I have an issue at the moment. I am making a game. When two imageViews collide the game will end. I am using CGRECTIntersects rect to detect if the two images collide.
The issue is that when i restart the game the collision will happen when in fact the two images have not actually touched one another?
Any suggestions would be much appreciated.
Thank you
-(void)collision {
if (CGRectIntersectsRect(object.frame, object2.frame)) {
object.hidden=YES;
object2.hidden=YES;
retry.hidden=NO;
[timer invalidate];
}
}
/- (void)viewDidLoad
{
retry.hidden=YES;
timer = [NSTimer scheduledTimerWithTimeInterval:0.01 target:self selector:#selector(object2) userInfo:nil repeats:YES];
objectSpeed1 = CGPointMake(3.0, 2.0);
[super viewDidLoad];
}
/- (IBAction)retry:(id)sender {
[self performSegueWithIdentifier:#"restart" sender:sender];
}
-(void)object2 {
object2.center = CGPointMake(object2.center.x + object2.x, object2.center.y + objectspeed1.y);
if (object2.center.x > 310 || object2.center.x < 10) {
objectspeed1.x = - objectspeed1.x;
}
if (object2.center.y > 558 || object2.center.y < 10) {
objectspeed1.y = - objectspeed1.y;
}
Just consider this case on the code. You can check if image views are on their start position or they came to this position from another. It's enough to keep BOOL property on viewcontroller's class like this:
// ViewController.m
#interface ViewController ()
#property (readonly) BOOL isStarted;
#end
#implementation
- (void)viewDidLoad {
[super viewDidLoad];
_isStarted = NO;
// Make some preparations for app's needs
_isStarted = YES;
}
#end
_isStarted is a flag which shows whether viewcontroller is ready to handle the data.
if(_isStarted) {
// Analyze image views' frame
}
else {
// Do nothing
}
Related
I am developing a game for class where a timer is ran when a button is pressed.
-(void)setTimer{
self->mTimer = [NSTimer scheduledTimerWithTimeInterval:5.0 target:self selector:#selector(buttonNotPushed) userInfo: nil repeats:NO];
}
-(void)resetTimer{
[self->mTimer invalidate];
self->mTimer = nil;
Here is a snippet of how the timer code is used.
- (IBAction)yellowDot1:(id)sender {
if ([_labelColor.text isEqualToString:#"Yellow"]) {
[ self Scoring];
[self label];
[self resetTimer];
[self setTimer];
}
else ([self GameOver]);
}
- (IBAction)redDot1:(id)sender {
if ([_labelColor.text isEqualToString:#"Red"]) {
[ self Scoring];
[self label];
[self resetTimer];
[self setTimer];
}
else ([self GameOver]);
}
The game presents with a Play button which modals over to the next screen. Currently at 5 seconds, I would like to create a "difficult" mode where at the home screen, the user clicks on a "difficult" button and the timer for the game runs at 2 seconds instead. Right now, I am contemplating duplicating my storyboard and view controllers and going that way where I just make the timer a different interval. Is a shorter way possible through code for a difficult mode?
Simply declare a global a variable for this. Use a class (maybe a singleton) that holds the mode and use a -(float) getGameDuration; method
lets say...
// GameHandler.h
static GameHandler *sharedInstance = nil;
#interface GameHandler : NSObject
{
GameMode *mode;
}
typedef enum{
GAMEMODE_EASY = 0,
GAMEMODE_NORMAL,
GAMEMODE_HARD
} GameMode;
-(float) getGameDuration;
implementation
// GameHandler.m
+ (GameHandler *)sharedInstance // implement singleton
{};
-(float) getGameDuration
{
switch(mode)
{
case GAMEMODE_EASY:
return 10.f;
case GAMEMODE_NORMAL:
return 5.f;
case GAMEMODE_HARD:
return 2.f;
}
return 5.f;
}
// your other classes
float gameDurration = [[GameHandler sharedInstance] getGameDuration];
self->mTimer = [NSTimer scheduledTimerWithTimeInterval:gameDurration
target:self
selector:#selector(buttonNotPushed)
userInfo:nil
repeats:NO];
I'm trying to create a simple countdown timer app for myself. So far I've figured out how to create the countdown timers with a stop/reset action on them for a single button I've got attached to the timer.
However, I would like to add multiple timers to the same page and I'm not really sure how to do about making extra calls for the timers. Each of the timers would have it's own number to count down from (7 minutes for one, 3 minutes for the other, etc). These are set intervals that the user is not able to change. Google hasn't really worked out for me on how to do this so I'm hoping someone can at least guide me in the right direction. Below is my code snippets:
ViewController.h
#interface ViewController : UIViewController {
IBOutlet UILabel *firstCountdownLabel;
NSTimer *firstCountdownTimer;
bool timerActive;
int secondsCount;
}
- (IBAction)start:(id)sender;
- (void)timerRun;
#end
ViewController.m
#interface ViewController ()
#end
#implementation ViewController
- (void) timerRun {
secondsCount = secondsCount - 1;
int minutes = secondsCount / 60;
int seconds = secondsCount - (minutes * 60);
NSString *timerOutput = [NSString stringWithFormat:#"%2d:%.2d", minutes, seconds];
firstCountdownLabel.text = timerOutput;
if (secondsCount == 0) {
[firstCountdownTimer invalidate];
firstCountdownTimer = nil;
}
}
//- (void) setTimer {
- (IBAction)start:(id)sender {
secondsCount = 420;
if (timerActive == NO) {
timerActive = YES;
self->firstCountdownTimer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:#selector(timerRun) userInfo:nil repeats:YES];
}
else {
timerActive=NO;
[self->firstCountdownTimer invalidate];
self->firstCountdownTimer = nil;
}
}
- (void)viewDidLoad
{
[super viewDidLoad];
// [self setTimer];
// Do any additional setup after loading the view, typically from a nib.
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
#end
Google doesn't help in showing you how to implement original application ideas.
If you want multiple timers, define multiple timer instance variables:
#interface ViewController : UIViewController
{
IBOutlet UILabel *timer1Label;
IBOutlet UILabel *timer2Label;
IBOutlet UILabel *timer3Label;
NSTimer *timer1;
NSTimer *timer2;
NSTimer *timer3;
int timer1Count;
int timer2Count;
int timer3Count;
bool timer1Active;
bool timer2Active;
bool timer3Active;
}
Then create a separate IBAction for each button that starts each of the timers:
- (IBAction)startTimer1:(id)sender
{
timer1Count = 420;
if (timer1Active == NO)
{
timer1Active = YES;
timer1 = [NSTimer scheduledTimerWithTimeInterval:1.0
target:self
selector:#selector(timer1Run:)
userInfo:nil
repeats:YES];
}
else
{
timer1Active=NO;
[timer1 invalidate];
timer1 = nil;
}
}
- (void) timer1Run: (NSTimer*) timer
{
timer1Count -= 1;
int minutes = timer1Count / 60;
int seconds = timer1Count - (minutes * 60);
NSString *timerOutput = [NSString stringWithFormat:#"%2d:%.2d", minutes, seconds];
timer1Label = timerOutput;
if (timer1Count == 0) {
[timer2 invalidate];
timer2 = nil;
}
}
Duplicate the above code for each timer, using "timer2" and "timer3" in place of "timer1". Change the time counts for each one to the desired values. (I changed the names from "firstTimer" to "timer1" because it's easier to edit the code to support multiple timers that way.
I did not write 3 versions of each method for you because you need to figure this out rather than copy & pasting in code that you don't understand.
It would be possible, and require less code, to use the same IBAction method for all your start timer buttons, and have the code check the tag on the button to decide which timer to start.
The code might look like this:
- (IBAction)startTimer1:(id)sender
{
int tag = [sender tag];
switch (tag)
{
case 1: //timer 1
//Put code to start timer 1 here
break;
case 2: //timer 2
//put code to start timer 2 here
break;
}
}
But that might be a bit over your head at the moment.
By the way, forget you ever saw the "self->variable" syntax. it is slower and more error-prone than just referring to the instance variable directly. using object->variable syntax also allows you to access the instance variables of other objects, which is bad practice. You should always use properties to access the instance variables of objects other than yourself.
Also, the timer method should take a single parameter, a timer. I corrected the timer method in the above code.
Create a class as YourTimer with few properties like
NSString *timerLabel;
NSTimer *timer;
NSInteger timerCounter;
Now create an array of YourTimer objects. Then you can access it easily.
This will be modular, maintainable and reusable code, as may be later on you need one more identifier to be with all timers, hence wrap them in one class and use it.
I'm trying to keep a timer running on another page when you switch to other pages and complete other tasks, in essence keeping a clock on how long it takes to do the tasks. Whenever I switch to another page, it resets the timer back to what it was started, and does the same with some switches on other pages that I'm trying to keep on. Any ideas?
Screenshot of storyboards:
Code so far:
//
// ViewController.m
#import "ViewController.h"
#interface ViewController ()
#end
#implementation ViewController
- (IBAction)start{
ticker = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self ``selector:#selector(showActivity) userInfo:nil repeats:YES];
}
- (IBAction)reset{
[ticker invalidate];
time.text = #" 0:00";
}
- (void)showActivity{
int currentTime = [time.text intValue];
int newTime = currentTime + 1;
time.text = [NSString stringWithFormat:#"%d", newTime];
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
#end
// ViewController.h
#import <UIKit/UIKit.h>
#interface ViewController : UIViewController{
IBOutlet UILabel *time;
NSTimer *ticker;
}
- (IBAction)start;
- (IBAction)reset;
- (void)showActivity;
#end
Your NSTimer is a member variable of your view controller class. I'm assuming that when you switch between views, you're destroying this view controller and instantiating an instance of a new one. That means this view controller is gone, as well as the timer; it's not that the timer is being reset, it's that your old timer has been destroyed an a new one is being created.
What you need is to store your NSTimer and its functionality in a place where it will not be destroyed every time you change your view controller. One solution is to create a Singleton class which handles the timer. (A Singleton class is a class that can only be created one time; only one instance of it can exist. You can read more about them here.)
Here is an example of how you can create a Singleton class in Objective-C. The header:
//ApplicationManager.h
#interface ApplicationManager : NSObject
+(ApplicationManager*) instance;
#end
And the implementation:
//ApplicationManager.m
#import "ApplicationManager.h"
#implementation ApplicationManager
static ApplicationManager* appMgr = nil;
+(ApplicationManager*) instance
{
#synchronized([ApplicationManager class])
{
if(!appMgr)
{
appMgr = [[self alloc] init];
}
return appMgr;
}
return nil;
}
+(id) alloc
{
#synchronized([ApplicationManager class])
{
NSAssert((appMgr == nil), #"Only one instance of singleton class may be instantiated.");
appMgr = [super alloc];
return appMgr;
}
}
-(id) init
{
if(!(self = [super init]))
{
[self release];
return nil;
}
return self;
}
#end
The first time you call the instance method, the instance of the ApplicationManager will be created. Each time you want to access it, call the instance method again; the ApplicationManager will be returned. Now you simply add your NSTimer (and any other object you wish to persist throughout your application) as member variables of the ApplicationManager class.
You then must import the ApplicationManager class into your view controller class, and your view controller methods will change to:
-(IBAction) start
{
[[ApplicationManager instance] setTicker:[NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:#selector(showActivity) userInfo:nil repeats:YES]];
}
-(IBAction) reset
{
[[[ApplicationManager instance] ticker] invalidate];
time.text = #" 0:00";
}
-(void) showActivity
{
int currentTime = [time.text intValue];
int newTime = currentTime + 1;
time.text = [NSString stringWithFormat:#"%d", newTime];
}
If you want to make things nice and neat, you can also add this line to the top of your ApplicationManager class:
#define APPMGR [ApplicationManager instance]
Now instead of having to type [ApplicationManager instance] everywhere, you can simply refer to it as APPMGR instead. [APPMGR ticker] is a lot cleaner than [[ApplicationManager instance] ticker] :)
I have a method that draws a one sprite on the screen with the animation effects,
if I call in init this method
if( (self=[super init]) ) {
// ....
[self myMethod];
// .....
}
Then he does it once on my project
When I call by schedule
-(void)schedulMyMethod:(ccTime)dt {
[self myMethod];
}
if( (self=[super init]) ) {
// ....
[self schedule:#selector(schedulMyMethod:) interval:0.5];
// .....
}
It runs for an unlimited times
I need so that I can call the my method some amount
You mean, you want to have it repeat N times? You'll need to keep state on times remaining for it to run.
#property (nonatomic, assign) NSInteger timesToRunMyMethod;
- (void)beginRunningMyMethod {
self.timesToRunMyMethod = 100; // N==100
[self myMethod];
}
- (void)myMethod {
self.timesToRunMyMethod--;
// do stuff
if (self.timesToRunMyMethod > 0) {
// i used native delayed execution, you can replace it with whatever cocos2d offers if you want
[self performSelector:#selector(myMethod) withObject:nil afterDelay:0.5];
}
}
And it's probably wrong to start this on init. Is it a view controller? Then you can use viewDidAppear or willAppear.
I'm new to programming, and I've been stuck for a while on the following:
When I run the attached code, everything seems to work fine, then the progress bar starts counting up again. The console keeps printing the invalidation confirmation string, but the timer seems to keep rolling. I appreciate your help.
#import "ViewController.h"
#interface ViewController ()
#end
#implementation ViewController
#synthesize doneYet;
#synthesize cooking;
#synthesize hidebutton;
- (void)viewDidLoad;
{
[super viewDidLoad];
[doneYet setProgress:doneYet.progress=0.0];
// Do any additional setup after loading the view, typically from a nib.
}
- (void)viewDidUnload
{
[self setDoneYet:nil];
[self setHidebutton:nil];
[self setCooking:nil];
[super viewDidUnload];
// Release any retained subviews of the main view.
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}
-(void)startTimer
{CurrentTimer=[NSTimer scheduledTimerWithTimeInterval:1 target:self selector:#selector(timerFired) userInfo:Nil repeats:YES];}
-(void)timerFired
{ if (doneYet.progress<1) {
[doneYet setProgress:doneYet.progress+0.1];
}
else if (doneYet.progress=1)
{
(void) [CurrentTimer invalidate];
NSLog(#"invalidated CurrentTimer");
hidebutton.hidden = FALSE;
cooking.hidden = TRUE;
[doneYet setProgress:doneYet.progress=0.0];
}
}
- (IBAction)Eggtimer:(id)sender
{
[self startTimer];
hidebutton.hidden = TRUE;
cooking.hidden = FALSE;
;}
#end
This seems a problem
else if (doneYet.progress=1)
for 2 reasons:
the equality comparison operator is == and not = (which is the assign operator)
you are comparing a float number for an exact value, this is never good because floating numbers are not precise, you should check for progress >= 1.0, otherwise you could go over 1.0 (eg 1.0000001) and skip stop condition
In addition in the stop condition you do
[doneYet setProgress:doneYet.progress=0.0];
but formerly it should be
[doneYet setProgress:0.0];
I think you should do this, retain the NSTimer object.
CurrentTimer=[[NSTimer scheduledTimerWithTimeInterval:1 target:self selector:#selector(timerFired) userInfo:Nil repeats:YES] retain];
One thing you can do is change your startTimer as
-(void)startTimer
{
[CurrentTimer invalidate];
CurrentTimer=[NSTimer scheduledTimerWithTimeInterval:1 target:self selector:#selector(timerFired) userInfo:Nil repeats:YES];
}
This will invalidate old timer and there will be only one timer.
My error was in designating the button that commands startTimer as the FirstResponder.
Sorry for using your time and advice on something that was the result of an error not in the code.
Thanks again to everyone who offered their advice. It means a lot to a beginner!