calebd

#import <objc/runtime.h>

- (NSString *)description {
    unsigned int count;
    objc_property_t *properties = class_copyPropertyList([self class], &count);
    NSMutableDictionary *dictionary = [NSMutableDictionary dictionaryWithCapacity:count];
    for (unsigned int i = 0; i < count; i++) {
        NSString *name = [NSString stringWithUTF8String:property_getName(properties[i])];
        id value = [self valueForKey:name];
        if (value == self) {

calebd

A Better Build Date

Showing a build date in an app is pretty easy using __DATE__ and __TIME__ but the format is fixed. This script allows you to control the date and time format and pull the build date from the Info.plist using the CMDBundleBuildTime key.

calebd

Why does this work? In theory, creating a mutable version of an NSData object by referencing its original bytes using -[NSMutableData dataWithBytesNoCopy:length:freeWhenDone:], and then modifying those bytes would result in the original immutable object being modified as well.

It is worth noting that calling -[NSData dataWithBytesNoCopy:length:freeWhenDone:] results in both data objects having the same byte pointer address, and that memsetting the data returned by bytes on an immutable data object will in fact update the data that it represents.

Output:

DataTest[58994:303] original data pointer location: 0x10010a630
DataTest[58994:303] original data: <4c6f7265 6d206970 73756d20 646f6c6f 72207369 7420616d 65742c20 636f6e73 65637465 74757220 61646970 69736369 6e672065 6c69742e>
DataTest[58994:303] mutable data pointer location: 0x100201a00

calebd

I found an annoying behavior in UIColor today. If either saturation or brightness is 0 when creating an HSB color, other color values are ignored. This results in a valid color, and if drawn, it will be the correct color. But the values coming out of it are incorrect.

Assuming these defined values:

UIColor *color;
CGFloat inputHue, inputSaturation, inputBrightness, inputAlpha;
CGFloat outputHue, outputSaturation, outputBrightness, outputAlpha;

calebd

Keybase proof

I hereby claim:

• I am calebd on github.
• I am calebd (https://keybase.io/calebd) on keybase.
• I have a public key whose fingerprint is 90E2 D6FA 4617 A20E F17B A0FD C9D4 36D2 93D8 1A54

To claim this, I am signing this object: