Adding non editable NSTextField as a label into another NSTextField

问题

I am trying to implement a custom NSTextField that a) changes color when active and b) has a label in the top left hand corner.

I have the following implementation:

In TestTextField.h

@interface TestTextField : NSTextField

- (id)initFullWidthWithLabel:(NSString *)label andPreset:(NSString *)preset;
...
@end

In TestTextField.m

@interface TestTextField() {

    BOOL _thisFieldIsActive;
}

@property (nonatomic, strong) NSTextField *label;

@end

@implementation TestTextField

- (id)initFullWidthWithLabel:(NSString *)label andPreset:(NSString *)preset {

    self = [super initWithFrame:NSZeroRect];
    if (self) {

        _thisFieldIsActive = NO;

        [self setFocusRingType:NSFocusRingTypeNone];

        // small label top left
        _label = [[NSTextField alloc] initWithFrame:NSZeroRect];
        _label.stringValue = label;

        if (preset) {
            self.stringValue = preset;
        }
        else {
            self.stringValue = @"0";
        }

        [self layoutUI];

    }
    return self;

}
- (void)turnActiveOff {
    [self toggleActive:NO];
}

- (void)toggleActive:(BOOL)active {

    _thisFieldIsActive = active;

    if (_thisFieldIsActive) {
        self.backgroundColor = [NSColor blueColor];
        self.textColor = [NSColor whiteColor];
        _label.textColor = [NSColor whiteColor];
    }
    else {
        self.backgroundColor = [NSColor clearColor];
        self.textColor = [NSColor blackColor];
        _label.textColor = [NSColor grayColor];
    }

}
- (BOOL)becomeFirstResponder {

    NSLog(@"BecomeFirstResponder");

    [self selectText:self];
    [self toggleActive:YES];

    return [super becomeFirstResponder];
}

- (void)textDidEndEditing:(NSNotification *)notification {
    NSLog(@"DidEndEditing");

    [self toggleActive:NO];
    [super textDidEndEditing:notification];
}

- (void)layoutUI {

    self.alignment = NSRightTextAlignment;
    self.font = [NSFont fontWithName:@"HelveticaNeue-Light" size:32.0f];
    self.layer.borderColor = [NSColor whiteColor].CGColor;
    self.layer.borderWidth = 1.0f;
    [self.layer setCornerRadius:4.0f];

    // small label top left
    _label.font = [NSFont fontWithName:@"HelveticaNeue-Light" size:12.0f];
    _label.alignment = NSLeftTextAlignment;
    _label.textColor = [NSColor grayColor];
    _label.stringValue = [_label.stringValue uppercaseString];
    _label.selectable = NO;
    _label.editable = NO;
    _label.drawsBackground = NO;
    _label.bezeled = NO;
    [self addSubview:_label];

    NSDictionary *metrics = @{@"borderPadding": @5};

    _label.translatesAutoresizingMaskIntoConstraints = NO;
    [self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-(borderPadding)-[_label(100)]" options:0 metrics:metrics views:@{ @"_label" : _label }]];
    [self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-(borderPadding)-[_label(30)]" options:0 metrics:metrics views:@{ @"_label" : _label }]];

}

In my ViewController I implement these TestTextFields by simply calling the custom initFullWidthWithLabel:andPreset: method and adding them as a subview to the VCs view

I can see that the label gets positioned correctly, however as soon as the the field becomes active and the backgroundColor is set, it seems to cover up the label. How can I make sure the label stays on top? Even when the backgorund coloring is turned off, the label remains hidden.

Thanks

回答1:

The core of the solution was to use a custom subclassed NSTextFieldCell with one method:

- (NSRect)drawingRectForBounds:(NSRect)rect {
    NSRect rectInset = NSMakeRect(rect.origin.x + 100.0f, rect.origin.y, rect.size.width - 100.0f, rect.size.height);
    return [super drawingRectForBounds:rectInset];
}

来源：https://stackoverflow.com/questions/27579756/adding-non-editable-nstextfield-as-a-label-into-another-nstextfield

标签

objective-c

cocoa

nstextfield