UIView inheritance for multiple UIView in iOS - ios

I'm trying to build a simple iOS app that will simply roll dice with a different number of sides (d20, d12, etc...)
I'd like to create a view that I will re-use multiple times in the same UIViewController, as seen here: http://cl.ly/image/2s30353F3V1K (the only thing that changes is the # of sides)
What I can't figure out is how to properly create the UI element in the storyboard without simply copying and pasting the ContainerView's embeded object for each different number of sides.
Is there an easy way to sub class this properly? I'm new to iOS storyboards and was trying to use OO principles.

So you have a DieViewController, but you need the different instances to have different number of sides.
#interface DieViewController
…
#property (nonatomic) NSInteger numberOfSides;
…
#end
The question is how to communicate the proper number of sides to each contained instance. This is where the embed segue comes in. In the storyboard, set the storyboard embed segue identifier to something unique (I'll use 6SidedDie). Finally, in ViewController add a -prepareForSegue:sender:
##implementation ViewController
…
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([segue.identifier isEqualToString:#"6SidedDie"]) {
DieViewController *dieViewController = segue.destinationViewController;
dieViewController.numberOfSides = 6;
}
}
…
#end
of course, you can mix this up to allow for lots of dice. Here is code which could handle the identifiers 6SidedDie and 10SidedDie.
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([segue.identifier hasSuffix:#"Die"]) {
DieViewController *dieViewController = segue.destinationViewController;
if ([segue.identifier hasPrefix:#"6Sided"]) {
dieViewController.numberOfSides = 6;
} else if ([segue.identifier hasPrefix:#"10Sided"]) {
dieViewController.numberOfSides = 10;
}
}
}
UPDATE
You can use the self.viewControllers array to access the content in the DieViewController instances.
DieViewController *dieViewController = self.viewControllers[0]; // The first die view controller
if (dieViewController.numberOfSides == 6) {
// This is the six sided die.
}
NOTE: self.viewControllers will not be ordered. You will need to check numberOfSides to see which type of die this is.

I don't understand your question clearly but I have an idea
First, you get an instant of UIViewController
YourViewController *vc = [self.storyboard instantiateViewControllerWithIdentifier:#"Identifier"];
[vc methodToChangeTheSideProperty:(NSString *)side];
CGRect frame = vc.view.frame;
//change frame of the view as you want
...
...
vc.view.frame = frame;
Then, add the view of your controller to container you want to show it
[yourViewContainer addSubview:vc.view];

Related

Using the same view controller multiple times

I'm new to Objective-C and have a question. Did the search multiple times but I couldn't find what I was looking for.
I'm using storyboard for this app. On the homescreen you've got some buttons with labels above them. Those labels should tell a number. When pushing the button you go to a new viewController where you have input that (after 'save') goes back to the homescreen and updates the label with the correct number. All that works great for one button and I'm very happy about it.
The problems are:
1. Since I have multiple buttons with labels, I want to use the same viewController to give input over and over again. I tried connecting every button to slide to the viewController under the identifier "AddData", but Xcode doesn't allow the same identifiers twice or more in storyboard. So I would need something else for this. Any idea?
2. Currently I use the following code to bring back the data to the homescreen:
homeScreenViewController
- (IBAction)unwindToHomeScreen:(UIStoryboardSegue *)segue;
{
inputDataViewController *source = [segue sourceViewController];
self.logoOneLabel.text = source.endTotalNumber;
}
inputDataViewController:
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if (sender != self.saveButton) {
return;
} else {
if (endTotalLabelNumber > 0) {
self.endTotalNumber = [NSString stringWithFormat:#"%.0f", totalLabelNumber + endTotalLabelNumber];
} else if (endTotalLabelNumber == 0 && totalLabelNumber == 0){
self.endTotalNumber = 0;
} else {
self.endTotalNumber = [NSString stringWithFormat:#"%.0f", totalLabelNumber + endTotalLabelNumber];
}
}
}
This works great for the one button, but how to use this with multiple? I heard about Delegates to use the same viewController multiple time and get data back to different places, but I just don't get it. Any help?
You shouldn't need delegates.
What you will need is a property on the view controller that handles input to it knows which button it is handling input for.
When you segue to the input controller, set this property, based on which button was pushed. When you unwind back, fetch this property to know which label to modify.
For example, in your input view controller's .h file, add a property like this:
#property (nonatomic,assign) NSInteger handlingTag;
Or something, whatever name makes sense to you.
Now you need to implement your home screen view controller's prepareForSegue:sender:.
Use the sender argument to determine which button was pushed, and based on that, set the input view controller's new handlingTag property based on the button in a way that you will know what to do with it when we unwind.
Now in the unwind method:
switch (source.handlingTag)
Create a switch structure based on the source's handlingTag property, and set the appropriate label based on this value.
As Jeff points out in the comments, it'd be a really good idea to define an NS_ENUM to use here for the property rather than an NSInteger. The NS_ENUM would allow you to name the values you're using.
There is a few different way to implement what you need. But i think most common its a delegate.
This is how your inputDataViewController looks like:
#import <UIKit/UIKit.h>
#protocol inputDataDelegate;
#interface inputDataViewController : UIViewController
#property (weak) id<inputDataDelegate> delegate;
#property (strong, nonatomic) NSNumber *buttonTag;
#end
#protocol inputDataDelegate <NSObject>
-(void) inputDataViewControllerDismissed:(id)data;
#end
Then in #implementation, you should in "save" button action, message to you delegate method :
[self inputDataViewControllerDismissed:#{#"buttonTag":buttonTag,#"endTotalNumber":endTotalNumber}
Next in homeScreenViewController connect delegate :
#interface homeScreenViewController : UIViewController<inputDataDelegate>
After that in #implementation:
-(void)inputDataViewControllerDismissed:(id)data
{
// if you use modal
[self dismissViewControllerAnimated:YES completion:nil];
// or if you use push
//[self.navigationController popViewControllerAnimated:YES];
switch (data[#"buttonTag"]) {
case 1:
self.lableWtiTagOne = data[#"endTotalNumber"];
break;
case 2:
self.lableWtiTagTwo = data[#"endTotalNumber"];
break;
// number of cases depend how many buttons you have
}
Also, most important, thing didn't forget send self to our delegate:
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([[segue identifier] isEqualToString:#"inputDataController"])
{
inputDataViewController *inputCtrl = [segue destinationViewController];
inputCtrl.delegate = self;
inputCtrl.buttonTag = sender.tag
}
}

How can I pass data from parent to child view?

I have a container view, which uses a storyboard embed segue to load an embedded static table view. The segue ID is 'CONTAINER'.
When I run the following code, the prepareForSegue never actually gets called so no data is passed from the parent to the child.
- (void)viewDidLoad {
[super viewDidLoad];
if ([sGender isEqualToString:#"MALE"]) {
containerGender = #"MALE";
if ([containerGender isEqualToString:#"MALE"]){
NSLog(#"MALE");
}else{
NSLog(#"BROKEN");
}
}
else if ([sGender isEqualToString:#"FEMALE"]) {
containerGender = #"FEMALE";
}
}
-(void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
if ([segue.identifier isEqualToString:#"CONTAINER"]) {
if([containerGender isEqualToString:#"MALE"]) {
if ([containerGender isEqualToString:#"MALE"]){
NSLog(#"MALE");
}else{
NSLog(#"BROKEN");
}
SportTableViewController *tableView = segue.destinationViewController;
tableView.sportGender = #"MALE";
}
else if ([containerGender isEqualToString:#"FEMALE"]){
SportTableViewController *tableView = segue.destinationViewController;
tableView.sportGender = #"FEMALE";
}
}
}
My question is:
a)Why is prepareForSegue not called? Does the Storyboard Embed Segue behave differently to a standard seque?
b)Is there a better way of passing data from the container view to the embedded table?
Also please ignore the messy implementation/various log tests, just my attempts to work out whats going wrong.
My question actually stems from a misunderstanding of how container views load their embedded views. Apparently, it all happens before viewDidLoad. That means my conversion of sGender into containerGender took place too late.
I fixed it by passing sGender to the embedded view directly. I had thought I'd already tried this, but yesterday was obviously a slow day ;).
you can do it..
try
in childViewController
set-
#property(nonatomic,retain)parentViewController *parent;
and
in ParentViewController set-
ChildViewController *child = [[childviewController alloc]init];
child.parent=self;
It will set your parent class in childview and you can get data through parent object in child view controller.

NSMutableArray persistency while switching view controllers

I've searched a lot and still couldn't find an answer to this...
I'm working on an iphone App (for college) in xcode 5.0 using storyboards.
I have a View Controller with a table view and everything works fine (data sources, delegate...). Items are stored in an array (call it "array1"). I have an ADD button which brings up a list of items which I want to add (if checked) to array1. I store the checked items in another array ("array2"). The thing is, when I pass array2 to the previous view controller I lose all data in array1 (it becomes nil).
The code I'm using to pass data from array2 to the VC is:
-(void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
if ([segue.identifier isEqualToString:#"updateFavoritesSegue"]) {
FavoritesViewController *targetVC = (FavoritesViewController*) segue.destinationViewController;
[targetVC updateFavorites:[self newFavoritesArray]];
}
}
The updateFavorites method is implemented as below.
-(void) updateFavorites:(NSArray *)newFavorites {
[self.favorites addObjectsFromArray:newFavorites];
[self.favoritesTableView reloadData];
}
Thank you very much for your help.
Why don't you just use some handler?
secondVC.h
#property (nonatomic, copy) void (^didFinishPickingItemsHandler)(NSArray *items);
then from the firstVC:
- (void)showSecondScreen {
MYSecondVC *secondVC = /* initialisation code here */
__weak MyFirstVC *self_ = self;
secondVC.didFinishPickingItemsHandler = ^(NSArray *items) {
/* update you data here with your array1 and received picked items */
[self.navigationController popViewControllerAnimated:YES];
};
[self.navigationController pushViewController:secondVC animated:YES];
}

Adding two Text Fields in a ViewController and displaying it in another ViewController

I'm using a NavigationViewController and 2 View Controllers (named ViewController and ResultViewController), to make a simple app, that will sum 2 textFields in the first ViewController and display the result in a label, in the ResultViewController. I'm using a push segue to connect the VCs, but I can't create a variable that receives the sum from the textFields. The error says: "property sum not found on object of type 'ViewController' ". I also tried to create the sum variable inside the prepareForSegue method, without success...
Below, my first ViewController.m code snippet:
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
}
- (IBAction)addButtonPressed:(UIButton *)sender {
ResultViewController *tempView = [self.storyboard instantiateViewControllerWithIdentifier:#"ResultViewController"];
double sum = [_fieldOne.text doubleValue] + [_fieldTwo.text doubleValue];
tempView.answer = self.sum.text; //here appears the error I mentioned
[self presentViewController:tempView animated:YES completion:nil];
}
The ResultViewController.m snippet:
- (void)viewDidLoad
{
[super viewDidLoad];
self.displaySum.text = self.answer;
}
Any help will be really appreciated! Thanks in advance!!
Sum is a local variable. You want
tempView.answer = [NSString stringWithFormat:#"%d",sum];

xcode storyboard Container View - How do I access the viewcontroller

I'm trying to use storyboard and get things working properly. I've added a a Container View to one of my existing views. When I try to add a reference to this in my view controller .h file (ctrl-drag), I get a IBOutlet UIView *containerView. How do I get a reference to the container view's view controller instead? I need the container view controller so I can set it's delegate to my view's controller so they can "talk" to each other.
I have my story board setup as:
And its referenced in my .h file as:
Notice in the .h that is is a UIView, not my InstallViewController for the view. How do I add a reference to the view controller? I need to be able to set its delegate.
There is another solution by specifying an identifier for the embed segue(s) and retrieve the corresponding view controllers in method prepareForSegue:
The advantage of this way is that you needn't rely on a specific order in which your child view controllers are added due to the fact that each child view controller is embedded via an unique segue identifier.
Update 2013-01-17 - Example
- (void) prepareForSegue:(UIStoryboardSegue*)segue sender:(id)sender
{
// -- Master View Controller
if ([segue.identifier isEqualToString:c_SegueIdEmbedMasterVC])
{
self.masterViewController = segue.destinationViewController;
// ...
}
// -- Detail View Controller
else if ([segue.identifier isEqualToString:c_SegueIdEmbedDetailVC])
{
self.detailViewController = segue.destinationViewController;
// ...
}
}
c_SegueIdEmbedMasterVC & c_SegueIdEmbedDetailVC are constants with the corresponding ID of the segue IDs defined in the storyboard.
When you add a container view the xcode calls the UIViewController method addChildViewController:
In your case, you can get the container ViewController looking for it on the SplashViewController's list of childViewControllers, something like this:
for (UIViewController *childViewController in [self childViewControllers])
{
if ([childViewController isKindOfClass:[InstallViewController class]])
{
//found container view controller
InstallViewController *installViewController = (InstallViewController *)childViewController;
//do something with your container view viewcontroller
break;
}
}
I had the same doubt yesterday :)
The answer of Vitor Franchi is correct but could be more performant and convenient. Especially when accessing the child view controller several times.
Create a readonly property
#interface MyViewController ()
#property (nonatomic, weak, readonly) InstallViewController *cachedInstallViewController;
#end
Then create a convenient getter method
- (InstallViewController *)installViewController
{
if (_cachedInstallViewController) return _cachedInstallViewController;
__block InstallViewController *blockInstallViewController = nil;
NSArray *childViewControllers = self.childViewControllers;
[childViewControllers enumerateObjectsUsingBlock:^(id childViewController, NSUInteger idx, BOOL *stop) {
if ([childViewController isMemberOfClass:InstallViewController.class])
{
blockInstallViewController = childViewController;
*stop = YES;
}
}];
_cachedInstallViewController = blockInstallViewController;
return _cachedInstallViewController;
}
From now on access the child view controller that way
[self.installViewController doSomething];
UIView* viewInsideOfContainer = installerView.subviews[0];
Will give you the UIView inside of the UIViewController that your controller UIView references. You can cast the subview to any type that inherits from UIView.
If the nib is loaded it will call addChildViewController as part of the initialisation process
so a performant solution could be also to overwrite
- (void)addChildViewController:(UIViewController *)childController
there you can catch your childController e.g. by comparing its Class and assign it to a property / ivar
-(void)addChildViewController:(UIViewController *)childController
{
[super addChildViewController:childController];
if([childController isKindOfClass:[InstallViewController class]])
{
self.installViewController = (InstallViewController *)childController;
}
}
This will save your from iterating trough the childViewControllers.

Resources