Question

I followed a guide about dragging multiple images on screen with gesture recognizers however i have a problem. I want the images to be dragged inside the bounds of the screen which maybe iPad or iPhone. The code i am using estimates the image’s center so half of the image is getting off screen when reaching the bounds. Could you please help me with this?

- (IBAction)handlePan:(UIPanGestureRecognizer *)recognizer {

CGPoint translation = [recognizer translationInView:self.view];
recognizer.view.center = CGPointMake(recognizer.view.center.x + translation.x, 
                                     recognizer.view.center.y + translation.y);
[recognizer setTranslation:CGPointMake(0, 0) inView:self.view];

if (recognizer.state == UIGestureRecognizerStateEnded) {

    CGPoint velocity = [recognizer velocityInView:self.view];
    CGFloat magnitude = sqrtf((velocity.x * velocity.x) + (velocity.y * velocity.y));
    CGFloat slideMult = magnitude / 200; //original divider 200
    NSLog(@"magnitude: %f, slideMult: %f", magnitude, slideMult);

    float slideFactor = 0.1 * slideMult /4; // Increase for more of a slide (original doesn't have a divider)
    CGPoint finalPoint = CGPointMake(recognizer.view.center.x + (velocity.x * slideFactor), 
                                     recognizer.view.center.y + (velocity.y * slideFactor));
    finalPoint.x = MIN(MAX(finalPoint.x, 0), self.view.bounds.size.width);
    finalPoint.y = MIN(MAX(finalPoint.y, 0), self.view.bounds.size.height);

    [UIView animateWithDuration:slideFactor*2 delay:0 options:UIViewAnimationOptionCurveEaseOut animations:^{
        recognizer.view.center = finalPoint;
    } completion:nil];
  }
}

Answer 1

Well, i managed to find out the solution to my problem. I divided the image width and height by two. In my case the results were 100 and 70. The rest can be seen in code box :

finalPoint.x = MIN(MAX(finalPoint.x, 70), self.view.bounds.size.width-70);
finalPoint.y = MIN(MAX(finalPoint.y, 100), self.view.bounds.size.height-100);