I've got a scroll view, in which I have an imageview displaying a 960x960 image, but it scrolls to something close to 4x that. I've tried to log the widths of all possible views and everything claims that it's 960x960 (or smaller, I think I logged the screen width once...?)
I need this image to stop scrolling at the bottom right corner of the image rather than entering deadspace. Any help would be greatly appreciated.
Heck, even telling me what the name of the object is that is larger than my scrollView.contentSize would put me on the right track...
//Test-Image is just a 960 by 960 image that's numbered around the edges 1-10 so you can tell if it's being moved
UIImageView *tempImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"Test-Image.png"]];
self.imageView = tempImageView;
[tempImageView release];
scrollView.contentSize = CGSizeMake(imageView.frame.size.width, imageView.frame.size.height);
//Tested with this, results the same.
//[scrollView setContentSize:CGSizeMake(960, 960)];
NSLog(#"What is my scrollView's height attribute?...%f", scrollView.contentSize.height);
// Returns 960
NSLog(#"What is in scrollView's width attribute?...%f", scrollView.contentSize.width);
// Returns 960
scrollView.contentOffset = CGPointMake(480, 480);
scrollView.maximumZoomScale = 8.0;
scrollView.minimumZoomScale = 0.25;
// Commenting clipsToBounds out doesn't seem to have any effect
scrollView.clipsToBounds = YES;
scrollView.delegate = self;
[scrollView addSubview:imageView];
Unfortunately, I do not have a specific answer.
Reference. Try [scrollView addSubview: self.imageView]; instead of [...addSubview: imageView];
Content Size. Try setting the content size after adding the ImageView.
[scrollView setContentSize: CGSizeMake(imageView.frame.size.width, imageView.frame.size.height)];
Delegate. Did you use and set the scrollview's delegate property (oIWScroll.delegate = self;)?
Clipping. It should not matter.
ScrollView Frame. Make sure the frame of the scrollview is equal to or smaller than [UIScreen mainScreen].applicationFrame.
Framing. When I had a situation similar to what you described, one of the the things I did was to create a container UIView, add it to the scroll view and stuff the objects into the container view. But you really should not have to do that for one image.
I also set the contentMode = UIViewContentModeTop.
I hope these suggestions help.
Related
Before you bash me for duplicate, please know that I have looked nearly every other method but none of them have helped. I have a long view in which I have a scroll view.
The view is 320 by 671. The scroll view has been linked to the outlet "scrollView" correctly.
The property "scrollView" has been properly declared and synthesised.
My code:
[scrollView setScrollEnabled: YES];
scrollView.contentSize = CGSizeMake(320, 671);
scrollView.clipsToBounds = YES;
scrollView.delegate = self; // I have adopted the delegate protocol in .h
So, my problem is that the view doesn't scroll, and the scroll bar doesn't even show up.
EDIT:
I resized the uiview to normal 320 by 460. I deleted the scroll view in xib and decided to add like this:
UIScrollView *scrollView = [[UIScrollView alloc] initWithFrame: CGRectMake(self.view.center.x, self.view.center.y, 320, 460)];
[scrollView setScrollEnabled: YES];
scrollView.contentSize = CGSizeMake(320, 671);
scrollView.clipsToBounds = YES; scrollView.delegate = self;
[self.view addSubview: scrollView];
OK, now what happens is when I scroll the screen, the bar comes up and I can scroll around to change the bar's position, but the actual view doesn't scroll
You need set the ContentSize of UIScrollView to the size of your CONTENT.
Do not set "ContentSize" to the size of the view. The "Content Size" should tell the size of the content within the scroll view.
Your scrollview should be 320x460 and your scrollview.contentsize should be 320x671.
You must layout your subviews "outside" of the view in IB.
EDIT:
Your layout should look like this:
http://ge.tt/api/1/files/4qGbz2N/2/blob/x675
The textview is placed outside the views frame but inside the scrollview. The scrollviews content size should be set accordingly to fit all subviews. In this case yValue should be 550 + 128
This should be a pretty common thing to do, but I haven't been able to get it to work exactly right.
I have rectangular content. It normally fits in 320x361: portrait mode minus status bar minus ad minus tab bar.
I have put that content in a UIScrollView and enabled zooming. I also want interface rotation to work. The content will always be a tall rectangle, but when zoomed users might want to see more width at a time and less height.
What do I need to do in Interface Builder and code to get this done? How should I set my autoresizing on the different views? How do I set my contentSize and contentInsets?
I have tried a ton of different ways and nothing works exactly right. In various of my solutions, I've had problems with after some combination of zooming, interface rotation, and maybe scrolling, it's no longer possible to scroll to the entire content on the screen. Before you can see the edge of the content, the scroll view springs you back.
The way I'm doing it now is about 80% right. That is, out of 10 things it should do, it does 8 of them. The two things it does wrong are:
When zoomed in portrait mode, you can scroll past the edge of the content, and see a black background. That's not too much to complain about. At least you can see all the content. In landscape mode, zoomed or not, seeing the black background past the edge is normal, since the content doesn't have enough width to fill the screen at 1:1 zoom level (the minimum).
I am still getting content stuck off the edge when it runs on a test device running iOS 3.0, but it works on mine running 4.x. -- Actually that was with the previous solution. My tester hasn't tried the latest solution.
Here is the solution I'm currently using. To summarize, I have made the scroll view as wide and tall as it needs to be for either orientation, since I've found resizing it either manually or automatically adds complexity and is fragile.
View hierarchy:
view
scrollView
scrollableArea
content
ad
view is 320x411 and has all the autoresizing options on, so conforms to screen shape
scrollView is 480 x 361, starts at origin -80,0, and locks to top only and disables stretching
scrollableArea is 480 x 361 and locks to left and top. Since scrollView disables stretching, the autoresizing masks for its subviews don't matter, but I tell you anyway.
content is 320x361, starts at origin 80,0, and locks to top
I am setting scrollView.contentSize to 480x361.
shouldAutorotateToInterfaceOrientation supports all orientations except portrait upside down.
In didRotateFromInterfaceOrientation, I am setting a bottom content inset of 160 if the orientation is landscape, resetting to 0 if not. I am setting left and right indicator insets of 80 each if the orientation is portrait, resetting if not.
scrollView.minimumZoomScale = 1.0
scrollView.maximumZoomScale = 2.0
viewForZoomingInScrollView returns scrollableArea
// in IB it would be all options activated
scrollView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
scrollView.contentSize = content.frame.size; // or bounds, try both
what do you mean with scrollableArea?
your minZoomScale is set to 1.0 thats fine for portrait mode but not for landscape. Because in landscape your height is smaller than in portrait you need to have a value smaller than 1.0. For me I use this implementation and call it every time, the frame of the scrollView did change:
- (void)setMaxMinZoomScalesForCurrentBounds {
CGSize boundsSize = self.bounds.size; // self is a UIScrollView here
CGSize contentSize = content.bounds.size;
CGFloat xScale = boundsSize.width / contentSize.width;
CGFloat yScale = boundsSize.height / contentSize.height;
CGFloat minScale = MIN(xScale, yScale);
if (self.zoomScale < minScale) {
[self setZoomScale:minScale animated:NO];
}
if (minScale<self.maximumZoomScale) self.minimumZoomScale = minScale;
//[self setZoomScale:minScale animated:YES];
}
- (void)setFrame:(CGRect)rect { // again, this class is a UIScrollView
[super setFrame:rect];
[self setMaxMinZoomScalesForCurrentBounds];
}
I don't think I understood the entire problem from your post, but here's an answer for what I did understand.
As far as I know (and worked with UIScrollView), the content inside a UIScrollView is not automatically autoresized along with the UIScrollView.
Consider the UIScrollView as a window/portal to another universe where your content is. When autoresizing the UIScrollView, you are only changing the shape/size of the viewing window... not the size of the content in the other universe.
However, if needed you can intercept the rotation event and manually change your content too (with animation so that it looks good).
For a correct autoresize, you should change the contentSize for the scrollView (so that it knows the size of your universe) but also change the size of UIView. I think this is why you were able to scroll and get that black content. Maybe you just updated the contentSize, but now the actuall content views.
Personally, I haven't encountered any case that required to resize the content along with the UIScrollView, but I hope this will get you started in the right direction.
If I understand correctly is that you want a scrollview with an image on it. It needs to be fullscreen to start with and you need to be able to zoom in. On top of that you want it to be able to rotate according to orientation.
Well I've been prototyping with this in the past and if all of the above is correct the following code should work for you.
I left a bit of a white area for the bars/custombars.
- (void)viewDidLoad
{
[super viewDidLoad];
//first inits and allocs
scrollView2 = [[UIScrollView alloc] initWithFrame:self.view.frame];
imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"someImageName"]];
[scrollView2 addSubview:imageView];
[self drawContent]; //refreshing the content
[self.view addSubview:scrollView2];
}
-(void)drawContent
{
//this refreshes the screen to the right sizes and zoomscales.
[scrollView2 setBackgroundColor:[UIColor blackColor]];
[scrollView2 setCanCancelContentTouches:NO];
scrollView2.clipsToBounds = YES;
[scrollView2 setDelegate:self];
scrollView2.indicatorStyle = UIScrollViewIndicatorStyleWhite;
[scrollView2 setContentSize:CGSizeMake(imageView.frame.size.width, imageView.frame.size.height)];
[scrollView2 setScrollEnabled:YES];
float minZoomScale;
float zoomHeight = imageView.frame.size.height / scrollView2.frame.size.height;
float zoomWidth = imageView.frame.size.width / scrollView2.frame.size.width;
if(zoomWidth > zoomHeight)
{
minZoomScale = 1.0 / zoomWidth;
}
else
{
minZoomScale = 1.0 / zoomHeight;
}
[scrollView2 setMinimumZoomScale:minZoomScale];
[scrollView2 setMaximumZoomScale:7.5];
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
// Return YES for supported orientations
if (interfaceOrientation == UIInterfaceOrientationPortrait || interfaceOrientation == UIInterfaceOrientationPortraitUpsideDown) {
// Portrait
//the 88pxls is the white area that is left for the navbar etc.
self.scrollView2.frame = CGRectMake(0, 88, [UIScreen mainScreen].bounds.size.width, self.view.frame.size.height - 88);
[self drawContent];
}
else {
// Landscape
//the 88pxls is the white area that is left for the navbar etc.
self.scrollView2.frame = CGRectMake(0, 88, [UIScreen mainScreen].bounds.size.height, self.view.frame.size.width);
[self drawContent];
}
return YES;
}
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
return self.imageView;
}
I hope this will fix your troubles. If not leave a comment.
When you want to put a content (a UIView instance, let's call it theViewInstance ) in a UIScrollView and then scroll / zoom on theViewInstance , the way to do it is :
theViewInstance should be added as the subview of the UIScrollView
set a delegate to the UIScrollView instance and implement the selector to return the view that should be used for zooming / scrolling:
-(UIView*)viewForZoomingInScrollView:(UIScrollView *)scrollView {
return theViewInstance;
}
Set the contentSize of the UIScrollView to the frame of the theViewInstance by default:
scrollView.contentSize=theViewInstance.frame.size;
(Additionally, the accepted zoom levels can be set in the UIScrollView :)
scrollView.minimumZoomScale=1.0;
scrollView.maximumZoomScale=3.0;
This is the way a pinch to zoom is achieved on a UIImage : a UIImageView is added to a UIScrollView and in the UIScrollViewDelegate implementation, the UIImageView is returned (as described here for instance).
For the rotation support, this is done in the UIViewController whose UIView contains the UIScrollView we just talked about.
What I wanted to achieve here is simply fit the image width to the screen on both orientations and use UIScrollView to just allow scroll vertically to see the whole image.
Both viewController and view are created pragmatically.
The image loaded is larger than screen on both width and height.
Here is the related code in my viewController:
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
return YES;
}
- (void)loadView {
UIScreen *screen = [UIScreen mainScreen];
CGRect rect = [screen applicationFrame];
self.view = [[UIView alloc] initWithFrame:rect];
self.view.contentMode = UIViewContentModeScaleAspectFill;
self.view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
UIImage *img=[[UIImage alloc] initWithContentsOfFile:[[NSBundle mainBundle] pathForResource:#"image" ofType:#"png"]];
UIImageView *imgView =[[UIImageView alloc] initWithImage:img];
[img release];
imgView.contentMode = UIViewContentModeScaleAspectFill;
imgView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
[self.view addSubview:imgView];
[imgView release];
}
I tried all combinations for both contentMode above, did not give me correct result.
The most close I am getting now: I manually resize imgView in loadView, portrait mode would display correctly since app always starts with portrait mode, but in landscape mode, the width fits correctly, but image is centered vertically rather than top aligned.
If I add the imgView to a scrollView, in landscape mode it looks like contentSize is not set to full image size. but when I scroll bounce I can see the image is there in full size.
Questions:
why I need to resize it manually?
in landscape mode how and where I can 'move' the imgView, so imgView.frame.origin is (0,0) and works correctly with a scroll view?
Update
I added:
imgView.clipsToBounds = YES;
and find out in landscape mode the image bounds is smaller than screen in height.
So the question becomes how to have the image view keeps original ratio (thus shows the full image always) when rotated to landscape? Do I need to manually resize it after rotation again?
Instead of manually take care of orientation change and change view details. I plan to follow Apple document and make separate view controllers for each orientations.
see P42 # ViewControllerProgrammingGuide:
Creating an Alternate Landscape Interface
Here in the code you are not using any scrollView.
You need to add that imageView to ScrollView. and set the scrollView frame as same as the main view and contentSize to imageView or image Size.
If you are using scroll view in the app, then have you also resized the scroll view and the subviews as well, your code if fine just try to resize the subviews as well.
I use the following code to do so.
self.homescroll.autoresizingMask=UIViewAutoresizingFlexibleWidth |UIViewAutoresizingFlexibleHeight;// | UIViewAutoresizingFlexibleRightMargin |UIViewAutoresizingFlexibleLeftMargin;
self.homescroll.autoresizesSubviews=YES;
[self.homescroll setNeedsLayout];
[self.view addSubview:homescroll];
Just resize the subviews as well.
I already did several searches on Stack Overflow and Google, but I couldn't find a solution to my problem.
I have a Detail View for a product that includes a UIScrollView and a few subviews (UIImageView, UILabel, UITextView). You can find an example here.
First I wanna autoresize the UITextView (not the text itself!) to the corresponding height. Then I wanna autoresize the entire UIScrollView so that it fits the height of my UITextView and the elements above it. I've tried the following code:
myUITextView.frame = CGRectMake(2.0, 98.0, 316.0, self.view.bounds.size.height);
[scrollView setContentOffset:CGPointMake(0.0, 0.0) animated:NO];
scrollView.contentSize = CGSizeMake(320.0, 98.0 + [myUITextView frame].size.height);
[self.view addSubview:scrollView];
98.0 + [myUITextView frame].size.height) because my thought was: After getting the height of myUITextView, add the height of the other subviews (98.0) to it.
Unfortunately it doesn't work very well. Depending on the content of the UIScrollView, it is too short or too long. I did some logging with the result that the height of the UITextView is always the same:
2010-01-27 14:15:45.096 myApp[1362:207] [myUITextView frame].size.height: 367.000000
Thanks!
There is actually a very easy way to do resize the UITextView to its correct height using its contentSize.
CGRect frame = _textView.frame;
frame.size.height = _textView.contentSize.height;
_textView.frame = frame;
One thing to note is that the correct contentSize is only available after the UITextView has been added to the view with addSubview. Prior to that it is equal to frame.size
A UITextView won't automatically resize itself to it's contents (not as far as I know anyway) so you need to get the size of the text yourself and size the UIView accordingly.
The functions on this page will help - you can use them to get the width and height of a string, something like
// Get the size that the string will render at
NSString *contents = #"This is the content of your UITextView";
CGSize areaSize = [contents sizeWithFont:myView.font forWidth:myView.frame.size.width lineBreakMode:UILineBreakModeWordWrap];
// Then set the frame of your UITextView to be the right size
myView.bounds = CGRectMake(0, 0, areaSize.width, areaSize.height);
Then, you can layout the other components around it.
Hope this helps,
S
PS Warning, the link to the docs is correct but my code example is untested, sorry :)
UIScrollView in paging mode assumes the pages are located right next to each other, with no gap. However if you open a photo in the Photos app and swipe through photos, you can see that it has some gap between pages. I want these gaps too.
I'm looking for existing solutions if any, or for some more bizarre ideas about implementing the page gaps besides the one I have explained below. Or maybe there's some obvious easy way I am missing?
To be clear: I want the gap to only be visible while scrolling, so I cannot simply inset the page content.
My plan is to try moving the page content from inside scrollViewDidScroll callback, so that (assuming you're scrolling to the right) initially the target page is slightly offset to the right of its page boundaries, and by the time you arrive at the target page it's back at its proper location, and the source page is slightly offset to the left of its boundaries. (Or maybe instead of moving things continuously, I'll be better off shifting the offsets, say, exactly halfway between pages.)
I'm the author of the ScrollingMadness article+example that I've been referring some people to here. I've implemented progammatic zooming, and got in-photo zooming+scrolling working together with inter-photo paging. So I know how to play with UIScrollView, and am looking for the advanced stuff.
Please don't point me at TTScrollView. I've already pointed many people to it myself, but I consider it's feel too far from the native UIScrollView behaviour, and do not want to use it in my projects.
Note that this answer is quite old. The basic concept still works but
you should not be hard coding view sizes in iOS7 and 8. Even if you ignore
that advice, you should not use 480 or 330.
Have you tried making the frame of the UIScrollView slightly larger than the screen (assuming that you want to display your images fullscreen and then arranging your subviews on the same slightly-larger-than-the-screen boundaries.
#define kViewFrameWidth 330; // i.e. more than 320
CGRect scrollFrame;
scrollFrame.origin.x = 0;
scrollFrame.origin.y = 0;
scrollFrame.size.width = kViewFrameWidth;
scrollFrame.size.height = 480;
UIScrollView* myScrollView = [[UIScrollView alloc] initWithFrame:scrollFrame];
myScrollView.bounces = YES;
myScrollView.pagingEnabled = YES;
myScrollView.backgroundColor = [UIColor redColor];
UIImage* leftImage = [UIImage imageNamed:#"ScrollTestImageL.png"];
UIImageView* leftView = [[UIImageView alloc] initWithImage:leftImage];
leftView.backgroundColor = [UIColor whiteColor];
leftView.frame = CGRectMake(0,0,320,480);
UIImage* rightImage = [UIImage imageNamed:#"ScrollTestImageR.png"];
UIImageView* rightView = [[UIImageView alloc] initWithImage:rightImage];
rightView.backgroundColor = [UIColor blackColor];
rightView.frame = CGRectMake(kViewFrameWidth * 2,0,320,480);
UIImage* centerImage = [UIImage imageNamed:#"ScrollTestImageC.png"];
UIImageView* centerView = [[UIImageView alloc] initWithImage:centerImage];
centerView.backgroundColor = [UIColor grayColor];
centerView.frame = CGRectMake(kViewFrameWidth,0,320,480);
[myScrollView addSubview:leftView];
[myScrollView addSubview:rightView];
[myScrollView addSubview:centerView];
[myScrollView setContentSize:CGSizeMake(kViewFrameWidth * 3, 480)];
[myScrollView setContentOffset:CGPointMake(kViewFrameWidth, 0)];
[leftView release];
[rightView release];
[centerView release];
Apologies if this doesn't compile, I tested it in a landscape app and hand edited it back to portrait. I'm sure you get the idea though. It relies on the superview clipping which for a full screen view will always be the case.
So I don't have enough "rep" to post a comment on the answer above. That answer is correct, but there is a BIG issue to be aware of:
If you're using a UIScrollView in a viewController that's part of a UINavigationController, the navigation controller WILL resize the frame of your scrollView.
That is, you have an app that uses a UINavigationController to switch between different views. You push a viewController that has a scrollView and you create this scrollView in the viewController's -init method. You assign it a frame of (0, 0, 340, 480).
Now, go to your viewController's -viewDidAppear method, get the frame of the scrollView you created. You'll find that the width has been reduced to 320 pixels. As such, paging won't work correctly. You'll expect the scrollView to move 340 pixels but it will, instead, move 320.
UINavigationController is a bit notorious for messing with subviews. It moves them and resizes them to accommodate the navigation bar. In short, it's not a team player -- especially in this case. Other places on the web suggest that you not use UINavigationController if you need precise control over your views' size and locations. They suggest that, instead, you create your own navigationController class based on UINavigationBar.
Well that's a ton of work. Fortunately, there's an easier solution: set the frame of the scrollView in your viewController's -viewDidAppear method. At this point, UINavigationController is done messing with the frame, so you can reset it to what it should be and the scrollView will behave properly.
This is relevant for OS 3.0. I have not tested 3.1 or 2.2.1. I've also filed a bug report with Apple suggesting that they modify UINavigationController with a BOOL such as "-shouldAutoarrangeSubviews" so that we can make that class keep its grubby hands off subviews.
Until that comes along, the fix above will give you gaps in a paginated UIScrollView within a UINavigationController.
Apple has released the 2010 WWDC session videos to all members of the iphone developer program. One of the topics discussed is how they created the photos app!!! They build a very similar app step by step and have made all the code available for free.
It does not use private api either. Here is a link to the sample code download. You will probably need to login to gain access.
http://connect.apple.com/cgi-bin/WebObjects/MemberSite.woa/wa/getSoftware?code=y&source=x&bundleID=20645
And, here is a link to the iTunes WWDC page:
http://insideapple.apple.com/redir/cbx-cgi.do?v=2&la=en&lc=&a=kGSol9sgPHP%2BtlWtLp%2BEP%2FnxnZarjWJglPBZRHd3oDbACudP51JNGS8KlsFgxZto9X%2BTsnqSbeUSWX0doe%2Fzv%2FN5XV55%2FomsyfRgFBysOnIVggO%2Fn2p%2BiweDK%2F%2FmsIXj
The way to do this is like you said, a combination of a few things.
If you want a gap of 20px between your images, you need to:
First, expand your scroll view's total width by 20px and move it left by 10px.
Second, when you lay out the xLoc of your images, add 20px for each image so they're spaced 20px apart.
Third, set the initial xLoc of your images to 10px instead of 0px.
Fourth, make sure you set the content size of your scroll view to add 20px for each image. So if you have kNumImages images and each is kScrollObjWidth, then you go like this:
[scrollView setContentSize:CGSizeMake((kNumImages * (kScrollObjWidth+20)), kScrollObjHeight)];
It should work after that!
This is just a hunch, so apologies if completely wrong, but is it possible that the contentSize is just set to slightly wider than the screen width.
The correct information is then rendered within the view to the screen width and UIScrollView takes care of the rest ?
Maybe you want to try UIScrollView's contentInset property?
myScrollView.contentInset = UIEdgeInsetsMake(0, 0, 0, 10.0);
I just thought I'd add here for posterity the solution I ended up going with. For a long time I've been using Bryan's solution of adjusting the frame in -viewDidAppear, and this has worked brilliantly. However since iOS introduced multitasking I've been running into a problem where the scroll view frame gets changed when the app resumes from the background. In this case, -viewDidAppear was not being called and I couldn't find a delegate method that would be called at the right time to reverse the change. So I decided to make my scroll view a subview of my View Controller's view, and this seemed to fix the problem. This also has the advantage of not needing to use -viewDidAppear to change the frame - you can do it right after you create the scroll view. My question here has the details, but I'll post them here as well:
CGRect frame = CGRectMake(0, 0, 320, 460);
scrollView = [[UIScrollView alloc] initWithFrame:frame];
// I do some things with frame here
CGRect f = scrollView.frame;
f.size.width += PADDING; // PADDING is defined as 20 elsewhere
scrollView.frame = f;
[self.view addSubview:scrollView];
To avoid messing with UIScrollView's frame, you could subclass UIScrollView and override layoutSubviews to apply an offset to each page.
The idea is based on the following observations:
When zoomScale !=1, the offset is zero when it is at the left / right edge
When zoomScale ==1, the offset is zero when it is at the visible rect centre
Then the following code is derived:
- (void) layoutSubviews
{
[super layoutSubviews];
// Find a reference point to calculate the offset:
CGRect bounds = self.bounds;
CGFloat pageGap = 8.f;
CGSize pageSize = bounds.size;
CGFloat pageWidth = pageSize.width;
CGFloat halfPageWidth = pageWidth / 2.f;
CGFloat scale = self.zoomScale;
CGRect visibleRect = CGRectMake(bounds.origin.x / scale, bounds.origin.y / scale, bounds.size.width / scale, bounds.size.height / scale);
CGFloat totalWidth = [self contentSize].width / scale;
CGFloat scrollWidth = totalWidth - visibleRect.size.width;
CGFloat scrollX = CGRectGetMidX(visibleRect) - visibleRect.size.width / 2.f;
CGFloat scrollPercentage = scrollX / scrollWidth;
CGFloat referencePoint = (totalWidth - pageWidth) * scrollPercentage + halfPageWidth;
// (use your own way to get all visible pages, each page is assumed to be inside a common container)
NSArray * visiblePages = [self visiblePages];
// Layout each visible page:
for (UIView * view in visiblePages)
{
NSInteger pageIndex = [self pageIndexForView:view]; // (use your own way to get the page index)
// make a gap between pages
CGFloat actualPageCenter = pageWidth * pageIndex + halfPageWidth;
CGFloat distanceFromRefPoint = actualPageCenter - referencePoint;
CGFloat numOfPageFromRefPoint = distanceFromRefPoint / pageWidth;
CGFloat offset = numOfPageFromRefPoint * pageGap;
CGFloat pageLeft = actualPageCenter - halfPageWidth + offset;
view.frame = CGRectMake(pageLeft, 0.f, pageSize.width, pageSize.height);
}
}