objective-c - 在 NSTextField 中设置文本垂直居中

Question

在某个高度 NSTextField ，如果文本的大小很小，布局将是这样的

文本流到顶部，如何使文本中心像这样：

Answer 1

class CustomTextFieldCell: NSTextFieldCell {

    func adjustedFrame(toVerticallyCenterText rect: NSRect) -> NSRect {
        // super would normally draw text at the top of the cell
        var titleRect = super.titleRect(forBounds: rect)

        let minimumHeight = self.cellSize(forBounds: rect).height
        titleRect.origin.y += (titleRect.height - minimumHeight) / 2
        titleRect.size.height = minimumHeight

        return titleRect
    }

    override func edit(withFrame rect: NSRect, in controlView: NSView, editor textObj: NSText, delegate: Any?, event: NSEvent?) {
        super.edit(withFrame: adjustedFrame(toVerticallyCenterText: rect), in: controlView, editor: textObj, delegate: delegate, event: event)
    }

    override func select(withFrame rect: NSRect, in controlView: NSView, editor textObj: NSText, delegate: Any?, start selStart: Int, length selLength: Int) {
        super.select(withFrame: adjustedFrame(toVerticallyCenterText: rect), in: controlView, editor: textObj, delegate: delegate, start: selStart, length: selLength)
    }

    override func drawInterior(withFrame cellFrame: NSRect, in controlView: NSView) {
        super.drawInterior(withFrame: adjustedFrame(toVerticallyCenterText: cellFrame), in: controlView)
    }

    override func draw(withFrame cellFrame: NSRect, in controlView: NSView) {
        super.draw(withFrame: cellFrame, in: controlView)
    }
}

Answer 2

我基本上使用亚历克斯的答案，但有一个修正：如果我们增加 y 原点，我们应该减少 titleRect 的高度。否则，我们的 titleRect 将在其父视图的末尾下方结束，可能会将任何内容隐藏在 NSTextField 下方。

.h：

#import <Cocoa/Cocoa.h>

@interface VerticallyCenteredTextFieldCell : NSTextFieldCell

@end

他们：

#import "VerticallyCenteredTextFieldCell.h"

@implementation VerticallyCenteredTextFieldCell

- (NSRect) titleRectForBounds:(NSRect)frame {

CGFloat stringHeight = self.attributedStringValue.size.height;
NSRect titleRect = [super titleRectForBounds:frame];
CGFloat oldOriginY = frame.origin.y;
titleRect.origin.y = frame.origin.y + (frame.size.height - stringHeight) / 2.0;
titleRect.size.height = titleRect.size.height - (titleRect.origin.y - oldOriginY);
return titleRect;
}

- (void) drawInteriorWithFrame:(NSRect)cFrame inView:(NSView*)cView {
[super drawInteriorWithFrame:[self titleRectForBounds:cFrame] inView:cView];
}

@end

此外，VerticallyCenteredTextFieldCell 是 NSTextFieldCell 的子类。如果您将其子类化，请在 Interface Builder 中更改 NSTextFieldCell 的类，而不是 NSTextField（我不知道这一点）。

Answer 3

只是子类NSTextFieldCell（或混合它）......并实现......

- (NSRect) titleRectForBounds:(NSRect)frame {  

  CGFloat stringHeight       = self.attributedStringValue.size.height;
   NSRect titleRect          = [super titleRectForBounds:frame];
          titleRect.origin.y = frame.origin.y + 
                              (frame.size.height - stringHeight) / 2.0;
   return titleRect;
 }
- (void) drawInteriorWithFrame:(NSRect)cFrame inView:(NSView*)cView {
  [super drawInteriorWithFrame:[self titleRectForBounds:cFrame] inView:cView];
 }

Answer 4

在 Erik 和 Hejazi 的回答中添加一些内容，您还需要实现selectWithFrame，这是 Swift 2.2 中的解决方案：

class VerticallyCenteredTextFieldCell: NSTextFieldCell {
    override func titleRectForBounds(rect: NSRect) -> NSRect {
        var titleRect = super.titleRectForBounds(rect)

        let minimumHeight = self.cellSizeForBounds(rect).height
        titleRect.origin.y += (titleRect.height - minimumHeight) / 2
        titleRect.size.height = minimumHeight

        return titleRect
    }

    override func drawInteriorWithFrame(cellFrame: NSRect, inView controlView: NSView) {
        super.drawInteriorWithFrame(titleRectForBounds(cellFrame), inView: controlView)
    }

    override func selectWithFrame(aRect: NSRect, inView controlView: NSView, editor textObj: NSText, delegate anObject: AnyObject?, start selStart: Int, length selLength: Int) {
        super.selectWithFrame(titleRectForBounds(aRect), inView: controlView, editor: textObj, delegate: anObject, start: selStart, length: selLength);
    }
}

Answer 5

Erik Wegener 的答案的 Swift 版本（也修改为使用多行）：

class VerticallyCenteredTextFieldCell : NSTextFieldCell {
    override func titleRect(forBounds rect: NSRect) -> NSRect {
        var titleRect = super.titleRect(forBounds: rect)

        let minimumHeight = self.cellSize(forBounds: rect).height
        titleRect.origin.y += (titleRect.height - minimumHeight) / 2
        titleRect.size.height = minimumHeight

        return titleRect
    }

    override func drawInterior(withFrame cellFrame: NSRect, in controlView: NSView) {
        super.drawInterior(withFrame: titleRect(forBounds: cellFrame), in: controlView)
    }
}

Answer 6

我的解决方案是基于使用 NSLayoutManager 计算字体高度。这种方式允许使用属性字符串的方法计算高度的更多性能。

- (NSRect)titleRectForBounds:(NSRect)theRect {
    NSRect titleFrame = [super titleRectForBounds:theRect];

    CGFloat fontHeight = [[[NSLayoutManager alloc] init] defaultLineHeightForFont:self.font];
    if (fontHeight < titleFrame.size.height) {
        titleFrame.origin.y = theRect.origin.y + (theRect.size.height - fontHeight) * 0.5f;
        titleFrame.size.height = fontHeight;
    }
    return titleFrame;
}

- (void) drawInteriorWithFrame:(NSRect)frame inView:(NSView *)view {
    [super drawInteriorWithFrame:[self titleRectForBounds:frame] inView:view];
}