UiTableview ContentInset - iphone

I am working on very small app. In this app I am using UIrootviewController's table view to display some content in it. I want that content to be displayed at particular position so I am setting its contentInset. when I do it in viewDidLoad or in xib it is not showing any effect at first time. I have written it in shouldAutorotateToInterfaceOrientation function it is giving me proper location after orientation change but at first time it is showing table content at same location whatever may be the content insets values
here is my code for setting content insets
self.tableView.contentInset = UIEdgeInsetsMake(120, 150, 0.0, 0.0);
I have wrote this code inside viewDidLoad, and shouldAutorotateToInterfaceOrientation
but it is not showing any effect when application starts. is there any other method to achieve this.
i even tried setFrame, but did not worked.

I think you may be confused about what method to use. If you want to set the position and size of the view you should set its frame.

Put your code in the viewWillAppear method.

Try the following in viewDidLoad or viewWillAppear:
self.tableView.contentInset = UIEdgeInsetsMake(120.0f, 150.0f, -120.0f, -150.0f);

Related

UIScrollView made in storyboard has frame value of zero

I made a scrollview in my storyboard which contains severals UIImageView.
The problem is, the frame of that scrollview is equal to {0, 0, 0, 0} and I don't know why. The scrollview is visible on my screen, but I'm not able to scroll it.
I already try to set a content size, and a frame, but without success.
Fixed it out !
In fact, I develop the app on iOS 6.0 and I had to uncheck the "use autolayout" checkbox on storyboard properties...
Thanks to all anyway !
I was getting this problem too but I need to use auto layout.
I was trying to set an UIImageView as a subview then do some calcs to work out the minimum, maximum zoom scales and set the zoomScale.
The problem was that I was trying to set zoomScale to zero as the scroll views frame was zero which was giving me this error:
<Error>: CGAffineTransformInvert: singular matrix.
So I setup the image and imageView in viewDidLoad / viewWillAppear (and hide the imageView) and then set the zoomScale in viewDidAppear (then unhide imageView).
This seems to work well, although I can't say for sure why. I guess it gives the scroll view a chance to set its bounds correctly.
The issue here is AutoLayout, as some of the other answers have indicated. Specifically, the issue is that autolayout does not occur until after viewWillAppear, and if you put your code in viewDidAppear, you will get funky display artifacts as you change things on the screen while the user is watching...
If you need AutoLayout enabled, the best place to put your frame dependent code is in:
- (void)viewDidLayoutSubviews
Keep in mind that this gets called again and again though, so if you only want some initialization code run once, when the view is displayed, then you can create a BOOL property that stores whether the initial layout has already been done.
#property (assign, nonatomic) BOOL initialLayoutComplete;
And then you can write your viewDidLayoutSubviews this way:
- (void)viewDidLayoutSubviews {
[super viewDidLayoutSubviews];
if (!self.initialLayoutComplete) {
// frame dependent code here...
}
}
As I mentioned in this answer: The frame of the scrollview will not be initialised until you are in the viewWillAppear method.
This seems to be a new behaviour in iOS 6, not sure if it's a bug or an intentional change.
You should be able to use auto layout without worrying about this.
Did you connect IBOutlet?
Did you init scrollView with this code:
self.scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, 280, 360)];
self.scrollView.contentSize = CGSizeMake(500, 360);
//values are of course only example values
How you add UIImageView to scrollView?
I think one clarification is in place to Enrico comment below.
The frame size will have the right values at viewDidAppear (and in viewWillAppear the value will be set, but they are still zero in that method)

How to set UITextView's content inset like Notes App

I am working in an app in which I need to give feature like Notes App in iphone. as shown in first screen shot , initially , notes leaves a tab before the content starts, I also wanted to do the same and for that when I set Left Content inset (of UITextView) by 25 , it shows like in screenshot 2, here you may see the image also gets shifted. I have set image as background. I don't know how to solve this problem.
I also tried by adding image as subview of UITextview but it won't repeat the lines, while scrolling (image of lines) like notes app.
I'm setting the background of Textview by following code.
[textView setBackgroundColor:[UIColor colorWithPatternImage:[UIImage imageNamed:#"line_image.png"]]];
Please tell me if I am going wrong or any extra effort needed to get desired output.
Thanks
UITextView is UIScrollView subclass so all relevant delegate method are available for you (e.g. scrollViewDidScroll:) - you can adjust your custom background in that method.
There's very nice post on Dr.Touch blog about recreating Notes app interface - you can get general idea about how it is done from it. Basically what is done there is adding custom view that draws background behind the text view and adjust it in text view's delegate methods and also using KVO on its 'contentSize' property.
#Dinesh gave nice solution but it doesn't sound to be generic as I want to use image of lines instead of drawing them. Image has some special effects that can not be achieved by drawing. So to solve it I created a table view below the textview keeping textview's background transparent. Now just added the image of line to my tableview's custom cell and set content offset of UItableview same as of the scrollview (subview of text view ,refering to the answer of #Vladimir ) .
And used the following code to scroll my tableview with scrolling the textview and got the desired output.
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
tableView.contentOffset =scrollView.contentOffset;
}
Keeping my tableview's number of rows at a very large number.
PS: instead of setting the content inset of textview, i set its frame's X position and decreased the width relaively.

Problem with UIScrollView inside another UIView

I have this UIScrollView inside another UIView, not occuping the entire area (all this is initialized via nib file). I added some content to the scroll view, but whenever I scroll it, the UIScrollView content area moves outside the ScrollView frame, over the UIView area not designated for displaying it.
Shouldn't it remain inside its frame even when I scroll it?
It may be that the clipsToBounds property of your UIScrollView is set to NO. Check the setting in IB, or you can set it in code like so:
scrollView.clipsToBounds = YES;
Failing that, double check that your UIScrollView has exactly the bounds you think it does. Is there any autoresizing flag stuff going on that might be changing the scroll view's bounds?
try to set the clipsToBounds to YES, it may be that:
yourViewController.clipsToBounds = YES;
if not... fbreto is right, post your code...
Make sure you have setContentSize. And also set the frame size of the uiviews inside the uiscrollview correctly when you add them.
Here is a sample code of it http://developer.apple.com/library/ios/#samplecode/Scrolling/Introduction/Intro.html

UITableview changing height when shown from different UINavigationControllers ('More')

I'm having an issue with UITableViewController's tableView changing its frame position when presented from a UITabBarController, within a UINavigationController. The frame is fine when displayed from a regular tab. However, if I move and show the UITableViewController from the 'More' Section, the tableview moves down the same height as the navigation bar (which I don't want it to). When I tested the runtime frame coordinates between proper and nonproper positions, it shows as the same (0.0, 0.0, 320.0, 411.0).
This issue only happens AFTER I've shown the tableView in one Nav Controller and then it's moved and shown in another, like the 'More' VC to the tab, or tab to the 'More' VC
What's going on here and how can I fix this?
The last image is how it looks like when the app launch, as it should be, with he table view right below the nav bar. In the first two however, you can see that the tableview has been moved down.
Thanks in advance!
I was able to solve the issue. It turns out that when you move a UITableView controller within a UINavigationController to the moreNavigationController, 44 pixels are added to the 'top' variables of contentInset and scrollIndicatorInsets. I'm not sure why this is happening or why those 44 pixels aren't being removed when the tableView leaves the 'moreNavigationController', but here's the answer. I'm calling these two lines from within viewWillAppear.
self.tableView.contentInset = UIEdgeInsetsMake(44.0, 0.0, 0.0, 0.0);
self.tableView.scrollIndicatorInsets = UIEdgeInsetsMake(44.0, 0.0, 0.0, 0.0);
The UITableViewController has this behaviour that it always try to best fit the screen size. UITableViewController is perfect for fullscreen tableview but otherwize I recommend not using the UITableViewController but instead implement a tableViewControler yourself by implementing both the datasource and delegate. Some did set resizeSubViews to NO and solve their problem but I really advice recreate the controller yourself which is not that much work.
Reset autosizing property of table view nib file.
You can find it inside :
Tool>Attribute Inspector
First take a UITableView in the view using XIB. Then add navigation bar and resize the tableview. You will get what do you actually want.
If you still find any problem then please let me know.
If you can display your code, or take a screenshot of your setup, it would be a lot easier. From my experience, creating UITableViewController instances and hooking them up in Interface Builder will expand to fill the screen.
How are you connecting it to the "More" tab? If it's in two tabs, and you're doing ANYTHING dynamic, check your UITableViewController class viewDidLoad method. You shouldn't have to add / delete / re-add the table unless they're separate instances.
Some places to check:
NSLog your tableHeaderView height and position
NSLog your tableFooterView height and position
Create a backgroundView and assign it to the tableView's backgroundView property to see what it's true dimensions are and where it's being displayed
Check where the UITableViewController's view starting position is.
Wish I could help more. Would like to see your setup / code.

How do I properly handle rotation of a UIScrollView containing UIImageViews?

I'm developing an image viewer, much like the Photos App.
It's a UIScrollView with paging enabled with images loaded from the internet, so I've adapted portions of the LazyTableImages sample. The Scroll View and each ImageView inside of it have all of their autoresize mask flags set.
When I first observed how resizes were happening during rotation, it looked good, but once I started trying to interact with the scroll view, I realized that I also had to programmatically change the size of the contentView. I did that by implementing didRotateFromInterfaceOrientation: in my view controller.
[self.scrollView setContentSize:CGSizeMake(numberOfImages * portraitWidth, [scrollView bounds].size.height)];
With interaction behaving properly, I then discovered that, if I was viewing the second photo and rotated, portions of both the 1st and 2nd photos would be shown on the screen. I needed to change the contentOffset as well.
I've tried to fix this two ways - both by using the scrollRectToVisible:animated: method of UIScrollView, as well as trying to set the contentOffset property directly. And I've experimented by putting this code in implementations of both the "one-step" and "two-step" responses to changes in Orientation. For example:
-(void)didAnimateFirstHalfOfRotationToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation {
[self.scrollView setContentOffset:CGPointMake(currentlyViewedPhotoIndex * largeImageHeight,0) animated:YES];
In all cases though, it just looks janky as hell. Either I clearly see the scroll happen, or it just jumps. Uuuuuuuuuuugly! Is there a way to do this so that it behaves exactly like the Photos app does?
What I wound up doing instead - just before rotation starts, hide the UIScrollView and create a UIImageView that contains the currently viewed image. Rotate, that image will rotate all nice and pretty, and when rotation completes remove the ImageView and unhide the Scroll View.
Update - if you're reading this today (anytime after iOS 6), use a UIPageViewController and set transitionStyle to UIPageViewControllerTransitionStyleScroll, for crissakes.
I did something slightly different when faced with the same problem. In willRotateToInterfaceOrientation:duration:, I hide all of the UIScrollView's subviews except for the currently displayed subview, and in didRotateFromInterfaceOrientation: I unhide the subviews.