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The iOS doc says that we can present one or 2 pages at a time depending on the spine location or position and double sided state...
But, I am unable to understand "What exactly spine is in UIPageViewController ?"enter image description here

aMother
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    spine is in the central of two pages in this case. – chancyWu Jan 02 '14 at 07:16
  • Then What do we mean by spine location none, min, max, mid... Is that the separator b/w 2 pages... in that case using min and max will give more screen space to one page and less screen space to other – aMother Jan 02 '14 at 07:19
  • in Uipageview controller you can see that in landscape mode 2 child view controller seen. so when you rotate from potrait to landscape it needs 2 view controller. so the spine location delegate method handle this operation for 2 different controller. – Anjan Jan 02 '14 at 08:19
  • @Anjan Please explain the second comment from top – aMother Jan 02 '14 at 11:24
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    The spine in a book is its binding. In your image it's in the middle. Min means the spine is on the left of the screen. Imagine then that you have a large book with the binding on the left of the iPad, and the pages turn from right to left as you go forward in your book. – Joseph Chen Jan 02 '14 at 14:47
  • Thanks! It will be nice for everyone if you post this as answer... – aMother Jan 02 '14 at 15:15

1 Answers1

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It applies only when transitionStyle is set to PageCurl (otherwise it evaluates to None); during the animation of the UIPageViewController a 3D page is displayed: this property controls where the border of the page is attached with respect to the parent controller (that is, the position of the 'spine' of the displayed 3D book).

Min means it is attached on the left side, Max for the right, and Mid displays two consecutive pages split in the middle. In pictures (the spine is in red):

Apple example PageViewController app with different spine settings

Reference: Apple documentation.

Pietro Saccardi
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