I have an iPad app, using Storyboards, XCode 4.6 and iOS 6.1. I have a scene that contains a UIViewController. Inside that UIViewController, I have a UIScrollController, all created using IB. Programmatically, in viewDidLoad I created two (2) UIViews (one called subViewGrid, the other called subViewData) and added them to the UIViewController; they both display correctly in the Simulator. Here's the code:
- (void)viewDidLoad {
[super viewDidLoad];
// notify me when calendar has been tapped and CFGregorianDate has been updated
[[NSNotificationCenter defaultCenter] removeObserver:self];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(calendarTapNotification:)
name:#"calendarDateSelected" object:nil ];
// UIScrollVIew settings
CGSize scrollableSize = CGSizeMake(760, 1379); // set size of scheduleView
[self.schedScrollView setContentSize:scrollableSize];
self.schedScrollView.contentInset = UIEdgeInsetsMake(0,0,44,44); // allow for scroll bar
self.schedScrollView.directionalLockEnabled = YES; // prevents diagonal scrolling
// create a sub-view to hold the appointment GRID
CGRect frame = CGRectMake(0,0,760,1390); // 110,48,760,1390
subViewGrid = [[UIView alloc] initWithFrame:frame];
subViewGrid.tag = 12; // use tag to get correct sub-view
subViewGrid.backgroundColor = [UIColor grayColor];
subViewGrid.alpha = 1.0; // make it opaque
[self.schedScrollView addSubview:subViewGrid];
// create a sub-view to hold the appointment DATA
frame = CGRectMake(110,48,670,750);
subViewData = [[UIView alloc] initWithFrame:frame];
subViewData.tag = 22; // use tag to get correct sub-view
subViewData.backgroundColor = [UIColor redColor];
subViewData.alpha = 0.2; // make it sort of transparent
[self.schedScrollView addSubview:subViewData];
[self.subViewGrid setNeedsDisplay]; // **** UPDATED ****
}
Here is the .h file contents for the UIViewController:
#interface CalendarViewController : UIViewController {
UIView *subViewGrid;
UIView *subViewData;
}
#property (strong, nonatomic) IBOutlet UIScrollView *schedScrollView;
- (void) calendarTapNotification:(NSNotification *) notification;
-(NSDate *)beginningOfDay:(NSDate *)date;
-(NSDate *)endOfDay:(NSDate *)date;
#end
In my drawRect method, I have some code that is supposed to draw a "grid" on the subViewGrid. The problem is drawRect never gets called.`
I have read the UIView Programmer's Guide and looked in SO and did a Google search, but found nothing that addresses the issue, which is: why won't [self.subViewGrid setNeedsDisplay] call drawRect from where I have it placed?
Your view controller needs to call setNeedsDisplay for the view it controls, not for itself. So, you want
[self.subViewGrid setNeedsDisplay]
This is just an error in your reading the documentation. Understanding the documentation is critical for objective-C programming so I'll try to help you get a grasp of it.
If you look at the documentation for setNeedsDisplay you will see that it is either a CALayer or UIView class method. If you then look at inheritance, you will see that UIView is UIResponder:NSObject and CALayer is NSObject. None of these inherit from UIViewController which is why you are getting the error. You need to call [self.subViewGrid setNeedsDisplay]
Related
Having an issue with MPMoviePLayerController with an overlay in iOS6, prior to iOS6 things were working fine.
It seems I can play a movie in full screen, before I had this code:
#interface MovieOverlayViewController : UIViewController
{
UIImageView *skiparrow;
}
#end
#implementation MovieOverlayViewController
-(void) viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
touchtoskip.frame = CGRectMake( xAdjust,
yAdjust,
touchtoskip.image.size.width / scale,
touchtoskip.image.size.height / scale);
[self.view addSubview:touchtoskip];
}
Then:
overlay = [[MovieOverlayViewController alloc] init];
UIWindow *keyWnd = [[UIApplication sharedApplication] keyWindow];
[keyWnd addSubview:overlay.view];
On my MoviePlayerViewController the view DOES appear. And adds the UIViews, but I see NOTHING anymore.
Really stuck, any suggestions?
I think part of the problem is that you are getting the key window and adding a subview to that, rather than getting the window's view and adding a subview to that.
Have a look at the MoviePlayer sample, which shows how to add a player with subviews to control playback.
Major head-scratcher all day on this one :-(
I have an instance of a UIPageViewController that does not appear to be firing the delegate method:
-(UIPageViewControllerSpineLocation)pageViewController:(UIPageViewController *)pageViewController
spineLocationForInterfaceOrientation:(UIInterfaceOrientation)orientation
I have tried various methods of displaying the UIPageViewController and have settled on a programatic approach (as opposed to a Storyboard one) that appears to be working correctly, with one exception... when rotating the iPad to landscape the spine does not appear mid-point as expected. I simply cannot find out why the delegate method does not get called.
Code Explanation (simplified for example)
Consider three classes as follows:
RootViewController - loaded when the app starts
PageViewController - loaded by RootViewController upon user initiation
PageContentViewController - loaded by PageViewController when pages are needed
Fairly self-explanatory. The RootViewController is loaded by the app upon launch. When the user taps an image within this view controller's view (think magazine cover opening a magazine) it launches the PageViewController as follows:
PageViewController *pvc = [[PageViewController alloc] initWithNibName:#"PageView"
bundle:[NSBundle mainBundle]];
pvc.view.frame = self.view.bounds;
[self.view addSubview:pvc.view];
In the actual app there is animation etc to make the transition all nice, but essentially the PageViewController's view is loaded and takes fullscreen.
PageViewController
This is the workhorse (only relevant methods shown). I have tried various examples from the infinite world of Google and written directly from the Apple docs...
#interface PageViewController : UIViewController <UIPageViewControllerDelegate, UIPageViewControllerDataSource>
#property (nonatomic, strong) UIPageViewController *pageViewController;
#property (nonatomic, strong) NSMutableArray *modelArray;
#end
#implementation TXCategoryController
-(void)viewDidLoad
{
[super viewDidLoad];
// Simple model for demo
self.modelArray = [NSMutableArray alloc] init];
for (int i=1; i<=20; i++)
[self.modelArray addObject:[NSString stringWithFormat:#"Page: %d", i]];
self.pageViewController = [[UIPageViewController alloc]
initWithTransitionStyle:UIPageViewControllerTransitionStylePageCurl
navigationOrientation:UIPageViewControllerNavigationOrientationHorizontal options:nil];
self.pageViewController.delegate = self;
self.pageViewController.dataSource = self;
PageContentViewController *startupVC = [[PageContentViewController alloc] initWithNibName:#"PageContent" bundle:nil];
startupVC.pageLabel = [self.modelArray objectAtIndex:0];
[self.pageViewController setViewControllers:[NSArray arrayWithObject:startupVC]
direction:UIPageViewControllerNavigationDirectionForward
animated:NO
completion:nil];
[self addChildViewController:self.pageViewController];
[self.view addSubview:self.pageViewController.view];
[self.pageViewController didMoveToParentViewController:self];
self.pageViewController.view.frame = self.view.bounds;
self.view.gestureRecognizers = self.pageViewController.gestureRecognizers;
}
-(UIViewController *)pageViewController:(UIPageViewController *)pageViewController
viewControllerBeforeViewController:(UIViewController *)viewController
{
// Relevant code to add another view...
}
-(UIViewController *)pageViewController:(UIPageViewController *)pageViewController
viewControllerAfterViewController:(UIViewController *)viewController
{
// Relevant code to add another view...
}
-(UIPageViewControllerSpineLocation)pageViewController:(UIPageViewController *)pageViewController
spineLocationForInterfaceOrientation:(UIInterfaceOrientation)orientation
{
// Setting a break point in here - never gets called
if (UIInterfaceOrientationIsPortrait(orientation))
{
// Relevant code to create view...
return UIPageViewControllerSpineLocationMin;
}
// Relevant code to create 2 views for side-by-side display and
// set those views using self.pageViewController setViewControllers:
return UIPageViewControllerSpineLocationMid
}
#end
This all works perfectly well as I mentioned earlier. The PageViewController's view gets shown. I can swipe pages left and right in both portrait and landscape and the respective page number appears. However, I don't ever see two pages side-by-side in landscape view. Setting a breakpoint in the spineLocationForInterfaceOrientation delegate method never gets called.
This is such a head-scratcher I have burned out of ideas on how to debug/solve the problem. It almost behaves like the UIPageViewController isn't responding to the orientation changes of the device and therefore isn't firing off the delegate method. However, the view gets resized correctly (but that could be just the UIView autoresizing masks handling that change).
If I create a brand new project with just this code (and appropriate XIb's etc) it works perfectly fine. So something somewhere in my actual project is causing this. I have no idea where to continue looking.
As usual, any and all help would be very much appreciated.
Side Note
I wanted to add the tag 'uipageviewcontrollerspinelocation' but couldn't because it was too long and I didn't have enough reputation (1500 required). I think this is a devious ploy on Apple's part to avoid certain tags in Stackoverflow... ;-)
Finally found the problem. It was something of a red herring in its symptoms, but related just the same.
Putting a break point in the shouldAutorotateToInterfaceOrientation: method was a natural test to see if the UIViewController was even getting a rotation notification. It wasn't which led me to Apple's technical Q&A on the issue: http://developer.apple.com/library/ios/#qa/qa1688/_index.html
The most relevant point in there was:
The view controller's UIView property is embedded inside UIWindow but alongside an additional view controller.
Unfortunately, Apple, in its traditional documentation style, doesn't provide an answer, merely confirmation of the problem. But an answer on Stack Overflow yielded the next clue:
Animate change of view controllers without using navigation controller stack, subviews or modal controllers?
Although my RootViewController was loading the PageViewController, I was doing it as a subview to the main view. This meant I had two UIViewController's in which only the parent would respond to changes.
The solution to get the PageViewController to listen to the orientation changes (thus triggering the associated spine delegate method) was to remove addSubview: and instead present the view controller from RootViewController:
[self presentViewController:pac animated:YES completion:NULL];
Once that was done, the orientation changes were being picked up and the PageViewController was firing the delegate method for spine position. Only one minor detail to consider. If the view was launched in landscape, the view was still displaying portrait until rotated to portrait and back to landscape.
That was easily tweaked by editing viewDidLoad as follows:
PageContentViewController *page1 = [[PageContentViewController alloc] initWithNibName:#"PageContent" bundle:nil];
NSDictionary *pageViewOptions = nil;
NSMutableArray *pagesArray = [NSMutableArray array];
if (IS_IPAD && UIInterfaceOrientationIsLandscape(self.interfaceOrientation))
{
pageViewOptions = [NSDictionary dictionaryWithObject:[NSNumber numberWithInt:UIPageViewControllerSpineLocationMid]
forKey:UIPageViewControllerOptionSpineLocationKey];
PageContentViewController *page2 = [[PageContentViewController alloc] initWithNibName:#"PageContent" bundle:nil];
[pagesArray addObject:page1];
[pagesArray addObject:page2];
}
else
{
[pagesArray addObject:page1];
}
self.pageViewController = [[UIPageViewController alloc] initWithTransitionStyle:UIPageViewControllerTransitionStylePageCurl
navigationOrientation:UIPageViewControllerNavigationOrientationHorizontal
options:pageViewOptions];
self.pageViewController.delegate = self;
[self.pageViewController setViewControllers:pagesArray
direction:UIPageViewControllerNavigationDirectionForward
animated:NO
completion:NULL];
Job done and problem solved.
I'm having a lot of trouble finding a tutorial for implementing multiple views in Xcode 4.2 without storyboard, this is for a class so I can't use storyboard yet. I'm just trying to have a 2nd view with a UIPicker come up when a button is clicked in the main view, I just can't find one for this version of Xcode and it's different enough from the older versions to confuse me.
Any help appreciated if someone can give me a quick description of what I need to do this or a newer tutorial I'd appreciate it :)
I think you should read the UIView Programming Guide to get a good handle on how UIViews work exactly. I find nibs/storyboard are really great at confusing new iOS developers.
In essence, a UIViewController has 1 view which you set in the viewDidLoad or loadView method by using the [self setView:someUIView]. You add more stuff to the screen by adding UIViews as a subview of the viewcontroller's "Main" view. For example
-(void)loadView {
// Create a view for you view controller
UIView *mainView = [[UIView alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
[self setView:mainView];
// Now we have a view taking up the whole screen and we can add stuff to it
// Let's try a button, a UIButton is a subview of UIView
UIButton *newButton = [[UIButton buttonWithType:UIButtonTypeRoundedRect];
// We need to set a frame for any view we add so that we specify where it should
// be located and how big it should be!
[newButton setFrame:CGRectMake(x,y,width,height)];
// Now let's add it to our view controller's view
[self.view addSubview:newButton];
// You can do the same with any UIView subclasses you make!
MyView *myView = [[MyView alloc] init];
[myView setFrame:CGRectMake(x,y,width,height)];
[self.view addSubview:myView];
}
Now here we have our viewController who'se view is just a plain UIView which in turn has 2 subviews; newButton and myView. Since we created the MyView class, maybe it contains subviews as well! Let's take a look at what a UIView subclass could look like:
// Here is the init method for our UIView subclass
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Let's add a button to our view
UIButton *newButton2 = [[UIButton buttonWithType:UIButtonTypeRoundedRect];
// Of course, the frame is in reference to this view
[newButton2 setFrame:CGRectMake(x,y,width,height)];
// We add just using self NOT self.view because here, we are the view!
[self addSubview:newButton2];
}
return self;
}
So in this example we would have a view controller who'se view now contains 2 button! But the view structure is a tree:
mainView
/ \
newButton myView
\
newButton2
Let me know if you have any other questions!
Matt
I'm trying to create a NSImageView programmatically as a subview of another NSImageView when awakeFromNib is called.
My code is as follows (Fader is defined in MyImageView.h):
#implementation MyImageView
- (void)awakeFromNib {
Fader = [NSImageView initWithFrame: [self frame]];
}
I get the warning message "NSImageView may not respong to +initWithFrame". When I build, the app simply frizzes without showing anything, and I have to "force quit".
What am I doing wrong?
You’ve forgotten to send +alloc in order to allocate the object. Change that line to:
Fader = [[NSImageView alloc] initWithFrame: [self frame]];
I'm working on a custom implementation of UISegmentedControl.
I'd like to create a component that able to receive config data and from which obtain a custom View similar to UISegmentedControl.
I started subclassing a UIView and i can create a custom UISegmentedControl with this code:
CustomSegment *segment = [[CustomSegment alloc]
initWithTitles:[NSArray arrayWithObjects:#"one",#"two",nil]];
[self.window addSubview:segment];
But now i'd like to improve my class and add some more customizable parameters to it.
For example i'd like add a custom separators, define the button fonts and so on... here my doubt:
Is it better to work on a UIView subClass or you suggest me to subclass a UIViewController, where i can manage View hierarchy in method like -(void)loadView and -(void)viewDidLoad ?
In a simple UIView subclass, when i launch the custom init method, i setup immediately subviews... while using a UIViewController i can call custom init and define how my subview is builded into -(void)loadView.
Don't use an UIViewController, just extend the UIView class like you did and keep extending its functionality.
Remember to save a pointer to each subview you add (i.e. buttons) in order to be able to access them later.
Define custom setters, for example, a custom setter for changing a button label title would be:
- (void) setButton1Title:(NSString*)str forState:(UIControlState)state{
//You can add some control here
if ([str length] > 20) return;
[_button1 setTitle:str forState:state]; //_button1 is my reference to the button
}
And so on. Don't provide direct access to your subviews, use methods instead.
Also, you can use "layoutSubviews" method to define how your views are going to be displayed in your custom view.
Hope it helps you.
Edit: In your case, I don't see why using lauoutSubviews method but I want to show you what I was trying to say.
Lets say that for example I need to create an UIView class to represent a "Contact" object in my application.
This is what I would do:
#interface ContactView : UIView{
UILabel* _nameLabel;
UILabel* _ageLabel;
Contact* _contact;
}
#property (retain) Contact* contact;
#end
#implementation ContactView
#synthetize contact = _contact;
-(id)initWithContact:(Contact*)c{
self = [super init];
if (self) {
_nameLabel = [[UILabel alloc] init];
_nameLabel.frame = CGRectZero;
[self addSubview:_nameLabel];
[_nameLabel release];
_ageLabel = [[UILabel alloc] init];
_ageLabel.frame = CGRectZero;
[self addSubview:_ageLabel];
[_ageLabel release];
self.contact = c;
}
}
- (void) layoutSubviews{
[super layoutSubviews];
_nameLabel.frame = CGRectMake(0.0f, 0.0f, 200.0f, 25.0f);
_ageLabel.frame = CGRectMake(0.0f, 25.0f, 200.0f, 25.0f);
if (self.contact){
_nameLabel.text = self.contact.name;
_ageLabel.text = self.contact.age;
}else{
_nameLabel.text = #"Unavailable";
_ageLabel.text = #"Unavailable";
}
}
- (void) setContact:(Contact*)c{
self.contact = c;
[self layoutSubviews];
}
#end
Check out how the "layoutSubiews" is used to set the correct frame and data to the labels.
Usually, I use it a lot when creating custom UITableViewCells where you have to reuse the view.
Let me know if I'm being confusing.