Moving Media

I just bought two external USB drives to serve as a mirrored set. Setting up the RAID was easy using Disk Utility. Now I'm copying over iTunes, iPhoto, etc. Here's some handy instructions for iTunes: http://support.apple.com/kb/ht1449

WP7 Emulator on Parallels 6 for Mac

I just upgraded to Parallels 6 and thought I would attempt to run the Windows Phone 7 emulator. Simply building and running did not work. However, I ran the emulator from the Start menu. It took a long time for it to start up. The emulator rebooted a few times, then it arrived at the phone home screen. From there, I could launch the debugger from Visual Studio.

While re-testing for this post, I would occasionally see the following error when attempting to attach the debugger:

a specified communication resource (port) is already in use by another application.

I did a Build -> Clean and retried. Success!

The app that I built does nothing. It was simply the Visual Studio template. So I can’t yet attest to performance while debugging, or the availability of features.

The virtual machine is Windows 7 Ultimate. With the first few tests, it had 1 processor and 1GB of ram, which was an error in configuration. I changed it to 2 processors and 4GB of ram. That didn't seem to increase the speed of the emulator startup by very much.

Please give it a try! I am curious if others can reproduce the success.

devLink presentation: New Features for iPad and iOS 4 SDK

source | slides

devLink presentation: iOS SDK: Core Data

source | slides

devLink presentation: Introduction to the iOS SDK

Here's the slide deck and source code for my "Introduction
to the iOS SDK" talk. Thanks for coming to devLink. Hope you had a great time!

source | slides

Custom tintColor for each segment of UISegmentedControl

The UISegmentedControl offers the ability to set the tint color for the entire control, but it does not offer the ability to set the tint color for an individual segment. In fact, the UISegment class, the actual class for the individual segments, is not publicly documented. So, what I propose here does go a bit off the farm, but it only uses publicly available API to accomplish it. Here is the end result.

The first step is to create an extension to the UISegmentedControl. The extension neatly wraps up the new functionality so that it can be easily reused instead of cluttering up your view controllers.

UISegmentedControlExtension.h

@interface UISegmentedControl(CustomTintExtension)
-(void)setTag:(NSInteger)tag forSegmentAtIndex:(NSUInteger)segment;
-(void)setTintColor:(UIColor*)color forTag:(NSInteger)aTag;
-(void)setTextColor:(UIColor*)color forTag:(NSInteger)aTag;
-(void)setShadowColor:(UIColor*)color forTag:(NSInteger)aTag;
@end

UISegmentedControlExtension.m

#import "UISegmentedControlExtension.h"


@implementation UISegmentedControl(CustomTintExtension)

-(void)setTag:(NSInteger)tag forSegmentAtIndex:(NSUInteger)segment {
[[[self subviews] objectAtIndex:segment] setTag:tag];
}

-(void)setTintColor:(UIColor*)color forTag:(NSInteger)aTag {
// must operate by tags.  Subview index is unreliable
UIView *segment = [self viewWithTag:aTag];
SEL tint = @selector(setTintColor:);

// UISegment is an undocumented class, so tread carefully
// if the segment exists and if it responds to the setTintColor message
if (segment && ([segment respondsToSelector:tint])) {
 [segment performSelector:tint withObject:color];
}
}

-(void)setTextColor:(UIColor*)color forTag:(NSInteger)aTag {
UIView *segment = [self viewWithTag:aTag];
for (UIView *view in segment.subviews) {
 SEL text = @selector(setTextColor:);

 // if the sub view exists and if it responds to the setTextColor message
 if (view && ([view respondsToSelector:text])) {
  [view performSelector:text withObject:color];
 }
}
}

-(void)setShadowColor:(UIColor*)color forTag:(NSInteger)aTag {

// you probably know the drill by now
// you could also combine setShadowColor and setTextColor
UIView *segment = [self viewWithTag:aTag];
for (UIView *view in segment.subviews) {
 SEL shadowColor = @selector(setShadowColor:);
 if (view && ([view respondsToSelector:shadowColor])) {
  [view performSelector:shadowColor withObject:color];
 }
}
}

@end

Once that is in place, here is an example of a typical UIViewController taking advantage of it.

SegmentColorsViewController.m

#import "SegmentColorsViewController.h"
#import "UISegmentedControlExtension.h"

#define kTagFirst 111
#define kTagSecond 112
#define kTagThird 113

@interface SegmentColorsViewController(PrivateMethods)
-(void)segmentChanged:(id)sender;
-(void)setTextColorsForSegmentedControl:(UISegmentedControl*)segmented;
@end

@implementation SegmentColorsViewController

-(void)viewDidLoad {

// create a simple segmented control
// could have done this in Interface Builder just the same
NSArray *items = [[NSArray alloc] initWithObjects:@"orange", @"yellow", @"green", nil];
UISegmentedControl *colors = [[UISegmentedControl alloc] initWithItems:items];
[items release];
[colors setSegmentedControlStyle:UISegmentedControlStyleBar];
[colors setTintColor:[UIColor lightGrayColor]];
[colors setFrame:CGRectMake(20.0f, 20.0f, 280.0f, 30.0f)];
[colors addTarget:self action:@selector(segmentChanged:) forControlEvents:UIControlEventValueChanged];
[self.view addSubview:colors];


// ... now to the interesting bits

// at some point later, the segment indexes change, so
// must set tags on the segments before they render
[colors setTag:kTagFirst forSegmentAtIndex:0];
[colors setTag:kTagSecond forSegmentAtIndex:1];
[colors setTag:kTagThird forSegmentAtIndex:2];

[colors setTintColor:[UIColor orangeColor] forTag:kTagFirst];
[colors setTintColor:[UIColor yellowColor] forTag:kTagSecond];
[colors setTintColor:[UIColor greenColor] forTag:kTagThird];

[self setTextColorsForSegmentedControl:colors];
[colors release];
}

-(void)segmentChanged:(id)sender {
// when a segment is selected, it resets the text colors
// so set them back
[self setTextColorsForSegmentedControl:(UISegmentedControl*)sender];
}

-(void)setTextColorsForSegmentedControl:(UISegmentedControl*)segmented {
[segmented setTextColor:[UIColor yellowColor] forTag:kTagFirst];
[segmented setTextColor:[UIColor blackColor] forTag:kTagSecond];
[segmented setTextColor:[UIColor blueColor] forTag:kTagThird];

[segmented setShadowColor:[UIColor redColor] forTag:kTagFirst];
[segmented setShadowColor:[UIColor whiteColor] forTag:kTagSecond];
[segmented setShadowColor:[UIColor clearColor] forTag:kTagThird];
}
@end

Pre-compiled Libraries for iPhone OS

Digging into the RedLaser SDK. Their sample includes several ".a" files that seem to contain all the real magical guts of the their product. Intrigued. This link describes how to create such a thing for myself.

UPDATE: Here are a few other similar links:

• StackOverflow: A Guide for Creating your own Library for Cocoa(touch) development
• StackOverflow: Can I develop my own objective-C Framework for Cocoa Touch Applications?
• Building static libraries with the iPhone SDK
• StackOverflow: How do I add a third party Framework to iPhone project?