Odd Behavior with Segmented Control (iPhone OS 3.1)

Question

I have this method, which is supposed to change the color that a shape is to be drawn in when I change the value of a segmented control:
- (IBAction)changeColor: (id)sender {
UISegmentedControl *control = sender;
NSInteger index = [control selectedSegmentIndex];
QuartzFunView *quartzView = (QuartzFunView *)self.view;
switch (index) {
case kRedColorTab:
quartzView.currentColor = [UIColor redColor];
quartzView.useRandomColor = NO;
break;
case kBlueColorTab:
quartzView.currentColor = [UIColor blueColor];
quartzView.useRandomColor = NO;
case kYellowColorTab:
quartzView.currentColor = [UIColor yellowColor];
quartzView.useRandomColor = NO;
break;
case kGreenColorTab:
quartzView.currentColor = [UIColor greenColor];
quartzView.useRandomColor = NO;
break;
case kRandomColorTab:
quartzView.useRandomColor = YES;
break;
default:
break;
The issue here is that everything works...except for just the blue segment (the second segment).
The drawRect method I'm using is as follows:
- (void)drawRect:(CGRect)rect {
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetLineWidth(context, 2.0);
CGContextSetStrokeColorWithColor(context, currentColor.CGColor);
switch (shapeType) {
case kLineShape:
CGContextMoveToPoint(context, firstTouch.x, firstTouch.y);
CGContextAddLineToPoint(context, lastTouch.x, lastTouch.y);
CGContextStrokePath(context);
break;
case kRectShape:
break;
case kImageShape:
break;
default:
break;
and kBlueColorTab is defined as
typedef enum {
kRedColorTab = 0,
kBlueColorTab,
kYellowColorTab,
kGreenColorTab,
kRandomColorTab
} ColorTabIndex;
As I've said before, all the tabs except for that specific one works. I've double checked the connections and syntax as well, and I can't figure out what's wrong. Am I'm just missing something, or is there something else going on here that I'm not aware of?
BTW, this code is from Chapter 12 of Mark and LaMarche's +Beginning iPhone 3 Development+ book, for the sake of a context.
Message was edited by: musicwind95
UPDATE: After filling in the rest of that switch statement, the same issue occurs for rectangles and ellipses. The fill color, which is the same as the stroke, is red for the red segment, yellow for both the blue and yellow segment, and green for the green segment. The random segment works properly as well, just not the blue one.
Message was edited by: musicwind95

Answer 1

You just forgot the break statement at the end of the blue case. Thus execution "falls through" into the yellow case, so the color for kBlueColorTab is yellow. Some C programmers move the break back one tab so it's absence is more visible. E.g.:
switch (index) {
case kRedColorTab:
quartzView.currentColor = [UIColor redColor];
quartzView.useRandomColor = NO;
break;
case kBlueColorTab:
quartzView.currentColor = [UIColor blueColor];
quartzView.useRandomColor = NO;
break
case kYellowColorTab:
quartzView.currentColor = [UIColor yellowColor];
quartzView.useRandomColor = NO;
break;
- Ray