To let you know from the beginning, I am a newbie at iPhone development, and I have taken an a monstrous task.
First of all, I am writing an application that allows to you to online shop. We have an affiliate account with a known online shopping website, are trying to tie our app into searching that site, and putting the results into a table, with hyperlinks to the site, etc.
But first problems first, one thing at a time:
In Interface Builder, I have a Search Bar, and an outlet connected to the search bar. I also have an IBAction made just to take the text that is entered into the search bar, storing it into a variable, and then searching this website (yes, that's a lot of stuff for an action).
Because I am so new at this process with IB, how do I connect the Search Bar with the IBAction? I know, stupid question.
Assuming you don't have a specific SEARCH button, set your View Controller as the delegate for UITextField and implement your action on
- (BOOL)textFieldShouldReturn:(UITextField *)textField
{
// Code here...
return YES;
}
Don't forget to declare the protocol in your interface file too
#interface ... : ... <UITextFieldDelegate>
Once that's done, everytime the GO/SEARCH key is pressed on the keyboard, it will call the method above.
[EDIT]
Here's the apple Doc for your reference http://developer.apple.com/library/ios/#documentation/UIKit/Reference/UITextFieldDelegate_Protocol/UITextFieldDelegate/UITextFieldDelegate.html
You can set your view controller as the search bar's delegate in IB (or programmatically), and implement the UISearchBarDelegate protocol to define actions for your search bar.
As a beginner, you should familiarize yourself with the delegate pattern, since a lot of the iOS SDK relies on it (the iOS Application Programming Guide is a good place to start).
Update
You need to implement the UISearchBarDelegate methods in your search bar's delegate. For example, if your search bar is a property of MyViewController, you probably want to have this line in MyViewController's implementation:
[self.searchBar setDelegate:self];
It's as simple as that; now, as long as you have those methods implemented in MyViewController, they will automatically get called when the related action occurs.
Related
What needs to be hooked up for an NSDocument subclass to call its print methods when File->Print... is chosen?
How does the File->Print menu get hooked up? (Right now the selector/action is hooked up to first responder's print method. That's in a storyboard, while my NSDocument subclass has its own xib.)
I've tried implementing all of:
-(void)print:(id)sender;
-(void)printDocument:(id)sender;
-(void)printDocumentWithSettings:(NSDictionary *)printSettings showPrintPanel:(BOOL)showPrintPanel delegate:(id)delegate didPrintSelector:(SEL)didPrintSelector contextInfo:(void *)contextInfo;
-(NSPrintOperation*)printOperationWithSettings:(NSDictionary *)printSettings error:(NSError *__autoreleasing *)outError;
But none of them are ever called when I choose Print. Where are these methods supposed to go/who calls them? (I also tried a basic app with a custom view and didn't have luck there either.)
Okay. Looks like the problem is due to a bug in Xcode: When creating a Document based app using storyboards the file menu is by default hooked to print: and printDocument: is not available.
The strange part is that my print: call is getting hijacked somewhere along the line but I can't figure out where (at the application level, not the document, because the print dialog is a window not a sheet). printDocument: works as expected, but must be defined manually in order to hook it up.
This is for a document-based app, targeting 10.10, and using storyboards.
In the storyboard with Main Menu, add a User Defined Action for printDocument: (This is where storyboard based differs, and I feel is a bug. Xib based do not require this User Defined Action.)
Hook up the selector for File -> Print to First Responder and choose printDocument: instead of print:
Don't define printDocument: in your NSDocument subclass. If you want to, then be sure to call super or perhaps one of the methods below.
From NSDocument.h
/* The action of the File menu's Print... item in a document-based application.
The default implementation of this method merely invokes
[self printDocumentWithSettings:[NSDictionary dictionary]
showPrintPanel:YES
delegate:nil
didPrintSelector:NULL
contextInfo:NULL].
*/
- (IBAction)printDocument:(id)sender;
The default implementation of printDocumentWithSettings in turn calls printOperationWithSettings, so you can use either of those methods to draw custom information prior to the print sheet appearing.
The accepted solution of setting the menu item to -printDocument: is correct, but not (technically) because of an Xcode bug. (It is very a poor default setting, though.)
The menu item is calling the -print: of the whatever is the first-responder. NSView implements -print:, so if anything has been set as first-responder you will print with NSView's -print:, not your document's -print:. If editing your document requires text editing, the control you are using to implement editing will be set to first-responder, and that control will get the -print:.
Take a look at the TextEdit sample code from Apple (https://developer.apple.com/library/mac/samplecode/TextEdit/Introduction/Intro.html)
In my non-document based app I have set a custom action for the print menu item. In that method I notified my controller about the print operation via NSNotificationCenter. Maybe that works for you too :)
OK, here is my situation and I'm really not sure on which design approach to use. So, I'd be glad to read some input on my particular case...
The scenario :
I've got a tab-based application
Initially we create an instance of NSWindowController (e.g. MyDocumentManager) which takes care of the tab creation/manipulation
Each tab contains (= is attached to) an instance of MyDocument
Now, I'm about to implement the menu actions.
For each menu there is a separate Menu Controller (actually a subclass of NSObject grouping all relevant functions), e.g. MyFileMenuController
File Menu's actions are linked to actions in a MyFileMenuController object, via Interface Builder
The question :
How is it possible that MyFileMenuController "knows" about MyDocumentManager (created in my AppDelegate.m), so that we can access current document details and perform all relevant actions? Any ideas? Which approach is preferable?
My ideas :
Passing object from class to class (not sounding that great)
Singletons (although I've honestly never used them, and do not know whether/how it could be my particular case)
Notifications & Notification Listeners
(Looking at it from the opposite side, though not sure) Delegate methods
OK (not sure if that's the best way to do it), but this is what I decided to do :
[[[NSApplication sharedApplication] delegate] MyDocumentManager]
So, as long as an object is part of my AppDelegate, this way I can access it from anywhere.
I would make an initial UIViewController linked to appDelegate.rootViewController.
In this new view controller (just call it "mainViewController") I would put my tabBar and the menuController.
I understand your interface is similar to facebook with a leftBarbutton which makes horizontal scroll and discover the menu. So in the selector for this leftBarButton I would call a method like:
- (void)discoverMenuForDocument:(MyDocument*)document {
// Set menu configuration for specific document
// Make animation to discover menu
}
Where document could be something like:
self.selectedViewController (<-- You cand make this in several ways depending on your code...)
Realize that (MyDocument*) is not an object but just a reference, so in my opinion there isn't any problem doing this.
Good luck!
i have been working on moving one of my apps away from the "shared appdelegate" process which seems to be frowned up, despite its over whelming use. i have been attempting to setup protocol methods for what i want to do but am having zero luck. my question is, can you even have lets say a single viewcontroller send delegate requests to multiple classes? from what im finding out it doesn't seem like you can. which doesn't make sense because i thought that was the whole point of delegates and protocols with mvc. now just to clarify, i know you can have a single viewcontroller act as the delegate for multiple other viewcontrollers. but that's not what i am asking. for a simple example, lets say you have apples flip-utility template. the "done" button just calls a delegate method to the mainvc to dismiss it. now lets say we added a new class called...
#interface NewClass : NSObject <TheOtherDelegate>
and it had a delegate method...
- (void)doSomething
{
NSLog(#"The Delegate did something...");
}
can we have a button on the flipsideviewcontroller, that we wanted to call that delegate method, but still keep the "done" button call to the delegate method on the mainviewcontroller that dismisses it?
that being said, i put together a quicky project just to see if it would work and it doesn't. i came across an "answer" that says you have to instantiate the class first you want to be the delegate...
NewClass *myDelegate = [NewClass alloc] init]
[fillInMethodHere setDelegate:myDelegate];
not sure why it got a correct answer check, because needless to say it doesn't work. is there something i am missing? i scoured ib to see if there is some "delegate" connection somewhere but i couldn't find anything.
on a side note, as i was working in my working project, i read a suggestion about removing the #import and adding #class. again, that broke all kinds of things. the strange thing is before doing that, what i had so far was working and building fine. when i removed the new #class and un-commented the #import. xcode all of a sudden gave me an error "cannot find protocol deceleration for..." but yet, it worked seconds earlier. i would up having to remove the protocol code and re-add it for it to work again. very starge.
any help would be appreciated. everything iv read in docs, google, stack, etc that say something should work, don't in an actual project.
A "delegate" isn't some fancy object. It's simply a synthesized property of type id called delegate. If you wanted to, you could have an arbitrary number of properties that all conformed to the same protocol. Then when you wanted to issue a callback, you would just address all of them:
[self.mydelegateA doSomething];
[self.mydelegateB doSomething];
etc.
You could also have an NSMutableArray property that you could add objects to, and then use [self.myMutableArrayOfDelegates makeObjectsPerformSelector:#selector(doSomething)].
Finally, there's always the route of NSNotificationCenter (not to be confused with push notifications) is a class that provides an inter-object messaging system. Many objects can register for a message that any other object can send.
Please see the Apple's documentation for more information. Click Here.
Regardless of the fact that this is OS X documentation, it's still quite good at explaining things visually: click here.
Here's an example of simply changing the name of the delegate property: click here
And here's an example of adding another protocol and a second delegate: click here
Finally, here's an example that builds on the previous two and has a third delegate that also conforms to the same protocol: click here
I have created a fairly simple screensaver that runs on Mac OS 10.6.5 without issue.
The configuration screen has accumulated quite a few different options and I'm trying to implement my own preview on the configureSheet window so the user (just me, currently) can immediately see the effect of a change without having to OK and Test each change.
I've added an NSView to the configureSheet and set the custom class in Interface Builder to my ScreenSaverView subclass. I know that drawRect: is firing, because I can remove the condition for clearing the view to black, and my custom preview no longer appears with the black background.
Here is that function (based on several fine tutorials on the Internet):
- (void)drawRect:(NSRect)rect
{
if ( shouldDrawBackground )
{
[super drawRect:rect];
shouldDrawBackground = NO;
}
if (pausing == NO)
[spiroForm drawForm];
}
The spiroForm class simply draws itself into the ScreenSaverView frame using NSBezierPath and, as mentioned, is not problematical for the actual screensaver or the built-in System Preferences preview. The custom preview (configureView) frame is passed into the init method for, um, itself (since its custom class is my ScreenSaverView subclass.) The -initWithFrame method is called in configureSheet before returning the configureSheet object to the OS:
[configureView initWithFrame:[configureView bounds] isPreview:YES];
Maybe I don't have to do that? It was just something I tried to see if it was required for drawing.
I eventually added a delegate to the configureSheet to try triggering the startAnimation and stopAnimation functions of my preview via windowWillBeginSheet and windowWillEndSheet notifications, but those don't appear to be getting called for some reason. The delegate is declared as NSObject <NSWindowDelegate> and I set the delegate in the configureSheet method before returning the configureSheet object.
I've been working on this for days, but haven't been able to find anything about how the OS manages the ScreenSaverView objects (which I think is what I'm trying to emulate by running my own copy.)
Does anybody have any suggestions on how to manage this or if Apple documents it somewhere that I haven't found? This isn't really required for the screensaver to work, I just think it would be fun (I also looked for a way to use the OS preview, but it's blocked while the configureSheet is activated.)
OK, there are a couple of 'duh' moments involved with the solution:
First of all, I was setting the delegate for the sheet notifications to the sheet itself. The window that the sheet belongs to gets the notifications.
Secondly, that very window that the sheet belongs to is owned by System Preferences, I don't see any way to set my delegate class as a delegate to that window, so the whole delegate thing doesn't appear to be a viable solution.
I ended up subclassing NSWindow for the configureSheet so that I could start and stop animation on my preview by over-riding the makeKeyWindow and close methods.
- (void) makeKeyWindow
{
if (myPreview != nil)
if ( ! [myPreview isAnimating])
{
[myPreview startAnimation];
}
[super makeKeyWindow];
}
I also had to add an IBOutlet for my preview object itself and connect it in Interface Builder.
Still working out a couple of issues, but now when I click on my screensaver Options button, my configureSheet drops down and displays its own preview while you set options. Sheesh. The hoops I jump through for these little niceties. Anyway, I like it. Onward and upward.
I feel i am totally out of my depth here, im very new to objective c but have been asked to design an iphone app as part of my uni course. I designed a sinple quiz before, but I was hoping to design a more advanced quiz game with 3 levels (each level will have a different quiz).
I dont know how to use the UIViews and I have tried a tutorial online to help me code a navigation controller. It allows gives me 3 options to go into subview 1, 2 or 3. All the subviews have the same screen though, with one label and a button.
I have 3 classes so far, RootViewController, BasicNavigationAppDelegate and SubViewOneController.
I really dont understand the code at all, im familiar with Java but this objective c is nothing like it. Could someone maybe take a minute to help out a person in distress and explain if i am doing this right by using the navigation controller to display my levels? When i check the xib interface files i dont see the button or label, or dont know where to add the quiz interface objects!! I really am confused by all this. Could anyone help?
You should search google for sample source code, and see how some of the views can be handled. There are many ways you can handle a view, whether its by a UINavigationController, UITabBarController, etc. If you are new to Objective-C, then your not really going to get an answer to this question that will instruct you on what exactly to do.
Interface Builder + View Controllers
Here's a good one for you: View Controllers Programming Guide
(Apple's) View Controller Reference Guide
Some Code Samples
Getting Started Sample Code
I recommend Head First iPhone Development: A Learner's Guide to Creating Objective-C Applications for the iPhone. Within a few chapters you'll know everything you need to build this app and you'll actually understand what you're doing.
(I don't know the authors or the publisher, I just think it's a great book for quickly getting up to speed.)
for a 3 level quiz, UINavigationController is definitely an option.
if you need to find out how to use a class, in xcode, type its name, then press -alt- and double click the class name, this will bring up a short description, with two icons, one will take you to the header file, and the other to the documentation.
to add elements to the nib/xib files, you will need to open the library window, where you will find labels, buttons etc. to use a button, you will need to define an action in your header file, and hook it up in IB, to be able to interact with UIElements in your code, you want to set up outlets in the header file, and hook them up in IB.
something you need to decide on, is how you are going to present the questions, and will also depend if the answer will be true/false, multiple choice, or text entry.
if you arent familiar with obj-c and xcode, it is probably worth picking up an ebook from someone like http://www.pragprog.com. they have an iPhone one up there by Bill Dudney which is quite good(i believe he now works for apple.)
for the standard slide out transition you could use this.
//you would probably want to call this something like level1NavBarItemWasPushed: instead
- (IBAction)lvl1pushNavBarItem:(id)sender {
//create instance of AnswersViewController class.
AnswersViewController *level1AnswersVC= [[Level1AnswersViewController alloc] init];
//pass it some kind of identifier so it can tell which quiz/question it is dealing with and pull in the answers, so that you can reuse the view
[level1AnswersVC setAnswersObject:<<insert object dictionary here>>];
//push the view controller onto the navigationController's view stack
[self.navigationController pushViewController:level1AnswersVC animated:TRUE];
//pushing it onto the view stack has given it +1 retain, so we can now release it without worrying about it disappearing prematurely.
[level1AnswersVC release];
}
for the page flip transition you could use this.
- (IBAction)lvl1pushNavBarItem:(id)sender {
//create instance of AnswersViewController class.
AnswersViewController *level1AnswersVC= [[Level1AnswersViewController alloc] init];
//pass it some kind of identifier so it can tell which quiz/question it is dealing with and pull in the answers, so that you can reuse the view
[level1AnswersVC setAnswersObject:<<insert object dictionary here>>];
//set the current viewController as the delegate, so that it can call back to us when its done
level1AnswersVC.delegate = self;
//set the modal transition style
level1AnswersVC.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
//show answers as modal view, which has been setup to use the page flip transition.
[self presentModalViewController:level1AnswersVC animated:YES];
//pushing it onto the view stack has given it +1 retain, so we can now release it without worrying about it disappearing prematurely.
[level1AnswersVC release];
}