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//
// KTOneFingerRotationGestureRecognizer.m
//
// Created by Kirby Turner on 4/22/11.
// Copyright 2011 White Peak Software Inc. All rights reserved.
//
//
// 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 "KTOneFingerRotationGestureRecognizer.h"
#import <UIKit/UIGestureRecognizerSubclass.h>
@implementation KTOneFingerRotationGestureRecognizer
@synthesize rotation = rotation_;
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
// Fail when more than 1 finger detected.
if ([[event touchesForGestureRecognizer:self] count] > 1) {
[self setState:UIGestureRecognizerStateFailed];
}
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
if ([self state] == UIGestureRecognizerStatePossible) {
[self setState:UIGestureRecognizerStateBegan];
} else {
[self setState:UIGestureRecognizerStateChanged];
}
// We can look at any touch object since we know we
// have only 1. If there were more than 1 then
// touchesBegan:withEvent: would have failed the recognizer.
UITouch *touch = [touches anyObject];
// To rotate with one finger, we simulate a second finger.
// The second figure is on the opposite side of the virtual
// circle that represents the rotation gesture.
UIView *view = [self view];
CGPoint center = CGPointMake(CGRectGetMidX([view bounds]), CGRectGetMidY([view bounds]));
CGPoint currentTouchPoint = [touch locationInView:view];
CGPoint previousTouchPoint = [touch previousLocationInView:view];
CGFloat angleInRadians = atan2f(currentTouchPoint.y - center.y, currentTouchPoint.x - center.x) - atan2f(previousTouchPoint.y - center.y, previousTouchPoint.x - center.x);
[self setRotation:angleInRadians];
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
// Perform final check to make sure a tap was not misinterpreted.
if ([self state] == UIGestureRecognizerStateChanged) {
[self setState:UIGestureRecognizerStateEnded];
} else {
[self setState:UIGestureRecognizerStateFailed];
}
}
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event
{
[self setState:UIGestureRecognizerStateFailed];
}
@end