Creating a Menu in SpriteKit

July 26, 2014 Leave a comment
SpriteKit Menu by Santiapps.com Marcio Valenzuela

SpriteKit Menu

Cocos2d has a easy to use CCMenu object to which you add CCMenuItems.  In SpriteKit however, you are back to UIKit objects.  This doesn’t not mean its more complicated, its just different :-).  You will need to create a UIControl such as a button or you can use SpriteKit’s SKNode to create the visual object onscreen:

SKLabelNode*  someNode = [SKLabelNode labelNodeWithFontNamed:@"Chalkduster"];
[someNode setText:@"Play Game"];
[someNode setPosition:CGPointMake(CGRectGetMidX(self.frame)+5,CGRectGetMidY(self.frame)-40)];
[self addChild: someNode];

Now you simply connect the object action to some event like so:

for (UITouch *touch in touches) {
CGPoint location = [touch locationInNode:self];

if ([someNode containsPoint:location]) {
SKTransition* present = [SKTransition revealWithDirection:SKTransitionDirectionDown duration:1];
GameScene* gameScene = [[GameScene alloc] initWithSize:CGSizeMake(1024, 768)];
[self.scene.view presentScene: someNode transition:present];

}
}

Voila!  You are DONE!

Swift Tutorial II

June 7, 2014 Leave a comment

Ok so in the first tutorial we covered let, which is the keyword for defining constants.

let thisBeAConstant = 3.141

Now we are going to cover variables, which use the var keyword like so:

var thisVariable = time

Notice 2 things about Swift:

1) We don’t use ; at the end of a line.  That’s just weird :-)

2) We don’t have to specify the type.  The type is inferred by whatever value you pass in, so:

var someString = “this is a string”

var someInteger = 5

So Swift is kinda smart.  Now let’s meet some old friends “Hao jiu bu juan”

ARRAYS

var energies = ["solar""wind""fossil", "this is a mixed array", 39]

var energies:String[] = ["solar""wind""this is a string array"]

And of course we can perform some basic operations such as:

READ

var item1 = energies[0]   // “solar”

INSERT

energies.insert(“hydro”, atIndex: 2)

MODIFY

energies[3] = “geothermal”

APPEND

energies.append(“nuclear”)

or

energies += “nuclear”

COMBINE

energies += ["biomass""hamster"]

COUNT

var lengthofArray = energies.count

LOGIC

var arrayIsEmpty = energies.isEmpty

REMOVE

energies.removeAtIndex(3)
energies.removeLast()
energies.removeAll(keepCapacity: true)
MUTATE
If we used let energies, then our array is immutable, vs if we used var energies which means its mutable.
Easy as pie.
DICTIONARIES

var energies = [

    "Solar""Thermal",
    "Photovoltaic" : "Grid",
    "Nuclear" : "Dangerous"
]
Here our keys are Solar, Photovoltaic & Nuclear.  These keys can be strings or numeric values such as integers.
Once again we can:
READ
let cheapestSolarEnergy = energies["Solar"]
COUNT
var energiesCount = energies.count
MODIFY
energies["Solar"] = “PV”
REMOVE
energies["Nuclear"] = nil;
INSERT
energies["Geo"] = “Thermal”
and of course the value of a key can be an array or another dictionary:

var typesOfEnergy =

[
    platforms["Solar"]: ["Thermal""PV""GridTied"],
    platforms["Wind"]: ["Autonomous""GridTied"],
    platforms["Nuclear"] : ["Fusion""Fission","Meltdown"]
]
and we would read it:
var type1 = typesOfEnergy["Solar"][0]
See you next time! :-)

First SWIFT Tutorial ever! :-)

June 3, 2014 Leave a comment

let is used for assigning constants whereas var is used for creating variables.

ie:

let  salute: Character = “Hey there…”

let everyone: Character = “Swift World”

var saluteEveryone = salute + everyone

saluteEveryone = saluteEveryone + “!”

Categories: Swift Tags: , , , , ,

Comment Coding – Coding for Visual Learners

May 14, 2014 Leave a comment
Visual Learning iOS Coding

Visual Learning iOS Coding

I’ve mentioned this in my online courses as well as classroom courses and its usually overlooked.  I think its an important design technique for those of us who are Visual Learners.

What’s a Visual Learner?

Many people, prime examples are asian students, are great at math because they are quick to grasp abstract tasks.  They can read a sentence or paragraph and understand everything the first time.  Not me!

I’m the kind of person that has to read concepts 10 times over and still have trouble applying it.  I need visual representations of concepts in order to understand them.  As a matter of fact, I review iOS and Cocos2D books and my comments are usually “We should insert a sketch here showing how a block of code is passed to a method and executed at a given time…”.

We visual learners have a hard time organizing concepts in our mind unless we write things down or sketch what we believe is being said.

 

Coding in 3 Steps:

1.  Draw it!

Creating an app or game is just like understanding an abstract concept.  I usually start out drawing a storyboard on paper.  I need to see a sketched drawing of what the app’s views are going to look like.  I usually draw views and some important controls that transition between one view and the next.  I also try to visualize the flow of data from one view to another.  This can get a little tricky but if one sheet of paper won’t do, Ill usually end up with 4 sheets taped together, a whiteboard of which I take pictures of or Penultimate.  Unfortunately Penultimate runs on an iPad whose screen I wish were bigger :)

iOS Sketch Comment Coding

iOS Sketch Comment Coding

2. Comment it!

This is where the magic happens.  I will basically open up Xcode, create the classes I drew out as objects and comment all my ideas.  What Ill do is go into a class and create its methods, at least the methods I think it should have.  Originally these method names were simple, such as:

somehowGetDataFromFlickr

somehowShowDataInConsole

popAlertToUser

makeCopyOfData

showListOfDataToUser

but eventually, as I picked up more knowledge, learned that many tasks are repetitive patterns and understood UX and coding techniques, those names evolved:

downloadDataFromWeb

parseDataIntoFoundationObjects

notifyUserDataDownloaded

notifyUserDataIsParsed

shareDataWithObservers

logDataInCoreData

updateUIScreenWithNewData

So now I know, in layman’s terms, what I need to do.  This would, at first, take me to Google.com and eventually to StackOverflow.com.  I would basically append “How to…” that proposed name method and “…in iOS”.  This would give me some code samples and I would begin researching the examples I found.  Eventually I learned how to read Apple Documentation (How to Read iOS or Mac OS Programming Documentation) and Apple documentation took precedence over Google and StackOverflow.

What I would do next is take a particular method and insert comments of what that method should do:

-(void)downloadDataFromWeb{

//1. NSURLConnection

//2. Get data from delegate methods

}

Then I would begin coding right underneath each comment.

 

3. Code it!

Finally I would take examples from any source I found online and download them and tinker with them until I made sure I understood what they do.  In time this is replaced by understanding how OOP works and its many useful patterns.  This is when coding gets to be a pleasure!

So it takes a while, but you WILL eventually have FUN coding.  But its a lot easier to get to the fun part if you are a Visual Learner and use Comment Coding to get you there with a decent bit of sanity left :)

Enjoy Coding!

Categories: Iphone Developer

Creating a simple UICollectionView in iOS

May 9, 2014 1 comment

Steps

1) Create Master-Detail Application & Replace the MasterViewController

First we want to create a Master-Detail Application just because it sets up a Master-Detail relationship even though thats the first thing we are going to break :).  So go ahead and create a new project in XCode4 based on a Master-Detail Application type.  Use ARC, Storyboards and CoreData because we will use CoreData to store information.  Your storyboard should look like this:

Master-Detail Storyboard

Master-Detail Storyboard

Now select the Master scene until its highlighted in blue and delete it with the Delete key.  We simply replace it by dragging in a UICollectionViewController onto the storyboard in its place.  This places a UICollectionViewController scene with a small empty collectionview cell in the top left corner.  I made a few adjustments to mine and here is what it looks like but Ill go over those later:

UICollectionViewController Storyboard

UICollectionViewController Storyboard

The changes I made to it are the following:

a – Select the entire scene (again until its highlighted blue) and change its Class type from UICollectionViewController to MasterViewController.

b – Enlarged the UICollectionViewCell from 50×50 to 145×145 in the Dimension’s Inspector

Here are some clips of the Identity Inspector of the MasterViewController and Dimension’s Inspector of the UICollectionViewCell:

UICollectionViewController Identity Inspector

UICollectionViewController Identity Inspector

UICollectionViewCell Dimensions Inspector

UICollectionViewCell Dimensions Inspector

We did set the new UICollectionViewController to a new class, the MasterViewController class.  We must do the same with the UICollectionViewCell but we must create its class first.

2)  Modify the MasterViewController class with the following in the .m file:

#import “MasterViewController.h”

#import “DetailViewController.h”

#import “MyCustomCell.h”

#import “AppDelegate.h”

static NSString *CellIdentifier = @”MyCustomCell”;

@interface MasterViewController ()

{

NSMutableArray *_objectChanges;

NSMutableArray *_sectionChanges;

}

@end

Now let’s go through the methods.  First the UICollectionView methods, which are quite similar to the UITableViewController methods:

#pragma mark – UICollectionView

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section

{

id <NSFetchedResultsSectionInfo> sectionInfo = [self.fetchedResultsController sections][section];

return [sectionInfo numberOfObjects];

}

// The cell that is returned must be retrieved from a call to -dequeueReusableCellWithReuseIdentifier:forIndexPath:

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath

{

MyCustomCell *cell = (MyCustomCell *)[collectionView dequeueReusableCellWithReuseIdentifier:CellIdentifier forIndexPath:indexPath];

NSManagedObject *object = [self.fetchedResultsController objectAtIndexPath:indexPath];

[cell setImage:[UIImage imageWithData:[object valueForKey:@"photoImageData"]]];

return cell;

}

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender

{

if ([[segue identifier] isEqualToString:@”showDetail”]) {

NSIndexPath *indexPath = [[self.collectionView indexPathsForSelectedItems] lastObject];

NSManagedObject *object = [[self fetchedResultsController] objectAtIndexPath:indexPath];

[[segue destinationViewController] setDetailItem:object];

}

}

The MyCustomCell Class is the one we will create in the next section.  For now we are simply filling in the cell’s image data with some fetched managed object which we will also create later.  A couple of more interesting tidbits for example; we gave our UICollectionViewCell a reuse identifier and we gave our segue an identifier as well.  We must make sure these identifiers also exist in the storyboard inspectors for the cell and segue respectively.

3) Create UICollectionViewCell Class & Connect it

Let’s go ahead and Create a New File in our project, base it off of Objective C Class.  Type in UICollectionViewCell as the subclass and name it MyCustomCell.  We are simply going to define a class for our UICollectionViewCell and once we are finished, we must go to Storyboard and set our cell to use this new class type.

Add a UIImageView property to the class so that your .h file looks like this:

#import <UIKit/UIKit.h>

@interface MyCustomCell : UICollectionViewCell{

IBOutlet UIImageView *imageView;

}

-(void)setImage:(UIImage *)image;

@end

and now implement the setter in your .m so that it looks like this:

#import “MyCustomCell.h”

@implementation MyCustomCell

-(void)setImage:(UIImage *)image{

[imageView setImage:image];

}

@end

4) Create the data model.  First let’s do the easiest part, which is creating the data model.  Select your project’s xcdatamodel file and create a new Entity, call it Snapshots if you’d like.  Now add 3 attributes to it and make them of this type:

Core Data Entity Data Model

Core Data Entity Data Model

Once that is done, we have a storage container for our data.  Let’s look at the code used by our app to access this store and manipulate it.

#pragma mark – Fetched results controller

- (NSFetchedResultsController *)fetchedResultsController

{

if (_fetchedResultsController != nil) {

return _fetchedResultsController;

}

NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];

// Edit the entity name as appropriate.

NSEntityDescription *entity = [NSEntityDescription entityForName:@"Snapshots" inManagedObjectContext:self.managedObjectContext];

[fetchRequest setEntity:entity];

// Set the batch size to a suitable number.

[fetchRequest setFetchBatchSize:20];

// Edit the sort key as appropriate.

NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@”photoName” ascending:NO];

NSArray *sortDescriptors = @[sortDescriptor];

[fetchRequest setSortDescriptors:sortDescriptors];

// Edit the section name key path and cache name if appropriate.

// nil for section name key path means “no sections”.

NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:self.managedObjectContext sectionNameKeyPath:nil cacheName:@”Master”];

aFetchedResultsController.delegate = self;

self.fetchedResultsController = aFetchedResultsController;

NSError *error = nil;

if (![self.fetchedResultsController performFetch:&error]) {

// Replace this implementation with code to handle the error appropriately.

// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.

NSLog(@”Unresolved error %@, %@”, error, [error userInfo]);

abort();

}

return _fetchedResultsController;

}

- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo

atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type

{

NSMutableDictionary *change = [NSMutableDictionary new];

switch(type) {

case NSFetchedResultsChangeInsert:

change[@(type)] = @(sectionIndex);

break;

case NSFetchedResultsChangeDelete:

change[@(type)] = @(sectionIndex);

break;

}

[_sectionChanges addObject:change];

}

- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject

atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type

newIndexPath:(NSIndexPath *)newIndexPath

{

NSMutableDictionary *change = [NSMutableDictionary new];

switch(type)

{

case NSFetchedResultsChangeInsert:

change[@(type)] = newIndexPath;

break;

case NSFetchedResultsChangeDelete:

change[@(type)] = indexPath;

break;

case NSFetchedResultsChangeUpdate:

change[@(type)] = indexPath;

break;

case NSFetchedResultsChangeMove:

change[@(type)] = @[indexPath, newIndexPath];

break;

}

[_objectChanges addObject:change];

}

- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller

{

if ([_sectionChanges count] > 0)

{

[self.collectionView performBatchUpdates:^{

for (NSDictionary *change in _sectionChanges)

{

[change enumerateKeysAndObjectsUsingBlock:^(NSNumber *key, id obj, BOOL *stop) {

NSFetchedResultsChangeType type = [key unsignedIntegerValue];

switch (type)

{

case NSFetchedResultsChangeInsert:

[self.collectionView insertSections:[NSIndexSet indexSetWithIndex:[obj unsignedIntegerValue]]];

break;

case NSFetchedResultsChangeDelete:

[self.collectionView deleteSections:[NSIndexSet indexSetWithIndex:[obj unsignedIntegerValue]]];

break;

case NSFetchedResultsChangeUpdate:

[self.collectionView reloadSections:[NSIndexSet indexSetWithIndex:[obj unsignedIntegerValue]]];

break;

}

}];

}

} completion:nil];

}

if ([_objectChanges count] > 0 && [_sectionChanges count] == 0)

{

[self.collectionView performBatchUpdates:^{

for (NSDictionary *change in _objectChanges)

{

[change enumerateKeysAndObjectsUsingBlock:^(NSNumber *key, id obj, BOOL *stop) {

NSFetchedResultsChangeType type = [key unsignedIntegerValue];

switch (type)

{

case NSFetchedResultsChangeInsert:

[self.collectionView insertItemsAtIndexPaths:@[obj]];

break;

case NSFetchedResultsChangeDelete:

[self.collectionView deleteItemsAtIndexPaths:@[obj]];

break;

case NSFetchedResultsChangeUpdate:

[self.collectionView reloadItemsAtIndexPaths:@[obj]];

break;

case NSFetchedResultsChangeMove:

[self.collectionView moveItemAtIndexPath:obj[0] toIndexPath:obj[1]];

break;

}

}];

}

} completion:nil];

}

[_sectionChanges removeAllObjects];

[_objectChanges removeAllObjects];

}

I know its long, but its pretty simple.  The first method, – (NSFetchedResultsController *)fetchedResultsController, basically opens up the store, fetches all entities by the name “Snapshots” and places them into a special object called NSFetchedResultsController.

The didChangeSection method is called when there is a change within a section.  We only have 1 section in our UICollectionView.

The didChangeObject method is called when a particular object is changed within our UICollectionView.

The controllerDidChangeContent actually manages the changes made.  Basically we update our two arrays, _sectionChanges and _objectChanges with each change in the data in order to keep our UICollectionView current.

5) Connect to Flickr API.  So what constitutes a change in those sections and objects?  There is an acronym that datastore managers use, CRUD, which basically says that everytime you create, read, update or delete you create a transaction.  Thats basically what we want to track (except for the read part :)).  So whenever we download a new photo to our datastore, update a photo or delete one, we trigger changes in objects and thus in sections.

We want to use the Flickr API to get images from the web and populate our collection view.  We are basically going to perform a fetch to Flickr API using our own key or identifier.  You must register for one at flickr.com/.

a – Get FlickrAPIKey and add it here to this string constant atop your .m file like so:

NSString *const FlickrAPIKey = @"YOURAPIKEYVALUE";

b – Add the loadFlickrPhotos method to fetch pics from the web.  So add this method:

- (void)loadFlickrPhotos{

// 1. Build your Flickr API request w/Flickr API key in FlickrAPIKey.h

NSString *urlString = [NSString stringWithFormat:@"http://api.flickr.com/services/rest/?method=flickr.photos.search&api_key=%@&tags=%@&per_page=10&format=json&nojsoncallback=1", FlickrAPIKey, @"bayern"];

NSURL *url = [NSURL URLWithString:urlString];

// 2. Get URLResponse string & parse JSON to Foundation objects.

NSString *jsonString = [NSString stringWithContentsOfURL:url encoding:NSUTF8StringEncoding error:nil];

NSError *e = nil;

NSDictionary *results = [NSJSONSerialization JSONObjectWithData:[jsonString dataUsingEncoding:NSUTF8StringEncoding]options:NSJSONReadingMutableContainers error:&e];

photos = [[results objectForKey:@"photos"] objectForKey:@”photo”];

for (NSDictionary *photo in photos) {

// 3.a Get title for e/ photo

NSString *title = [photo objectForKey:@"title"];

[photoNames addObject:(title.length > 0 ? title : @"Untitled")];

// 3.b Construct URL for e/ photo.

NSString *photoURLString = [NSString stringWithFormat:@”http://farm%@.static.flickr.com/%@/%@_%@_s.jpg&#8221;, [photo objectForKey:@"farm"], [photo objectForKey:@"server"], [photo objectForKey:@"id"], [photo objectForKey:@"secret"]];

[photoURLs addObject:[NSURL URLWithString:photoURLString]];

}

// Process into CoreData

[self processCoreData];

}

It basically looks for Flickr photos of Bayern and stores the results in the photos ivar.  Now we must populate our CoreData db with these data.

c – Populate our CoreData model.  Add the processCoreData method to your MasterViewController.m like so:

-(void)processCoreData{

AppDelegate *myDelegate = [[UIApplication sharedApplication] delegate];

for (NSDictionary *photoDictionary in photos){

NSManagedObject *photoModel = [NSEntityDescription insertNewObjectForEntityForName:@"AFPhotoModel" inManagedObjectContext:myDelegate.managedObjectContext];

//[photoModel setValue:[photoDictionary valueForKey:@"rating"] forKey:@”photoRating”];

[photoModel setValue:[photoDictionary valueForKey:@"title"] forKey:@”photoName”];

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{

//Build URL

NSString *photoURLString = [NSString stringWithFormat:@”http://farm%@.static.flickr.com/%@/%@_%@_s.jpg&#8221;, [photoDictionary objectForKey:@"farm"], [photoDictionary objectForKey:@"server"], [photoDictionary objectForKey:@"id"], [photoDictionary objectForKey:@"secret"]];

NSData *imageData = [NSData dataWithContentsOfURL:[NSURL URLWithString:photoURLString]];

dispatch_async(dispatch_get_main_queue(), ^{

[photoModel setValue:imageData forKey:@"photoImageData"];

});

});

}

}

Voila!  Run your app!

iOS7 – UIKit Dynamics

April 25, 2014 Leave a comment

iOS7 Series – UIKit Dynamics

 

Incorporating UIKitDynamics into your app is pretty simple!  The great thing about it is that you really get the most bang for your buck because the end result has a really big WOW Factor which is certain to impress your users.  Let’s take a quick conceptual drive around UIKitDynamics.

First we adopt the protocol into the ViewController which will implement UIKitDynamics, why?  Well because the objects which will be animated in the end will have to send back a lot of signals like “Hey, I collided with a boundary” or “hey I just hit somebody else and I was going this fast, in this direction”.  In order to receive these messages we use a delegate and its callbacks.

@interface … <UICollisionBehaviorDelegate>

We would need to create the view to animate and the property to reference a UIDynamicAnimator, which is the object in charge of handling animations in UIKitDynamics.

@property (nonatomic, weak) IBOutlet UIView *square1;

@property (nonatomic) UIDynamicAnimator* animator;

Basically we would prep all we need in viewDidLoad, such as instantiating an animator to call the shots inside a particular reference view.  Then we create a behavior or set of behaviors we wish to assign to our animatable view.  We define boundaries so we can keep our objects inside a view.  Finally we add the behaviors to the animator and set the viewcontroller as the delegate as well as set that animator object to our property in order to hold a reference to it.

That’s it!  Now we just sit back and get messages from the animator and the animated view via the callbacks.

- (void)viewDidLoad{

[super viewDidLoad];

UIDynamicAnimator* animator = [[UIDynamicAnimator alloc] initWithReferenceView:self.view];

UIGravityBehavior* gravityBeahvior = [[UIGravityBehavior alloc] initWithItems:@[self.square1]];

UICollisionBehavior* collisionBehavior = [[UICollisionBehavior alloc] initWithItems:@[self.square1]];

collisionBehavior.translatesReferenceBoundsIntoBoundary = YES;

[animator addBehavior:gravityBeahvior];

[animator addBehavior:collisionBehavior];

collisionBehavior.collisionDelegate = self;

self.animator = animator;

}

-(void)collisionBehavior:(UICollisionBehavior *)behavior beganContactForItem:(id<UIDynamicItem>)item withBoundaryIdentifier:(id<NSCopying>)identifier atPoint:(CGPoint)p{

// Lighten the background color when the view is in contact with a boundary.

[(UIView*)item setBackgroundColor:[UIColor lightGrayColor]];

}

-(void)collisionBehavior:(UICollisionBehavior *)behavior endedContactForItem:(id<UIDynamicItem>)item withBoundaryIdentifier:(id<NSCopying>)identifier{

// Restore the default color when ending a contcact.

[(UIView*)item setBackgroundColor:[UIColor grayColor]];

}

Ok so let’s use it in a simple example.  Let’s say we are building a Restaurant rating app.  It’s a single view app with a plain vanilla UIViewController which has these properties connected to those outlets:

@property (nonatomic, strong) IBOutlet UILabel *restaurantName;

@property (nonatomic, strong) IBOutlet UILabel *restaurantAddress;

//STAR RATING

@property (nonatomic, strong) IBOutlet UIImageView *stars1;

@property (nonatomic, strong) IBOutlet UIImageView *stars2;

@property (nonatomic, strong) IBOutlet UIImageView *stars3;

@property (nonatomic, strong) IBOutlet UIImageView *stars4;

@property (nonatomic, strong) IBOutlet UIImageView *stars5;

 

First let’s create the animator that will handle the animation inside our viewDidLoad:

// Create animator

UIDynamicAnimator* animator = [[UIDynamicAnimator alloc] initWithReferenceView:self.view];

Now we add the views we want to animate to the behaviors we want to implement:

//Create behaviors

    UIGravityBehavior* gravityBeahvior = [[UIGravityBehavior alloc] initWithItems:@[self.stars1,self.stars2, self.stars3, self.stars4,self.stars5]];

UICollisionBehavior* collisionBehavior = [[UICollisionBehavior alloc] initWithItems:@[self.stars1,self.stars2, self.stars3, self.stars4,self.stars5]];

UIDynamicItemBehavior* propertiesBehavior = [[UIDynamicItemBehavior alloc] initWithItems:@[self.stars1,self.stars2, self.stars3, self.stars4,self.stars5]];

propertiesBehavior.elasticity = 5;

Notice that the last behavior is actually created to modify certain physical properties of an object, in this case elasticity.  There are other properties we can modify in this manner.

We can also add specific boundaries but in many cases we will want to simply use the view’s edges as the natural boundaries, so we use this line:

    collisionBehavior.translatesReferenceBoundsIntoBoundary = YES;

Finally we add the behaviors to the animator, set the delegate to self and reference our animator through its property:

[animator addBehavior:gravityBeahvior];

[animator addBehavior:collisionBehavior];

collisionBehavior.collisionDelegate = self;

self.animator = animator;

Finally just add the following delegate callbacks to decide what gets done when a collision occurs:

-(void)collisionBehavior:(UICollisionBehavior *)behavior beganContactForItem:(id<UIDynamicItem>)item withBoundaryIdentifier:(id<NSCopying>)identifier atPoint:(CGPoint)p{

// Lighten the background color when the view is in contact with a boundary.

[(UIView*)item setBackgroundColor:[UIColor lightGrayColor]];

}

-(void)collisionBehavior:(UICollisionBehavior *)behavior endedContactForItem:(id<UIDynamicItem>)item withBoundaryIdentifier:(id<NSCopying>)identifier{

// Restore the default color when ending a contcact.

[(UIView*)item setBackgroundColor:[UIColor grayColor]];

}

That’s it!  There are lots of neat effects you can use but don’t overdo it or your users will sue you for giving them vertigo! J

iOS Smarties :)

April 15, 2014 Leave a comment
iOS & Objective C Smarties Code Snippets by Marcio Valenzuela Santiapps.com

iOS & Objective C Smarties Code Snippets

Everyone loves Smarties!  And much the same way Smarties Candies make you smarter… today we are talking about Code Snippets that make you….er Smarter!  More than a source of cut/paste Objective C source code, this is meant to be a quick reference.  As such, some of these will be incomplete and I will be filling them up as I go along. 

1)   UIAlertView

UIAlertView *internetAlert = [[UIAlertView alloc] initWithTitle:@”No hay farmacias”

message:@”Favor cambie sus parámetros”

delegate:self

cancelButtonTitle:@”Cancelar”

otherButtonTitles:@”Ok”, nil];

[internetAlert show];

2)   NSNotification

//1. Register as observer of notifications in viewDidLoad

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(receiveTestNotification:) name:@”TestNotification” object:nil];

//2. NSNotifCtr CLEANUP in viewDidUnload

[[NSNotificationCenter defaultCenter] removeObserver:self];

//4. Post notif to NSNotif in calling method OTHER CLASS

[[NSNotificationCenter defaultCenter]

postNotificationName:@”TestNotification”

object:self];

//3. Method to prove notif received…

- (void) receiveTestNotification:(NSNotification *) notification

{

if ([[notification name] isEqualToString:@”TestNotification”])

NSLog (@”Successfully received the test notification!”);

}

3)   UIActivityIndicator – NSTimer – then completion blocks

//1. Set activity indicator

UIApplication *sharedApplication = [UIApplication sharedApplication];

sharedApplication.networkActivityIndicatorVisible = YES;

//INSERT NSTimer here J

//2. Hide activity indicator

UIApplication *sharedApplication = [UIApplication sharedApplication];

sharedApplication.networkActivityIndicatorVisible = NO;

works the same with an IBOutlet UIActivityIndicator

4)   UISearchBar

UISearchBarDelegate, UISearchDisplayDelegate

@property (strong,nonatomic) NSMutableArray *filteredResultsArray;

@property (strong,nonatomic) IBOutlet UISearchBar *resultsSearchBar;

//UISearch in INIT or LOAD method

// Initialize the filteredResults array with its count of Locations NSManagedObjects

self.filteredResultsArray = [NSMutableArray arrayWithCapacity:[self.originalArray count]];

//ios6 refresh control ONLY

if ([UIRefreshControl class]) {

self.refreshControl = [[UIRefreshControl alloc] init];

[self.refreshControl addTarget:self action:@selector(reload) forControlEvents:UIControlEventValueChanged];

[self reload];

[self.refreshControl beginRefreshing];

} else {

//do nothing

}

//nORIS

if (tableView == self.searchDisplayController.searchResultsTableView) {

return [filteredResultsArray count];

} else {

return [self.originalArray count];

}

//cFRAIP

if (tableView == self.searchDisplayController.searchResultsTableView) {

// IF ITS A SEARCH TABLE…>>>>>>>>>>

//Use filteredResultsArray data

} else {

//Otherwise use self.originalArray

}

5)   Reminders & Events

/////////EVENTS

// SPECIAL CALENDAR OBJECT CLASS

#import <EventKit/EventKit.h>

+(EKEventStore*)eventStore;

+(EKCalendar*)calendar;

+(EKCalendar*)createAppCalendar;

// WHAT IT DOES

static EKEventStore* eStore = NULL;

+(EKEventStore*)eventStore{

//keep a static instance of eventStore

if (!eStore) {

eStore = [[EKEventStore alloc] init];

}

return eStore;

}

+(EKCalendar*)createAppCalendar

{

EKEventStore *store = [self eventStore];

//1 fetch the local event store source

EKSource* localSource = nil;

for (EKSource* src in store.sources) {

if (src.sourceType == EKSourceTypeCalDAV) {

localSource = src;

}

if (src.sourceType == EKSourceTypeLocal && localSource==nil) {

localSource = src;

}

}

if (!localSource) return nil;

//2 CREATE A NEW CALEDNAR FOR ITEMS!!!!!!!!!!!!!!!

EKCalendar* newCalendar = [EKCalendar calendarWithEventStore: store];

newCalendar.title = kAppCalendarTitle;

newCalendar.source = localSource;

newCalendar.CGColor = [[UIColor colorWithRed:0.8 green:0.2 blue:0.6 alpha:1] CGColor];

//3 save the calendar in the event store

NSError* error = nil;

[store saveCalendar: newCalendar commit:YES error:&error];

if (!error) {

return nil;

}

//4 store the calendar id

NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];

[prefs setValue:newCalendar.calendarIdentifier forKey:@"appCalendar"];

[prefs synchronize]; return newCalendar;

}

+(EKCalendar*)calendar{

//1

EKCalendar* result = nil;

EKEventStore *store = [self eventStore];

//2 check for a persisted calendar id

NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];

NSString *calendarId = [prefs stringForKey:@"appCalendar"];

//3

if (calendarId && (result = [store calendarWithIdentifier: calendarId])) {

return result;

}

//4 check if calendar name exists

for (EKCalendar* cal in store.calendars) {

if ([cal.title compare: kAppCalendarTitle]==NSOrderedSame) {

if (cal.immutable == NO) {

[prefs setValue:cal.calendarIdentifier

forKey:@"appCalendar"]; [prefs synchronize]; return cal;

}

}

}

//5 if no calendar is found whatsoever, create one

result = [self createAppCalendar];

//6

return result;

}

// ADD ENTRY FROM VC THRU CALEDNAR OBJECT

-(void)addItem:(NSDictionary*)item toCalendar:(EKCalendar*)calendar{

EKEvent* event = [EKEvent eventWithEventStore:[AppCalendar eventStore]];

event.calendar = calendar;

EKAlarm* myAlarm = [EKAlarm alarmWithRelativeOffset: - 06*60 ];

[event addAlarm: myAlarm];

NSDateFormatter* frm = [[NSDateFormatter alloc] init];

[frm setDateFormat:@"MM/dd/yyyy HH:mm zzz"];

[frm setLocale:[[NSLocale alloc] initWithLocaleIdentifier:@”en_US”]];

event.startDate = [frm dateFromString:[show objectForKey:@"startDate"]];

event.endDate = [frm dateFromString:[show objectForKey:@"endDate"]];

event.title = [item objectForKey:@"title"];

event.URL = [NSURL URLWithString:[item objectForKey:@"url"]];

event.location = @”My Office”;

event.notes = [item objectForKey:@"tip"];

//add recurrence

NSNumber* weekDay = [item objectForKey:@"dayOfTheWeek"];

EKRecurrenceDayOfWeek* itemDay = [EKRecurrenceDayOfWeek dayOfWeek: [weekDay intValue]];

EKRecurrenceEnd* runFor3Months = [EKRecurrenceEnd recurrenceEndWithOccurrenceCount:12];

EKRecurrenceRule* myReccurrence = [[EKRecurrenceRule alloc] initRecurrenceWithFrequency:EKRecurrenceFrequencyWeekly interval:1

daysOfTheWeek:[NSArray arrayWithObject:itemDay] daysOfTheMonth:nil monthsOfTheYear:nil weeksOfTheYear:nil daysOfTheYear:nil setPositions:nil end:runFor3Months];

[event addRecurrenceRule: myReccurrence];

//1 save the event to the calendar

NSError* error = nil;

[[AppCalendar eventStore] saveEvent:event span:EKSpanFutureEvents commit:YES error:&error];

//2 show the edit event dialogue

EKEventEditViewController* editEvent = [[EKEventEditViewController alloc] init];

editEvent.eventStore = [AppCalendar eventStore]; editEvent.event = event;

editEvent.editViewDelegate = self;

[self presentViewController:editEvent animated:YES completion:^{

UINavigationItem* item = [editEvent.navigationBar.items objectAtIndex:0]; item.leftBarButtonItem = nil;

}];

}

//////REMINDERS

//EVENT CLASS OBJECT

- (id) init {

self = [super init];

if (self) {

_eventStore = [[EKEventStore alloc] init];

[_eventStore requestAccessToEntityType:EKEntityTypeEvent

completion:^(BOOL granted, NSError *error) {

if (granted) {

_eventAccess = YES;

} else {

NSLog(@"Event access not granted: %@", error);

}

}];

[_eventStore requestAccessToEntityType:EKEntityTypeReminder completion:^(BOOL granted, NSError *error) {

if (granted) { _reminderAccess = YES;

} else {

NSLog(@"Reminder access not granted: %@", error);

}

}];

//Initialize the dispatch queue

_fetchQueue = dispatch_queue_create(“com.santiapps.fetchQueue”, DISPATCH_QUEUE_SERIAL);

}

return self;

}

//LOOP THRU CALENDARS

NSArray * allCalendars = [_eventStore calendarsForEntityType:EKEntityMaskEvent |

EKEntityMaskReminder];
NSMutableArray * writableCalendars = [NSMutableArray array]; for (EKCalendar * calendar in allCalendars) {

if (calendar.allowsContentModifications) { [writableCalendars addObject:calendar];

} }

EKCalendar *calendar = eventStore.defaultCalendarForNewEvents;

//CREATE EVENT

//1

EKEvent *event = [EKEvent eventWithEventStore:eventStore]; event.title = @”Hello world!”;
event.startDate = startDate;
event.endDate = endDate;

EKAlarm *alarm = [EKAlarm alarmWithRelativeOffset:-1800]; [event addAlarm:alarm];

event.calendar = eventStore.defaultCalendarForNewEvents;

//2

NSError *err;
BOOL saved = [eventStore saveEvent:event span:EKSpanThisEvent commit:YES error:&err];

if (!saved) {
NSLog(@”Error creating the event”);

}

//REMINDER

//1

EKReminder *reminder = [EKReminder reminderWithEventStore:eventStore];

reminder.title = @”Creating my first reminder”; reminder.calendar = [eventStore defaultCalendarForNewReminders];

NSCalendar *calendar =
[NSCalendar currentCalendar];

NSUInteger unitFlags = NSEraCalendarUnit |

NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit;

NSDateComponents *dueDateComponents = [calendar components:unitFlags fromDate:dueDate];

//1.5. Set the due date

reminder.dueDateComponents = dueDateComponents;

//2

NSError *err;

BOOL success =

[eventStore saveReminder:reminder commit:YES error:&err];

if (!success) {
NSLog(@”Error creating reminder”);

}

6)   Local Notifications

//test notif

NSDate *date = [NSDate dateWithTimeIntervalSinceNow:10];

UILocalNotification *localNotification = [[UILocalNotification alloc] init];

localNotification.fireDate = date;

localNotification.timeZone = [NSTimeZone defaultTimeZone];

localNotification.alertBody = @”I am a local notification!”;

localNotification.soundName = UILocalNotificationDefaultSoundName;

[[UIApplication sharedApplication] scheduleLocalNotification:localNotification];

7)   Sort NSArrays for tableviews

-(void)sort{

NSSortDescriptor *sortDescriptor;

sortDescriptor = [[[NSSortDescriptor alloc] initWithKey:@”distance” ascending:YES] autorelease];

NSArray *sortDescriptors = [NSArray arrayWithObject:sortDescriptor];

NSArray *sortedArray;

sortedArray = [self.annotationsToSort sortedArrayUsingDescriptors:sortDescriptors];

self.annotationsToSort = [(NSArray*)sortedArray mutableCopy];

[self.tableView performSelector:@selector(reloadData) withObject:nil afterDelay:0.5];

}

8)   Contacts

// Read Contact list xml formatted (Array of Dictionaries)

//read directory here

dispatch_async(kBgQueue , ^{

contacts = [NSArray arrayWithContentsOfURL: kContactsList];

dispatch_async(dispatch_get_main_queue(), ^{

[self.tableView reloadData]; });

});

// Do this

//NO ADD THEM TO AB

dispatch_async(kBgQueue , ^{

NSString* request = [NSString stringWithFormat:@"%@?%@", kContactsList, ids]; //1

NSData *responseData = [NSData dataWithContentsOfURL:[NSURL URLWithString:request]]; //2

//parse vCard data

ABAddressBookRef addressBook = ABAddressBookCreate(); //1

ABRecordRef record = ABPersonCreate(); //2

NSArray* importedPeople = (__bridge_transfer NSArray*)

ABPersonCreatePeopleInSourceWithVCardRepresentation( record, (__bridge CFDataRef)responseData); //3

CFBridgingRelease(record); //4

//define few constants

__block NSMutableString* message = [NSMutableString stringWithString:

@"Contacts imported AB. Add them in Facebook: "];

NSString* serviceKey = (NSString*)kABPersonSocialProfileServiceKey;

NSString* facebookValue = (NSString*)

kABPersonSocialProfileServiceFacebook;

NSString* usernameKey = (NSString*)kABPersonSocialProfileUsernameKey;

//loop over people and get their facebook

for (int i=0;i<[importedPeople count];i++) { //1

ABRecordRef personRef = (__bridge ABRecordRef) [importedPeople objectAtIndex:i];

ABAddressBookAddRecord(addressBook, personRef, nil);

//2

ABMultiValueRef profilesRef = ABRecordCopyValue( personRef, kABPersonSocialProfileProperty);

NSArray* profiles = (__bridge_transfer NSArray*) ABMultiValueCopyArrayOfAllValues(profilesRef);

//3

for (NSDictionary* profile in profiles) { //4

NSString* curServiceValue = [profile objectForKey:serviceKey]; //5

if ([facebookValue compare: curServiceValue] == NSOrderedSame) { //6

[message appendFormat: @”%@, “, [profile objectForKey: usernameKey]];

}

}

//7

CFBridgingRelease(profilesRef);

}

//save to addressbook

ABAddressBookSave(addressBook, nil);

CFBridgingRelease(addressBook);

//show done alert

dispatch_async(dispatch_get_main_queue(), ^{ [[[UIAlertView alloc]

initWithTitle: @”Done!” message: message

delegate: nil cancelButtonTitle:@”OK” otherButtonTitles:nil] show];

});

});

9)   Mapkit

//CHECK LOCATION SERVICES

-(void)checkLocationServices{

BOOL locationAllowed = [CLLocationManager locationServicesEnabled];

if (locationAllowed==NO) {

UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@”Location Service Disabled”

message:@”Re-enable in Settings for this app.”

delegate:nil

cancelButtonTitle:@”OK”

otherButtonTitles:nil];

[alert show];

[alert release];

}

}

//GET LOCATION

-(void)getLocation{

locationManager = [[CLLocationManager alloc] init];

locationManager.delegate = self;

locationManager.distanceFilter = 10;

locationManager.desiredAccuracy = kCLLocationAccuracyBest;

[locationManager startUpdatingLocation];

//- (void)startMonitoringSignificantLocationChanges

_mapView.showsUserLocation = YES;

}

-(void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations {

self.userLocation = [locations lastObject];

NSLog(@”userLocation is %f, %f”, self.userLocation.coordinate.latitude, self.userLocation.coordinate.longitude);

CLLocationCoordinate2D zoomLocation;

zoomLocation.latitude = self.userLocation.coordinate.latitude;

zoomLocation.longitude = self.userLocation.coordinate.longitude;

NSLog(@”Using %g,%g”, zoomLocation.latitude, zoomLocation.longitude);

//StopUpdating Location so it wont change all the time

[locationManager stopUpdatingLocation];

}

//GET ANNOTATIONS

CLLocation *pinLocation = [[CLLocation alloc] initWithLatitude:annotation.coordinate.latitude longitude:annotation.coordinate.longitude];

CLLocationDistance calculatedDistance = [pinLocation distanceFromLocation:self.userLocation];

annotation.distance = calculatedDistance/1000;

//PLOT ANNOTATIONS

-(void)plotAnnotations{

//Clean out old annotations

for (id<MKAnnotation> annotation in _mapView.annotations) {

[_mapView removeAnnotation:annotation];

}

//THIS LOGS THE LOCATIONSTOSORT ARRAY OF FVC

//NSLog(@”self.myLocationsToSort %@”, self.myLocationsToSort);

for (MyLocation *annotation in self.myLocationsToSort) {

//Add annotation to mapview

[_mapView addAnnotation:annotation];

}

}

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation {

static NSString *identifier = @”MyLocation”;

if ([annotation isKindOfClass:[MyLocation class]]) {

//test if mapviewnil

if (_mapView == nil) {

NSLog(@”NIL”);

}

MKPinAnnotationView *annotationView = (MKPinAnnotationView *) [_mapView dequeueReusableAnnotationViewWithIdentifier:identifier];

if (annotationView == nil) {

annotationView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:identifier];

annotationView.enabled = YES;

annotationView.canShowCallout = YES;

annotationView.image=[UIImage imageNamed:@"arrest.png"];

} else {

annotationView.annotation = annotation;

}

//instatiate a detail-disclosure button and set it to appear on right side of annotation

UIButton *infoButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];

//[infoButton addTarget:self action:@selector(showDetailView:annotationView.annotation) forControlEvents:UIControlEventTouchUpInside];

annotationView.rightCalloutAccessoryView = infoButton;

return annotationView;

}

return nil;

}

//GET ANNOTATIONS

//ZOOM INTO LOCATION

- (void)mapView:(MKMapView *)mapView didUpdateUserLocation:(MKUserLocation *)userLocation {

// We have location, do your logic of setting the map region here.

CLLocationCoordinate2D zoomLocation;

NSLog(@”location in FirstVC %@”, self.userLocation);

//Test if userLocation has a value

NSLog(@”NOCITYSELECTED vDL FVC”);

zoomLocation.latitude = self.userLocation.coordinate.latitude;

zoomLocation.longitude = self.userLocation.coordinate.longitude;

CLLocationDistance visibleDistance = 5000; // 5 kilometers

MKCoordinateRegion adjustedRegion = MKCoordinateRegionMakeWithDistance(zoomLocation, visibleDistance, visibleDistance);

[_mapView setRegion:adjustedRegion animated:YES];

}

//TAP ON PINS – ANNOTATIONS

//Called when disclosure tapped

- (void)mapView:(MKMapView *)mapView annotationView:(MKAnnotationView *)view calloutAccessoryControlTapped:(UIControl *)control{

if (![view.annotation isKindOfClass:[MyLocation class]])

return;

// use the annotation view as the sender

[self performSegueWithIdentifier:@"DetailVC" sender:view];

}

10)                  UICustomization/Appearance

[[UINavigationBar appearance] setShadowImage:[[UIImage alloc] init]];

[self.tabBarItem setTitleTextAttributes:[NSDictionary dictionaryWithObjectsAndKeys:[UIFont fontWithName:@"Futura" size:10.0f], UITextAttributeFont, nil] forState:UIControlStateNormal];

UIImage *gradientImage32 = [[UIImage imageNamed:@"FirstCellLogo.png"] resizableImageWithCapInsets:UIEdgeInsetsMake(0, 0, 0, 0)];

[[UINavigationBar appearance] setBackgroundImage:gradientImage32 forBarMetrics:UIBarMetricsDefault];

[self.tabBarItem setTitleTextAttributes:[NSDictionary dictionaryWithObjectsAndKeys:[UIFont fontWithName:@"Futura" size:10.0f], UITextAttributeFont, nil] forState:UIControlStateNormal];

[[UITabBar appearance] setSelectedImageTintColor:[UIColor redColor]];

11)                  LetterPress Effect

//letterpress effect the label

//NSMutableAttributedString

NSMutableAttributedString *restName = [[NSMutableAttributedString alloc] initWithString:self.attributionText.text];

[restName addAttributes:@{ NSTextEffectAttributeName : NSTextEffectLetterpressStyle, NSFontAttributeName: [UIFont preferredFontForTextStyle:UIFontTextStyleHeadline] } range:NSMakeRange(0, restName.length)];

self.attributionText.attributedText = restName;

12)                  UIGesture

13)                  iCloud

14)                  Library.a

15)                  Instruments

16)                  Checklist App

17)                  UICollectionView & UIContainerView & SplitVC & Popover

18)                  SlideUp

19)                  Raised Tabbar

20)                  Passbook

21)                  AR

22)                  Export Data

23)                  TF

24)                  iAds & AppiRater

25)                  TimeCmoparator – String Parsing

26)                  UIApplicationDelegate sharedApplication & its methods

27)                  NSUserDefaults

// call the store object

NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];

// set an object for it

[prefs setObject:imageView.image forKey:@"keyToLookupImage"];

// call sync to save it

[prefs synchronize];

NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];

UIImage *retrievedImage = [prefs stringForKey:@"keyToLookupImage"];

imageView.image = retrievedImage;

28)                  Façade design pattern

29)                  Protocols & Delegates

30)                  InAppPurchases

31)                  Datepicker/uipicker

32)                  NSOperation

33)                  Date Formatter

NSDate *date = [NSDate date];

NSDateFormatter *dateFormatter = [[[NSDateFormatter alloc] init] autorelease];

[dateFormatter setDateStyle:NSDateFormatterShortStyle];

[dateFormatter setTimeStyle:NSDateFormatterFullStyle];

NSString *formattedDateString = [dateFormatter stringFromDate:date];

NSLog(@”formattedDateString for locale %@: %@”,

[[dateFormatter locale] localeIdentifier], formattedDateString);

timeLabel.text = [dateFormatter stringFromDate:date];

34)                  Letterpress Effect

35)                  asd

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