Incorrect behaviour in ios7 with constraints

[Adrian]

In ios 7, when the view is using autolayout with constaints, it only rotates and scales when doing pan, it seems that

self.center = CGPointMake(self.originalPoint.x + xFromCenter, self.originalPoint.y + yFromCenter);

isn't working properly in this case (in ios8 it works as expected). What I did to solve this is instead of changing the center property I changed the constraints values (I have four constraints in the view, one for each side), I couldn't figure out another solution. It would be something like this:

CGPoint translation = [gestureRecognizer translationInView:self.superview];

    case UIGestureRecognizerStateBegan:{
        self.originalPoint = self.center;

        originalTop = self.topSpace.constant;
        originalBottom = self.bottomSpace.constant;
        originalTrailling = self.trailingSpace.constant;
        originalLeading = self.leadingSpace.constant;

        break;
    };
    case UIGestureRecognizerStateChanged:{
        ... Stuff ...
        [self updatePositionWithDelta:translation];

• (void) updatePositionWithDelta:(CGPoint)delta {
  self.topSpace.constant = originalTop + delta.y;
  self.bottomSpace.constant = originalBottom - delta.y;

  self.leadingSpace.constant = originalLeading + delta.x;
  self.trailingSpace.constant = originalTrailling - delta.x;

  [self updateConstraintsIfNeeded];
  }

Hope it helps.

[Richard Kim]

Hey thanks for this. I might contact you later for more details when I look into this

—
(Choong-Won Richard Kim)

On Tue, Nov 18, 2014 at 1:29 PM, Nebla [e-mail] wrote:

In ios 7, when the view is using autolayout with constaints, it only rotates and scales when doing pan, it seems that
self.center = CGPointMake(self.originalPoint.x + xFromCenter, self.originalPoint.y + yFromCenter);
isn't working properly in this case (in ios8 it works as expected). What I did to solve this is instead of changing the center property I changed the constraints values (I have four constraints in the view, one for each side), I couldn't figure out another solution. It would be something like this:
CGPoint translation = [gestureRecognizer translationInView:self.superview];
case UIGestureRecognizerStateBegan:{
self.originalPoint = self.center;

        originalTop = self.topSpace.constant;
        originalBottom = self.bottomSpace.constant;
        originalTrailling = self.trailingSpace.constant;
        originalLeading = self.leadingSpace.constant;

        break;
    };
    case UIGestureRecognizerStateChanged:{
        ... Stuff ...
        [self updatePositionWithDelta:translation];

• (void) updatePositionWithDelta:(CGPoint)delta {
  self.topSpace.constant = originalTop + delta.y;
  self.bottomSpace.constant = originalBottom - delta.y;
  self.leadingSpace.constant = originalLeading + delta.x;
  self.trailingSpace.constant = originalTrailling - delta.x;

  [self updateConstraintsIfNeeded];
  }

  Hope it helps.

  Reply to this email directly or view it on GitHub:
  #6

[Matthew McArthur]

hey @Nebla and @cwRichardKim I am having the same issue on iOS 7. So I got it working like @Nebla said but I had to take out the rotation and scale transform.. it was behaving very weird and jumping and scaling weird. any ideas?

[Richard Kim]

Hey sorry for the late response. Are you still having this issue? I just tried to replicate it with iOS 7 and it's working fine for me. Are you using a device or a simulator?

[Matthew McArthur]

I was using a simulator. I ended up deciding that I didnt need the rotation. I still like the look of swiping without rotation. I may dig into it one day and try and figure it out.