Comments on Cocoa with Love: Multiple virtual pages in a UIScrollView with just...

Hi Matt, great stuff you write, Thanks a lot. It h...

2011-11-27T04:10:16.242-08:00

Hi Matt, great stuff you write, Thanks a lot. It has come very handy.

I've some problems in iOS5 with the code, apparently the contentOffset for the pages is not right! and it snaps to the middle of a page instead of placing it in the center.

I was looking for example codes like this because my problem is kind of similar in iOS5.

I have a ScrollView with several virtual pages that are returned by the datasource and the UX must be the next:

- When the user scrolls should be able to scroll with pagination disabled. This allows to navigate through the pages very fast.
- When the scrollview starts decelerating the pagination must be enabled in order to place the must visible page into the center of the screen.
- If the user drags the scroll and no deceleration occurs the pagination must be enabled in order to place the must visible page into the center of the screen. (When the user drags the scrollview the scroll is insanely fast, and this only happens in iOS5 not in iOS4).

I'm still unable to find out what's wrong although I've been playing with the UIScrollViewDelegate methods.

I hope you have an idea on how to fix this.

Thanks

Nice Tutorial Really...Please discuss such kind of...

2011-10-02T22:18:43.936-07:00

Nice Tutorial Really...Please discuss such kind of topics on regular basis.

Hi Matt, Just wanted to state that your code abov...

2010-12-22T02:53:50.000-08:00

Hi Matt,

Just wanted to state that your code above does not work anymore on iOS4.2.
I just downloaded your code and opened it up in my XCode, to see how this works, and well I'm somehow able to scroll to a page, then it just flicks through to the next one, or it stops halfway a page.
Dunno if this was the same on iOS 3, but it works partially now.

If this was intended somehow, I'm sorry for bringing this up!

If I'm able to fix this behaviour I will get back to you!

- B

Hi Matt, Thanks a lot Matt! I have using this sa...

2010-12-07T02:41:35.000-08:00

Hi Matt,

Thanks a lot Matt!

I have using this sample code in our application but need some help,
in my application need direct load 3rd page 10th page so how can i load any page from start.

Please help me.

Reading Arek's comment above. I've found i...

2010-11-30T08:04:12.000-08:00

Reading Arek's comment above. I've found it works if you enable scrolling in the UITextView but nothing else. Odd.

bit more info. It is actually this line that makes...

2010-11-30T08:00:17.000-08:00

bit more info. It is actually this line that makes it go weird
textView.text = [pageData objectForKey:@"pageText"];

so the label is fine but the UITextView setText makes everything go weird.

Bizarrely it works ok (except the text isn't u...

2010-11-30T07:58:12.000-08:00

Bizarrely it works ok (except the text isn't updated obviously) if I comment out these two lines

label.text = [pageData objectForKey:@"pageName"];
textView.text = [pageData objectForKey:@"pageText"];

I downloading the sample but I am finding that the...

2010-11-30T07:08:21.000-08:00

I downloading the sample but I am finding that the pages are always off center. Has something changed that has broken this?

Dear Matt is possible update to Xcode 3.2 and IOS4...

2010-11-16T04:31:23.000-08:00

Dear Matt
is possible update to Xcode 3.2 and IOS4, i have tried but only play 2 pages, or some one can help me to run this sample in this xcode version. best regards and thank you for your attention
Fredy ASencios
freddy@pixel.pe

Great Project Matt. Kudos. Would you say that ther...

2010-11-05T02:06:53.000-07:00

Great Project Matt. Kudos. Would you say that there Is enough of a memory footprint difference between this approach and the array based approach? (assuming that un-unsed views are destroyed when not in scope)

I had the same problem, couldn't find a soluti...

2010-08-25T15:05:33.000-07:00

I had the same problem, couldn't find a solution. Then, I've turned on user interaction and vertical scrolling for textview in interface builder, tried... it works flawless!

Thanks a lot for tutorial, it saved my life ;)

Thanks a lot Matt! I really appreciate your help. ...

2010-08-03T10:24:22.000-07:00

Thanks a lot Matt! I really appreciate your help. However now there is a going to be a problem I want to post something on the textView.text.Anyway, I was wondering if textView goes off the limits or something. It is weird. Once again thanks a lot!

In iOS4, there seems to be a weird conflict betwee...

2010-08-02T20:41:15.000-07:00

In iOS4, there seems to be a weird conflict between the UITextView that shows the "Some text for page X" message and the UIScrollView that handles the paging.

If you comment out like 35 of PageViewController.m (the line that sets the textView.text) then the weird offset will go away.

Why is this happening? I have no idea. If I find out, I'll update the project.

Hi everybody! This tutorial was a great help for m...

2010-08-02T18:44:51.000-07:00

Hi everybody! This tutorial was a great help for me. However I would like to know if you guys have any problem with the scrolling. What happens is when I scroll the page view instead of stopping to the next page it moves to the space between two consecutive pages. Does anyone have witness something similar? I run iOS 4.0. It happens both on simulator and on device. Please let me know.

I need to have some dostance between pages. Is it ...

2010-06-25T04:35:39.000-07:00

I need to have some dostance between pages. Is it possible to do with your code?

[p1] [p2] [p3]

Thanks!

Matt! U R D Best!

2010-05-26T02:47:17.000-07:00

Matt!

U R D Best!

Guest Matt: Thanks for sharing, I have been lo...

2010-05-25T09:08:56.000-07:00

Guest
Matt:

Thanks for sharing, I have been looking for a similar project for a while.

I changed the project to add a UITableView in a page which has 4 UITableViewCells. However, when the user selects a cell in the first page, the same cell gets selected in the third page which is not the effect I want. I want the cell in the first page to stay selected while the third page has no cells selected. If I programatically refresh the cell (similar to your updateTextViews method), the refresh happens both in the first and third page and the cell in first page gets unselected.

Is there any way I can achieve the above functionality in your project with just 2 pages? I think the "two page" approach will significantly save some memory in my app.

Thanks for your help,
Amy

-------

How did you manage to get the tableview to refresh at all?

Thanks in advance

Hey Elia, Did you get the rotation thing working ...

2010-05-19T10:58:22.000-07:00

Hey Elia,

Did you get the rotation thing working well? Would you have a code to share?

What I would actually love to accomplish is to switch the portrait image for a landscape version when the device is rotated.

Thanks,
Kris.

Matt, Thanks, this is very helpful for an app I am...

2010-05-14T09:49:29.000-07:00

Matt,
Thanks, this is very helpful for an app I am developing. One question. Any thoughts on wrap around? It seems like it would be easy to add a wrap to your concept. I'd like it to work like the lower scroll view in the stocks app where swiping off the leftmost view brings one to the rightmost view and vice versa.

Thanks, Jeff

Looks like I am answering my own question. On rota...

2010-05-13T08:44:04.000-07:00

Looks like I am answering my own question. On rotation, it looks like the scroll view does not readjust its contentSize property. I didn't want to change your code so left your contentSize assignment in viewDidLoad as you have it. Then added:

- (void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation {
scrollView.contentSize = CGSizeMake(scrollView.contentSize.width, scrollView.frame.size.height);
}

and called it from viewDidAppear as well to adjust on entry into the view. (I don't think I could call this from viewDidLoad as the view wouldn't know its dimensions until after it appeared.) I am sure I could make this cleaner but it works.

I should also note that I had the struts wrong from my previous comment. Scroll View should have all springs and struts set. I also have only left-right and horizontal spring set for TextView (although my final set up is slightly different than your example so you may have to play with your example to get all these right.)

Hope this helps someone else.

Matt, I am hoping you can help. I played with your...

2010-05-12T19:41:46.000-07:00

Matt, I am hoping you can help. I played with your sample code and was successfully able to implement it in portrait mode. I am not, however, able to adjust it so it rotates correctly to landscape mode. It seems that everything works fine as I am playing with it in IB but when I compile and put it on a device, I can scroll in all four directions in landscape, as if the page doesn't resize correctly.

I added the following to PagingScrollViewController:
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
return YES;
}

I set the struts and springs for MainWindow/PagingScrollViewController as follows:
- View: all set
- Scroll View: all but bottom strut set
- Page Control: left, right and bottom strut, horizontal spring

I set the struts and springs for PageView as follows:
- View: all set
- TextView: all set
- Label: all but vertical spring set

Can you offer any help or an adjustment to the source code that would make landscape work correctly? I sure would appreciate it.

I've used this tutorial to write those librari...

2010-04-12T08:51:01.000-07:00

I've used this tutorial to write those libraries ... it's a pre-programmed UIScrollView for horizontal and vertical display ... try to download this project from SVN repo. I've been unable to finish the documentation but check out IGUIScrollViewElements ... there is a short example for IGUIScrollViewImage and the code is quite similar ... I'll do my best to finish examples for the remaining ones asap ...

http://code.google.com/p/iphone-guru-uilibrary/

----------------------------------------

iPhone tutorial project on http://www.xprogress.com