Screencast Episode 4 Question posted by James Kerr @ Fri, 21 Nov 2008 23:13:35 -0000

James Kerr — Fri, 21 Nov 2008 23:13:35 -0000

Hi Bill—

Ahh, the lightbulb in my brain comes on! Thanks for the help.

Now I can go back to figuring out how to parse XML. ActionScript has me spoiled, with it’s support for E4X.

Jay

Application Design and Development Process... posted by Felipe Laso @ Fri, 21 Nov 2008 21:22:03 -0000

Felipe Laso — Fri, 21 Nov 2008 21:22:03 -0000

Thanks chris!

That never really crossed my mind :) and it’s actually a very handy way to “navigate” through your app before starting the coding process.

The back side is also great for notes and writing down stuff I need on each view controller!

Thanks a lot :D

Application Design and Development Process... posted by Chris Adamson @ Fri, 21 Nov 2008 21:10:40 -0000

Chris Adamson — Fri, 21 Nov 2008 21:10:40 -0000

I like to sketch ideas on index cards, since they’re about the size of the iPhone screen. Then, for navigation GUIs, I put the cards in a stack to understand how they’ll navigate, and for a tab navigation, I’ll create a card for the tabs and turn it sideways.

The key is that for each card you create (except the sideways “tabs” card, if any), you’re going to be writing a new view controller to manage that view. So you can look at the card and the widgets on it and figure out what to put in your view controller header file:

any buttons will need IBActions that they call
any text components, image views, web views, or other widgets that you’ll want to inspect or modify from code will need to be declared as IBOutlets
some widgets may need both outlets and actions, like a segmented control that you want to check the current selection of, and handle the Value Changed event

It’s nothing more than paper prototyping at 3-by-5 inches, but better to clarify your ideas early, rather than getting lost in Xcode.

Application Design and Development Process... posted by Felipe Laso @ Fri, 21 Nov 2008 20:57:53 -0000

Felipe Laso — Fri, 21 Nov 2008 20:57:53 -0000

Hi.

I finally decided to begin the development of my first to-be-distributed app. I just don’t really know where to begin.

I was hoping that some of the developers in the community gave me some of their workflows. Some people begin by writing ideas on a piece of paper, a feature list, etc. Then move on to the interface design, class design, etc.

I’m really lost since it’s going to be my first ‘real’ project, and I know that sitting down and writing code is the worst way to go.

Any suggestions, links or comments are welcome :)
Thanks!

Touch Detection in UIImageView posted by Ashish Sehra @ Fri, 21 Nov 2008 18:53:44 -0000

Ashish Sehra — Fri, 21 Nov 2008 18:53:44 -0000

Hi Bill,

Thanks for the advice.. Will do that right away.

Screencast Episode 4 Question posted by Bill Dudney @ Fri, 21 Nov 2008 18:30:21 -0000

Bill Dudney — Fri, 21 Nov 2008 18:30:21 -0000

Hi Jay,

Good question, the data dictionary contains the mutable arrays. Even though we type the array as NSArray in the ingredients controller since NSMutableArray is a subclass there is no change in the real underlying object, its the same object that lives in the dictionary.

To prove this to yourself set a breakpoint in the removeIngredient: method and look at the address of the array (in gdb use $p (id)[data objectForKey:recipeName]). and compare that to the ingredients array, they share the same address. Its identically the same object, the same patch of memory.

Hope this helps!

Screencast Episode 4 Question posted by James Kerr @ Fri, 21 Nov 2008 17:27:03 -0000

James Kerr — Fri, 21 Nov 2008 17:27:03 -0000

Hi Bill,

Wouldn’t the ingredients array need to be replaced in order for it’s count to decrease, as it is not mutable? It seems like the removeIngredient: method deletes a string value from the NSMutableArray within the “data” dictionary, which is a separate object from the ingredients NSArray of the IngredientsController.

Please excuse my noobiness… I am primarily a Flash developer, and Obj-C is a bit of a change from ActionScript3 (understatement =) ).

Jay

Touch Detection in UIImageView posted by Bill Dudney @ Fri, 21 Nov 2008 17:06:05 -0000

Bill Dudney — Fri, 21 Nov 2008 17:06:05 -0000

Hi Ashish,

Glad it works for you now!

One thing though, you need to put that code into both initWithFrame: and initWithCode: because of the way that IB deserialzes your objects there are times when either could be called.

Better yet set the property in IB then you won’t have to worry about it.

Touch Detection in UIImageView posted by Ashish Sehra @ Fri, 21 Nov 2008 16:34:50 -0000

Ashish Sehra — Fri, 21 Nov 2008 16:34:50 -0000

Hi Bill,

I have set the property in the initWithFrame method for the UIImageView subclass. And now it works properly. I am getting the logs on the console.

Thanks a lot for help..

Touch Detection in UIImageView posted by Bill Dudney @ Fri, 21 Nov 2008 16:00:41 -0000

Bill Dudney — Fri, 21 Nov 2008 16:00:41 -0000

Hi Ashish,

Make sure that you have the view enabled. UIView has a property ‘userInteractionEnabled’ that turn of and on the view listening to events. If that is set to NO (which I think is the default for UIImageView) then you won’t get any events. You can change it in IB or set the property in your initWithCoder: method.

Good luck!

Touch Detection in UIImageView posted by Ashish Sehra @ Fri, 21 Nov 2008 13:53:57 -0000

Ashish Sehra — Fri, 21 Nov 2008 13:53:57 -0000

Hi,
I am working on an application that requires touch detection on an image. So I made a class that inherits from UIImageView and added an object of that class as an instance variable in a view controller sub-class. I am trying out touch based application.. so just to try it out i added touchesBegan method in the uiimageView subclass. in that method i added a nslog string for debugging. In the UIViewController subclass i had added an image to the instance variable of uiImageView subclass.. so i expected the image in the view control to detect touches.. But when i ran the application and tapped on the image the touches began method was never invoked. Can anyone tell me whether i m proceeding in the right direction or do i need to do this in a different manner.

I added nothing in the UIImageView subclass:


#import <UIKit/UIKit.h>

@interface ZoomableImage : UIImageView {

}

@end

Touches Began method in the uiimageview subclass(named, ZoomableImage):


#import "ZoomableImage.h" 

@implementation ZoomableImage

- (id)initWithFrame:(CGRect)frame {
    if (self = [super initWithFrame:frame]) {
        // Initialization code
    }
    return self;
}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    NSLog(@"-- I AM TOUCHED --");
}

- (void)drawRect:(CGRect)rect {
    // Drawing code
}

- (void)dealloc {
    [super dealloc];
}

@end

Screencast Episode 4 Question posted by Bill Dudney @ Fri, 21 Nov 2008 11:51:27 -0000

Bill Dudney — Fri, 21 Nov 2008 11:51:27 -0000

Hi James,

The ingredients array is not copied, its the same object as the one held onto by the app delegate.

Hope this helps, if it does not please let me know.

Questions after chapter 2 posted by Matthias Lübken @ Fri, 21 Nov 2008 09:25:37 -0000

Matthias Lübken — Fri, 21 Nov 2008 09:25:37 -0000

Hi
so I’ve completed chapter 2 successfully. Now I have tons of questions in my head which I try to figure out before moving to the next chapter.

@Bill: I just wanted to let you know these questions. Maybe it gives your some ideas how to structure the chapter.

- How is a header file arranged? What is in the enclosing {-parenthesis? What after?

- What are directives? What does the @class directive do? – What does the @synthesize directive do?

- How does protocols work in general in Objective-C? How do the work with Interface Builder? Why can I connect them without declaring anything else?

- Why does the instance variable field has to be an property?

- How do the implementation of the UITextFieldDelegateMethods work?

- How does import work? At the end of this example StarterViewController.m imports both StarterViewController.h and EditorViewController.h . How do I know that StarterViewController.m is the implementation of StarterViewController.h ? Just a naming convention?

- What does the second Controller do in StarterViewController.xib? Just to connect to the editorViewController in StarterViewController.h? Could I implement it differently? When and what kind of classes do I need in my nib?

Screencast Episode 4 Question posted by James Kerr @ Fri, 21 Nov 2008 01:07:23 -0000

James Kerr — Fri, 21 Nov 2008 01:07:23 -0000

I’m not understanding how the count of ingredients is being decremented after an ingredient is deleted from the tableView.

The ingredients property is initially set from the AppDelegate when the user clicks on a Recipe cell by passing in an NSArray of ingredients from the data dictionary. Deleting an Ingredient updates the data dict for the appropriate Recipe key via the AppDelegates removeIngredient: forRecipe method, but I don’t see how the NSArray referenced by the ingredients property of the IngredientsViewController is updated. I can see the count of the ingredients array being decremented immediately after the data dictionary is updated, but don’t get how that event effects the ingredients array.

using NSURLRequest to retrieve RESTful data posted by Chris Adamson @ Thu, 20 Nov 2008 22:52:33 -0000

Chris Adamson — Thu, 20 Nov 2008 22:52:33 -0000

Actually, this is a teachable moment: in IB, the text components all default to spell checking, and this (and other automatic changes) are not necessarily helpful for fields that take atypical content, like URL fields. So check such fields with the inspector. Also, there’s a URL keyboard you might find helpful, as it eliminates characters that can’t be in URLs.

IPhone SDK Chapter 2 - Setting the textbox value posted by Adrian Collins @ Thu, 20 Nov 2008 21:46:39 -0000

Adrian Collins — Thu, 20 Nov 2008 21:46:39 -0000

Thanks Bill

I originally had the field set beneath the view load. It was the property in IB that caused the problem. Live & Learn :)

IPhone SDK Chapter 2 - Setting the textbox value posted by Bill Dudney @ Thu, 20 Nov 2008 21:45:52 -0000

Bill Dudney — Thu, 20 Nov 2008 21:45:52 -0000

Hi Adrian,

There are 2 parts to why what you are doing won’t work.

1) When the edit method is invoked the first time by the button editorViewController has no view and its nib file has not been loaded. (its loaded by a call to view during the process of presenting it)

2) field is set (in interface builder attributes inspector for the field) to clear its contents when editing begins, so when the editor’s view does appear the field becomes first responder, editing begins and the content is cleared out

you can flip the switch in IB to get the functionality on the 2nd try, to get it to work on the first try you will have to move the setting of the field’s text to below the present modal view call.

good luck!

IPhone SDK Chapter 2 - Setting the textbox value posted by Bill Dudney @ Thu, 20 Nov 2008 21:42:47 -0000

Bill Dudney — Thu, 20 Nov 2008 21:42:47 -0000

Hi Adrian,

There are 2 parts to why what you are doing won’t work.

you can flip the switch in IB to get the functionality on the 2nd try, to get it to work on the first try you will have to move the setting of the field’s text to below the present modal view call.

good luck!

IPhone SDK Chapter 2 - Setting the textbox value posted by Adrian Collins @ Thu, 20 Nov 2008 21:42:41 -0000

Adrian Collins — Thu, 20 Nov 2008 21:42:41 -0000

I have zipped up my project here

http://www.score-pro.co.uk/iphonesdk/

Many Thanks

Chapter 3.13 posted by Adrian Collins @ Thu, 20 Nov 2008 21:34:03 -0000

Adrian Collins — Thu, 20 Nov 2008 21:34:03 -0000

Not sure if this is an error or just something wrong with my code but in the method addButtonWasPressed, the line…

[addTeamViewController release];

...causes my app to crash after adding a team. If I comment that line out everything seems to work OK!

IPhone SDK Chapter 2 - Setting the textbox value posted by Iván Rancaño García @ Thu, 20 Nov 2008 20:17:21 -0000

Iván Rancaño García — Thu, 20 Nov 2008 20:17:21 -0000

Is simply i have a view with two buttons one of them text is “hello” and the other “bye”.

I want to open a new view with a textfield with the order presentModalViewController.

When you push the hello button, the textfield must have “hello” on it, and when you push “bye” it should have “bye”.

Thank you in advance.

IPhone SDK Chapter 2 - Setting the textbox value posted by Felipe Laso @ Thu, 20 Nov 2008 20:09:34 -0000

Felipe Laso — Thu, 20 Nov 2008 20:09:34 -0000

Could you please upload your app to some place where I can download it and test it on my computer?

I don’t really know what the problem is, although if it compiles without warnings or errors its probably something in your interface that is not connected, or a runtime error.

Post a link of your project here so I can get it and figure out what’s going on from here :)

Bye

Saving the state of a UITabBar and saving data to a .plist file! posted by Felipe Laso @ Thu, 20 Nov 2008 20:06:55 -0000

Felipe Laso — Thu, 20 Nov 2008 20:06:55 -0000

Nope.

I just made another project in Xcode with more than 4 views. I get the “More” button which in turn allows me to edit the tat bar items.

Even though I changed the order of the tab bar, whenever I quit my application it goes back to the default order.

Thought I would post the results of my test.
:)

IPhone SDK Chapter 2 - Setting the textbox value posted by Iván Rancaño García @ Thu, 20 Nov 2008 19:48:41 -0000

Iván Rancaño García — Thu, 20 Nov 2008 19:48:41 -0000

I am trying to do the same for 5 days, but it didn’t run. Help us, please.

IPhone SDK Chapter 2 - Setting the textbox value posted by Adrian Collins @ Thu, 20 Nov 2008 19:36:33 -0000

Adrian Collins — Thu, 20 Nov 2008 19:36:33 -0000

Hi, I was really hoping some could help me on this but I guess I didn’t explain it very well and there is a typo with the code, so I’ll give it another go.

It should be very simple really. After following chapter 2 to completion I wanted to be able to send the text back to the textbox so as to have it pre-populated with what the label read. This is kind of reverse to what the example did. This is the code is used


-(IBAction)edit{
    editorViewController.field.text = label.text; //This is what I added!!!!
    [self presentModalViewController:editorViewController animated:YES];
}

When I tap the button i try to set the textbox of the next form with the value of the label. For some reason this doesnt seem to work!

Thanks

Recent Posts in iPhone Development | Pragmatic Forums

Screencast Episode 4 Question posted by James Kerr @ Fri, 21 Nov 2008 23:13:35 -0000

Application Design and Development Process... posted by Felipe Laso @ Fri, 21 Nov 2008 21:22:03 -0000

Application Design and Development Process... posted by Chris Adamson @ Fri, 21 Nov 2008 21:10:40 -0000

Application Design and Development Process... posted by Felipe Laso @ Fri, 21 Nov 2008 20:57:53 -0000

Touch Detection in UIImageView posted by Ashish Sehra @ Fri, 21 Nov 2008 18:53:44 -0000

Screencast Episode 4 Question posted by Bill Dudney @ Fri, 21 Nov 2008 18:30:21 -0000

Screencast Episode 4 Question posted by James Kerr @ Fri, 21 Nov 2008 17:27:03 -0000

Touch Detection in UIImageView posted by Bill Dudney @ Fri, 21 Nov 2008 17:06:05 -0000

Touch Detection in UIImageView posted by Ashish Sehra @ Fri, 21 Nov 2008 16:34:50 -0000

Touch Detection in UIImageView posted by Bill Dudney @ Fri, 21 Nov 2008 16:00:41 -0000

Touch Detection in UIImageView posted by Ashish Sehra @ Fri, 21 Nov 2008 13:53:57 -0000

Screencast Episode 4 Question posted by Bill Dudney @ Fri, 21 Nov 2008 11:51:27 -0000

Questions after chapter 2 posted by Matthias Lübken @ Fri, 21 Nov 2008 09:25:37 -0000

Screencast Episode 4 Question posted by James Kerr @ Fri, 21 Nov 2008 01:07:23 -0000

using NSURLRequest to retrieve RESTful data posted by Chris Adamson @ Thu, 20 Nov 2008 22:52:33 -0000

IPhone SDK Chapter 2 - Setting the textbox value posted by Adrian Collins @ Thu, 20 Nov 2008 21:46:39 -0000

IPhone SDK Chapter 2 - Setting the textbox value posted by Bill Dudney @ Thu, 20 Nov 2008 21:45:52 -0000

IPhone SDK Chapter 2 - Setting the textbox value posted by Bill Dudney @ Thu, 20 Nov 2008 21:42:47 -0000

IPhone SDK Chapter 2 - Setting the textbox value posted by Adrian Collins @ Thu, 20 Nov 2008 21:42:41 -0000

Chapter 3.13 posted by Adrian Collins @ Thu, 20 Nov 2008 21:34:03 -0000

IPhone SDK Chapter 2 - Setting the textbox value posted by Iván Rancaño García @ Thu, 20 Nov 2008 20:17:21 -0000

IPhone SDK Chapter 2 - Setting the textbox value posted by Felipe Laso @ Thu, 20 Nov 2008 20:09:34 -0000

Saving the state of a UITabBar and saving data to a .plist file! posted by Felipe Laso @ Thu, 20 Nov 2008 20:06:55 -0000

IPhone SDK Chapter 2 - Setting the textbox value posted by Iván Rancaño García @ Thu, 20 Nov 2008 19:48:41 -0000

IPhone SDK Chapter 2 - Setting the textbox value posted by Adrian Collins @ Thu, 20 Nov 2008 19:36:33 -0000