:frame];
    }
}