Faire pivoter l'image correspondant au glissement tactile dans l'iPhone

Question

Je souhaite faire pivoter l'image dans le sens des aiguilles d'une montre ou dans le sens inverse des aiguilles d'une montre, en fonction de sa vitesse. Je pense que cela peut être fait avec un peu de maths et de logique. A quoi ressemblerait un exemple de code pour cela?

Answer 1

Si vous ciblez iOS 3.2 ou plus, vous pouvez utiliser UIRotationGestureRecognizer. Le code ressemblerait à quelque chose comme ceci:

Dans votre méthode de configuration (viewDidLoad ou init, etc.):

UIRotationGestureRecognizer *rotationGesture = 
    [[UIRotationGestureRecognizer alloc] initWithTarget:self 
               action:@selector(handleRotate:)]; 
rotationGesture.delegate = self; 
[myImageView addGestureRecognizer:rotationGesture]; 
[rotationGesture release]; 

Le gestionnaire d'événements:

- (void)handleRotate:(UIRotationGestureRecognizer *)recognizer { 
    if(recognizer.state == UIGestureRecognizerStateBegan || 
    recognizer.state == UIGestureRecognizerStateChanged) 
    { 
    recognizer.view.transform = CGAffineTransformRotate(recognizer.view.transform, 
                 recognizer.rotation); 
    [recognizer setRotation:0]; 
    } 
} 

J'ai quelques exemples de gestes reconnaissants (y compris celui ci-dessus) sur github.

Answer 2

-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event 
{ 
    for (UITouch *touch in touches) 
    { 
     currentTouch=touch; 
     if (CGRectContainsPoint([self.view frame], [touch locationInView:self.ViewRotationArrow])) 
     { 
      [self transformSpinnerwithTouches:touch]; 
     } 
     else if (!CGRectContainsPoint([ViewRotationArrow frame], [touch locationInView:self.ViewRotationArrow])) { 
      [self dispatchTouchEvent:[touch view]WithTouch:touch]; 
     } 
    } 
} 

-(void)transformSpinnerwithTouches:(UITouch *)touchLocation 
{ 
    CGPoint touchLocationpoint = [touchLocation locationInView:self.view]; 
    CGPoint PrevioustouchLocationpoint = [touchLocation previousLocationInView:self.view]; 

    //Origin is the respective point. From that I am going to measure the 
    //angle of the current position with respect to the previous position .... 
    CGPoint origin; 
    origin.x=240; 
    origin.y=160; 
    //NSLog(@"currentTouch Touch In Location In View:%F %F\n",touchLocationpoint.x,touchLocationpoint.y); 
    //NSLog(@"currentTouch Touch previous Location In View:%F %F\n",PrevioustouchLocationpoint.x,PrevioustouchLocationpoint.y); 
    CGPoint previousDifference = [self vectorFromPoint:origin toPoint:PrevioustouchLocationpoint]; 
    CGAffineTransform newTransform =CGAffineTransformScale(ViewRotationArrow.transform, 1, 1); 
    CGFloat previousRotation = atan2(previousDifference.y, previousDifference.x); 
    CGPoint currentDifference = [self vectorFromPoint:origin toPoint:touchLocationpoint]; 
    CGFloat currentRotation = atan2(currentDifference.y, currentDifference.x); 
    CGFloat newAngle = currentRotation- previousRotation; 
    NSLog(@"currentRotation of x %F previousRotation %F\n",currentRotation,previousRotation); 
    NSLog(@"Angle:%F\n",(temp1*180)/M_PI); 
    temp1=temp1+newAngle; 
    //NSLog(@"Angle:%F\n",(temp1*180)/M_PI); 
    newTransform = CGAffineTransformRotate(newTransform, newAngle); 
    [self animateView:ViewRotationArrow toPosition:newTransform]; 
} 

-(CGPoint)vectorFromPoint:(CGPoint)firstPoint toPoint:(CGPoint)secondPoint 
{ 
     CGPoint result; 
     CGFloat x = secondPoint.x-firstPoint.x; 
     CGFloat y = secondPoint.y-firstPoint.y; 
     result = CGPointMake(x, y); 
     return result; 
} 



-(void)animateView:(UIView *)theView toPosition:(CGAffineTransform) newTransform 
{ 
    //animating the rotator arrow... 
    [UIView setAnimationsEnabled:YES]; 
    [UIView beginAnimations:nil context:NULL]; 
    [UIView setAnimationCurve:UIViewAnimationCurveLinear]; 
    [UIView setAnimationBeginsFromCurrentState:YES]; 
    [UIView setAnimationDuration:0.0750]; 
    ViewRotationArrow.transform = newTransform; 
    [UIView commitAnimations]; 
} 

Answer 3

-(void)rotateView 
{ 

    //shape of eclipse 

    CAShapeLayer* circle = [[CAShapeLayer alloc] init]; 
    CGMutablePathRef path = CGPathCreateMutable(); 
    CGRect ViewRect = CGRectMake(self.view.bounds.size.width/2.8, (self.view.bounds.size.height-self.view.bounds.size.width/2)/2, self.view.bounds.size.width/4, self.view.bounds.size.width/2); 
    float midX = CGRectGetMidX(ViewRect); 
    float midY = CGRectGetMidY(ViewRect); 
    CGAffineTransform t = CGAffineTransformConcat(
                CGAffineTransformConcat(
                      CGAffineTransformMakeTranslation(-midX, -midY), 
                      CGAffineTransformMakeRotation(-1.57079633/0.99)), 
                CGAffineTransformMakeTranslation(midX, midY)); 
    CGPathAddEllipseInRect(path, &t, ViewRect); 
    circle.path = path; 
    circle.frame = self.view.bounds; 
    circle.fillColor = [UIColor clearColor].CGColor; 
    circle.strokeColor = [UIColor greenColor].CGColor; 
    circle.lineWidth = 3.0f; 
    [self.view.layer addSublayer:circle]; 

    CABasicAnimation* animation = [CABasicAnimation animationWithKeyPath:@"strokeEnd"]; 
    animation.duration = 0.0f; 
    animation.fromValue = [NSNumber numberWithFloat:0.0f]; 
    animation.toValue = [NSNumber numberWithFloat:1.0f]; 
    animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear]; 
    [circle addAnimation:animation forKey:@"strokeEnd"]; 


    // rotateView red color 


    testView=[[UIView alloc]init]; 
    testView.frame=CGRectMake(0, 0, 20, 20); 
    testView.backgroundColor=[UIColor redColor]; 
    testView.userInteractionEnabled=YES; 
    testView.center=CGPathGetCurrentPoint(path); 
    testView.transform = CGAffineTransformMakeRotation(1.57079633); 
    [testView sizeToFit]; 
    [self.view.layer addSublayer:testView.layer]; 


    // view Animation 

    CAKeyframeAnimation* ViewAnimation = [CAKeyframeAnimation animationWithKeyPath:@"position"]; 
    ViewAnimation.duration = 15.0f; 
    ViewAnimation.path = path; 
    ViewAnimation.rotationMode = kCAAnimationRotateAuto; 
    ViewAnimation.calculationMode = kCAAnimationCubicPaced; 
    //ViewAnimation.removedOnCompletion = NO; 
    [testView.layer addAnimation:ViewAnimation forKey:@"position"]; 

}