Question

I am writing an app for the iPhone using cocos2d where I have 4 Sprites that are buttons. I want to allow and respond to the following (allowing the user 3 seconds to apply his input before timing out):

— Single button presses (I have this part working).
— Pressing of more than 1 button at at the same time (each combination would have a different response).
— Flicking/Swiping gestures that originate from within each of the button Sprites.
— Shaking the iPhone.
— Tilting the iphone up, down, left, right (from landscape mode).

Any insight into different approaches would be greatly appreciated. B)

Answer 1

Here is how I implemented this in case anyone else is trying to do this (I attempted to add the shakes/gestures/tilts part yet just the Simultaneous button presses and for now I have limited it to only 2-button combos — but I could easily extend the logic to handle 3 and 4-button combos as well).

spuButton.h (a CCSprite Subclass)

#import <Foundation/Foundation.h>
#import "cocos2d.h"

typedef enum tagButtonState {
    kButtonStatePressed,
    kButtonStateNotPressed
} ButtonState;

typedef enum tagButtonStatus {
    kButtonStatusEnabled,
    kButtonStatusDisabled
} ButtonStatus;

@interface spuButton : CCSprite <CCTargetedTouchDelegate> {
@private
    ButtonState buttonState;
    CCTexture2D *buttonNormal;
    CCTexture2D *buttonLit;
    ButtonStatus buttonStatus;  
}

@property(nonatomic, readonly) CGRect rect;

+ (id)spuButtonWithTexture:(CCTexture2D *)normalTexture;

- (void)setNormalTexture:(CCTexture2D *)normalTexture;
- (void)setLitTexture:(CCTexture2D *)litTexture;
- (BOOL)isPressed;
- (BOOL)isNotPressed;
- (void)makeDisabled;
- (void)makeEnabled;
- (BOOL)isEnabled;
- (BOOL)isDisabled;
- (void)makeLit;
- (void)makeNormal;
- (void)dealloc;

@end

spuButton.m

#import "spuButton.h"
#import "cocos2d.h"

@implementation spuButton

- (CGRect)rect {
    CGSize s = [self.texture contentSize];
    return CGRectMake(-s.width / 2, -s.height / 2, s.width, s.height);
}

+ (id)spuButtonWithTexture:(CCTexture2D *)normalTexture {
    return [[[self alloc] initWithTexture:normalTexture] autorelease];
}

- (void)setNormalTexture:(CCTexture2D *)normalTexture {
    buttonNormal = normalTexture;
}
- (void)setLitTexture:(CCTexture2D *)litTexture {
    buttonLit = litTexture;
}

- (BOOL)isPressed {
    if (buttonState== kButtonStateNotPressed) return NO;
    if (buttonState== kButtonStatePressed) return YES;
    return NO;
}

- (BOOL)isNotPressed {
    if (buttonState== kButtonStateNotPressed) return YES;
    if (buttonState== kButtonStatePressed) return NO;
    return YES;
}

- (void)makeDisabled {
    buttonStatus = kButtonStatusDisabled;
    buttonState= kButtonStateNotPressed;
    [self makeNormal];
}
- (void)makeEnabled {
    buttonStatus = kButtonStatusEnabled;
    buttonState= kButtonStateNotPressed;
    [self makeNormal];
}

- (BOOL)isEnabled {
    if (buttonStatus== kButtonStatusDisabled) return NO;
    if (buttonStatus== kButtonStatusEnabled) return YES;
    return NO;
}

- (BOOL)isDisabled {
    if (buttonStatus== kButtonStatusEnabled) return NO;
    if (buttonStatus== kButtonStatusDisabled) return YES;
    return YES;
}

- (void)makeLit {
    [self setTexture:buttonLit];
}

- (void)makeNormal {
    [self setTexture:buttonNormal];
}

- (id)initWithTexture:(CCTexture2D *)aTexture {
    if ((self = [super initWithTexture:aTexture]) ) {       
        buttonState = kButtonStateNotPressed;
        buttonStatus = kButtonStatusEnabled;
    }
    return self;
}

- (void)onEnter {
    if (buttonStatus == kButtonStatusDisabled) return;
    [[CCTouchDispatcher sharedDispatcher] addTargetedDelegate:self priority:0 swallowsTouches:NO];
    [super onEnter];
}

- (void)onExit {
    if (buttonStatus == kButtonStatusDisabled) return;
    [[CCTouchDispatcher sharedDispatcher] removeDelegate:self];
    [super onExit];
}   

- (BOOL)containsTouchLocation:(UITouch *)touch {
    return CGRectContainsPoint(self.rect, [self convertTouchToNodeSpaceAR:touch]);
}

- (BOOL)ccTouchBegan:(UITouch *)touch withEvent:(UIEvent *)event {
    if (buttonStatus == kButtonStatusDisabled) return NO;
    if (buttonState== kButtonStatePressed) return NO;
    if ( ![self containsTouchLocation:touch] ) return NO;

    buttonState= kButtonStatePressed;
    [self makeLit];

    return YES;
}

- (void)ccTouchMoved:(UITouch *)touch withEvent:(UIEvent *)event {
    // If it weren't for the TouchDispatcher, you would need to keep a reference
    // to the touch from touchBegan and check that the current touch is the same
    // as that one.
    // Actually, it would be even more complicated since in the Cocos dispatcher
    // you get NSSets instead of 1 UITouch, so you'd need to loop through the set
    // in each touchXXX method.

    if (buttonStatus == kButtonStatusDisabled) return;
    if ([self containsTouchLocation:touch]) return;

    buttonState= kButtonStateNotPressed;
    [self makeNormal];
}

- (void)ccTouchEnded:(UITouch *)touch withEvent:(UIEvent *)event {
    if (buttonStatus == kButtonStatusDisabled) return;

    buttonState= kButtonStateNotPressed;
    [self makeNormal];
}

- (void)dealloc {
    [buttonNormal release];
    [buttonLit release];
    [super dealloc];
}

@end

HelloWorldScene.m (Just my tick: method to keep my other functions from confusing the example)

-(void)tick:(ccTime)dt {
    if ([[_otherControlsArray objectAtIndex:0] wasPressed]) {
        [[_otherControlsArray objectAtIndex:0] setWasPressed:NO];
        [self removeChild:[_otherControlsArray objectAtIndex:0] cleanup:YES];
        [self addChild:[_otherControlsArray objectAtIndex:1]];
        NSLog(@"Play");

        _gameHasNotBeenPlayedYet = NO;
        Snarfle_s_PowerUPAppDelegate *delegate = [[UIApplication sharedApplication] delegate];
        [delegate makeNotPaused];
        [self gameLogic];
    }

    if (_gameHasNotBeenPlayedYet) {
        return;
    }

    if (_buttonsPressedAndReleased > 0) {  //respond to button(s) released and reset
        NSLog(@"Buttons Pressed and Released-->%d",_buttonsPressedAndReleased);
        if ([self checkButtons:_buttonsPressedAndReleased]);
        _buttonsPressed = 0;
        _buttonsPressedAndReleased = 0;

        return;
    }
    if (_buttonsPressed <= 4) { // two buttons have not already been pressed
        for (spuButton *aButton in _fourButtonsArray) {
            if ([aButton isNotPressed]) continue; //this button is not pressed
            if (_buttonsPressed == 0) { //this button is pressed and no other buttons have been pressed
                _buttonsPressed = aButton.tag;
                continue;
            }
            //this button is pressed while another has been pressed
            //figure out which two buttons have been pressed
            if (_buttonsPressed == 1) {  //red plus another
                switch (aButton.tag) {
                    case 2:   //blue
                        _buttonsPressed = 5;
                        [[_fourButtonsArray objectAtIndex:2] makeDisabled];
                        [[_fourButtonsArray objectAtIndex:3] makeDisabled];
                        break;
                    case 3:  //green
                        _buttonsPressed = 6;
                        [[_fourButtonsArray objectAtIndex:1] makeDisabled];
                        [[_fourButtonsArray objectAtIndex:3] makeDisabled];
                        break;
                    case 4:  //yellow
                        _buttonsPressed = 7;
                        [[_fourButtonsArray objectAtIndex:1] makeDisabled];
                        [[_fourButtonsArray objectAtIndex:2] makeDisabled];
                        break;
                    default:
                        _buttonsPressed = 1;
                        break;
                }
            }
            if (_buttonsPressed == 2) {  //blue plus another
                switch (aButton.tag) {
                    case 1:   //red
                        _buttonsPressed = 5;
                        [[_fourButtonsArray objectAtIndex:2] makeDisabled];
                        [[_fourButtonsArray objectAtIndex:3] makeDisabled];
                        break;
                    case 3:  //green
                        _buttonsPressed = 8;
                        [[_fourButtonsArray objectAtIndex:0] makeDisabled];
                        [[_fourButtonsArray objectAtIndex:3] makeDisabled];
                        break;
                    case 4:  //yellow
                        _buttonsPressed = 9;
                        [[_fourButtonsArray objectAtIndex:0] makeDisabled];
                        [[_fourButtonsArray objectAtIndex:2] makeDisabled];
                        break;
                    default:
                        _buttonsPressed = 2;
                        break;
                }
            }
            if (_buttonsPressed == 3) {  //green plus another
                switch (aButton.tag) {
                    case 1:   //red
                        _buttonsPressed = 6;
                        [[_fourButtonsArray objectAtIndex:1] makeDisabled];
                        [[_fourButtonsArray objectAtIndex:3] makeDisabled];
                        break;
                    case 2:  //blue
                        _buttonsPressed = 8;
                        [[_fourButtonsArray objectAtIndex:0] makeDisabled];
                        [[_fourButtonsArray objectAtIndex:3] makeDisabled];
                        break;
                    case 4:  //yellow
                        _buttonsPressed = 10;
                        [[_fourButtonsArray objectAtIndex:0] makeDisabled];
                        [[_fourButtonsArray objectAtIndex:1] makeDisabled];
                        break;
                    default:
                        _buttonsPressed = 3;
                        break;
                }
            }
            if (_buttonsPressed == 4) {  //yellow plus another
                switch (aButton.tag) {
                    case 1:   //red
                        _buttonsPressed = 7;
                        [[_fourButtonsArray objectAtIndex:1] makeDisabled];
                        [[_fourButtonsArray objectAtIndex:2] makeDisabled];
                        break;
                    case 2:  //blue
                        _buttonsPressed = 9;
                        [[_fourButtonsArray objectAtIndex:0] makeDisabled];
                        [[_fourButtonsArray objectAtIndex:2] makeDisabled];
                        break;
                    case 3:  //green
                        _buttonsPressed = 10;
                        [[_fourButtonsArray objectAtIndex:0] makeDisabled];
                        [[_fourButtonsArray objectAtIndex:1] makeDisabled];
                        break;
                    default:
                        _buttonsPressed = 4;
                        break;
                }
            }
            if (_buttonsPressed > 4) break;  //more than one has been pressed and identified
        }
    }
    //now we know what buttons have been pressed now check to see if they have been released
    //if more than one has been pressed disable the other two
    //also if more than one has been pressed and one of them gets released disable the released one but keep it lit
    switch (_buttonsPressed) {
        case 1:  //red
            if ([[_fourButtonsArray objectAtIndex:0] isNotPressed]) _buttonsPressedAndReleased = 1;
            break;
        case 2:  //blue
            if ([[_fourButtonsArray objectAtIndex:1] isNotPressed]) _buttonsPressedAndReleased = 2;
            break;
        case 3:  //green
            if ([[_fourButtonsArray objectAtIndex:2] isNotPressed]) _buttonsPressedAndReleased = 3;
            break;
        case 4:  //yellow
            if ([[_fourButtonsArray objectAtIndex:3] isNotPressed]) _buttonsPressedAndReleased = 4;
            break;
        case 5:  //red & blue
            if (([[_fourButtonsArray objectAtIndex:0] isNotPressed]) && ([[_fourButtonsArray objectAtIndex:1] isNotPressed])) _buttonsPressedAndReleased = 5;
            else {
                if ([[_fourButtonsArray objectAtIndex:0] isNotPressed]) {
                    [[_fourButtonsArray objectAtIndex:0] makeDisabled];
                    [[_fourButtonsArray objectAtIndex:0] makeLit];
                }
                if ([[_fourButtonsArray objectAtIndex:1] isNotPressed]) {
                    [[_fourButtonsArray objectAtIndex:1] makeDisabled];
                    [[_fourButtonsArray objectAtIndex:1] makeLit];
                }
            }
            break;
        case 6:  //red & green
            if (([[_fourButtonsArray objectAtIndex:0] isNotPressed]) && ([[_fourButtonsArray objectAtIndex:2] isNotPressed])) _buttonsPressedAndReleased = 6;
            else {
                if ([[_fourButtonsArray objectAtIndex:0] isNotPressed]) {
                    [[_fourButtonsArray objectAtIndex:0] makeDisabled];
                    [[_fourButtonsArray objectAtIndex:0] makeLit];
                }
                if ([[_fourButtonsArray objectAtIndex:2] isNotPressed]) {
                    [[_fourButtonsArray objectAtIndex:2] makeDisabled];
                    [[_fourButtonsArray objectAtIndex:2] makeLit];
                }
            }
            break;
        case 7:  //red & yellow
            if (([[_fourButtonsArray objectAtIndex:0] isNotPressed]) && ([[_fourButtonsArray objectAtIndex:3] isNotPressed])) _buttonsPressedAndReleased = 7;
            else {
                if ([[_fourButtonsArray objectAtIndex:0] isNotPressed]) {
                    [[_fourButtonsArray objectAtIndex:0] makeDisabled];
                    [[_fourButtonsArray objectAtIndex:0] makeLit];
                }
                if ([[_fourButtonsArray objectAtIndex:3] isNotPressed]) {
                    [[_fourButtonsArray objectAtIndex:3] makeDisabled];
                    [[_fourButtonsArray objectAtIndex:3] makeLit];
                }
            }
            break;
        case 8:  //blue & green
            if (([[_fourButtonsArray objectAtIndex:1] isNotPressed]) && ([[_fourButtonsArray objectAtIndex:2] isNotPressed])) _buttonsPressedAndReleased = 8;
            else {
                if ([[_fourButtonsArray objectAtIndex:1] isNotPressed]) {
                    [[_fourButtonsArray objectAtIndex:1] makeDisabled];
                    [[_fourButtonsArray objectAtIndex:1] makeLit];
                }
                if ([[_fourButtonsArray objectAtIndex:2] isNotPressed]) {
                    [[_fourButtonsArray objectAtIndex:2] makeDisabled];
                    [[_fourButtonsArray objectAtIndex:2] makeLit];
                }
            }
            break;
        case 9:  //blue & yellow
            if (([[_fourButtonsArray objectAtIndex:1] isNotPressed]) && ([[_fourButtonsArray objectAtIndex:3] isNotPressed])) _buttonsPressedAndReleased = 9;
            else {
                if ([[_fourButtonsArray objectAtIndex:1] isNotPressed]) {
                    [[_fourButtonsArray objectAtIndex:1] makeDisabled];
                    [[_fourButtonsArray objectAtIndex:1] makeLit];
                }
                if ([[_fourButtonsArray objectAtIndex:3] isNotPressed]) {
                    [[_fourButtonsArray objectAtIndex:3] makeDisabled];
                    [[_fourButtonsArray objectAtIndex:3] makeLit];
                }
            }
            break;
        case 10:  //green & yellow
            if (([[_fourButtonsArray objectAtIndex:2] isNotPressed]) && ([[_fourButtonsArray objectAtIndex:3] isNotPressed])) _buttonsPressedAndReleased = 10;
            else {
                if ([[_fourButtonsArray objectAtIndex:2] isNotPressed]) {
                    [[_fourButtonsArray objectAtIndex:2] makeDisabled];
                    [[_fourButtonsArray objectAtIndex:2] makeLit];
                }
                if ([[_fourButtonsArray objectAtIndex:3] isNotPressed]) {
                    [[_fourButtonsArray objectAtIndex:3] makeDisabled];
                    [[_fourButtonsArray objectAtIndex:3] makeLit];
                }
            }
            break;
        default:
            _buttonsPressedAndReleased = 0;
            break;
    }
}