I have been trying to add/implement this example to my existing Split View app tests.
Apple Example
I what to use the concept of replacing the detail view or right view, otherwise my app will be different. It is this difference that is causing my problems.
I have a rootviewcontroller or left view and upon choosing something here a new view is pushed onto this view. Upon choosing something in this "pushed view" I want to change the detail view or right hand view. This is the difference to apples example where the rootview does not have a pushed view on it and thus references are not broken.
Below is my change code - the new View DVCases is being initialized but the didload is not happening.
The issues are learner issues to do with my classes.
This below code is in my RootViewController implementation code but my reference to splitviewcontroller is not working if there is a new view pushed.
Second self.navigationcontroller is not correct because I have pushed a second view to the rootviewcontroller.
To centralize and simplify the code what I have done is from the delegate of the pushed view in the didselect event i call a method found in the rootviewcontroller passing the index as a parameter. The code for my custom method contains what is below.
So my question is how do I do this in my situation where I have pushed other views onto the rootview or left side. It appears that after pushing a view the reference to splitviewcontroller is gone and self.navigationcontroller is also gone/or wrong.
UIViewController <SubstitutableDetailViewController> *detailViewController = nil;
if (value == 0) {
DVCases *newDetailViewController = [[DVCases alloc] initWithNibName:#"DVCases" bundle:nil];
detailViewController = newDetailViewController;
}
// Update the split view controller's view controllers array.
NSArray *viewControllers = [[NSArray alloc] initWithObjects:self.navigationController, detailViewController, nil];
splitViewController.viewControllers = viewControllers;
[viewControllers release];
// Dismiss the popover if it's present.
if (popoverController != nil) {
[popoverController dismissPopoverAnimated:YES];
}
// Configure the new view controller's popover button (after the view has been displayed and its toolbar/navigation bar has been created).
if (rootPopoverButtonItem != nil) {
[detailViewController showRootPopoverButtonItem:self.rootPopoverButtonItem];
}
[detailViewController release];
I would appreciate any tips or help you might have.
Initialization of any viewcontroller class does not mean that it will make call to viewDidLoad method.
viewDidLoad method will only be called when you load view of that viewController. Generally we do it either by following methods.
1. Pushing it on navigation stack.
2. Presenting it using modal transition.
3. Adding it on some other view using [someView addSubView:controller.view];
4. Selecting any tabBar item for the first time Or tapping tabBar Item twice.
there may be some other scenarios.
But right now in your code I don't see any of this element.
Initialization means you are calling the direct method for intialization(calling its constructor) like here in above code initWithNibName will call this method of DVClass not any other(until this method had call for other methods inside it).
Thanks
As I am learning to properly code - my problems centres around that.
The above code is perfect as long as you call it using the same instance. I was not. Thus it was not working.
In the end I made my RootViewController a delegate for a method that has the above code. Thus when in another view - this view can call this method and the proper or real instance of RootViewController will implement it.
Related
I want to create a custom segue that acts in the same way as the standard push segue does when used on UINavigationController view controllers. I've implemented my custom segue:
CustomSegue.m
-(void)perform {
UIViewController *source = (UIViewController *)[self sourceViewController];
UIViewController *dest =(UIViewController *)[self destinationViewController];
if (1==2 //test) {
[source.navigationController pushViewController:dest animated:YES];
}
else {
UIViewController *altDest = [[UIStoryboard storyboardWithName:#"MainStoryboard" bundle:NULL]
instantiateViewControllerWithIdentifier:#"alternateView"];
[source.navigationController pushViewController:altDest animated:YES];
}
As you can see, the reason I want to use a custom push segue is so that I can decide which view controller to push based on the user configuration (currently only checking a trivial 1==2 expression). I can instantiate the alternate view controller with no issue, but what I want to be able to do is go back and forth without reloading the view controller each time (using the back and next buttons). Is there a way to retrieve an existing instance from the storyboard, or some standard way of doing this?
Instead of a custom segue with its perform, the way to do what you describe, i.e. choose in real time whether to push dest or altDest, is either (1) do not use segues at all and just call pushViewController directly as you are doing here, or (2) prepare two segues emanating from the view controller as a whole, and call performSegueWithIdentifier: to say which we should perform.
As for going directly from dest to altDest, you can push altDest on top of dest and then remove dest from the stack of the navigation controller's view controllers.
Like so much about about iOS, this is all so much easier and more obvious if you do not use a storyboard at all. This is why I don't like storyboards: they are so simple-minded and limiting, and they distract one's attention from the way iOS really works.
There is no way to retrieve an existing controller from a storyboard -- it would be nice if there were a controllerWithIdentifier: method to do that, but there isn't. Segues (other than unwinds) always instantiate new controllers, so I don't think you can do what you want with a segue. If you want to be going forward (push) to the same controller multiple times, then you need to do it in code by creating a property that points to your controller, and checking if that controller exists before pushing to it.
As the others have pointed out, you can't use a segue to push to an existing instance of a controller. The process of performing a segue always creates a new instance the destination controller for you.
Personally, when I'm jumping between existing instances of view controllers, I think "container view controller", such as a UIPageViewController, which makes it really easy to transition between two or more controllers, without necessarily reinstantiating them every time.
If you don't like the constraints the page view controller imposes (e.g. maybe you don't like the fact that iOS 5 version only supports page curl transitions, or that iOS 6 only adds the scroll transition, and you want something else), then you'd do a custom container view controller.
For example, if I wanted to jump between two view controllers and not reinstantiate them every time, I'd first create a custom container view controller, the "parent", and make sure I have a property to keep track of which child I'm currently at:
#property (nonatomic) NSInteger childViewIndex;
If supporting iOS 6.0 and above only, I'd then add a "container view" to my parent view controller's scene. If supporting iOS versions prior to 6.0, I'd add a standard UIView to the scene and then manually instantiate the first child controller:
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
UIViewController *controller;
// add the first child
UIViewController *controller = [self addChildWithIdentifier:#"One"];
[self.containerView addSubview:controller.view];
[controller didMoveToParentViewController:self];
self.childViewIndex = 0;
}
- (UIViewController *)addChildWithIdentifier:(NSString *)storyboardIdentifier
{
UIViewController *controller = [self.storyboard instantiateViewControllerWithIdentifier:storyboardIdentifier];
[self addChildViewController:controller];
controller.view.frame = self.containerView.bounds;
controller.view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
return controller;
}
Then, when I want to transition to the second child (or transition back to the first child), I'd call the following routine in the parent view controller:
- (void)transitionToViewControllerIndex:(NSInteger)index
{
// don't do anything if we're trying to transition to ourselves!
if (index == self.childViewIndex)
return;
// identify the two controllers in question
UIViewController *sourceController = self.childViewControllers[self.childViewIndex];
UIViewController *destinationController;
// if we're asking for page 2, but we only have one defined, then we'll have to instantiate it
BOOL instantiateDestination = (index == 1 && [self.childViewControllers count] < 2);
if (instantiateDestination)
destinationController = [self addChildWithIdentifier:#"Two"];
else
destinationController = self.childViewControllers[index];
// configure the destination controller's frame
destinationController.view.frame = sourceController.view.frame;
// if you're jumping back and forth, set the animation appropriate for the
// direction we're going
UIViewAnimationOptions options;
if (index > self.childViewIndex)
{
options = UIViewAnimationOptionTransitionFlipFromRight;
}
else
{
options = UIViewAnimationOptionTransitionFlipFromLeft;
}
// now transition to that destination controller
[self transitionFromViewController:sourceController
toViewController:destinationController
duration:0.5
options:options
animations:^{
// for simple flip, you don't need anything here,
// but docs say this can't be NULL; if you wanted
// to do some other, custom annotation, you'd do it here
}
completion:^(BOOL finished) {
if (instantiateDestination)
[destinationController didMoveToParentViewController:self];
}];
self.childViewIndex = index;
}
Thus, to transition to the second child view controller, you could simply call:
[self transitionToViewControllerIndex:1];
If you want to transition back, you could call:
[self transitionToViewControllerIndex:0];
I'm only scratching the surface here, but container view controllers (or if none of the standard ones do the job for you, a custom container view controller) is precisely what you need.
For more information, see:
Creating Custom Container View Controllers in the View Controller Programming Guide for iOS.
Implementing UIViewController Containment in the WWDC 2011 Session Videos (Apple developer ID required).
Implementing a Container View Controller in the UIViewController Class Reference.
Page View Controllers in the View Controller Catalog for iOS.
I have a view that shows a map. I have a custom subclass of UIViewController (DetailViewController) that gets shown when the detailDisclosureButton of the callout above the pin is pressed. While in my map class, I create my detailview and add it to the subview like this:
DetailViewController *detailView = [[DetailViewController alloc] initWithNibName:#"DetailView" bundle:nil];
detailView.locationPoint = locationPoint;
detailView.locationCoordinate = locationCoordinate;
[self.view addSubview:detailView.view];
[detailView release];
My DetailViewController has a TableView and parses the data in DetailViewController. However I get an error of sending the numberOfSectionsInTable message to a dealloc'd instance. I'm assuming it is this since I originally had this as a property and it worked fine with (nonatomic, retain). I'm assuming that I'm releasing it before the next view is done with it. If that is the case, when would I clean up the memory??? It seems like this would be the place to do it. Thanks.
I am not sure what makes you adding the view of DetailViewController into this mapviewcontroller's view. Don't you think right approach would be to either presentModalViewController or pushNavigationController?
DetailViewController *detailView = [[DetailViewController alloc] initWithNibName:#"DetailView" bundle:nil];
detailView.locationPoint = locationPoint;
detailView.locationCoordinate = locationCoordinate;
//[self.view addSubview:detailView.view];
[self.navigationController pushViewController:detailView animated:YES];
//OR
[self presentModalViewController:detailView animated:YES];
[detailView release];
You are getting the error because you are only using the view and deallocating the view controller immediately and hence tableview datasource and delegates are hitting a nil object.
Views do not retain their view controllers. Someone needs to retain the VC or else it will get released, and then the app will crash when the view makes a call into its delegate. When you use a navigation controller, the navcon has a stack of view controllers that it retains. Likewise with presentModalViewController, the OS takes care of retaining the detail VC.
Adding a detail view as a subview is not the normal way to navigate to a new view. Instead, one either uses a navigation controller and [navcon pushViewController::], or a modal subview and [self presentModalViewController::]. If the detail view occupies only a portion of the parent view, then it is normal to retain the view controller for the subview within the parent controller. That is, within the parent VC (your map class) add a property for the detail VC. Actually, it's more common to not even use a VC for a subview, but rather for screen-filling detail views.
I'm trying to switch between several table views as the root of a navigation controller. Depending on the settings of my app, I want to use different sets of data with different methods, and prefer to have these encapsulated in separate classes.
My thought was to set a view manager class (UIViewController) as the root view controller of the navigation controller. In the view manager we check the settings to see which view we want to load:
if([application_mode intValue]==APPLICATION_MODE_A){
AViewController *aView = [[DeviceTableViewController alloc] init];
[self.view insertSubview:aView.view atIndex:0];
}
else if([application_mode intValue]==APPLICATION_B){
BViewController *bView = [[BViewController alloc] init];
[self.view insertSubview.bView.view atIndex:0];
}
That does in fact insert the appropriate view into the view manager, at the cost of a white bar at the top of the inserted view and no info on the navigation bar, ie the subview is not connected to the navigation controller.
What's the proper way to do this? I'd really prefer not to have one ginormous table view!
Where do you set your navigationController's rootViewController? Can't you just set it to an AviewController's object or an BViewController's object at this time ? You may not need an intermediate UIViewController
I would do at the beginning :
//navigationController comes from a Xib or previous code
if([application_mode intValue]==APPLICATION_MODE_A){
AViewController *aView = [[DeviceTableViewController alloc] init];
navigationController.rootViewController = aView;
[aView release];
}
else if([application_mode intValue]==APPLICATION_B){
BViewController *bView = [[BViewController alloc] init];
navigationController.rootViewController = bView;
[bView release];
}
Since there is no view controller containment, I like the approach outlined in Jonah William's blog:
http://blog.carbonfive.com/2011/03/09/abusing-uiviewcontrollers/
You can't effectively place a view controller inside another; instead, we create something with similar lifecycle methods (viewDidLoad, viewDidAppear, etc) and forward those methods from the parent to the child. This 'psudo-viewcontroller' has a view property that we add as a subview to the parent's view, using UIView addSubView
http://developer.apple.com/library/ios/#documentation/uikit/reference/UIView_Class/UIView/UIView.html#//apple_ref/occ/instm/UIView/addSubview:
With this approach, we can encapsulate view elements, switch them out dynamically in a view controller, place several within a single view controller, etc. This way they can be considered separately from your navigation stack. It's a bit of work, but the cleanest UI encapsulation approach in iOS 4 in my opinion.
So I have a modal view displaying in my app that has a little info for the user to fill out. The problem is that when the device is rotated, some animation occurs, but only in the frame. The form itself does not rotate. All the autorotate options are set to YES. I am displaying it when the user clicks on a field in a popover. This makes me suspect it has something to do with that but I am not sure. It is bizzare because if the device is in either view and then the modal window is displayed, it is fine. It only happens when the device is rotated in the modal view. Does anyone have any idea what may be causing this behavior when the device is rotated? Thanks!
Here is a snippet that is handled in the popover view controller:
if (currentLevel == 1 && businessOrLocation == 0){
if(tbsViewController == nil)
tbsViewController = [[BusinessFilteredViewController alloc] initWithNibName:#"BusinessFilteredView" bundle:[NSBundle mainBundle]];
NSMutableArray *tempBusiness = [[NSMutableArray alloc] init];
for (id theKey in appDelegate.groupedBusiness) {
NSMutableArray *tempArr = [appDelegate.groupedBusiness objectForKey:theKey];
[tempBusiness addObject:tempArr];
}
tbsViewController.businessOrLocation = businessOrLocation;
tbsViewController.modalPresentationStyle = UIModalPresentationFullScreen;
tbsViewController.modalTransitionStyle = UIModalPresentationFullScreen;
[self presentModalViewController:tbsViewController animated:YES];
}
I ran into this problem as well. The fundamental problem is that popover controllers cannot present modal views—it seems that case wasn’t properly considered or designed for. In my situation, it was easy enough to work around. I just extended the delegate protocol for my popover-hosted view controller. The main view sets itself up as the delegate to the popover view, and takes responsibility for displaying and dismissing the modal views the user requests from within the popover.
Since I already had a delegate protocol to cleanly dismiss the popover view when the user clicks “done” it was only a small stretch to get autorotation working the way I wanted it to. Here are some snippets:
#protocol InfoViewControllerDelegate <NSObject>
#optional
// Implement this to close the info view once the user clicks done.
- (void)infoViewDidFinish:(InfoViewController *)view;
// Implement this method if the delegate launched us as a popup view and must therefore
// take responsibility for diplaying help.
- (void)infoViewDidRequestHelp:(InfoViewController *)view;
#end
And in my main iPad view which presents this popup view:
#pragma mark - InfoViewControllerDelegate methods
- (void)infoViewDidFinish:(InfoViewController *)view {
[self hideInfo:self];
}
- (void)infoViewDidRequestHelp:(InfoViewController *)view {
[self hideInfo:self]; // Close the info view first
HelpViewController *help = [[HelpViewController alloc] init];
help.delegate = self;
[self presentModalViewController:help animated:YES];
[help release];
}
To make life simple for cases where I am launching the info view outside of a popup view (for example, on the iPhone, it is a simple modal view), it checks to see if the delegate handles the modal subviews, and if not, handles them itself. That way I didn’t need to change the iPhone base controller at all, since autorotation already worked fine there. Here’s the “Help” button action in the info view controller, showing how I did that:
- (IBAction)help:(id)sender {
if ([delegate respondsToSelector:#selector(infoViewDidRequestHelp:)]) {
[delegate infoViewDidRequestHelp:self];
} else {
HelpViewController *help = [[HelpViewController alloc] init];
help.delegate = self;
[self presentModalViewController:help animated:YES];
[help release];
}
}
With this code in place, my entire interface autorotates smoothly on both devices, whether or not popup views were involved.
Just so i understand correctly... You are displaying a popover and inside that popover if the user taps a certain element then you are displaying a full screen modal view controller? Vie never tried that before and it seems odd for two reasons.
First it seems jarring to the user in my opinion. The popover gives you a nice, integrated UI and the modal takes you away.
More importantly though, your popover view controller doesn't really have authority over the whole screen so presenting a full screen modal from a popover just seems inherently wrong.
I would suggest you display a nav controller in the popover controller and instead of presenting the new view controller modally over the whole screen just push it on to the nav controller in the popover and keep the user inside the popover.
If that doesn't really work for you, then I would suggest reviewing your UI needs and redesigning the layout.
I am guessing that you implemented - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation in BusinessFilteredViewController and returns YES
Could you check that you add more than 1 subviews to application window . If so, try to create container UIViewController for all viewControllers that you want to add to window.
I am having a problem with a table and showing another view when the user touches a table cell. I am using a UITabBarController for the main view to show different views. I then use a UINavigationController when the user selects a UITableView view to display the next view from the table cell selection.
My problem is this: when they select the table cell, the cell is highlighted and the next view does not appear. I am using IB. All of the examples I have found are doing this the same way I am, except the examples work!
I have the controllers loaded in a NSMutableArray with a Dictionary. I also tried this code by directly creating a view controller rather than using the array item. Same results....
I checked the target controller (Calc1ViewController) to make sure there was nothing wrong with the controller. When showing it directly, the controller (Calc1ViewController) displays correctly.
Here is some code.....
The initialization of the view controller in the dictionary:
Calc1ViewController *calc1ViewController = [[Calc1ViewController alloc] init];
[menuList addObject:[NSDictionary dictionaryWithObjectsAndKeys:
NSLocalizedString(#"SSC - page 1",#""), #"title",
calc1ViewController, #"viewController",
nil]];
[calc1ViewController release];
I also tried this without using the dictionary -- creating a view controller in place of the [[menuList objectAtIndex:...]; line -- by creating the view controller like this:
Calc1ViewController *targetViewController = [[Calc1ViewController alloc] init];
// the table's selection has changed, switch to that item's UIViewController
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
UIViewController *targetViewController = [[menuList objectAtIndex: indexPath.row] objectForKey:#"viewController"];
[[self navigationController] pushViewController:targetViewController animated:YES];
targetViewController = nil;
}
The navigation controller is defined in the AppDelegate and connected to the RootViewController through IB.
When I select a table row, it shows in the debugger that the pushViewController code is executed, but the next view does not show. Here is an example:
alt text http://thecoolestcompany.com/ssc-table-view.jpg
Any ideas?
Finally figured it out......
I had the UINavigationController and the UITabBarController on the same level. After moving the Navigation Controller as a child to the tab bar controller, everything worked. You may add as many navigation controllers to a tab bar as you would like. In IB is is a little confusing. You need to drag the NavigationController into the TabBar to as it as a new Tab Bar item.
Theres not much to go by with t he code you have provided. Only thing i can think of without looking at more code is that perhaps you have not initialized your view controller (the one in your dictionary) correctly, or at all, or the dictionary you are accesing there is not the correct one...
What is the value of [self navigationController] when pushViewController is called. Is it nil?
What is the value of targetViewController when it is passed to pushViewController. Is it nil?