/*

     File: APLCollisionGravityViewController.m

 Abstract: Provides the "Collision + Gravity" demonstration.

  Version: 1.3

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 */

#import "APLCollisionGravityViewController.h"

@interface APLCollisionGravityViewController () <UICollisionBehaviorDelegate>

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

@property (nonatomic, strong) UIDynamicAnimator *animator;

@end

@implementation APLCollisionGravityViewController

//| ----------------------------------------------------------------------------

- (void)viewDidLoad

{

    [super viewDidLoad];

    // Make the square a template image so its color can be changed

    // by adjusting the tintColor of the UIImageView displaying it.

    self.square1.image = [self.square1.image imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];

    self.square1.tintColor = [UIColor darkGrayColor];

}

//| ----------------------------------------------------------------------------

- (void)viewDidAppear:(BOOL)animated

{

    [super viewDidAppear:animated];

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

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

    [animator addBehavior:gravityBeahvior];

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

    // Creates collision boundaries from the bounds of the dynamic animator's

    // reference view (self.view).

    collisionBehavior.translatesReferenceBoundsIntoBoundary = YES;

    collisionBehavior.collisionDelegate = self;

    [animator addBehavior:collisionBehavior];

    self.animator = animator;

}

//| ----------------------------------------------------------------------------

//  This method is called when square1 begins contacting a collision boundary.

//  In this demo, the only collision boundary is the bounds of the reference

//  view (self.view).

//

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

{

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

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

}

//| ----------------------------------------------------------------------------

//  This method is called when square1 stops contacting a collision boundary.

//  In this demo, the only collision boundary is the bounds of the reference

//  view (self.view).

//

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

{

    // Restore the default color when ending a contcact.

    [(UIView*)item setTintColor:[UIColor darkGrayColor]];

}

@end