Question

I’m creating a jigsaw application. When each piece is touched, the idea is that a bool (droppedInPlace) is assigned YES if it is put in its correct place, and NO if it is dropped in the wrong place. I then think I need to create an array of 40 bools (the number of jigsaw pieces), each of these entries will be initially set to NO.

This bool (droppedInPlace) is then inserted into an array using replaceObjectAtIndex. I then want to loop through this array. If all entries are true/yes/1, then the jigsaw is completed and i’ll run some code.

I’m having some trouble doing this. I can’t figure out how to code my idea above. Below is my code:

-(void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
UIView *touchedView = [touch view];
// filename to be read from
NSString *filePath = [[NSBundle mainBundle]
                      pathForResource: 
                      @"jigsawHomeCenterPoints" 
                      ofType:@"plist"];
// array of cgpoints in string format
NSArray *jigsawHomeCentersArray = [NSArray arrayWithContentsOfFile:filePath];
// the tag number of the selected image
int tag = touchedView.tag;
NSLog(@"tag: %i", tag);
// says that the piece has not been dropped in it's holder
bool droppedInPlace = NO;
// if what has been touched is part of the array of images
if ([imagesJigsawPieces indexOfObject:touchedView] != NSNotFound) {
    // preparing new snap-to-center position
    // using (tag-1) as an index in the HomeCentersArray corresponds to where the image should be placed
    // this was a conscious decision to make the process easier
    CGPoint newcenter = CGPointFromString([jigsawHomeCentersArray objectAtIndex:tag-1]);
    // the location of the current touch
    CGPoint location = [touch locationInView:self.view];
    // call the animate method upon release
    [self animateReleaseTouch:touchedView withLocation:location];
    // setting a proximity range - if it is within this 80x80 area the image will snap to it's corresponding holder (HomeCenter)
    if (location.x > newcenter.x-40 && location.x < newcenter.x+40 
        && location.y > newcenter.y-40 && location.y < newcenter.y+40) {
        touchedView.center = newcenter;
        touchedView.alpha = 1.0;
        droppedInPlace = YES;
    } else {
        touchedView.alpha = 0.5;
        droppedInPlace = NO;
    }
    NSLog(@"True or false: %i", droppedInPlace);
[self checkJigsawCompleted:droppedInPlace withTag:tag];
}
}

And the check function:

-(void) checkJigsawCompleted:(BOOL)inPlace withTag:(NSInteger)tag {
NSMutableArray *piecesInPlace;
[piecesInPlace replaceObjectAtIndex:tag-1 withObject:[NSNumber numberWithBool:inPlace]];
//code to loop through array - check if all entries are true/yes/1
//if so, jigsaw is completed - run some other code
//else, do nothing
}

Answer 1

You want to know how to loop through an array? You can use a for(;;) loop or a for(.. in ..) loop or, my favourite for this sort of thing: -enumerateObjectsUsingBlock:

__block jigsawIsComplete = true;
[piecesInPlace enumerateObjectsUsingBlock: ^(id obj, NSUInteger i, BOOL* stop)
    {
        jigsawIsComplete = jigSawIsComplete && [obj boolValue];
        *stop = !jigsawIsComplete;
    }];