How do I vertically center align text in a NSTextField?

Question

I have an NSTextField and I want to vertically center align the text in it. Basically I need the NSTextField answer of How do I vertically center UITextField Text?

Anyone got some pointers? Thanks!

Answer 1

You could subclass NSTextFieldCell to do what you want:

MDVerticallyCenteredTextFieldCell.h:

#import <Cocoa/Cocoa.h>

@interface MDVerticallyCenteredTextFieldCell : NSTextFieldCell {

}

@end

MDVerticallyCenteredTextFieldCell.m:

#import "MDVerticallyCenteredTextFieldCell.h"

@implementation MDVerticallyCenteredTextFieldCell

- (NSRect)adjustedFrameToVerticallyCenterText:(NSRect)frame {
    // super would normally draw text at the top of the cell
    NSInteger offset = floor((NSHeight(frame) - 
           ([[self font] ascender] - [[self font] descender])) / 2);
    return NSInsetRect(frame, 0.0, offset);
}

- (void)editWithFrame:(NSRect)aRect inView:(NSView *)controlView
         editor:(NSText *)editor delegate:(id)delegate event:(NSEvent *)event {
    [super editWithFrame:[self adjustedFrameToVerticallyCenterText:aRect]
          inView:controlView editor:editor delegate:delegate event:event];
}

- (void)selectWithFrame:(NSRect)aRect inView:(NSView *)controlView
                 editor:(NSText *)editor delegate:(id)delegate 
                  start:(NSInteger)start length:(NSInteger)length {

    [super selectWithFrame:[self adjustedFrameToVerticallyCenterText:aRect]
                    inView:controlView editor:editor delegate:delegate
                     start:start length:length];
}

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

@end

You can then use a regular NSTextField in Interface Builder, and specify MDVerticallyCenteredTextFieldCell (or whatever you want to name it) as the custom class for the text field's text field cell (select the textfield, pause, then click the textfield again to select the cell inside the text field):