在NSTextField中设置文本垂直中心

Question

在某个高度NSTextField中，如果文字的大小很小，布局就像这样

文字流向顶部，如何使文字中心像这样：

Answer 1

我基本上使用Alex的答案，有一个修正案：如果我们增加y-origin，我们应该减少titleRect的高度。否则我们的titleRect将在其超级视图的末尾下方结束，可能隐藏NSTextField下面的任何内容。

.h：

#import <Cocoa/Cocoa.h>

@interface VerticallyCenteredTextFieldCell : NSTextFieldCell

@end

.m：

#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。如果你将它子类化，请在Interface Builder中更改NSTextFieldCell的类，而不是NSTextField（我不知道这个）。

Answer 2

只是继承NSTextFieldCell（ or swizzle it ）...并实施......

- (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 3

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 4

在Erik和Hejazi的回答中添加一点，你还需要实现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

Swick版本的Erik Wegener的答案（也修改为可以使用多行）：

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

我的解决方案基于使用NSLayoutManager计算字体高度。 这样可以提高使用归因字符串方法计算高度的性能。

- (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];
}