Adding UIScrollView using interface builder - iphone

I am adding a UIScrollView as a subview to the controllers view. After that i am adding 2 views to the scroll view as the content view.
When I am printing the subviews of the scroll views using NSLog(#"Scroll View Subviews : %#", [scrollViewObj subviews]);
then it is displaying 4 subviews , 2 for the views added to the scroll view and it is automatically adding 2 image views ?
I cann't get why the image views are added as subviews to the UIScrollView ?
I am adding the Scroll view and 2 views to the scroll view using the interface builder.
thanks.

I bet those are used for the scroll indicators to the right and bottom of the view.

The two extra subviews are indeed for the scrollbars. You'll only see those in there if you opt to use anything other than the default scrollbars.
If you want to know the number of your own subviews, set the tag property on each one before adding it in (to a positive integer, for instance). That way you can walk the subviews and see which ones have a tag value > 0.

I'm sure UIScrollView has a bunch of child views that are part of how it functions. I wouldn't worry too much about it.

Related

Content positioning into a UIScrollView

I'm trying to add a scroll view to an existing screen of my app to help scroll the screen upward when keyboard hides a text field into this view.
I have added the scroll view as a subview of the main view in Interface Builder. Then I added all other objects as subviews to this scrollview. I have set the scroll view size to 320x460 with x=0 and y=0. Now, I notice the layout is broken and all objects (labels,text fields overlap in the same place).
Do you know the proper way to position this scrollview in interface builder so that I can easily position the other objects?
Thx for helping,
Stephane
What you did is correct. It sounds like you moved the other UI elements into the scroll view after you positioned them. In this case they would default to the center position and be overlapped.
If you find it difficult to use dragging in Xcode's Interface Builder, try the position and size tab and type in the coordinates. Alternatively, reposition your UI elements in code.

How do you add an UIView over a scroll but the view should stay still?

iPhone Interface Builder question: Does anybody know how to add a small UIView over a ScrollView yet the image should stay still? Basically I already have a full image (320 x 480) over the Scroll, so the image scrolls, but now I need to add a AdMob View (320 x 48) on top of them. The problem is after i build and run, the ad scrolls as well. How do you make it stay still?
Thank you!
Not sure if this is how you've done it in your code, but if you've added the AdMob view as a subview of the scroller, then it will scroll.
It should not scroll if you add it as a subview elsewhere, either the superview of the scroller or the window itself.
I admit though that I generally do not use Interface Builder and would generally handle this programmatically, but I hope this helps.
Just place the AdMob view at the same hierarchical level of the ScrollView but being in front. Then when the Ad is available, set adMobView.hidden=NO, when it is not available set adMobView.hidden=YES. Essentially the hierarchy is:
RootView -
|---- UIScrollView
|----- any UIView (to be scrolled)
|---- AdMobView --> not subview of ScrollView but subview of RootView
Of course when the Ad is visible you will not be able to tap on it to scroll, unless you subclass it to pass the tap to next level in hierarchy. But probably you have not this problem thanks to the reduced size of the Ad (48) with respect to the entire scrollView (480).

Resizing content in a UIScrollView

I am creating a scrollview programmatically and adding subviews to it programmatically. The subviews are created programmatically as well.
I am just wondering how to rotate / resize the subview so that it remains visible in landscape mode.
I have set the scrollview to autorotateSubviews:YES and in my subview i have set the mask to be flexiblewidth|flexibleheight is this correct?
I am used to doing this in IB with the springs and struts section of the inspector.
Thanks
Your scroll view is probably contained in a view witha corresponding controller that receives willAnimateRotationToInterfaceOrientation:duration: and didRotateFromInterfaceOrientation: notifications. Use these opportunities to resize the subviews of the scrollview.

Prevent subview from scrolling in a UIScrollView

I have a UIScrollView subclass with a certain subview I'd like to prevent from scrolling (while all the other subviews scroll as normal).
The closest example to this I can think of is UITableView's "index strip" on the right side (look in the Contacts app to see an example). I am guessing this is a subview of the table (scrollview) but it does not move as the user scrolls.
I can't seem to make my subview stay put! How can I accomplish this?
The trick is to adjust the frame of the "non-scrollable" subview inside -layoutSubviews.
Add the view that you want not to move as a sibling view of the scroll view on top of the scroll view instead of as a subview.
You can set it's property called userInteractionEnabled to NO

How should child views of UIScrollView report their bounds for contentSize?

I'm looking more for advice on the correct design for a view.
What I have is a UIScrollView that contains one or more custom Views I have created. My problem is, who reports to the scrollview what it's contentSize should be? I have the following:
UIView
+-UIScrollView
+-CustomView 1 with dynamic height depending on data
+-CustomView 2 with dynamic Height depending on data
The UIViewController creates new instances of the custom views with data and then adds them as subviews to the UIScrollView. The problem I'm having is how to set the value of the scrollview's contentSize? Right now, I'm not doing that and the contents of the scrollview are clipped with no scrolling possible.
Should the custom view call [parent setContentSize:] in its drawRect:?
Should the UIViewController query the custom view after creation to get its bounds and then call setContentSize?
Should I subclass the UIScrollView to override addSubView to query each subview's height?
Is there something else I'm missing?
I hope I explained that properly. I'm new to this and still getting a handle on things.
The contentSize of the scroll view should be the size of the union of the frames of all your custom views. Whenever the size of a custom view changes, or one is added or removed, the view controller should calculate the new contentSize and apply it.
Setting it from drawRect: could essentially set up an infinite loop.
Using the bounds does not give the coordinates within the parent view.
You could subclass UIScrollView if the custom views do not change size.