如何让NSTextField自动调整字体大小以适应文本？

Question

寻找基本上无论是[UILabel adjustsFontSizeToFitWidth]的可可等价物。

Answer 1

我用Jerry Krinock的优秀NS（Attributed）String + Geometrics (located here)和一个像下面这样的小方法。我仍然对更简单的方式感兴趣。

- (void) prepTextField:(NSTextField *)field withString:(NSString *)string 
{ 
    #define kMaxFontSize 32.0f 
    #define kMinFontSize 6.0f 
    float fontSize = kMaxFontSize; 
    while (([string widthForHeight:[field frame].size.height font:[NSFont systemFontOfSize:fontSize]] > [field frame].size.width) && (fontSize > kMinFontSize)) 
    { 
      fontSize--; 
    } 
    [field setFont:[NSFont systemFontOfSize:fontSize]]; 

    [field setStringValue:string]; 

    [self addSubview:field]; 
} 

Answer 2

不要忘记看超类。 NSTextField是一种NSControl，每个NSControl都响应the sizeToFit message。

Answer 3

我已经通过创建覆盖字符串绘图的NSTextFieldCell子类来解决它。它看起来该字符串是否合适，如果不合适，它会减小字体大小直到它合适。这可能会变得更加高效，我不知道cellFrame的宽度为0时它的表现如何。尽管如此，它还是符合我的需求的Good Enough™。

- (void)drawInteriorWithFrame:(NSRect)cellFrame inView:(NSView *)controlView 
{ 
    NSAttributedString *attributedString; 
    NSMutableAttributedString *mutableAttributedString; 
    NSSize stringSize; 
    NSRect drawRect; 

    attributedString = [self attributedStringValue]; 

    stringSize = [attributedString size]; 
    if (stringSize.width <= cellFrame.size.width) { 
     // String is already small enough. Skip sizing. 
     goto drawString; 
    } 

    mutableAttributedString = [attributedString mutableCopy]; 

    while (stringSize.width > cellFrame.size.width) { 
     NSFont *font; 

     font = [mutableAttributedString 
      attribute:NSFontAttributeName 
      atIndex:0 
      effectiveRange:NULL 
     ]; 
     font = [NSFont 
      fontWithName:[font fontName] 
      size:[[[font fontDescriptor] objectForKey:NSFontSizeAttribute] floatValue] - 0.5 
     ]; 

     [mutableAttributedString 
      addAttribute:NSFontAttributeName 
      value:font 
      range:NSMakeRange(0, [mutableAttributedString length]) 
     ]; 

     stringSize = [mutableAttributedString size]; 
    } 

    attributedString = [mutableAttributedString autorelease]; 

drawString: 
    drawRect = cellFrame; 
    drawRect.size.height = stringSize.height; 
    drawRect.origin.y += (cellFrame.size.height - stringSize.height)/2; 
    [attributedString drawInRect:drawRect]; 
}