How can I make OpenFlow work correctly in iOS 5.0?

Question

I recently updated my application to use the iOS 5.0 SDK. Within it, I am using Alex Fajowski's OpenFlow cover flow implementation.

I found that when I run the application on iOS 5.0, OpenFlow is making an incorrect transformation or Z repositioning when I swipe through images.

Is there something I can do to make OpenFlow work correctly on the iOS 5.0 SDK?

yes, i am also facing same problem, it looks like image flip in 3D effect. Provide some solution if anyone has. — Mobile App Dev, Oct 07 '11 at 12:34
I can't make a screen shot, because the rudeness occurs on swipe and it is very fast. — Oleg Danu, Oct 07 '11 at 14:21
Are you using this library only for Coverflow effect? If I suggest you any other library for the same effect will you like to have a try on this? — UPT, Oct 14 '11 at 06:20
As you can see, I have already posted the solution for this issue. Thank you. — Oleg Danu, Oct 15 '11 at 10:53

score 7 · Answer 1 · answered Oct 17 '11 at 00:53

I made an improvement over what you have here and it certainly makes it work smoothly (the way it used to be in iOS 4).

In AfOpenFlowView.m, instead of what you stated above (in -setUpInitialState):

leftTransform = CATransform3DTranslate(CATransform3DIdentity, 0, 0, SIDE_COVER_ZPOSITION / 2.0);
leftTransform = CATransform3DRotate(leftTransform, SIDE_COVER_ANGLE, 0.0f, 1.0f, 0.0f);
rightTransform = CATransform3DTranslate(CATransform3DIdentity, 0, 0, SIDE_COVER_ZPOSITION / 2.0);
rightTransform = CATransform3DRotate(rightTransform, SIDE_COVER_ANGLE, 0.0f, -1.0f, 0.0f);

Inside -layoutCover:selectedCover:animated, place the following code:

CGFloat newZPosition = SIDE_COVER_ZPOSITION / 2.0;

…

CABasicAnimation *zPositionAnimation = [CABasicAnimation animationWithKeyPath:@"zPosition"];
[zPositionAnimation setToValue:[NSNumber numberWithFloat:newZPosition]];
[zPositionAnimation setDuration:(animated ? .3 : 0.0)];
[zPositionAnimation setTimingFunction:[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]];
[zPositionAnimation setRemovedOnCompletion:NO];
[zPositionAnimation setFillMode:kCAFillModeForwards];

Now, instead of doing:

aCover.layer.zPosition = newZPosition;

Replace it with:

[aCover.layer addAnimation:zPositionAnimation forKey:nil];

You can conditionally enable either depending on whether it's running on iOS 4 or 5.

Best,

Yes, it worked but still lacked some 'smoothness' on the animation, which I fixed by adding what I just posted (which of course is based on what you originally commented). — boliva, Oct 17 '11 at 12:51

score 2 · Accepted Answer · answered Oct 10 '11 at 13:20

Today, I finally found the solution for this issue. Apparently, in iOS 5, zPosition is not being animated anymore (too bad, cause the documentation does say so). This is why, this bug may be fixed, by including the correct transition into the CATransform3D.

Earlier:

    leftTransform = CATransform3DIdentity;
    leftTransform = CATransform3DRotate(leftTransform, SIDE_COVER_ANGLE, 0.0f, 1.0f, 0.0f);
    rightTransform = CATransform3DIdentity;
    rightTransform = CATransform3DRotate(rightTransform, SIDE_COVER_ANGLE, 0.0f, -1.0f, 0.0f);

Now it looks like this:

    leftTransform = CATransform3DTranslate(CATransform3DIdentity, 0, 0, SIDE_COVER_ZPOSITION);
    leftTransform = CATransform3DRotate(leftTransform, SIDE_COVER_ANGLE, 0.0f, 1.0f, 0.0f);
    rightTransform = CATransform3DTranslate(CATransform3DIdentity, 0, 0, SIDE_COVER_ZPOSITION);
    rightTransform = CATransform3DRotate(rightTransform, SIDE_COVER_ANGLE, 0.0f, -1.0f, 0.0f);

Hope it helps you guys, as it did help me.

Nice, thanks! You should definitely submit a fix over github and close the issue (https://github.com/thefaj/OpenFlow/issues/21), I think it was yourself who posted it? — boliva, Oct 16 '11 at 22:33
Ok, this definitely provides an improvement but the animation still doesn't go as smooth as it used to… — boliva, Oct 16 '11 at 23:13

How can I make OpenFlow work correctly in iOS 5.0?

2 Answers2