Ah. I see some of your points. Very dumb of me. I'm new to Cocoa, but I did
program in a number of other languages for 30 years. I apologize for not being
clear enough. Pain and nausea tend to mess up the clarity of my thinking.
Unfortunately, I'm ill most of the time (don't ask about my health. It's too
depressing). This also makes it take an extremely long time to get any program
done. In the past, I got into the habit of not asking for help, and forcing
myself to figure out the solution on my own. I don't like to bother other
people with my problems (besides, learning from my mistakes was the way I
learned before). Maybe with Cocoa this is a bad idea.
Is this your exact code? You use wordsFromPhrase: here but the method below
is wordsInPhrase:.
This is a typo. The same method names are used in my code. I tried to pare
down the source code to a manageable length for posting my question. When I
looked at it afterwards, I didn't notice my own typos. I always the a long
time to check for such typos when within Xcode.
To give you a little more background about the context of the code snippets in
the full program, I'm trying to animate the individual words of the phrase in
sequence with fading in and out, color changes, etc. I'm using Core Animation
in conjunction with the NSTimer because I could not find an elegant way to
create an NSKeyframeAnimation in which each individual word of my phrase
(displayed in a CATextLayer) could be swapped in sync with the other
animatable properties. Each individual word had to be set before the animation
started. My solution was to use the timer's changeWords: method to change the
words and trigger a one-shot animation on each invocation, with the timer's
duration slightly longer than the animation's duration. Yes, I know this is a
kludge, but it was the only way that I could come up with to solve this
problem. I ran it past a few other people and they thought it would work. Any
other approaches would be appreciated.
Another thing: you are ignoring the argument thePhrase.
Right. In paring down the code for my post, I passed an argument. In my
working code, I simply use the phrase property within the method. Sorry about
making that mistake and confusing the issue. And, yes, I am declaring ivars
for all of the properties.
phrase = @This is the phrase to display;// stringWithString: is almost
never what you intend.
God, was that stupid! Of course I should have done that!
Do you ever want to change .words without doing [self start]? If not, make
the call to -start inside setWords:. Then self.words = [self wordsFromPhrase:
self.phrase] can completely replace -setUp.
Good point. Within start: I call different methods for each type of animation
to use, but I never change the words without calling [self start]. This would
be a good place to move that call. I had not refactored my code yet.
NSArray *wordArray;
[wordArray arrayByAddingObjectsFromArray:[phrase
componentsSeparatedByString:@ ]];
I did not notice that mistake. That _should_ crash. Thanks.
and that you _really_ mean:
@property(nonatomic, readonly) NSUInteger numWords;
@property(nonatomic, readonly) NSArray *words;
@property(nonatomic, retain) NSArray * backingWordsArray;
I thought that properties such as NSString and NSArray needed to be retained or
copied. Am I wrong?
wordChangeTimer = [[NSTimer scheduledTimerWithTimeInterval:wordChangeInterval
[My customary objection to accessing an ivar directly.]
I tried both wordChangeTimer and self.wordChangeTimer when I was testing the
program. Both worked, so I left it as is.
self.wordChangeTimer = [NSTimer ... repeats: YES];
If you let the property manage your memory, you won't have to do it yourself.
And if you have a setter method, you can invalidate the old timer.
Would invalidating within the setter as the NSTimer is assign in the code above
for the first time cause a problem?
What are setUpDisplay and startDisplay? Are they the same as setUp and start?
Yeah. Another typo. You know, when I took a mandatory typing class in junior
high school, I was the worst typist in the class. That's probably why I was
also a terrible piano player.
I ran everything through the debugger, and stepped though it. That's how I
knew that words had a non-nil value in start and not have it in changeWords:.
As for Instruments, I find Apple's documentation very unclear. I've only used
Instruments on one project before this, and managed to remove a leak. When I
ran Instruments on this project, I did not notice a leak. However, since I'm so
new to Instruments, it's entirely possible that I forgot how to use it properly
again on this project. ;-) Is there a good tutorial on using Instruments? All
I've seen on-line are descriptions of the tools within Instruments, but not
clear instructions on how to use them.
I will take your advice and correct my code. I appreciate your
