hope everyone is doing good. I have a small problem I can't find any solution. I have a scrollView where I activated isPagingEnabled on it. The scrollview contains multiple images the size of the scrollView.frame.width. My problem is I am trying to find a solution where when the scrollView changes the "page of the picture" I am notified. I tried different methods. I have tried with delegate scrollViewWillEnd and both DidEnd. My method was this
var pagePositionOfScrollView = Int(scrollView.contentOffset.x/self.scrollView.frame.width)
var positionActualIncremented = self.positionActual + 1;
print("positionofscroll view page \(positionOfScrollView)")
print("position actual \(positionActualIncremented)")
I have found that with this implementation there is a problem, the user could drag only to half of it, the page will still scroll to the next one because of isPagingEnabled, but the ending position would be still on the same page and so the pagePositionOfScrollView will be the same. As well isPagingEnabled offers the possibility that if the user slides with velocity the page is changed, but the final scrollView.contentOffset.x still gonna be on the same page, not on the next.
Does anybody have any ideas?
Related
I have a problem where I have to create a view as similar as instagram's profile view. I have managed to get very close by digging into many solutions and I think I have found the best one for the purpose. I just need to get the final touch to resemble Instagram's profile view completely and I can't find the solution.
I leave the complete source code here so you can keep up with me: https://github.com/eduasinco/ProfileView
When you look at the project you will see a headerView on top of all other views, I have set the view of this header to be a PassthroughView which means that every action on that view will be ignored and pass to the next in the responder chain which in this case is one of the scroll views behind.
So far so good, nevertheless there is a small nuance, inside the header view there is a segmentControlView which is in charge of switching the pages, if you touch that segment control it will change pages just fine, the problem comes when you try to scroll the view from the segmentControlView it wont work. I would like to make this scroll behaviour happen as similar as Instagram's profile view.
To sum up, I would like to have a way to make segmentControlView work as it is doing now but also be able to scroll from it in the same way you can scroll when you are touching any other place inside the header view.
I have also tried all kinds of touch overriding but none of them works.
Any help will be appreciated
I am a french 17 years old guy so excuse my english.
I am creating an app' using an UIScrollView with an UIPageControl to display multiple UIView pages from UIViewControllers (which display an object) . Everything works pretty great.
Now i would like to add a new page (and a new empty object but that is not a problem) when I swipe the UIScrollView to the right in the last view.
How could I do that ? And if it's not possible, how can I update the UIScrollView ?
Thank you very much !
I think you need to keep an eye on two things. scrollViewDidScroll: & UIPageControl's currentPage. When you determine that the user is currently viewing the rightmost page & the UIScrollView was scrolled, you can add a new page to the UIPageControl. The amount by which the scroll view was scrolled is related to scrollView.contentOffset.x. A new page can be added to the page control by incrementing its numberOfPages & setting the currentPage to the newest page.
HTH,
Akshay
This is what you are looking for I think : a sample code from Apple to build a photo viewer that load images just before they appear on screen.
https://developer.apple.com/library/ios/#samplecode/PhotoScroller/Introduction/Intro.html#//apple_ref/doc/uid/DTS40010080
I'm working on a app that has a paging UIScrollView that contains three scrollViews as subviews which display images that you can pinch and zoom on. The code came from Apple's "PhotoScroller" sample code but I've stripped out the tiling functionality because I'm trying to master the basics first.
I can zoom in on my different images and page through them, which is great. When I leave an image that has been zoomed in to go to the next "page" of the pagingScrollView I want it to be restored to it's original zoom size, right now it stays at the zoom level that I left it at.
I imagine I need to write some code that tells the zoomed UIScrollView to go back to the appropriate zoom scale when I get to the next page. My question is how do I do that?
So far I've been working with UIScrollView's Delegate method "scrollViewDidScroll" and and the "contentOffset" property. Another thought is somehow getting a notification that the pagingScrollView has moved to the next "page."
Any ideas?
If you're interested in knowing when the scroll view has stopped (e.g. the user has let go and the scroll view has snapped into position on a new page) you can use scrollViewDidEndDecelerating:. However, the user may scroll several pages before allowing the scroller to fully stop, so the last page the user stopped on may not be the immediately preceding or immediately following page. You can keep a pointer to the current page and each time the user stops on a page restore the previously current page to the default zoom level before updating the current page pointer.
I'm building an iPhone application and like most I am trying to implement a UIScrollView with a UIPageControl, however I am coming across a very quirky behavior, which I assume may be a bug. Hopefully one of you has seen this before because it is driving me nuts.
Basically, the page control works fine, everything is hooked up and works normally on all accounts EXCEPT, with certain placements of the UIPageControl within the UIView, the UIPageControl will cease to render.
I'll just take screenshots of the XIB window to help illustrate... here's a placement that works perfectly fine:
http://www.jasconi.us/prob1.png
The UIPageControl is placed physically above the UIScrollView. Works great, everything is visible and working.
The next two DO NOT work:
http://www.jasconi.us/prob2.png
http://www.jasconi.us/prob3.png
The first one is simply placed below the scroll view. Doesn't render at all.
The second one is placed above the scroll view without technically being inside of it. Also doesn't render.
What the hell is up with this? I've tried using
[[self view] bringSubviewToFront:pageControl];
...to no avail.
Any ideas?
OK I found the answer to this, it's a little six degrees of Kevin Bacon.
This isn't actually a software bug, but a XIB quirk, for some reason the lower placement of the page control in combination with the default settings for autosize and anchor seem to jettison the control into outer space.
If you turn off all auto-scaling and auto-sizing and auto-anchoring and all that other crap, the controls appear exactly as you expected. The fact that it appears reliably when placed above the ScrollView is an oddity.
shrug.
Hope this helps future iPhone initiates.
Did you check to make sure that numberOfPages is not 0?
If you set a breakpoint can you see that pageControl is not nil?
I was still encountering this exact same problem, even after trying everyone's posted answers. My issue ended up being a little more "DOH":
I was using UIPageControl at the bottom of a modal FormSheet, however, I forgot to set the size of the view as Form Sheet in the xib. This caused my page control to be off the screen and never visible.
Moral: set view size (Full, Form, Page, etc) in your xib on the base view.
This will sound like a real no brainer, but I got caught out by it.
By default, UIPageControl expects to be on a dark background. IE: The dots are light gray, and white for the current page.
I used UIPageControl on it's own with no scrollview to change the time range of a graph I was rendering with drawRect:
Long story short, the graph background was white, so the page controller worked, I just couldn't see it. The solution was putting the graph itself in a subview, and making the parent that contained the page control have a dark background.
I have been facing the same nested UIScrollView problem for long time.I tried some open source codes like Scrolling madness ,three-20 and others but all fails finaly.I am trying to make a photo Viewer application same as iPhone.For that I have created the structure like this:-
1)one View controller.
2)on view of view controller one UIScrollView (i.e inner/parent scroll view) as a child.
3)on inner/parent scroll view number of child scroll views(i.e. outer/child scroll views) ,each represents one page of photos application.
4)On each scroll view one image View on which i am displaying my image.
So what I want is when user scrolls the outer scroll view it should scroll horizontally with all the child views so I will get the look and feel of paging in photos application.Also when user is on one specific image(i.e. child/outer scroll view) he should be able to zoom in/out,swipes and perform single/double tapping.I was able to make it work in sdk 2.1,but it dosnt work since sdk 3.0.Please tell me the idea behind your project.Means which scroll view you are subclassing ,in which view to detect touches.How this completely child - parent relation should be.
If possible provide any sample code also.
There is a WWDC session from 2010 that deals with this very issue.
Here's the short of it:
You need a single scroll view that is paginated and scrolls horizontally. Each "page" of that scroll view is another scroll view containing a photo.
First, it looks like you want to subclass UIScrollView? Every interaction method you need is provided for you in either the delegate callbacks or the touch methods. (Many of Apple's more advanced classes, such as UIScrollView, react poorly to subclassing.)
Second, it sounds like you have a first responder problem. IOW, your innermost scrollview isn't getting the first crack at the touch events.
Andrew
I also struggled with this for a long time trying samples you mentioned. I could finally figure it out with the samples provided by apple (iphone dev center).
http://developer.apple.com/iphone/library/samplecode/Scrolling/Introduction/Intro.html
http://developer.apple.com/iphone/library/samplecode/ScrollViewSuite/Introduction/Intro.html
The first one is pretty basic and probably what u already have. The second one is all about zooming, etc. Just study these and the samples you already have, I think you will be able to figure it out. On specific topics just come back here search for answers or post another question.
EDIT: I forgot this one check out these examples by Andrey Tarantsov hosted on github. This is what you want... http://github.com/andreyvit/ScrollingMadness