如何告诉NSTextField自动调整它的字体大小以适合它的文本？

Question

寻找基本上与Cocoa相当的东西[UILabel adjustsFontSizeToFitWidth].

Answer 1

我通过创建一个覆盖字符串绘图的NSTextFieldCell子类来解决它.它查看字符串是否适合,如果不适合它会减小字体大小,直到它适合.这可以更有效率,我不知道当cellFrame宽度为0 时它会如何表现.然而,对于我的需要,它是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];
}

Answer 2

我使用了 Jerry Krinock 优秀的 NS(Attributed)String+Geometrics （位于此处）和如下所示的小方法。我仍然对更简单的方法感兴趣。

- (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];
}