Question

我试图使用以下方法测量宽度恒定的NSAttributedString高度：

-(CGFloat)calculateHeightForAttributedString:(NSAttributedString*)attributedNotes {
    CGFloat scrollerWidth = [NSScroller scrollerWidthForControlSize:NSRegularControlSize scrollerStyle:NSScrollerStyleLegacy];
    CGFloat width = self.tableView.frame.size.width - self.cellNotesWidthConstraint - scrollerWidth;
    // http://www.cocoabuilder.com/archive/cocoa/54083-height-of-string-with-fixed-width-and-given-font.html
    NSTextView *tv = [[NSTextView alloc] initWithFrame:NSMakeRect(0, 0, width - 20, 1e7)];
    tv.font = [NSFont userFontOfSize:32];
    [tv.textStorage setAttributedString:attributedNotes];
    [self setScaleFactor:[self convertSliderValueToFontScale:self.fontScaleSlider] forTextView:tv];

    [tv.layoutManager glyphRangeForTextContainer:tv.textContainer];
    [tv.layoutManager ensureLayoutForTextContainer:tv.textContainer];

    return [tv.layoutManager usedRectForTextContainer:tv.textContainer].size.height + 10.0f; // add a little bit of a buffer
}

基本上，宽度是表格视图的大小减去滚动条，以及用于显示其他信息的每个单元格的一小部分。只要文本比例（通过convertSliderValueToFontScale:）为1.0，此方法就可以正常工作。如果改变比例因子，usedRectForTextContainer的结果是不正确的 - 好像没有考虑比例因子。

在NSTextView的setScaleFactor:forTextView:中设置比例如下（标量是实际比例数量）：

[textView scaleUnitSquareToSize:NSMakeSize(scaler, scaler)];

有关如何解决此问题的任何想法？

编辑：我有一个示例项目可以在这里尝试：Github。奇怪的是，如果比例为＆lt; 0，它们随机似乎随时在4.XXX范围内工作......

Answer 1

答案很简单：将NSTextView添加为NSClipView的子视图，其框架与NSTextView相同。

最终高度函数如下：

-(CGFloat)calculateHeightForAttributedString:(NSAttributedString*)attributedNotes {
    CGFloat width = self.textView.frame.size.width;
    // http://www.cocoabuilder.com/archive/cocoa/54083-height-of-string-with-fixed-width-and-given-font.html
    NSTextView *tv = [[NSTextView alloc] initWithFrame:NSMakeRect(0, 0, width, 1e7)];
    tv.horizontallyResizable = NO;
    tv.font = [NSFont userFontOfSize:32];
    tv.alignment = NSTextAlignmentLeft;
    [tv.textStorage setAttributedString:attributedNotes];
    [self setScaleFactor:self.slider.floatValue forTextView:tv];

    // In order for usedRectForTextContainer: to be accurate with a scale, you MUST
    // set the NSTextView as a subview of an NSClipView!
    NSClipView *clipView = [[NSClipView alloc] initWithFrame:NSMakeRect(0, 0, width, 1e7)];
    [clipView addSubview:tv];

    [tv.layoutManager glyphRangeForTextContainer:tv.textContainer];
    [tv.layoutManager ensureLayoutForTextContainer:tv.textContainer];
    return [tv.layoutManager usedRectForTextContainer:tv.textContainer].size.height;
}

NSLayoutManager / NSTextContainer忽略比例因子

1 个答案: