I'm creating a application with an sqlite database. I update the database with information retrieved from a web service. I call the web service from AppDelegate like this:
-(void)applicationDidBecomeActive:(UIApplication *)application{
// get new information from web service
// update sqlite database
}
The web service can take quite a long time so I want to add a UIActivityIndicatorView to whatever viewController that is active. And of course, remove it when then update is done.
Ideas?
- (void)applicationDidBecomeActive:(UIApplication *)application
{
testView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 420, 480)];
testView.backgroundColor = [UIColor redColor];
[self.window.rootViewController.view addSubview:testView];
}
Then whenever you are done do:
[testView removeFromSuperview];
In each of your view controllers (or common super class view controller) listen for UIApplicationDidBecomeActiveNotification notification which is being sent when application becomes active.
This way you can have custom logic for each view controller without coupling app delegate to other parts of your code by using lots of ifs (if you need to distinguish which view controller is active one).
Because your view hierarchy can take any form, tracking the currently visible view controller is something you will have to do yourself. The exception: if everything in your app happens within a UINavigationController, you can always get the current view controller with this.
[navigationController topViewController];
If all you need to do is present an overlay, however, you can just add that view to the root view controller's view; all child view controllers are just presented as subviews anyway.
UIActivityIndicatorView *activityIndicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
[self.window.rootViewController.view addSubview:activityIndicator];
[activityIndicator startAnimating];
Manually throwing views into the mix like this is not very elegant, though. I would consider posting notifications when various network events occur, and letting each view controller update itself appropriately.
Related
I have a problem on how to properly do a certain kind of action.
The image below shows a UIViewController, but the second part of the view is a custom UIView (the one with the profile pic, name and Show View button).
The subclassed UIView is allocated using this code:
profileView = [[GPProfileView alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, 70)];
profileView.myTripGradientColor = YES;
[self.view addSubview:profileView];
The problem is of course, that the button on the UIView can't show any view, since it's only the UIViewController that can push another ViewController to the window(correct?).
The UIView is used in several places in the app and needs to be added easily and have the same behavior across the application.
This worked great until I added the button, and I'm starting to think I've made this wrong, and there has to be a better way to do it (maybe change the UIView to something else?).
I was thinking I should be able to call:
self.superview
And then somehow get the ViewController so I can push another ViewController into the view hierarchy, but nope.
Any suggestions and a tips on how to do this correctly?
UPDATE:
I have no idea on how to push another UIViewController from the button.
What should I do in this method when pressing the button in the UIView:
- (void) showViewButtonTouched:(UIButton*)sender {
GPProfileSocialFriendsViewController *friendsSettings = [[GPProfileSocialFriendsViewController alloc] init];
}
How do I push GPProfileSocialFriendsViewController?
Your - (void) showViewButtonTouched:(UIButton*)sender method should be in your controller and would probably be better named - (void) showView:(UIButton*)sender or - (void) showProfile:(UIButton*)sender so it clearly denotes what it does (not how you got there).
It's not the view's responsibility to manage transitions from a state to another. If you move your method to your controller, your problem is no more (you can easily access self.navigationController or push directly if you don't have an navigation controller like this:
[self presentViewController:vcThatNeedsToBePushed animated:YES completion:nil];
I think you can create weak reference in GPProfileView on UIViewController. Like this:
#property (weak, nonatomic) UIViewController *rootController;
when you create GPProfileView, assign rootController-property:
profileView = [[GPProfileView alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, 70)];
profileView.myTripGradientColor = YES;
profileView.rootController = self; // if view created in view controller
[self.view addSubview:profileView];
and in implementation of button selector:
self.rootController push... // or pop
May be this not correct, but you can try
You could let the view controller push the next view controller when the button is pushed. The view controller can add a target/action on the button, so that the action method in the view controller is called on the touch up inside event.
I'm still very new to iOS developing. In fact, if there is a super noob, I would be one :p. Currently I am working on creating an IBAction button that accesses a subview. I have 2 ViewControllers, AddClientVC and NewClientVC, both with .nib files. So basically, inside my AddClientVC I implement an IBAction button with the following code:
- (IBAction)buttonPressed:(id)sender
{
UIView *transparentBG = [[UIView alloc] initWithFrame:CGRectMake(-5, -5, 1500, 2500)];
transparentBG.backgroundColor = [UIColor blackColor];
transparentBG.opaque = NO;
transparentBG.alpha = 0.5;
[self.view addSubview:transparentBG];
transparentBG.center = transparentBG.center;
vc = [[NewClientVC alloc] initWithNibName:#"NewClientVC" bundle:nil];
[self.view addSubview:vc.view];
vc.view.center = self.view.center;
}
As you can see I implemented a UIView as a transparent background. Basically AddClientVC --> Transparent Background --> NewClientVC. Now I have created another IBAction button but this time inside NewClientVC as a function to dismiss the accessed subview which looks like this:
- (IBAction)saveDismiss:(id)sender
{
[self.view removeFromSuperview];
}
The problem I'm having right now is when I click the saveDismiss button it only removes the subview that I called previously on AddClientVC but it didn't remove the transparent background I have created as a UIView. So the problem is how do I implement an action which simultaneously removes my subview and the UIView transparent background I created.
I need all the help I can get :)
I'm not too sure I fully understand what you want to happen, but maybe you could try something like this?
- (IBAction)saveDismiss:(id)sender
{
[vc removeFromSuperView];
[self.view removeFromSuperview];
}
I recommend not to manage your screens by adding subviews manually but instead use
- (void)presentModalViewController: (UIViewController *)modalViewController
animated: (BOOL)animated
method on your root viewController.
Or better instantiate a UINavigationController and use push and pop methods to drill down/up your views.
See apple reference here
Do not worry about code execution speed and stay confident in apple's SDK. UIKit is optimized for best user experience. Trying to boost your code by doing inappropriate SDK use is, in my opinion, a risky strategy. ;) – Vincent Zgueb
Sorry Vincent but I don't agree with you. I reached here because I want to implement an gesture that adds a sub-view for my view, which will be the navigation of my app.
[self.view addSubview:ctrl.view];
is faster presenting the view than
[self.navigationController presentModalViewController:ctrl animated:NO]
and by the way, the solution to the topic in my case was:
[self.view sendSubviewToBack:ctrl.view];
I have a UIViewController subclass that contains an instance of UIImagePickerController. Let's call this controller CameraController. Among other things, the CameraController manages the UIImagePickerController instance's overlayView, and other views, buttons, labels etc. that are displayed when the UIImagePickerController, let's call this instance photoPicker, is displayed as the modal controller.
The photoPicker's camera overlay and the elemets that are part of the CameraController view hierarchy display and function as expected. The problem I'm having is that I cannot use UIViewController's default initializer to create the CameraController's view heirarchy.
I am initializing CameraController from within another UIViewController. Let's call this controller the WebViewController. When the user clicks on a button in a view managed by WebViewController, the launchCamera method is called. It currently looks like this:
- (void) launchCamera{
if (!cameraController) {
cameraController = [[CameraController alloc] init];
// cameraController = [[CameraController alloc] initWithNibName:#"CameraController"
// bundle:[NSBundle mainBundle]];
cameraController.delegate = self;
}
[self presentModalViewController:cameraController.photoPicker animated:NO];
}
I want to be able to create CameraController by calling initWithNibName:bundle: but it's not working
as I'll explain.
CameraController's init method looks like this:
- (id) init {
if (self == [super init]) {
// Create and configure the image picker here...
// Load the UI elements for the camera overlay.
nibContents = [[NSBundle mainBundle] loadNibNamed:#"CameraController" owner:self options:nil];
[nibContents retain];
photoPicker.cameraOverlayView = overlay;
// More initialization code here...
}
return self;
}
The only way I can get the elements to load from the CameraController.xib file is to call loadNibNamed:owner:options:. Otherwise the camera takes over but no overlay nor other view components are displayed. It appears that a side-effect of this problem is that none of the view management methods on CameraController are ever called, like viewDidLoad, viewDidAppear etc.
However, all outlets defined in the nib seem to be working. For example, when the camera loads a view is displayed with some instructions for the user. On this view is a button to dismiss it. The button is declared in CameraController along with the method that is called that dismisses this instructions view. It is all wired together through the nib and works great. Furthermore, the button to take a picture is on the view that servers as photoPicker's overlay. This button and the method that is called when it's pressed is managed by CameraController and all wired up in the nib. It works fine too.
So what am I missing? Why can't I use UIViewController's default initializer to create the CameraController instance. And, why are none of CameraController's view mangement methods ever called.
Thanks.
Your problem is easy but need some steps.
Well... First, if overlay is an IBOutlet, it can not be loaded at init time. So move picker and co in viewDidLoad. Place also here all other items that your say that they are not loaded. They should be loaded there (viewDIDLoad). Check that outlets are connected.
Second, call
cameraController = [[CameraController alloc] initWithNibName:#"CameraController"
bundle:nil];
and ensure that CameraController contains (just) a view, and CameraController inherits UIViewController. Check also file's owner.
And at some time, you may consider that calling :
[self presentModalViewController:cameraController.photoPicker animated:NO];
does not make the CameraController control your picker. Does that make sense to you ?
What does that do regarding your problem ?
It seems you are confusing some things. I try to explain in another way :
The one that controls the picker is the one that is its delegate. Your may consider creating in a MAIN view.
The controller of the overlay (added as subview) is the one that own its view in File's Owner. That may be created from the MAIN view, adding its view as subview of the controller. Basically, it is loaded just to get the overlay, but viewDidLoad, ... won't be called.
That's all and I belive those steps are not ok in your code.
That should give something like :
MainController
Loadcamera {
self.picker = [UIImagePicker alloc] init.....];
self.picker.delegate = self;
SecondController* scnd = [[SecondController alloc] initWithNibName:#"SecondController" bundle:nil];
[self.picker addOverlay:scnd.view];
[self presentModalViewController:self.picker animated:NO];
}
/// And here manage your picker delegate methods
SecondController
// Here manage your IBActions and whatever you want for the overlay
I have an app that's pretty much a large presentation of a companies product.
I have some additional functionality which I need to be accessible throughout my app.
The intended functionality for this toolbar is that it'll sit as a small, subtle tab along the bottom of the screen. When you tap the tab, the menu will expand upward (i.e. animate it's frame.y property), allowing you to tap any of the buttons contained within the menu.
The difficulty I'm having is that the app currently spans over several view controllers, and as I need this accessible throughout, in the interest of not duplicating code it would seem appropriate to make this ViewController also, that I would just load into my other view controllers, but this, by all accounts isn't recommended by Apple.
How can I build this menu functionality without duplicating code? I've tried a few things but cannot get the menu to display on my view.
Below, I'll show what I have at the moment.
Code that will sit on any view controller:
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
ToolboxMenu *toolboxMenu = [[ToolboxMenu alloc] init];
[self.view addSubview:toolboxMenu.view];
}
Code that builds the toolbar:
- (void)viewDidLoad
{
[super viewDidLoad];
NSLog(#"Creating View");
self.view = [[UIView alloc] initWithFrame:CGRectMake(0,0,88,209)];
self.view.backgroundColor = [UIColor clearColor];
UIImageView *toolboxImage = [[UIImageView alloc] initWithImage:[[UIImage alloc] initWithContentsOfFile:[[NSBundle mainBundle] pathForResource:#"popup_toolbox" ofType:#"jpg"]]];
toolboxImage.frame = self.view.frame;
[self.view addSubview:toolboxImage];
}
In the above code, the NSLog fires when the menu is initialised, but I see no menu.
Rather than try to inject this into every view, I would recommend creating a separate UIWindow and float it over the main UIWindow. This is how the keyboard is implemented. Doing it that way will avoid any changes to any of the existing views. You will need to handle device rotation by hand for it, but that shouldn't be too difficult.
IIRC Apple's TabViewController was designed differently in that it's backwards to how you describe above. A TabViewController is the main or master ViewController with siblings being the display ViewControlers. Basically you have one TabViewController that will tab between views.
I would recommend you either redesign your view hierarchy OR extend UIViewController with a class that manages and displays the lower tab menu. Then you can easily init a single class that handles that in each of your views.
I am trying to work my way through basic iPhone programming and I have a good basic understanding of how Interface Builder works, so I decided to try my hand at doing the views programmatically. I have gone through the ViewController Apple guide and searched everywhere and I cannot seem to find a solution to my problem. This leads me to believe it is a very simple solution, but I am just really banging my head against the wall. Basically all I am trying to do is create a view that gets main window as a subview. I know that if self.view is not defined then the loadView method is supposed to be called, and everything is supposed to be set up there. Here is the current state of my code:
The delegate:
- (void)applicationDidFinishLaunching:(UIApplication *)application {
StartMenuViewController *aViewController = [[StartMenuViewController alloc] init];
self.myViewController = aViewController;
[aViewController release];
UIView *controllersView = [myViewController view];
window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
[window setBackgroundColor:[UIColor redColor]];
[window addSubview:controllersView];
[window makeKeyAndVisible];
}
The view controller:
- (id)init {
if (self = [super init]) {
self.title = #"Start Menu";
}
return self;
}
// Implement loadView to create a view hierarchy programmatically, without using a nib.
- (void)loadView {
UIView *startView = [[UIView alloc] initWithFrame:[UIScreen mainScreen].applicationFrame];
[startView setAutoresizingMask:UIViewAutoresizingFlexibleHeight|UIViewAutoresizingFlexibleWidth];
[startView setBackgroundColor:[UIColor greenColor]];
self.view = startView;
[startView release];
}
Thanks for the help in advance!
Are you sure that you're inheriting from UIViewController and not overriding the implementation of - (UIView*)view?
EDIT: More info:
UIViewController has a special implementation of the "-(UIView*) view" message so that when it's called, the loadView method is called if the view member variable is not set. So, if you provide an implementation of "- (id)view" in your subclass, (or a property named view) it will break the auto-calling of "- loadView".
Just to document a "loadView is not called" case:
I wrote a 2 UITableViewController(s) to handle detail data for a master ViewController. Since the devil was in #2, I made a simple UITableViewController for #1, and referenced it in the XIB for the "master" ViewController.
When I was done with #2, I could simply copy the code to #1, remove the complicated code, and go on with life.
But to my dismay and several days work, no matter what I did, viewLoad was not being called for my simple #1 UITableViewController.
Today I finally realised that I was referencing the UITableViewController in the XIB to the master ViewController program. - and of course, loadView was never being called.
Just to help some other dork that makes the same mistake....
Best Regards,
Charles
viewDidLoad only if the view is unarchived from a nib, method is invoked after view is set.
loadView only invoked when the view proberty is nil. use when creating views programmatically. default: create a UIView object with no subviews.
(void)loadView {
UIView *view = [[UIView alloc] initWithFrame:[UIScreen
mainScreen].applicationFrame];
[view setBackgroundColor:_color];
self.view = view;
[view release];
}
By implementing the loadView method, you hook into the default memory management behavior. If memory is low, a view controller may receive the didReceiveMemoryWarning message. The default implementation checks to see if the view is in use. If its view is not in the view hierarchy and the view controller implements the loadView method, its view is released. Later when the view is needed, the loadView method is invoked
again to create the view.
I would strongly recommend you use interface builder for at least your initial Window/View.
If you create a new project in XCode you should be able to select from one of many pre-defined iPhone templates that come with everything setup.
Unless I am reading this wrong, you did not associate any view with the the controller's view property like this
myViewController.view = controllersView;
So as far as Cocoa is concerned the view you are setting in the window has no controller to call loadView on. loadView is a View controller, not view, method. The view you assign to the window is not associated with any view controller. So your view controller loadView method is never called. Get it? The view you are trying to display, has no view controller associated with it.
When you use interface builder to create views you can link the UIView object you created in IB to the view property in the controller in IB which the framework automatically
But if not done in IB you have to set it