I have code that works but I want to make sure I am doing things properly and cleanly.
I have four versions of the same collection of views displayed on a screen. Each collection which will be used to control the volume and rate of four different sounds. The collections are linked with IBOutletCollection to 4 different NSArrays (soundView0, soundView1, soundView2, soundView3).
I used the following code to determine which volume slider is being adjusted:
-(IBAction)whichVolume:(UISlider *)sender
{
if ([soundView0 containsObject:sender]) {
soundIndex = 0;
}
else if (([soundView1 containsObject:sender]))
{
soundIndex = 1;
}
else if ([soundView2 containsObject:sender])
{
soundIndex = 2;
}
else if ([soundView3 containsObject:sender])
{
soundIndex = 3;
}
//send a message to set volume of sound at index soundIndex
NSLog(#"The soundIndex is %d", soundIndex);
NSLog(#"The volume is %f", [sender value]);
}
Did I get this right or is there a better way to accomplish this?
You can use tag property to set an numeric index on a control, and then simply use sender.tag in event callback.
Related
I'm making a game using SpriteKit and Objective-C.
I have four different texture drops (Blue, Green, Orange and Red) that falls down on screen randomly.
In my ANBDropNode class I have this method:
+(instancetype)dropOfType:(ANBDropType)type {
ANBDropsNode *drop;
if (type == ANBDropTypeBlue) {
drop = [self spriteNodeWithImageNamed:#"bluedrop"];
} else if (type == ANBDropTypeGreen) {
drop = [self spriteNodeWithImageNamed:#"greendrop"];
} else if (type == ANBDropTypeOrange) {
drop = [self spriteNodeWithImageNamed:#"orangedrop"];
} else if (type == ANBDropTypeRed){
drop = [self spriteNodeWithImageNamed:#"reddrop"];
}
[drop setupPhysicsBody];
return drop;
}
And in my GamePlayScene these two:
-(void)addDrops {
NSUInteger randomDrop = [ANBUtil randomWithMin:0 max:4];
self.drop = [ANBDropsNode dropOfType:randomDrop];
float y = self.frame.size.height + self.drop.size.height;
float x = [ANBUtil randomWithMin:10 + self.drop.size.width
max:self.frame.size.width - self.drop.size.width - 10];
self.drop.position = CGPointMake(x, y);
[self addChild:self.drop];
}
-(void)update:(NSTimeInterval)currentTime {
if (self.lastUpdateTimeInterval) {
self.timeSinceDropAdded += currentTime - self.lastUpdateTimeInterval;
}
if (self.timeSinceDropAdded > 1) {
[self addDrops];
self.timeSinceDropAdded = 0;
}
self.lastUpdateTimeInterval = currentTime;
}
The question is (and it may sound a little dumber, I know): before the drop hits the ground it has already changed it value. If ANBDropNode *drop is a bluedrop, before it hits the ground the method randomly create another drop and change it value for greendrop, for example. But I don't want this behavior. I want the drop to continue with its value until it reaches the ground so I can detect its color in my didBeginContact method.
Sorry in advance for any english mistakes, as I'm not an native english speaker.
From your question I understand that the reason you are keeping a reference to the drop (self.drop) is to check what is its colour when it hits the ground.
So you could just delete that, and create a new SKSpriteNode object each time, instead of just changing the reference of the current property.
If you have any other reason for keeping a reference to that drop, just still keep a reference.
Note that doing any of the above, will not affect the code below.
I think that you were in the right direction (when asking about didBeginContact) but took the wrong approach/mindset, since there is no need to keep a reference when using didBeginContact, because you can get the nodes in contact from this method.
Anyway, here is the code + explanations
// MyScene.m
// First, conform to SKPhysicsContactDelegate, so you can get didBeginContact 'calls'
#interface MyScene () <SKPhysicsContactDelegate>
#end
#implementation MyScene
// Now add the following constant, that you'll use as the physics body category bit masks
static const uint32_t groundCategory = 0x01 << 0;
static const uint32_t dropsCategory = 0x01 << 1;
// Somewhere in your initialisation, set yourself to be the physicsWorld
// contact delegate, so you'll receive the didBeginContact 'calls',
// And also call setupGround method, that we will create in here as well
-(id)initSceneWithSize:(CGSize)size {
...
...
self.physicsWorld.contactDelegate = self;
[self setupGround];
...
}
// Here we will create the ground node, so we can detect when a drop
// Hits the ground.
// The reason that, in the below code, I am setting just the ground,
// and not the whole borders of the screen, is because the drops
// are added above the screen 'borders', and if we would make
// a 'frame' node, and not a 'ground' node, we will also receive
// contact delegate calls, when the nodes first enter the scene
// and hits the top 'border' of the frame
-(void)setupGround {
SKNode *groundNode = [SKNode node];
groundNode.strokeColor = [SKColor clearColor];
groundNode.fillColor = [SKColor clearColor];
// Not sure if the above two are mandatory, but better be safe than sorry...
// Here we set the physics body to start at the bottom left edge of the screen
// and be the width of the screen, and the size of 1 points
// Then, we also set its category bit mask
CGRect groundRect = CGRectMake(0, 0, self.size.width, 1);
groundNode.physicsBody = [SKPhysicsBody bodyWithEdgeLoopFromRect:groundRect];
groundNode.physicsBody.categoryBitMask = groundCategory;
[self addChild:groundNode];
}
// Next we will modify your current method of creating drops, to also have
// their name property to holds the corresponding colour name
+(instancetype)dropOfType:(ANBDropType)type {
ANBDropsNode *drop;
if (type == ANBDropTypeBlue) {
drop = [self spriteNodeWithImageNamed:#"bluedrop"];
drop.name = #"Blue";
} else if (type == ANBDropTypeGreen) {
drop = [self spriteNodeWithImageNamed:#"greendrop"];
drop.name = #"Green";
} else if (type == ANBDropTypeOrange) {
drop = [self spriteNodeWithImageNamed:#"orangedrop"];
drop.name = #"Orange";
} else if (type == ANBDropTypeRed){
drop = [self spriteNodeWithImageNamed:#"reddrop"];
drop.name = #"Red";
}
[drop setupPhysicsBody];
return drop;
}
// In your setupPhysicsBody method of the drop, add the following to define
// the drop's bit mask, contact test, and collision.
// Make sure you are adding them AFTER setting the physics body, and not before.
// Since you revealed no code regarding this method, I will assume 'self' is
// referring to the drop, since you call this method on the drop.
-(void) setupPhysicsBody {
...
...
...
self.physicsBody.categoryBitMask = dropsCategory;
self.physicsBody.contactTestBitMask = groundCategory;
self.physicsBody.collisionBitMask = 0;
// The above code sets the drop category bit mask, sets its contactTestBitMask
// to be of the groundCategory, so whenever an object with drop category, will
// 'touch' and object with groundCategory, our didBeginContact delegate will
// get called.
// Also, we've set the collision bit mask to be 0, since we only want to
// be notified when a contact begins, but we don't actually want them both to
// 'collide', and therefore, have the drops 'lying' on the ground.
...
...
...
}
// Now we can set the didBeginContact: delegate method.
// Note that, as the name of the method suggests, this method gets called when a
// Contact is began, meaning, the drop is still visible on screen.
// If you would like to do whatever you want to do, when the drop leaves the screen,
// just call the didEndContact: delegate method
-(void)didBeginContact:(SKPhysicsContact *)contact {
// SKPhysicsContact have two properties, bodyA and bodyB, which represents
// the two nodes that contacted each other.
// Since there is no certain way to know which body will always be our drop,
// We will check the bodies category bit masks, to determine which is which
ANBDropsNode *drop = (contact.bodyA.categoryBitMask < contact.bodyB.categoryBitMask) ? (ANBDropsNode *)contact.bodyB.node : (ANBDropsNode *)contact.bodyA.node;
// In the above we are checking the category bit masks,
// Note that we set groundCategory to be 1, and dropsCategory to be 2,
// So we are checking which is higher.
// If bodyA bit mask is lower than bodyB bit mask, that means the bodyA is
// the ground, and bodyB is the drop, so we set the drop to be bodyB's node
// Else, we set it to be bodyA's node.
// Now you can easily get the drop colour from the name property we've set in
// the beginning. you can do some sort of if-else statement, that check
// 'if isEqualToString'. Here I just NSLog the colour
NSLog(#"%#", drop.name);
}
Good luck mate.
You can simply associate a property with the ANBDropsNode class which can be set when the drop is instantiated.
In the ANBDropsNode.h file,
#interface ANBDropsNode
#property (strong, nonatomic) NSString *dropColor; //This property will hold the value associated with the color.
Then in the dropOfType class method:
+(instancetype)dropOfType:(ANBDropType)type {
NSString *strDropColor;
if (type == ANBDropTypeBlue) {
strDropColor = #"bluedrop";
} else if (type == ANBDropTypeGreen) {
strDropColor = #"greendrop";
} else if (type == ANBDropTypeOrange) {
strDropColor = #"orangedrop";
} else if (type == ANBDropTypeRed){
strDropColor = #"reddrop";
}
ANBDropsNode *drop = [self spriteNodeWithImageNamed:strDropColor];
drop.dropColor = strDropColor;
[drop setupPhysicsBody];
return drop;
}
Now, in your collision detection delegate method, you can find out the color of the node by simply referring the dropColor property.
I am new to the community, so let me know if my question is unclear. I am trying to make a choice reaction exercise on the iPAD. There are two images that should appear in random sequence on the left and right of the screen, and the user will respond by tapping a button that corresponds to the position of the appeared image. Here's the problem, I tried to get the two images to appear at random order using the following way:
- (void) viewDidAppear:(BOOL)animated
{
for(int n = 1; n <= 20; n = n + 1)
{
int r = arc4random() % 2;
NSLog(#"%i", r);
if(r==1)
{
[self greenCircleAppear:nil finished:nil context: nil];
}
else
{
[self redCircleAppear:nil finished:nil context: nil];
}
}
}
However, 20 random numbers get generated while only 1 set of animation is run. Is there a way to let the animation finish running in each loop before the next loop begins? Any help is appreciated, thanks in advance!
When you say "only one set of animation is run" I'm assuming that means greenCircleAppear and redCircleAppear begin the sequence of images appearing and the user pressing a button. If that's the case, I'd recommend not using a for loop in viewDidAppear but instead have viewDidAppear initialize the current state and call a method that presents the next animation. When the animation is finished, have it call the method that presents the next animation. Something along these lines:
Add this to the interface:
#interface ViewController ()
#property NSInteger currentIteration;
#end
This is in the implementation:
- (void)viewDidAppear:(BOOL)animated {
self.currentIteration = 0;
[self showNextAnimation];
}
- (void)greenCircleAppear:(id)arg1 finished:(id)arg2 context:(id)arg3 {
//perform animation
NSLog(#"green");
[self showNextAnimation];
}
- (void)redCircleAppear:(id)arg1 finished:(id)arg2 context:(id)arg3 {
//perform animation
NSLog(#"red");
[self showNextAnimation];
}
- (void)showNextAnimation {
self.currentIteration = self.currentIteration + 1;
if (self.currentIteration <= 20) { //you should replace '20' with a constant
int r = arc4random() % 2;
NSLog(#"%i", r);
if(r==1)
{
[self greenCircleAppear:nil finished:nil context: nil];
}
else
{
[self redCircleAppear:nil finished:nil context: nil];
}
}
else {
//do what needs to be done after the last animation
}
}
I am new to OS X App development. I have a number of check boxes in the App. I need to store the values as 1's and 0's depending on whether the check box is selected or not. How do I get the value to an NSInteger variable say "NSInteger sampleValue".
Create IBAction and connect to checkbox
-(IBAction)checkBoxState : (id)sender;
{
NSLog(#"state %d", [sender state]);
}
If you have multiple checkbox, connect all checkbox to same IBAction method. change tag value of checkbox
-(IBAction)checkBoxState : (id)sender;
{
if (0==[sender tag]) {
NSLog(#"1st checkbox state %d", [sender state]);
}
else if (1==[sender tag]) {
NSLog(#"2nd checkbox state %d", [sender state]);
}
else if (2==[sender tag]) {
NSLog(#"3rd checkbox state %d", [sender state]);
}
}
Take a look at sample project.
If you want to get NSInteger value use [checkbox state]. It can be done like this:
NSInteger integValue = [checkBoxOutlet state];
NSLog(#"%li", integValue); //Show value on screen
checkBoxOutlet is Your checkbox Outlet in header file.
You can find as to this: (check1 is the property name for checkBox)
NSLog(#"%ld",[_check1 state]);//will give -1, 0 or 1, as mixed, off or on.
Also, if you want to be more futuristic (i.e. if in future the value of 1 or 0 or -1 is changed, then use these enums )
if ([_check1 state]==NSOnState) {
NSLog(#"ON-Checked");
}
else if([_check1 state]==NSOffState){
NSLog(#"OFF-UnChecked");
}
else if([_check1 state]==NSMixedState){
NSLog(#"OFF-MixedChecked");
}
Annoying newbie problem here. This variable isPlayerTouchingAnotherPlayer is being set to true as soon as I touch the piece. I'm almost positive I know why but I can't find a way to display this in log to confirm. I could probably do it by setting different flag numbers for each of the objects but I was hoping there is another way.
The problem is that piece is an object that is also located in p1Array so as soon as I touch it it hits itself and isPlayerTouchingAnotherPlayer is evaluated to true.
Is there a way I could print out the view or image name of the objects touching somehow to confirm this? And furthermore, is there a way to somehow avoid this annoying conflict.
for (int i = 0; i <[p1Array count]; i++) {
UIImageView *tempP1;
tempP1 =[p1Array objectAtIndex:i];
if (CGRectIntersectsRect(piece.frame, tempP1.frame)) {
NSLog(#"selected piece: %#, touched piece: %# ", piece, tempP1);
isPlayerTouchingAnotherPlayer = TRUE;
}
}
why not use fast enumeration and skip the image view you are not interested in checking.
for (UIImageView *imageView in p1Array) {
if (imageView == piece)
continue;
if (CGRectIntersectsRect(imageView.frame, piece.frame)) {
// do whatever
}
}
it seems like you are already printing out the names of the objects touching in the code sample you have provided. if you want to print out specific properties of the objects you can do that to.
as soon as i touch it it hits itself and isPlayerTouchingAnotherPlayer
is evaluated to true.
Then you should get a log message that shows the same object for the selected piece and the touched piece. If that's what's happening, then just add a condition to your if to prevent it:
if (piece != tempP1 && CGRectIntersectsRect(piece.frame, tempP1.frame)) {
Simply
NSLog(#"%# %#", piece, tempP1);
or
NSLog(#"%ld %ld", (NSInteger) piece, (NSInteger) tempP1);
The first will show you the description of the object, the second the address in memory, if it's same address, it's the same object.
You can simply check if it's the same object (pointer) with a simple equal check to exclude the same object :
if (piece != tempP1) {
if (CGRectIntersectsRect(piece.frame, tempP1.frame)) {
...
}
Furthermore, you would like to write this:
for ( int i = 0;
( ( i < [p1Array count] )
&& ( ! isPlayerTouchingAnotherPlayer )
);
i++
) {
...
}
I have an NSMUtable array of images where a different image is displayed with a previous and a next button, but when I get to the end of the array the simulator crashes. I want to loop the end of the array to the beginning so that when I get to the end of the array of images when I hit the next button again it loops back to the first image, also when Im at the first image if I hit the previous button it loops to the last image with no crashes
What you want is a circular array, which is easy to implement using a standard NSMutableArray. For instance, say you store your images in an array called imageArray and use a simple variable to keep track of the index of your current image, like:
int currentImageIndex = 0;
...then you might implement nextImage and previousImage like:
- (UIImage*) nextImage {
currentImageIndex = (currentImageIndex + 1) % [imageArray count];
return [imageArray objectAtIndex:currentImageIndex];
}
- (UIImage*) previousImage {
currentImageIndex--;
if (currentImageIndex < 0) {
currentImageIndex = [imageArray count] - 1;
}
return [imageArray objectAtIndex:currentImageIndex];
}
Then just use nextImage and previousImage whenever you want to step through the array, and problem solved.
Simple enough to do. all you need to do is create a check to see if you're on the last element, and if so, set your tracker (like count or i etc) to 0 again,
Heres the psudo code
//set index
if ( array [ index ] == len(array) - 1) //at end
{
index = 0
}
if(array [index] == -1)//at beginning
{
index = len(array) -1
}
// do something with array[index]
I want to propose this solution:
A property for the selected UIImage, a NSInteger property to hold the current index.
-(IBAction) nextButtonTapped:(id)sender
{
self.currentIndex = self.currentIndex++ % [self.images count];
self.selectedImage= [self.images objectAtIndex:self.currentIndex];
[self reloadImageView];
}
-(IBAction) previousButtonTapped:(id)sender
{
self.currentIndex--;
if (self.currentIndex < 0)
self.currentIndex += [self.images count];
self.selectedImage= [self.images objectAtIndex:self.currentIndex];
[self reloadImageView];
}
-(void)reloadImageView
{
//do, what is necessary to display new image. Animation?
}