UIView subclass doesn't respond to touches - objective-c

Question

I'm making an iPad project in which a class named "Car" (this is a separate file from the view controller) is supposed to be dragged around the main view.
I setup the class as I saw in an Apple example and I'm able to view my image when I run the application but it's like my class doesn't respond to my touches event and I can't solve the problem.
Here is my class code:
Car.h
#import <UIKit/UIKit.h>
#interface Car : UIView {
UIImageView *firstPieceView;
CGPoint startTouchPosition;
}
-(void)animateFirstTouchAtPoint:(CGPoint)touchPoint forView:(UIImageView *)theView;
-(void)animateView:(UIView *)theView toPosition:(CGPoint) thePosition;
-(void)dispatchFirstTouchAtPoint:(CGPoint)touchPoint forEvent:(UIEvent *)event;
-(void)dispatchTouchEvent:(UIView *)theView toPosition:(CGPoint)position;
-(void)dispatchTouchEndEvent:(UIView *)theView toPosition:(CGPoint)position;
#property (nonatomic, retain) IBOutlet UIImageView *firstPieceView;
#end
and this is my other class code: Car.m
#import "Car.h"
#implementation Car
#synthesize firstPieceView;
#define GROW_ANIMATION_DURATION_SECONDS 0.15 // Determines how fast a piece size grows when it is moved.
#define SHRINK_ANIMATION_DURATION_SECONDS 0.15 // Determines how fast a piece size shrinks when a piece stops moving.
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
// Enumerate through all the touch objects.
NSUInteger touchCount = 0;
for (UITouch *touch in touches) {
// Send to the dispatch method, which will make sure the appropriate subview is acted upon
[self dispatchFirstTouchAtPoint:[touch locationInView:self] forEvent:nil];
touchCount++;
}
}
// Checks to see which view, or views, the point is in and then calls a method to perform the opening animation,
// which makes the piece slightly larger, as if it is being picked up by the user.
-(void)dispatchFirstTouchAtPoint:(CGPoint)touchPoint forEvent:(UIEvent *)event
{
if (CGRectContainsPoint([firstPieceView frame], touchPoint)) {
[self animateFirstTouchAtPoint:touchPoint forView:firstPieceView];
}
}
// Handles the continuation of a touch.
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
NSUInteger touchCount = 0;
// Enumerates through all touch objects
for (UITouch *touch in touches) {
// Send to the dispatch method, which will make sure the appropriate subview is acted upon
[self dispatchTouchEvent:[touch view] toPosition:[touch locationInView:self]];
touchCount++;
}
}
// Checks to see which view, or views, the point is in and then sets the center of each moved view to the new postion.
// If views are directly on top of each other, they move together.
-(void)dispatchTouchEvent:(UIView *)theView toPosition:(CGPoint)position
{
// Check to see which view, or views, the point is in and then move to that position.
if (CGRectContainsPoint([firstPieceView frame], position)) {
firstPieceView.center = position;
}
}
// Handles the end of a touch event.
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
// Enumerates through all touch object
for (UITouch *touch in touches) {
// Sends to the dispatch method, which will make sure the appropriate subview is acted upon
[self dispatchTouchEndEvent:[touch view] toPosition:[touch locationInView:self]];
}
}
// Checks to see which view, or views, the point is in and then calls a method to perform the closing animation,
// which is to return the piece to its original size, as if it is being put down by the user.
-(void)dispatchTouchEndEvent:(UIView *)theView toPosition:(CGPoint)position
{
// Check to see which view, or views, the point is in and then animate to that position.
if (CGRectContainsPoint([firstPieceView frame], position)) {
[self animateView:firstPieceView toPosition: position];
}
}
-(void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event
{
// Enumerates through all touch object
for (UITouch *touch in touches) {
// Sends to the dispatch method, which will make sure the appropriate subview is acted upon
[self dispatchTouchEndEvent:[touch view] toPosition:[touch locationInView:self]];
}
}
#pragma mark -
#pragma mark === Animating subviews ===
#pragma mark
// Scales up a view slightly which makes the piece slightly larger, as if it is being picked up by the user.
-(void)animateFirstTouchAtPoint:(CGPoint)touchPoint forView:(UIImageView *)theView
{
// Pulse the view by scaling up, then move the view to under the finger.
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:GROW_ANIMATION_DURATION_SECONDS];
theView.transform = CGAffineTransformMakeScale(1.2, 1.2);
[UIView commitAnimations];
}
// Scales down the view and moves it to the new position.
-(void)animateView:(UIView *)theView toPosition:(CGPoint)thePosition
{
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:SHRINK_ANIMATION_DURATION_SECONDS];
// Set the center to the final postion
theView.center = thePosition;
// Set the transform back to the identity, thus undoing the previous scaling effect.
theView.transform = CGAffineTransformIdentity;
[UIView commitAnimations];
}
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
UIImage *img = [ UIImage imageNamed: #"CyanSquare.png" ];
firstPieceView = [[UIImageView alloc] initWithImage: img];
//[img release];
[super addSubview:firstPieceView];
[firstPieceView release];
}
return self;
}
/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
// Drawing code
}
*/
- (void)dealloc
{
[firstPieceView release];
[super dealloc];
}
#end
And here is my code for the view controller: (ParkingviewController.h)
#import <UIKit/UIKit.h>
#import "Car.h"
#interface ParkingViewController : UIViewController {
}
#end
and last but not least the ParkingViewController.m
#import "ParkingViewController.h"
#implementation ParkingViewController
- (void)dealloc
{
[super dealloc];
}
- (void)didReceiveMemoryWarning
{
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
#pragma mark - View lifecycle
// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad
{
Car *car1 = [[Car alloc] init];
[self.view addSubview:car1];
[car1 release];
[super viewDidLoad];
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
// Return YES for supported orientations
return YES;
}
#end
Please forgive me if I've posted all the code but I want to be clear in every aspect of my project so that anyone can have the whole situation to be clear.

Answer 1

You need to set a frame for Car object that you are creating for touches to be processed. You are able to see the image as the clipsToBounds property of the view is set to NO by default.