I have a custom slider-type object, that I wish to make more usable. Currently I use UIPanGestureRecognizer
and translationInView
to make it work. It works pretty well but I'd like some sort of velocity in there to make it feel a bit more useful. I've tried a few things but cant quite figure out how to properly implement velocity changedLevel
equation.
- (void)panDetected:(UIPanGestureRecognizer *)gesture {
CGPoint swipeLocation = [gesture locationInView:self.tableView];
NSIndexPath *indexPath = [self.tableView indexPathForRowAtPoint:swipeLocation];
LevelCounterTableCell *swipedCell = (LevelCounterTableCell *)[self.tableView cellForRowAtIndexPath:indexPath];
if([gesture state] == UIGestureRecognizerStateBegan) {
NSString *originalLevelString = swipedCell.levelNumber.text;
originalLevel = [originalLevelString intValue]; // int originalLevel
}
if ([gesture state] == UIGestureRecognizerStateChanged) {
CGFloat xTranslation = [gesture translationInView:[[gesture view] superview]].x;
CGFloat xVelocity = [gesture velocityInView: [[gesture view] superview]].x;
// Pan threshold is currently set to 8.0.
// 8.0 is a decent level for slow panning
// for fast panning 2.0 is more reasonable
changedLevel = ceilf((xTranslation / panThreshold) + originalLevel); // int changedLevel
// Raw velocity seems to go from around 3 (slow)
// to over 200 (fast)
NSLog(@"raw velocity = %f", xVelocity);
if (changedLevel >= 15 && changedLevel <= 100) {
swipedCell.levelNumber.text = [NSString stringWithFormat:@"%i", changedLevel];
swipedCell.meter.frame = [self updateMeter: changedLevel];
}
}
if ([gesture state] == UIGestureRecognizerStateEnded || [gesture state] == UIGestureRecognizerStateCancelled) {
if (changedLevel >= 15 && changedLevel <= 100) {
//... Save the values...
}
}
}
Any help would be greatly appreciated. Thank you.