I'm moving on from iOS to Cocoa and trying to muddle through my first few programs. I thought it would be simple to add an NSComboBox to my form, well that part was. I added <NSComboBoxDelegate, NSComboBoxDataSource> to my interface, two data callbacks, and the notifier:
#interface spcAppDelegate : NSObject <NSApplicationDelegate,
NSComboBoxDelegate, NSComboBoxDataSource>
- (id)comboBox:(NSComboBox *)aComboBox objectValueForItemAtIndex:(NSInteger)index;
- (NSInteger)numberOfItemsInComboBox:(NSComboBox *)aComboBox;
- (void)comboBoxSelectionDidChange:(NSNotification *)notification;
#end
I control dragged the combobox to the app delegate (which is the only class in my simple default app) and wired up the delegate and data source but none of those events fire. I thought app delegate was correct but since it didn't fire, I also tried "file owner" and "application". I didn't think those would work and they didn't.
Whats the right way to wire up the delegate/data source for an NSComboBox in a Cocoa app?
Thanks!
Provided you've actually implemented those methods in your spcAppDelegate.m file, you may want to double-check that Uses Data Source is checked for the NSComboBox in the nib file in Interface Builder:
Note that it wasn't set by default in a quick test project I created. Running without that checkbox set should log the following to console when you launch the app:
NSComboBox[2236:403] *** -[NSComboBox setDataSource:] should not be called when
usesDataSource is set to NO
NSComboBox[2236:403] *** -[NSComboBoxCell setDataSource:] should not be called
when usesDataSource is set to NO
While the NSComboBox Class Reference is somewhat helpful, when I was first learning, I found that if there were companion guides linked to for a class, those were much more helpful in understanding how one should use the class in practice. If you look at the top of the NSComboBox class reference at the Companion Guide, you'll see Combo Box Programming Topics.
To set up a combo box that uses a data source, you could use something like the following:
spcAppDelegate.h:
#import <Cocoa/Cocoa.h>
#interface spcAppDelegate : NSObject <NSApplicationDelegate,
NSComboBoxDelegate, NSComboBoxDataSource> {
IBOutlet NSWindow *window;
IBOutlet NSComboBox *comboBox;
NSMutableArray *comboBoxItems;
}
#property (assign) IBOutlet NSWindow *window;
#end
spcAppDelegate.m:
#import "spcAppDelegate.h"
#implementation spcAppDelegate
#synthesize window;
- (id)init {
if ((self = [super init])) {
comboBoxItems = [[NSMutableArray alloc] initWithArray:
[#"Cocoa Programming setting the delegate"
componentsSeparatedByString:#" "]];
}
return self;
}
- (void)dealloc {
[comboBoxItems release];
[super dealloc];
}
- (NSInteger)numberOfItemsInComboBox:(NSComboBox *)aComboBox {
return [comboBoxItems count];
}
- (id)comboBox:(NSComboBox *)aComboBox objectValueForItemAtIndex:(NSInteger)index {
if (aComboBox == comboBox) {
return [comboBoxItems objectAtIndex:index];
}
return nil;
}
- (void)comboBoxSelectionDidChange:(NSNotification *)notification {
NSLog(#"[%# %#] value == %#", NSStringFromClass([self class]),
NSStringFromSelector(_cmd), [comboBoxItems objectAtIndex:
[(NSComboBox *)[notification object] indexOfSelectedItem]]);
}
#end
Sample Project: http://github.com/NSGod/NSComboBox.
I was having a similar situation yesterday until I remembered to hook up the File Owner data source to the IBOutlet in IB:
Related
I am quite new to react native and and the bridging mechanism with native code, especially when the framework has delegates. Assume I am trying to bridge the following framework:
#protocol BRPtouchNetworkDelegate;
#class PLNetworkModule;
#interface BRPtouchNetworkManager : NSObject <NSNetServiceBrowserDelegate,NSNetServiceDelegate>
#property(retain, nonatomic) NSMutableArray* registeredPrinterNames;
#property(assign, nonatomic) BOOL isEnableIPv6Search;
- (int)startSearch: (int)searchTime;
- (NSArray*)getPrinterNetInfo;
- (BOOL)setPrinterNames:(NSArray*)strPrinterNames;
- (BOOL)setPrinterName:(NSString*)strPrinterName;
- (id)initWithPrinterNames:(NSArray*)strPrinterNames;
- (id)initWithPrinterName:(NSString*)strPrinterName;
#property (nonatomic, assign) id <BRPtouchNetworkDelegate> delegate;
#end
#protocol BRPtouchNetworkDelegate <NSObject>
-(void) didFinishSearch:(id)sender;
#end
The following is the bridge module I implemented:
RCTBRPtouchNetworkManager.h
#import <React/RCTBridgeModule.h>
#import <BRPtouchPrinterKit/BRPtouchPrinterKit.h>
#interface RCTBRPtouchNetworkManager : NSObject <RCTBridgeModule, BRPtouchNetworkDelegate>
#end
RCTBRPtouchNetworkManager.m
#import "RCTBRPtouchNetworkManager.h"
#import <BRPtouchPrinterKit/BRPtouchPrinterKit.h>
#import <React/RCTLog.h>
#implementation RCTBRPtouchNetworkManager {
BRPtouchNetworkManager *_networkManager;
}
RCT_EXPORT_MODULE();
RCT_EXPORT_METHOD(addEvent:(NSString *)name location:(NSString *)location)
{
RCTLogInfo(#"Pretending to create an event %# at %#", name, location); //a dummy method to test the bridge
}
RCT_EXPORT_METHOD(startSearchWithTimeout:(int)time) {
RCTLogInfo(#"Bridge started search with time %d", time);
_networkManager = [[BRPtouchNetworkManager alloc] init];
_networkManager.delegate = self; //I'm setting delegate here
_networkManager.isEnableIPv6Search = NO;
NSString * path = [[NSBundle mainBundle] pathForResource:#"PrinterList" ofType:#"plist"];
if( path )
{
NSDictionary *printerDict = [NSDictionary dictionaryWithContentsOfFile:path];
NSArray *printerList = [[NSArray alloc] initWithArray:printerDict.allKeys];
[_networkManager setPrinterNames:printerList];
} else {
RCTLogInfo(#"PrinterList path not found");
}
// Start printer search
[_networkManager startSearch: 5.0];
}
- (void)didFinishSearch:(id)sender {
NSLog(#"didFinishedSearch"); //this delegate method is not called
}
#end
I can easily call the dummy method and see the results in the logs. However, the delegate method didFinishSearch() is never called. I call this from javascript as follows:
componentDidMount() {
let networkManager = NativeModules.BRPtouchNetworkManager;
networkManager.startSearchWithTimeout(5.0);
}
I there something I am missing? Am I implementing delegate properly? Is this kind of functionality even possible (can't seem to not since the delegate method was used by iOS community for a long time). Your help is much appreciated.
EDIT
I found that adding the following to my bridge manager file made the delegate to fire (thanks to this post)
- (dispatch_queue_t)methodQueue
{
return dispatch_get_main_queue();
}
However, even though this solves the problem, I'd like a more technical understanding on what is going on here since I can't seem to exactly grasp it. Thank you
I know this isn’t an an answer to the post but for the bit where you’ve asked for a more technical understanding - dispatch_get_main_queue(); puts the delegate method responses on to the main thread. Since JS is single threaded any process on the background thread won’t be visible to it.
I have a main window with a couple of popupbuttons. I want to clear them, then load the lists from a method in a custom class. I've got my view controller working and I know the method in the custom class (newRequest) is working because I added a NSLog command to print "Test" when the method executes. In AppDelegate I'm calling the method via:
[polyAppRequest newRequest];.
As I said, I know the method is executing. Why can't I removeallitems from the popupbutton from this custom class method?
Thanks
Keith
I read that you should use an NSWindowController to manage a window. See here:
Windows and window controllers
Adding views or windows to MainWindow
Then if your window gets complicated enough, the NSWindowController can employ various NSViewControllers to manage parts of the window.
In any case, I used an NSWindowController in my answer.
The image below shows the outlet's for File's Owner, which is my MainWindowController:
I created MainWindowController .h/.m in Xcode6.2 by:
Selecting File>New>File>OS X - Source - Cocoa Class
Selecting NSWindowController for Subclass of:
Checking also create .xib file for user interface
Then I deleted the window--not the menu--in the default MainMenu.xib, and I changed the name of MainWindowController.xib, created by the steps above, to MainWindow.xib.
The following code works for me (but I'm a Cocoa beginner!):
//
// AppDelegate.m
// PopUpButtons
#import "AppDelegate.h"
#import "MainWindowController.h"
#interface AppDelegate ()
#property(strong) MainWindowController* mainWindowCtrl;
#end
#implementation AppDelegate
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
// Insert code here to initialize your application
[self setMainWindowCtrl:[[MainWindowController alloc] init]];
[[self mainWindowCtrl] showWindow:nil];
}
- (void)applicationWillTerminate:(NSNotification *)aNotification {
// Insert code here to tear down your application
}
#end
...
//
// MainWindowController.m
// PopUpButtons
//
#import "MainWindowController.h"
#import "MyData.h"
#interface MainWindowController ()
#property(strong) MyData* data;
#property(weak) IBOutlet NSPopUpButton* namePopUp;
#property(weak) IBOutlet NSPopUpButton* agePopUp;
#end
#implementation MainWindowController
-(id)init {
if (self = [super initWithWindowNibName:#"MainWindow"]) {
_data = [[MyData alloc] init]; //Get data for popups
}
return self;
}
- (void)windowDidLoad {
[super windowDidLoad];
// Implement this method to handle any initialization after your window controller's window has been loaded from its nib file.
[[self namePopUp] removeAllItems];
[[self namePopUp] addItemsWithTitles:[[self data] drinks]];
[[self agePopUp] removeAllItems];
[[self agePopUp] addItemsWithTitles:[[self data] extras]];
}
#end
...
//
// MyData.h
// PopUpButtons
//
#import <Foundation/Foundation.h>
#interface MyData : NSObject
#property NSArray* drinks;
#property NSArray* extras;
#end
...
//
// MyData.m
// PopUpButtons
//
#import "MyData.h"
#implementation MyData
- (id)init {
if (self = [super init]) {
_drinks = #[#"coffee", #"tea"];
_extras = #[#"milk", #"sugar", #"honey"];
}
return self;
}
#end
I hope that helps. If you need any more screenshots, let me know.
Edit1:
I think I see what you are asking about. Although I don't think it is a very good approach, if I change my code to this:
//
// MyData.h
// PopUpButtons
//
#import <Cocoa/Cocoa.h>
#interface MyData : NSObject
#property (copy) NSArray* drinks;
#property (copy) NSArray* extras;
-(void)newRequest;
#end
...
//
// MyData.m
// PopUpButtons
//
#import "MyData.h"
#interface MyData()
#property (weak) IBOutlet NSPopUpButton* drinksPopUp;
#property (weak) IBOutlet NSPopUpButton* extrasPopUp;
#end
#implementation MyData
- (id)init {
if (self = [super init]) {
_drinks = #[#"coffee", #"tea"];
_extras = #[#"milk", #"sugar", #"honey"];
}
return self;
}
-(void)newRequest {
[[self drinksPopUp] removeAllItems];
[[self drinksPopUp] addItemsWithTitles:[self drinks]];
[[self extrasPopUp] removeAllItems];
[[self extrasPopUp] addItemsWithTitles:[self extras]];
}
#end
I am unable to populate the NSPopUpButtons. This is what I did:
I dragged an Object from the Object Library to the dock in IB, and in the Identity Inspector, I changed the Object's class to MyData.
Then I clicked on the Connections Inspector, and the two instance variables in MyData, drinksPopUp and extrasPopUp, were listed in the Outlets.
I dragged from the outlets to the respective NSPopUpButtons.
I guess I assumed, like you, that when my program ran, the NSPopUpButtons would be assigned to the instance variables drinksPopUp and extrasPopUp--but that doesn't seem to be the case. According to the Apple docs, you should be able to do that:
An application typically sets outlet connections between its custom
controller objects and objects on the user interface, but they can be
made between any objects that can be represented as instances in
Interface Builder,...
Edit2:
I am able to pass the NSPopUpButtons from my MainWindowController to the newRequest method, and I can use the NSPopUpButtons inside newRequest to successfully populate the data.
Edit3:
I know the method in the custom class (newRequest) is working because
I added a NSLog command to print "Test" when the method executes.
But what happens when you log the variables that point to the NSPopUpButtons? With my code in Edit1, I get NULL for the variables, which means the NSPopUpButtons never got assigned to the variables.
Edit4:
If I add an awakeFromNib method to MyData, and inside awakeFromNib I log the NSPopUpButton variables for the code in Edit1, I get non NULL values. That tells me that the MainWindowController's windowDidLoad method is executing before MyData's awakeFromNib method, and therefore you cannot call newRequest inside MainWindowController's windowDidLoad method because MyData has not been fully initialized.
Edit5:
Okay, I got the code in Edit1 to work. The Apple docs say this:
About the Top-Level Objects
When your program loads a nib file, Cocoa recreates the entire graph
of objects you created in Xcode. This object graph includes all of the
windows, views, controls, cells, menus, and custom objects found in
the nib file. The top-level objects are the subset of these objects
that do not have a parent object [in IB]. The top-level objects typically
include only the windows, menubars, and custom controller objects that
you add to the nib file [like the MyData Object]. (Objects such as File’s Owner, First
Responder, and Application are placeholder objects and not considered
top-level objects.)
Typically, you use outlets in the File’s Owner object to store
references to the top-level objects of a nib file. If you do not use
outlets, however, you can retrieve the top-level objects from the
nib-loading routines directly. You should always keep a pointer to
these objects somewhere because your application is responsible for
releasing them when it is done using them. For more information about
the nib object behavior at load time, see Managing the Lifetimes of
Objects from Nib Files.
In accordance with the bolded line above, I changed this declaration in MainWindowController.m:
#interface MainWindowController ()
#property(strong) MyData* data;
...
#end
to this:
#interface MainWindowController ()
#property(strong) IBOutlet MyData* data;
...
#end
Then, in IB I dragged a connection from the MainWindowController data outlet to the MyData Object(the Object I had previously dragged out of the Object Library and onto the doc).
I guess that causes MyData to unarchive from the .xib file and initialize before MainWindowController.
I have a Model Class like this:
Header:
#interface RTSecurityModel : NSObject
{
NSString *code;
}
#property NSString *code;
#end
Implementation:
#implementation RTSecurityModel
#synthesize code;
#end
Then I have my App Delegate:
Header:
#interface RTAppDelegate : NSObject <NSApplicationDelegate>
{
RTSecurityModel *security;
}
#property (assign) IBOutlet NSWindow *window;
#property RTSecurityModel *security;
#end
Implementation:
#implementation RTAppDelegate
#synthesize security;
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
security = [[RTSecurityModel alloc] init];
security.code = #"test";
}
Then in my MainMenu.xib I've create a label and in the Bindings Inspector set "Bind To: App Delegate" with "Model Key Path: security.code".
But nothing is showing when I'm starting my application.
I tried soooo many ways to bind this variable, but no one gave success.
Please help me not to hate XCode and Cocoa!
UPD: http://www.experts-exchange.com/Programming/Languages/C/A_3381-Simple-Binding-Cocoa-GUI-Application-without-Outlets.html
Here is the sample how to set Property and Label value by editing the Text Field
But is there a way to edit Label without editing the Text Field? Or without Text Field at all?
UPD2:
You must not create another instance of Object
security = [[RTSecurityModel alloc] init]; // Kill this
Many many thanks to Viktor Lexington
Instead of using security.code as the model path use code. Use the class RTSecurityModel in the value section of the bindings tab instead of the AppDelegate.
Here is a demo project.
Do not bind the Text Field Cell, use the Text Field.
You can check if a value is null if you fill the Null Placeholder with text, will it show that text instead? Then in time of binding the value it null.
To see your RTSecurityModel in the Interface Builder you must let it know your class, it won't look for it.
Add an Object and then set the custom class of it to RTSecurityModel.
Then you can choose this object and set the referencing outlet to the property in the App Delegate.
Assignment will now be directly reflected in the label.
I can think of two ways to solve this programmatically without Interface Builder:
Key Value Coding
// add an observer for the value on the object that has the method below implemented
[self addObserver: self forKeyPath: #"security.code" options: NSKeyValueObservingOptionNew context: NULL];
// method will be called when the observer has 'seen' a value change
-(void) observeValueForKeyPath: (NSString *)keyPath ofObject: (id) object change: (NSDictionary *) change context: (void *) context {
label.text = ...
}
Use a custom setter for code (#synthesize will still create the getter for you)
- (void)setCode:(NSString *)aString {
label.text = aString;
}
I'm messing around with using objects to launch background threads, however when I call an objects method to call the method that will spawn a background thread, nothing happens. I'm a bit puzzled as to why, and it looks like the -init function isn't even being called. Anyways, here's what I have:
ViewController.h
#import <UIKit/UIKit.h>
#import "Threader.h"
#interface ViewController : UIViewController
#property(nonatomic, strong) Thread* threadedObject;
- (IBAction)StartBackgroundThreadButtonClicked:(id)sender;
#end
ViewController.m
#import "ViewController.h"
#import "Threader.h"
#interface ViewController ()
#end
#implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
_threadedObject = [[Threader alloc]init];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (IBAction)StartBackgroundThreadButtonClicked:(id)sender {
NSLog(#"Clicked.");
[_threadedObject RunInBackground];
}
#end
Threader.h
#import <Foundation/Foundation.h>
#interface Threader : NSObject
#property(nonatomic) bool IsFinishedRunning;
#property(nonatomic) bool IsThreading;
//Constructor and Destructor
-(id)init;
-(void)dealloc;
-(void)RunInBackground;
-(void)WaitForTenSeconds;
#end
Threader.m
#import "Threader.h"
#implementation Threader
//constructor
-(id)init{
[super init];
if(self != nil)
{
_IsFinishedRunning = NO;
_IsThreading = NO;
}
return self;
}
//destructor
-(void)dealloc{
[super dealloc];
}
//Runs a thread in the background
-(void)RunInBackground{
NSLog(#"Initiating thread...");
[self performSelectorInBackground:#selector(WaitForTenSeconds) withObject:nil];
}
//Waits for 10 seconds, then sets IsFinishedRunning to YES
-(void)WaitForTenSeconds{
NSLog(#"Starting to run in the background.");
_IsThreading = YES;
sleep(10);
_IsFinishedRunning = YES;
NSLog(#"Finished running in the background.");
}
#end
When I run the program, this is my output(I clicked the button a few times)
2013-05-17 15:30:57.267 ThreadedObjects Clicked.
2013-05-17 15:30:59.003 ThreadedObjects Clicked.
2013-05-17 15:30:59.259 ThreadedObjects Clicked.
2013-05-17 15:30:59.443 ThreadedObjects Clicked.
2013-05-17 15:30:59.675 ThreadedObjects Clicked.
I should be getting messages telling me that the Threader object was created, and that it is preparing to launch a background thread, that the thread has been spawned and then after 10 seconds, that the thread is done running.
So, where's my glaring obvious error?
init isn't a constructor, it's for setup after construction. You need the class object to create an instance before you can send init, and, most importantly, you need to assign the results to your variable.
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
threadedObject = [[Threader alloc] init];
}
You can't send alloc to an object that's not a class; instances don't respond to it. The only reason that this isn't crashing is that globals are initialized to 0/NULL/nil, and [nil someMessage] does nothing.
Not assigning the results to your variable is the same as:
int x = 0;
x + 10;
There's no change to x's value.
Additionally, you don't seem to have an ivar there, just a global variable. Ivars need to go into a curly-brace block at the head of the #implementation:
#implementation Threader
{
Threader * threadedObject;
}
// etc...
You never alloc the object.............
Also, this is curious:
#import <UIKit/UIKit.h>
#import "Threader.h"
#interface ViewController : UIViewController
- (IBAction)StartBackgroundThreadButtonClicked:(id)sender;
#end
Threader* threadedObject;
Where exactly did you declare the threadedObject? Like above? Use an iVar
or, better, a property for it!
A couple of reactions:
Show us where your definition and alloc/init of threadedObject.
I'm not sure what business problem you're trying to solve, but this smells like the precursor of some custom NSOperation solution. Operation queues are ideally suited for these sorts of implementations.
I'd be inclined to subclass NSOperation when trying to do something like this. See the custom NSOperation object in the Concurrency Programming Guide.
I'd suggest using camelCase for your method and variable names.
If you say with this, I'd steer you away from the "thread" name, as it might imply that you're doing something with NSThread, which you're not.
I'm learning Objective-C right now and in order to practice I wrote a simple random maze generator for OS X, which works fine. Next I tried to add some more interaction with buttons, but I'm having trouble with the instance variables as they don't retain the value I assign them. I have come across multiple questions about the same problem, but the solutions to those haven't solved my problem. I also tested if the same problem persists in a simplified version of the program, which it does.
I guess I'm doing something wrong, but I don't know what. Here's what I did:
Created a new project
Added a subclass of NSView called "TestClass"
Added a view with class TestClass in the window in MainMenu.xib
Added an object for TestClass in MainMenu.xib
Added a button to the view and set its tag to 1
Added the following code to TestClass.h and TestClass.m and connected the button to it:
TestClass.h:
#import
#interface TestClass : NSView
{
NSNumber *number;
NSButton *test;
}
#property (nonatomic, retain) NSNumber *number;
#property (assign) IBOutlet NSButton *test;
- (IBAction)testing:(id)sender;
#end
TestClass.m:
#import "TestClass.h"
#implementation TestClass
#synthesize number;
#synthesize test;
- (id)initWithFrame:(NSRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code here.
}
return self;
}
- (IBAction)testing:(id)sender
{
self.number = [[NSNumber numberWithLong:[sender tag]] retain];
}
- (void) drawRect:(NSRect)dirtyRect
{
NSLog(#"%#", number);
}
#end
Whenever I press the button, NSLog just returns null several times.
I normally figure out everything by myself (eventually...), but this time it's really driving me insane, so is there anyone who can help me?
Put the NSLog in testing:, or just put a breakpoint there and see what's stored in number.
Note that self.number = [[NSNumber numberWithLong:[sender tag]] retain]; is double-retaining the NSNumber object (which is wrong), but that shouldn't cause any immediate error.