Rotary Control Blog 2

//
//  RotaryControlBlogCircleImageView.h
//  RotaryControlBlog
//
//  Created by Ryan Dillon on 9/6/11.
//  Copyright 2011 Gig Bag Productions.

/*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/

#import <UIKit/UIKit.h>


@interface RotaryControlBlogCircleImageView : UIImageView {

    double  touchBeginAngle;

}

@end


//
//  RotaryControlBlogCircleImageView.m
//  RotaryControlBlog
//
//  Created by Ryan Dillon on 9/6/11.
//  Copyright 2011 Gig Bag Productions.
//

#import "RotaryControlBlogCircleImageView.h"
#import <QuartzCore/QuartzCore.h>

@implementation RotaryControlBlogCircleImageView

-(void)setup {
    self.image = [UIImage imageNamed:@"CircleInSquare"]; // Obviously, you'll have to provide your own image. Or don't even use one and just subclass UIView. The numbers will still show up just fine.
    self.userInteractionEnabled = YES;
    // Calculate the angle between each label based on the number of labels.
    int numberOfSections = 9;
    CGFloat angleSize = 2*M_PI/numberOfSections;

    // Each label gets the exact same inital frame, but a different transform is applied to space them around the circle.
    for (int i = 0; i < numberOfSections; ++i) {
        UILabel *sectionLabel = [[UILabel alloc] initWithFrame:CGRectMake(0.0f, 0.0f, self.bounds.size.width/2.0f, 50.0f)];
        sectionLabel.text = [NSString stringWithFormat:@"%i", i];
        sectionLabel.font = [UIFont systemFontOfSize:50.0];
        sectionLabel.textColor = [UIColor whiteColor];
        sectionLabel.backgroundColor = [UIColor clearColor];
        //sectionLabel.backgroundColor = [UIColor colorWithRed:1.0f green:0.0f blue:0.2f alpha:0.5f];

        /***** Here's the most important part: changing the anchorPoint, adjusting the position accordingly, and applying rotation ****/
        sectionLabel.layer.anchorPoint = CGPointMake(1.0f, 0.5f);
        sectionLabel.layer.position = CGPointMake(self.bounds.size.width/2.0, self.bounds.size.height/2.0); // places anchorPoint of each label directly in the center of the circle.
        sectionLabel.transform = CGAffineTransformMakeRotation(angleSize*i);
        [self addSubview:sectionLabel];
    }

    touchBeginAngle = 0.0;
}

-(double)angleBetweenCenterAndPoint:(CGPoint)point {

    CGPoint center = CGPointMake(self.bounds.size.width/2.0f, self.bounds.size.height/2.0f);
    double theAngle = atan2f(center.y - point.y, point.x - center.x);
    return theAngle;

}

-(id)initWithFrame:(CGRect)frame {

    self = [super initWithFrame:frame];

    if (!self) {
        return nil;
    }
    else {
        [self setup];
        return self;
    }
}

-(id)initWithCoder:(NSCoder*)aDecoder {

    self = [super initWithCoder:aDecoder];

    if (!self) {
        return nil;
    }
    else {
        [self setup];
        return self;
    }
}

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {

    CGPoint thisPoint = [[touches anyObject] locationInView:self];
    touchBeginAngle = [self angleBetweenCenterAndPoint:thisPoint];

}

-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {

    CGPoint thisPoint = [[touches anyObject] locationInView:self];
    CGFloat currentAngle = [self angleBetweenCenterAndPoint:thisPoint];
    CGFloat angleDiff = (touchBeginAngle - currentAngle);
    self.transform = CGAffineTransformRotate(self.transform, angleDiff);

}



@end