I want to make NSMutableArray to store the touch time gap, but came across a problem:
The NSMutableArray's count is only 1.
What can I do?
NSInteger count = 0;
float firstTempTime = 0;
float nTempTime = 0;
float nTouchTimegap = 0;
#pragma mark –
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
messageLabel.text = #"Touches Began";
[self updateLabelsFromTouches:touches];
NSArray *array = [touches allObjects];
for (UITouch *touch in array){
count = count +1;
NSLog(#"began touch count: %d", count);
nTempTime = [touch timestamp];
NSLog(#"n TempTime stamp : %lf", nTempTime);
if (count == 1) {
firstTempTime = [touch timestamp];
}
else {
nTouchTimegap = nTempTime - firstTempTime;
firstTempTime = nTempTime;
}
NSLog(#"nTouchTimegap : %lf", nTouchTimegap);
nTouchTimegapArray = [NSMutableArray arrayWithCapacity:count];
[nTouchTimegapArray addObject:[NSNumber numberWithFloat: nTouchTimegap]];
for(id obj in nTouchTimegapArray){
NSLog(#"nTouchTimegapArray : %i", [nTouchTimegapArray count]);
NSLog(#"nTouchTimegapArray : %#", obj);
}
}
touchesBegan: will be called once you touch the screen, if you touch the screen with a second finger it will be called again.
You should take a look at touchesEnded: and touchesCancelled:
I guess I have to spell it out:
nTouchTimegapArray = [NSMutableArray arrayWithCapacity:count];
[nTouchTimegapArray addObject:[NSNumber numberWithFloat: nTouchTimegap]];
That sequence effectively erases the array on each iteration. There's no possible way to ever have more than one entry in the array.
Move the first line out of the loop, and, if you want to accumulate touches from all invocations of the method, move it to the init routine or viewDidLoad or some such.
Related
In my .h file, I have:
#property (nonatomic) NSMutableArray *cards;
In my .m file, I have, in the initializer:
- (id) init
{
self = [super init];
self.cards = [NSMutableArray alloc];
return self;
}
In a loop that populates a number of items visible and on-screen:
[self.cards addObject:noteView];
And in a touch event handler, I have:
- (void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
NSLog(#"In touchesBegan.");
UITouch *touch = [touches anyObject];
UIView *selectedView = nil;
CGPoint touchLocation = [touch locationInView:self.view];
for (UIView *card in _cards)
{
CGRect cardRect = [card frame];
NSLog(#"%f", cardRect.origin.x);
NSLog(#"%f", cardRect.origin.y);
NSLog(#"%f", cardRect.size.height);
NSLog(#"%f", cardRect.size.width);
if (CGRectContainsPoint(cardRect, touchLocation)) {
NSLog(#"Match found.");
selectedView = card;
CGRect selectedFrame = selectedView.frame;
selectedFrame.origin.y = -selectedFrame.size.height;
selectedFrame.size = selectedView.frame.size;
float heightRatio = (float) floor([[UIScreen mainScreen] bounds].size.height + .4) / (float) selectedFrame.size.height;
float widthRatio = (float) floor([[UIScreen mainScreen] bounds].size.width + .4) / (float) selectedFrame.size.width;
float ratio = MIN(heightRatio, widthRatio);
selectedFrame.size.height *= ratio;
selectedFrame.size.width *= ratio;
selectedFrame.origin.x = -selectedFrame.origin.x * ratio;
}
}
}
The output for every touch I've made has been that the unconditional NSLog statement is output, but none of the "Log this float" statements execute. It seems that I have not correctly initialized or not correctly populated NSMutableArray.
I seem to get the same behavior whether I refer to _cards or self.cards.
Thanks for any help,
--EDIT--
I seem to be sticking on something else than originally thought of. I now have self.cards = [[NSMutableArray alloc] init], but identical behavior: I go through a loop and populate a bunch of cards, but when I tap one of them, the touch handler outputs "In touchesBegan." but none of the floats. Given an updated init, why would touchesBegan be acting as if it hadn't seen any cards after a number of cards are visible onscreen? (The other output should give a number of lines of floats whether or not the touch was on target for a particular card.)
You need to init the array!
self.cards = [[NSMutableArray alloc] init];
Or
self.cards = [NSMutableArray new];
They are both equivalents
With alloc the only thing you are doing is reserve space in the memory for that variable.
From Apple Documentation:
alloc
Returns a new instance of the receiving class.
init
Implemented by subclasses to initialize a new object (the receiver) immediately after memory for it has been allocated.
Are you using a storyboard for this? Try to initialize your cards property in viewDidLoad.
As a quick check, try to initialize that property right before the loop that is adding objects to it.
I'm making a little game, here is some example code of whats going on:
-(id) init
{
self.arrowProjectileArray = [[[NSMutableArray alloc] init] autorelease];
self.batchNode = [CCSpriteBatchNode batchNodeWithTexture:[[CCTextureCache sharedTextureCache] addImage:#"arrow.png"]];
[self addChild:_batchNode z:2];
for (CCSprite *projectile in _arrowProjectileArray) {
[_batchNode removeChild:projectile cleanup:YES];
}
[_arrowProjectileArray removeAllObjects];
self.nextProjectile = nil;
}
}
-(void) callEveryFrame:(ccTime)dt{
for (int i = 0; i < [_arrowProjectileArray count];i++) {
CCSprite *cursprite = [_arrowProjectileArray objectAtIndex:i];
if (cursprite.tag == 1) {
float x = theSpot.x+10;
float y = theSpot.y+10;
cursprite.position = ccp(x, y);
}
}
- (void)ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
[_batchNode addChild:_nextProjectile z:1 tag:1];
[_arrowProjectileArray addObject: _nextProjectile];
[self spriteMoveFinished];
}
-(void) dealloc
{
self.arrowProjectileArray = nil;
self.nextProjectile = nil;
[super dealloc];
}
The only code that I included was code that is relevant to the arrow's projection.
The arrow shoots fine, the problem is every time I shoot the stupid thing, I think it shoots a new arrow, but puts multiple arrows onto of that 1 arrow and makes it look like a fat ugly arrow pixel thing. What am I doing wrong? I'm not too familiar with NSMutableArray, but I'm currently stuck.
In init method, you create a new NSMutableArray instance and assign it to self.arrowProjectileArray, then you traverse the arrowProjectileArray in the following lines using a for loop. If addChild: method does not add anything to arrowProjectileArray, then your code has a logic mistake, because what you do by traversing arrowProjectileArray is traversing an empty array, which means you do nothing in that code.
You should double-check what you intend to do and what your code is doing actually.
I solved my own problem by doing a little bit of research, I also got rid of the batch node.
I have a UIView subclass that moved around 'event's when the user touches them, using the following overridden method:
// In a custom UIView...
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
CGPoint point = [[touches anyObject] locationInView:self];
UIView *eventView = [self.ringOfEvents hitTest:point withEvent:event];
for (EventView *e in self.events) {
if (e == eventView) {
event.position = point;
}
}
}
Why is it that when I make EventView a CALayer instead of UIView, the movement slows down to a creep? I can post that code too, but it is so similar that I don't think it is necessary.
I would think that abstracting to a lower level would speed up event handling, but I must be missing something.
By the way, either if *eventView is a subclass of UIView or CALayer, the position property is as follows:
- (void)setPosition:(CGPoint)pos {
self.layer.position = pos;
}
- (CGPoint)position {
return self.layer.position;
}
Not sure why I get a huge decrease in latency when using UIView as apposed to CALayer..
Most CALayer properties are changed with animation by default, so decrease in latency is probably caused by that.
You may want to disable animations when layer position is changed. Possible solutions are discussed for example in here and here
This is due to implicit animations.
I've implemented a category method which removes implicit animation for givven keys and can be used like this
[view.layer setNullAsActionForKeys:#[#"bounds", #"position"]];
Implementation
#implementation CALayer (Extensions)
- (void)setNullAsActionForKeys:(NSArray *)keys
{
NSMutableDictionary *dict = [self.actions mutableCopy];
if(dict == nil)
{
dict = [NSMutableDictionary dictionaryWithCapacity:[keys count]];
}
for(NSString *key in keys)
{
[dict setObject:[NSNull null] forKey:key];
}
self.actions = dict;
}
#end
I'm a beginner level programmer trying to make a game app for the iphone and I've encountered a possible issue with the memory management (exc_bad_access) of my program so far. I've searched and read dozens of articles regarding memory management (including apple's docs) but I still can't figure out what exactly is wrong with my codes. So I would really appreciate it if someone can help clear up the mess I made for myself.
//in the .h file
#property(nonatomic,retain) NSMutableArray *fencePoleArray;
#property(nonatomic,retain) NSMutableArray *fencePoleImageArray;
#property(nonatomic,retain) NSMutableArray *fenceImageArray;
//in the .m file
- (void)viewDidLoad {
[super viewDidLoad];
self.gameState = gameStatePaused;
fencePoleArray = [[NSMutableArray alloc] init];
fencePoleImageArray = [[NSMutableArray alloc] init];
fenceImageArray = [[NSMutableArray alloc] init];
mainField = CGRectMake(10, 35, 310, 340);
..........
[NSTimer scheduledTimerWithTimeInterval:0.05 target:self selector:#selector(gameLoop) userInfo:nil repeats:YES];
}
So basically, the player touches the screen to set up the fences/poles
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
if(.......) {
.......
}
else {
UITouch *touch = [[event allTouches] anyObject];
currentTapLoc = [touch locationInView:touch.view];
NSLog(#"%i, %i", (int)currentTapLoc.x, (int)currentTapLoc.y);
if(CGRectContainsPoint(mainField, currentTapLoc)) {
if([self checkFence]) {
onFencePole++;
//this 3 set functions adds their respective objects into the 3 NSMutableArrays using addObject:
[self setFencePole];
[self setFenceImage];
[self setFencePoleImage];
.......
}
}
else {
.......
}
}
}
}
The setFence function (setFenceImage and setFencePoleImage is similar to this)
-(void)setFencePole {
Fence *fencePole;
if (!elecFence) {
fencePole = [[Fence alloc] initFence:onFencePole fenceType:1 fencePos:currentTapLoc];
}
else {
fencePole = [[Fence alloc] initFence:onFencePole fenceType:2 fencePos:currentTapLoc];
}
[fencePoleArray addObject:fencePole];
[fencePole release];
and whenever I press a button in the game, endOpenState is called to clear away all the extra images(fence/poles) on the screen and also to remove all existing objects in the 3 NSMutableArray. Point is to remove all the objects in the NSMutableArrays but keep the array itself so it can be reused later.
-(void)endOpenState {
........
int xMax = [fencePoleArray count];
int yMax = [fenceImageArray count];
for (int x = 0; x < xMax; x++) {
[[fencePoleImageArray objectAtIndex:x] removeFromSuperview];
}
for (int y = 0; y < yMax; y++) {
[[fenceImageArray objectAtIndex:y] removeFromSuperview];
}
[fencePoleArray removeAllObjects];
[fencePoleImageArray removeAllObjects];
[fenceImageArray removeAllObjects];
........
}
The crash happens here at the checkFence function.
-(BOOL)checkFence {
if (onFencePole == 0) {
return YES;
}
else if (onFencePole >= 1 && onFencePole < currentMaxFencePole - 1) {
CGPoint tempPoint1 = currentTapLoc;
CGPoint tempPoint2 = [[fencePoleArray objectAtIndex:onFencePole-1] returnPos]; // the crash happens at this line
if ([self checkDistance:tempPoint1 point2:tempPoint2]) {
return YES;
}
else {
return NO;
}
}
else if (onFencePole == currentMaxFencePole - 1) {
......
}
else {
return NO;
}
}
So the problem here is, everything works fine until checkFence is called the 2nd time after endOpenState is called. So its like tap_screen -> tap_screen -> press_button_to_call_endOpenState -> tap screen -> tap_screen -> crash
What I'm thinking of is that fencePoleArray got messed up when I used [fencePoleArray removeAllObjects] because it doesn't crash when I comment it out. It would really be great if someone can explain to me what went wrong. And thanks in advance.
First, a couple of suggestions:
if (!elecFence) {
fencePole = [[Fence alloc] initFence:onFencePole
fenceType:1 fencePos:currentTapLoc];
}
else {
fencePole = [[Fence alloc] initFence:onFencePole
fenceType:2 fencePos:currentTapLoc];
}
You’re making this too hard, how about this:
const int fenceType = elecFence ? 2 : 1;
Fence *fencePole = [[Fence alloc] initFence:onFencePole
fenceType:fenceType fencePos:currentTapLoc];
And this:
int xMax = [fencePoleArray count];
int yMax = [fenceImageArray count];
for (int x = 0; x < xMax; x++) {
[[fencePoleImageArray objectAtIndex:x] removeFromSuperview];
}
for (int y = 0; y < yMax; y++) {
[[fenceImageArray objectAtIndex:y] removeFromSuperview];
}
Could be shortened using makeObjectsPerformSelector:
const SEL remove = #selector(removeFromSuperview);
[fencePoleImageArray makeObjectsPerformSelector:remove];
[fenceImageArray makeObjectsPerformSelector:remove];
This is shorter and safer, as the xMax bound in your code is computed from fencePoleArray and used to iterate over fencePoleImageArray. (Could be right, could be wrong.)
Now to the objectAtIndex: call. If the array is still in memory and you tried to access an object beyond the array bounds, you would get an exception. So that I guess that either the array or some of the objects in it got released without you knowing it. You could try to NSLog the array and the object on given index and try to log their retainCount. If the logging line crashes, you have found the object that’s been released and can start looking for the cause.
(And one more thing: You should split the game logic into a separate model class. This simplifies the code and makes it easier to reason about.)
If you want to use properties, you should use self.propertyName = ... instead of propertyName = ....
Hope this will help.
I have UIScrollView which has subviews (pictures) added do it. each time a user touches the a picture in the scrollview, it toggles a checkmark ontop of it.
NSMutableIndexSet *picturesArray; <- declared in .h
- (void) touchesEnded: (NSSet *) touches withEvent: (UIEvent *) event {
if (!self.dragging) {
[self.nextResponder touchesEnded: touches withEvent:event];
NSLog(#"Touch down");
for (UITouch *touch in touches) {
for (int i = 1; i <= [self subviews].count; i++)
{
if(CGRectContainsPoint([[self viewWithTag:i]frame], [touch locationInView:self])){
NSLog(#"touched %d th view",i);
NSArray *subviews = [[self viewWithTag:i] subviews];
UIImageView *view = nil;
view = [subviews objectAtIndex:0];
if(view.hidden){
// add the index
[picturesArray addIndex:i];
view.hidden = NO; //check mark is shown
}else{
[picturesArray removeIndex:i];
view.hidden = YES; //check mark is not shown
}
// UIImageWriteToSavedPhotosAlbum([(UIImageView *)[self viewWithTag:i]image], nil, nil, nil); <- WORKS IF CALLED
}
}
}
}
Question 1: is this the best way of doing this? It seems like using a for (int i = 1; i <= [self subviews].count; i++) is pretty slow. I basically need to capture which subview was touched. I havent figured this out other than going through EACH subview
savePhotos is called and basically searches through which of the pictures was touched and saves them to the Photo Album. However the call to UIImageWriteToSavedPhotosAlbum fails. This is in the same file as TouchesEnded. But when called in TouchesEnded, it works.
(IBAction) savePhotos: (id) sender{
NSLog(#"The index set is %#",picturesArray );
const NSUInteger arrayCount = picturesArray.count;
NSUInteger *theIndexBuffer = (NSUInteger *)calloc(picturesArray.count, sizeof(NSUInteger));
UIImageWriteToSavedPhotosAlbum([(UIImageView *)[self viewWithTag:0]image], nil, nil, nil);
[picturesArray getIndexes:theIndexBuffer maxCount:arrayCount inIndexRange:nil];
for(int i = 0; i < arrayCount; i ++){
NSLog(#"Element is %d",theIndexBuffer[i]);
UIImageWriteToSavedPhotosAlbum([(UIImageView *)[self viewWithTag:i]image], nil, nil, nil); <- THIS CRASHES
}
}
Question 2: Why is it that UIImageWriteToSavedPhotosAlbum is failing ?
1) instead of using UIImageView, implement a child of UIImageView. Then try listening for touches on the individual subviews, that should solve your O(n) problem
2) something is probably getting auto-released, double check your reference counting is correct
try UIView* targetView = [self hitTest:location withEvent:nil];