I would like to create a scrollview inside of another view. I put a UIScrollview element in IB and declared a UIScrollview in my view controller file that is associated with the main view. I also declared it a property in the view controller header file and synthesized in the corresponding implementation file.
Do I set the size of the scrollview in the app delegate or in the view controller? If I set it in view controller do I still have to do the allocation and initialization commands for that instance? Or do I rely on the getter and setter methods that exist as a result of the scrollview being a property?
I should add that I only want the scrollview to occupy a part of the main view.
Here's my viewDidLoad method:
- (void)viewDidLoad
{
[super viewDidLoad];
[scrollView setFrame:CGRectMake(0, 44, 768, 1000)];
[scrollView setContentSize:CGSizeMake(768, 1000)];
// Do any additional setup after loading the view, typically from a nib.
}
The actual size of the UIScrollview in IB is 768 by 804, there should be a vertical scrollbar present (some of the UI elements in the scrollview are clipped, so there should definitely be a scrollbar if this view is set up correctly.)
Yes you can set the frame property of the scrollView instance using setFrame.
i.e. irrespective of what frame size you have defined in IB, using [scrollView setFrame:CGFrameMake()]; you can redefine the exact width, height & x, y coordinates.
In fact this is how one goes about creating a dynamic view in iOS.
Once you are exiting this view entirely make sure you dealloc & release this IB instance since it would have been defines as retain.
Related
I noticed that sometimes on viewDidLoad I got the view size right. Sometimes I don't.
For example
- (void)viewDidLoad
{
[super viewDidLoad];
self.pullToRefreshController = [self.pullToRefreshController initWithDelegate:self];
PO(self.view);
PO(self.view.superview);
PO(self.view.superview.superview);
PO(self.view.superview.superview.superview);
while(false);
}
-(void)viewWillLayoutSubviews
{
PO(self.view);
PO(self.view.superview);
PO(self.view.superview.superview);
PO(self.view.superview.superview.superview);
while (false);
}
at viewDidLoad the size of self.view is still 320 to 480. At viewWillLayoutSubviews that have been fixed.
I wonder what happen in between and where should I initialize stuffs? Or what stuffs should be in viewDidLoad and what stuffs should be in viewWillLayoutSubviews?
viewDidLoad is a good place to create and initialize subviews you wish to add to your main view. It is also a good place to further customize your main view. It's also a good place to initialize data structures because any properties should have been set on the view controller by the time this is called. This typically only needs to be done once.
viewWillLayoutSubviews is where you position and layout the subviews if needed. This will be called after rotations or other events results in the view controller's view being sized. This can happen many times in the lifetime of the view controller. You should only layout the views here.
I have a very basic container view that contains a sidebar and swaps out the view controllers in the content area (think UISplitView but with a small icon sidebar / vertical UITabBar).
The container view controller uses autoLayout and resizes correctly when rotated.
Content viewController 1 uses autolayout and was made with IB, so it has a xib file.
Content viewController 2 inherits from UITableViewController and does not use a xib.
If I assign viewController 1 as the root view controller and rotate, the resize works and here are the callbacks that I get in viewController 1:
willRotateToInterfaceOrientation
updateViewConstraints
viewWillLayoutSubviews
didRotateFromInterfaceOrientation
However, if I assign my container view controller as the root view controller, load viewController 1 and rotate, the resize does not work. And I only get the following callbacks inside viewController 1:
willRotateToInterfaceOrientation
didRotateFromInterfaceOrientation
Inside my view controller container, here's how I swap the view controllers:
[self addChildViewController:toViewController];
[toViewController didMoveToParentViewController:self];
// Remove the old view controller
[fromViewController willMoveToParentViewController:nil];
[fromViewController.view removeFromSuperview];
[fromViewController removeFromParentViewController];
// Add the new view
[self.contentContainerView addSubview:toViewController.view];
Now, I do get the callbacks that a rotation is about to happen, but it seems as if neither updateViewConstraints nor viewWillLayoutSubviews is called. This explains why the resize is not happening, but why are those methods not called once I put the view controller in a container view?
I also tried to explicitly return YES in my container on both
shouldAutomaticallyForwardAppearanceMethods
and
shouldAutomaticallyForwardAppearanceMethods
although this should be the default already.
Also, the view controller not made with IB (view controller 2) resizes correctly when rotating inside the container. However, I don't explicitly use NSLayoutConstraints on this one, so I suspect it's defaulting to Springs and Struts for the resizing when rotating.
Do I need to forward some other events on my view controller container to get the auto layout view controller to resize correctly when rotating?
OK, I think I was missing this method here in my view controller container:
- (void)willAnimateRotationToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration {
self.contentViewController.view.frame = self.contentContainerView.bounds;
}
While this resizes now correctly when rotating, it still doesn't trigger
updateViewConstraints
in my child view controller. Interesting
Seems like iOS 8 does call updateViewConstraints for you. But iOS 7 didn't. To get this called in iOS 7, call setNeedsUpdateConstraints, like this:
- (void)willAnimateRotationToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation duration:(NSTimeInterval)duration
{
[super willAnimateRotationToInterfaceOrientation:interfaceOrientation duration:duration];
BOOL isiOS7 = floor(NSFoundationVersionNumber) <= NSFoundationVersionNumber_iOS_7_1;
if (isiOS7) {
// Trigger a call to updateViewConstraints
[self.view setNeedsUpdateConstraints];
}
}
In updateLayoutConstraints, a good way to check which orientation is the one to layout for is to check the status bar's orientation. This works for 7 and 8.
UIInterfaceOrientation orientation = [[UIApplication sharedApplication] statusBarOrientation];
BOOL layoutAsLandscape = UIInterfaceOrientationIsLandscape(orientation);
I am currently using iOS 6.0.
I have a custom UIView that needs to have a certain size. If I programmatically init the view and add it it's fine. However, I can't find a place where I can set the size of the view in the storyboard.
Setting its size in the storyboard doesn't work because the storyboard thinks it's empty and set it's size to zero. Setting its size in viewDidLoad or viewDidAppear doesn't work because later on the size will be overwritten by _applyISEngineLayoutValue.
You can do that in your Interface Builder. Open the storyboard where you have your view and open the utilities menu:
Then you can select a button that looks like a ruler on the top of the utilities menu:
In that menu you can set the size of your view and how you want it to expand.
Also, please make sure you setted your Class' view in the class inspector:
Image token from this site.
Finally, make sure you override the initWithFrame and initWithCoder methods:
- (id)initWithFrame:(CGRect)frame {
return [super initWithFrame:frame];
}
//Needs to be overrided when you set your size in interface builder
- (id)initWithCoder:(NSCoder *)aDecoder {
return [self initWithFrame:[self frame]];
}
I am facing the same problem, and I think the short answer is: you can't rely on the frame or bounds in the view's init method when using storyboards.
When your view is initialized by the segue, it will call the initWithCoder: method rather than other init methods, since it is deserializing your view object from the .xib file. Before storyboards, the frame and bounds would be set by the time the initWithCoder: was called, but that appears to no longer be the case with storyboards -- the iOS code sets those values later.
I've used a couple workarounds, depending on the situation:
If I know the size of the view in advance (for example a specialty view that only supports one size) I set my own frame in the initWithCoder: method.
If I don't know the size of the view, I defer initialization of size-specific things until my view's layoutSubviews method is called.
If it's more convenient, I sometimes just explicitly do the size-specific initialization in my view's ViewController. (Not pretty, but sometimes quick-and-easy. I'm not proud.)
I have the same problem as you, and when I select the view and switch to the attributes inspector , setting
"Simulated Metrics" as follows, I can resize the view in the Size inspector.
Make sure that Size is set to either "Freeform" or "None"
I have a app out for testing right now that's almost completely done - just a few bug fixes left. Unfortunately, the customer decided that they'd like the entire main page of the app to be inside of a scroll view (so that there's more room for the table at the bottom). I already have everything set up and I don't really want to move everything and change references. Is there an easy way to change the class of the main view to a scroll view? I've already tried changing the class in IB and setting the class type in the init method. If there isn't I'll probably just throw the top section of the view into a nib file and load it as a custom cell.
-EDIT- I ended up changing the class type in IB and then doing
[(UIScrollView *) self.view setScrollEnabled:YES];
[(UIScrollView *) self.view setContentSize:CGSizeMake(0,2000)];
in viewDidLoad. Thanks for the help, wish I could accept all your answers.
When you are referring to [self view], I am going to assume you mean in a view controller. The view of a view controller can be any view that derives from UIView. Thus a scrollview is completely acceptable.
I don't really want to move everything and change references.
what would you have to move? why would you have to change references? Only thing you should need to do is add a scroll view to your view controller, set the view controllers view to it, and add the current view as a subview to the new scroll view. No references need to be changed, nothing has to be moved.
Refer to loadView method in documentation of view controller.
Here is a simple (untested!) example
- (void)loadView {
UIScrollView *scrollView = [[UIScrollView alloc] init] autorelease];
//Set the properties of scrollview appropriately....
self.view = scrollView;
}
Now the root view of your view controller will be a scroll view.
Note
- As the documentation states, do not do this if you are using interface builder to initialize your views/view controller. I could not tell from your description if this was the case or not. If it is, you should be able to change the view type in interface builder.
You need to set the contentSize property of your scrollview.
Since you are using IB, the easiest way to do this is to put all your UI elements into a view and add this single view to your scroll view. In the viewDidLoad method, set the content size of the scrollview to be the same size as the view that contains all your UI.
As an aside, there are much easier ways to reference views than walking down the view hierarchy, as you seem to be doing. viewcontroller.view.something.tableview. Add a connection to the tableview from your view controller in IB and it doesn't matter where that tableview is in the view hierarchy. You'll always be able to reach it from viewcontroller.tableview, no matter how you rearrange your nibs.
I think you have to use a pointer with proper type. Example for Google Maps: let's say you changed you base view's class to GMSMapView.
MapViewController.h
#property GMSMapView *mapView;
MapViewController.m
-(void)awakeFromNib{
[super awakeFromNib];
self.mapView = (GMSMapView*)self.view;
// ... etc.
}
Im loading a root view controller in landscape mode at launch(no interface builders are used).
In viewDidLoad, I am adding subviews to root view controllers view, like this
- (void)viewDidLoad
{
[super viewDidLoad];
// self.view.
UIView *toolBar=[[UIView alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, 50)];
toolBar.backgroundColor=[UIColor darkGrayColor];
[self.view addSubview:toolBar];
//code contiues...
}
but self.view.frame.size.width returns width of portrait mode instead of landscape.
thanks in advance
EDIT:
Implement the -loadView method:
- (void)loadView
{
self.view = [[UIView alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
self.view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
}
Also normally the parent view controller is responsible for setting the frame size of its children view controllers views. In the case of the root view controller, I believe it takes the size of the UIWindow it's attached to (so if you set the window size in you app delegate, you can just use [[UIView alloc] init] and then set the autoresizing mask in the -loadView method).
You might need to take the status bar into account in the above code, depending on your own code.
may be, portrait orientations are first in your project file (click to project in xcode, info tab in target, unit Supported interface orientations) ? If so, your app can launched in portrait orientation, then send viewDidLoad and rotate to landscape only after this.
When you do not use Interface Builder/xib files and neither create your view manually within loadview, the systems creates one with the maximum dimensions. This is stated in the loadview method documentation:
If the view controller does not have an associated nib file, this
method creates a plain UIView object instead.
This system generated UIView object has a transform property that is not the identiy transformation and thus you are not allowed to rely on the values from the frame property as stated here:
http://developer.apple.com/library/ios/documentation/uikit/reference/UIView_Class/UIView/UIView.html#//apple_ref/occ/instp/UIView/transform
Warning: If this property is not the identity transform, the value of
the frame property is undefined and therefore should be ignored.
So, what should you to instead? I guess the best solution is to use the bounds property of you UIView. This contains the already rotated coordinates.