is default backgroundColor or not?

Question

I want know programatically, my TextView has default backgroundColor or changed. for example:

if (myTextView.backgroundColor == defaultColor){
NSLog(@"default");
} else {
NSLog(@"changed");
}

I have one idea:

UITextView *etalon = [UITextVew new];
if (myTextView.backgroundColor == etalon.backgroundColor){
NSLog(@"default");
} else {
NSLog(@"changed");
}

But I think it's not quite right. Anybody have better ideas?

Out of curiosity, why do you want to know this? – Jesse Rusak Nov 01 '13 at 11:51 — Jesse Rusak, Nov 01 '13 at 11:51

score 5 · Answer 1 · edited Nov 06 '13 at 05:21

5

Try this -

const float* color1 = CGColorGetComponents(myTextView.backgroundColor.CGColor);
const float* color2 = CGColorGetComponents(etalon.backgroundColor.CGColor);

if(color1 == color2) {
    NSLog(@"Default");
} else {
     NSLog(@"Changed");
}

edited Nov 06 '13 at 05:21

Suyash Nene

35
4

answered Nov 01 '13 at 12:34

Akshay Nalawade

1,447
2
14
29

score 3 · Answer 2 · answered Nov 01 '13 at 12:15

3

You should use [myTextView.backgroundColor isEqual:etalon.backgroundColor] in order to make a color compare. Also be careful because different color spaces are going to give you a not equal result.

answered Nov 01 '13 at 12:15

D33pN16h7

2,030
16
20

score 1 · Answer 3 · answered Nov 01 '13 at 11:55

1

The property backgroundColor returns a UIColor object, with the color of you background. Just compare it with another UIColor.

Both of your options seems right, as long as etalon.backgroundColor and defaultColor are UIColor.

answered Nov 01 '13 at 11:55

Antonio MG

20,382
3
43
62

score 0 · Answer 4 · answered Nov 01 '13 at 12:05

I don't know the context of your problem (ie. what are you trying to do), but another approach to your problem may involve using Key Value Observing to observe changes to your text view background color, and act accordingly.

Here's some documentation to get you started with KVO.

In code:

static void * kBackgroundColorCtx = &kBackgroundColorCtx;

[self.myTextView addObserver:self
                 forKeyPath:@"backgroundColor"
                    options:NSKeyValueObservingOptionOld
                    context:kBackgroundColorCtx];

Then, in your view controller implement this:

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {
    if (context == kBackgroundColorCtx) {
        NSLog(@"Background color changed from %@ to %@", 
              [change objectForKey:NSKeyValueChangeOldKey],
              self.myTextView.backgroundColor);
    } else {
        // Not interested in this, pass to superclass
        [super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
    }
}

score 0 · Answer 5 · edited Nov 01 '13 at 12:18

0

Check like this:

   if (myTextView.backgroundColor == [UIColor clearColor])
   {
       // your code here
   }

edited Nov 01 '13 at 12:18

Gustavo Barbosa

1,340
1
17
27

answered Nov 01 '13 at 12:12

Hussain Shabbir

14,801
5
40
56

score 0 · Answer 6 · edited May 23 '17 at 12:12

0

How about using the appearance proxy to grab the default:

UITextView *appearanceProxy = (UITextView *)[UITextView appearance];
if ([myTextView.backgroundColor isEqualToColor:appearanceProxy.backgroundColor]){
    NSLog(@"default");
} else {
    NSLog(@"changed");
}

See samvermette's answer at How to compare UIColors? for the definition of isEqualToColor.

edited May 23 '17 at 12:12

Community

1
1

answered Nov 01 '13 at 12:20

Jonathan Arbogast

9,620
4
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47

is default backgroundColor or not?

6 Answers6