I will be very short because of this simple issue:
(This is a document based app, and i will provide just the code I have the issue with)
.h :
#import <Cocoa/Cocoa.h>
#interface Document : NSDocument {
IBOutlet NSTextField *someText;
}
.m :
- (id)init
{
self = [super init];
if (self) {
//Some initialization..
[someText setStringValue:#"Downloading data..."]; //This is not updating !
//Some others..
}
return self;
}
That label is not updating, but why ?? This seem to be a very stupid problem but I can't figure out what I'm doing wrong..
Outlets will not yet be connected when the init method runs. You'll want to move code that depends on nib objects existing to awakeFromNib.
Related
I am trying to update the contents of an NSTextView that is connected to myViewController as a referencing outlet to the Files Owner which is the subclass myViewController.
When I use an IBAction from a button, or use the viewDidLoad method of the controller, I can update the text fine. However, when I try run the method from another class (referred to in this example as anotherViewController), it runs the method, but the textview does not change.
myViewController.h:
#import <Cocoa/Cocoa.h>
#import "anotherViewController.h"
#interface myViewController : NSViewController { }
#property (unsafe_unretained) IBOutlet NSTextView *outText;
#property (weak) IBOutlet NSButton *updateMeButton;
- (void)updateTextView:(NSString *)argText;
- (void)updateTextViewWithoutArg;
#end
myViewController.m:
#import "myViewController.h"
#interface myViewController ()
#end
#implementation myViewController
- (void)viewDidLoad {
[super viewDidLoad];
self.outText.string = #"I work successfully";
}
- (IBAction)updateMeButton:(id)sender {
self.outText.string = #"I am updated text! I also work!";
}
- (void)updateTextView:(NSString *)argText {
self.outText.string = #"I don't make it to the NSTextView :(";
NSLog(#"Should have updated text view");
}
- (void)updateTextViewWithoutArg {
self.outText.string = #"I don't make it to the NSTextView :(";
NSLog(#"Should have updated text view");
}
#end
In anotherViewController.m , which has all the relevant imports, I call this:
myViewController *viewtask = [[myViewController alloc] init];
[viewtask updateTextViewWithoutArg];
Nothing happens. The method runs and logs that it should have updated, but no text updates. I have tried many different approaches, including textstorage and scrollrange methods, they all work the already working sections, but make no difference in the sections not working.
I've also tried just for fun:
myViewController *viewtask;
[viewtask updateTextViewWithoutArg];
Also using the instance variable _outText
Also using [self.outText setString:#"string"];
Also using [_outText setString:#"string"];
Again, they work but only in the already working sections.
This should be simple but isn't logical to me. In swift all I need to do is
self.outText.string = "I update whenever I'm called!"
Views you create in Interface Builder are lazily created, so if you access them before viewDidLoad is called they are nil.
If your case, calling
myViewController *viewtask = [[myViewController alloc] init];
does not cause the views to be created so when you call
[viewtask updateTextViewWithoutArg];
self.outText is nil.
You can see that this is what is happening by updating your code as below:
- (void)updateTextView:(NSString *)argText {
NSAssert(self.outText != nil, #"self.outText must not be nil");
self.outText.string = #"I don't make it to the NSTextView :(";
NSLog(#"Should have updated text view");
}
you should see the assert fire.
I appear to have found a solution by making myViewController a singleton class and using sharedInstance. For this particlar app, myViewController is a debug output window and will never need to be placed in another view.
I won't accept this answer yet, as it's not the best one I'm sure. There may still be a proper solution presented that allows finding the applicable myViewController instance, and modifying the outText property attached to it. Using this singleton makes subclassing tedious as I would have to make a new class for every instance if I wanted to be able to address say 10 View Controllers.
Anyway - the way I've been able to satisfy my simple requirement:
myViewController.h:
#import <Cocoa/Cocoa.h>
#import "anotherViewController.h"
#interface myViewController : NSViewController { }
#property (unsafe_unretained) IBOutlet NSTextView *outText;
#property (weak) IBOutlet NSButton *updateMeButton;
- (void)updateTextView:(NSString *)argText;
- (void)updateTextViewWithoutArg;
+ (id)sharedInstance;
#end
myViewController.m:
#import "myViewController.h"
#interface myViewController ()
#end
#implementation myViewController
static myViewController *sharedInstance = nil;
+ (myViewController *)sharedInstance {
static myViewController *sharedInstance = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
sharedInstance = [[myViewController alloc] init];
});
return sharedInstance;
}
- (void)viewDidLoad {
[super viewDidLoad];
sharedInstance = self;
}
- (void)viewDidUnload {
sharedInstance = nil;
}
- (void)viewDidLoad {
[super viewDidLoad];
self.outText.string = #"I work successfully";
}
- (IBAction)updateMeButton:(id)sender {
sharedInstance.outText.string = #"Button Pressed";
}
- (void)updateTextView:(NSString *)argText {
sharedInstance.outText.string = argText;
}
- (void)updateTextViewWithoutArg {
sharedInstance.outText.string = #"I make it to the TextView now";
}
#end
Now when I use this code from within anotherViewController.m it updates the right instance:
[myViewController.sharedInstance updateTextView:#"Updating with this string"];
This is a follow-up on the previous question.
Sorry. I could not figure out how to add code or edit something written over 5 minues ago.
A brief summary. I am trying to display a customized/derived TableView over a regular View. I am not using IB, but doing everything from the code. The goal here is to build the application, but also to learn Cocoa/OSX programming. This is my first OSX coding attempt.
NSView atop of which I would like to display my custom TableView is being displayed fine. Please excuse the NSLog garbage. It helps me to learn about the app lifecycle.
Header:
#import <Cocoa/Cocoa.h>
#import "MSNavigationTableView.h"
#interface MSNavigationPanelView : NSView
#property (strong, nonatomic) IBOutlet MSNavigationTableView *myNavigationTable;
#end
code:
#import "MSNavigationPanelView.h"
#implementation MSNavigationPanelView
- (id)initWithFrame:(NSRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code here.
NSLog(#"Initializing Navigation Panel");
}
self.myNavigationTable = [[MSNavigationTableView alloc] initWithFrame:self.frame];
[self.myNavigationTable setDataSource:self.myNavigationTable];
[self.myNavigationTable setDelegate:self.myNavigationTable];
[self addSubview:self.myNavigationTable];
return self;
}
- (void)drawRect:(NSRect)dirtyRect
{
[super drawRect:dirtyRect];
// Drawing code here.
NSLog(#"Drawing navigation view!");
}
#end
Now the NSTableView derived class.
Header:
#import <Cocoa/Cocoa.h>
#interface MSNavigationTableView : NSTableView <NSTableViewDataSource>
#end
NSArray *myNavigationArray;
Source:
#import "MSNavigationTableView.h"
#implementation MSNavigationTableView
+ (void)initialize {
NSLog(#"Called NavigationTableView::initialize!");
myNavigationArray = [NSArray arrayWithObjects:#"Call History" #"Contacts", #"Messages", #"Voicemail", nil];
}
- (id)initWithFrame:(NSRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code here.
}
return self;
}
- (void)drawRect:(NSRect)dirtyRect
{
[super drawRect:dirtyRect];
// Drawing code here.
}
- (NSInteger)numberOfRowsInTableView: (NSTableView *) aTableView
{
return [myNavigationArray count];
}
- (id)tableView: (NSTableView*) aTableView objectValueForTableColumn: (NSTableColumn *)aTableColum row: (NSInteger)rowIndex
{
NSLog([myNavigationArray objectAtIndex:rowIndex]);
return [myNavigationArray objectAtIndex:rowIndex];
}
#end
Thank you. I am sure that I am doing something stupid, and/or perhaps not doing something necessary. I have tried to figure this out for a couple of hours. No ideas so far.
You really need to use Interface Builder to make a table.
I would never try to programmatically initialized a table... to many things to configure.
NSTableView needs to have NSTableColumns, NSTableColumns need to have NSCell's, etc. etc.
NSTableView needs to be embedded in an NSScrollView.
I figured out what needs to be done.
First, array initialization has to be moved from +(void)initialize to another method. For me - (id)initWithFrame works fine.
Second, while this was not clear for me, overwriting NSTableViewDataSource is not enough.
One has to create NSTableColumn(s) then add the column(s) to the table using addTableColumn method of NSTableView class. Once that is done, we proceed with setDataSource and so on.
My approach to this may be all wrong so I appreciate your patience.
I have a button in my main XIB file linked to this method in my document.m file:
- (IBAction)showTagModal:(id)sender {
if (!_FileTagWindowController){
_FileTagWindowController = [[FileTagWindowController alloc]init];
}
[_FileTagWindowController showWindow:self];
}
_FileTagWindowController is declared as a property in document.h and using breakpoints when the method is called, as far as I can tell is initializing properly, however _windowNibName and _window remains nil.
FileTagWindowController.h looks like this.
#import <Cocoa/Cocoa.h>
#interface FileTagWindowController : NSWindowController{
}
#property (strong) IBOutlet NSArrayController *tagsArray;
- (IBAction)saveContext:(id)sender;
#end
FileTagWindowController.m looks like this:
#import "FileTagWindowController.h"
#interface FileTagWindowController ()
#end
#implementation FileTagWindowController
- (id)initWithWindow:(NSWindow *)window
{
self = [super initWithWindow:window];
if (self) {
// Initialization code here.
}
return self;
}
- (void)windowDidLoad
{
[super windowDidLoad];
NSLog(#"Window Did Load!");
// Implement this method to handle any initialization after your window controller's window has been loaded from its nib file.
}
- (IBAction)saveContext:(id)sender {
}
#end
in my FileTagWindowController.xib I have File Owner set to FileTagWindowController as the custom class. I have the File Owner's "window" outlet linked to the window (NSPanel). That's all that should be required correct? The NSLOG statement in WindowDidLoad never gets called. I tried using [super initWithWindowNibName] in FileTagWindowController.m but that crashes not only the app, but Xcode as well with an endless initialization loop. Am I missing something obvious here?
Thanks all so much.
Try something like the following.
// document.h
#import "FileTagWindowController.h"
#property (strong) filetagWindowController *FileTagWindowController;
// document.m
#synthesize filetagWindowController;
- (IBAction)showTagModal:(id)sender {
if (self.filetagWindowController == nil) {
self.filetagWindowController = [[FileTagWindowController alloc] initWithWindowNibName:#"FileTagWindowController"];
}
[filetagWindowController showWindow:self];
[[filetagWindowController window] setReleasedWhenClosed:NO];
[NSApp runModalForWindow:filetagWindowController.window];
filetagWindowController = nil;
}
You may also want to call NSWindowWillCloseNotification to observe its state and see if filetagWindowController is closed.
OK, what am I doing wrong?
1. Created cocoa app and appDelegate named: window2AppDelegate
2. window2AppDelegate.h
#import "PrefWindowController.h"
#interface window2AppDelegate : NSObject <NSApplicationDelegate> {
NSWindow *window;
PrefWindowController * ctrl;
}
#property (assign) IBOutlet NSWindow *window;
- (IBAction) buttonClick:(id)sender;
- (IBAction) buttonCloseClick:(id)sender;
#end
3. in xib editor, window connected to window controller - set to appdelegate, buttonclick actions to buttons
4, created
#import <Cocoa/Cocoa.h>
#interface PrefWindowController : NSWindowController {
#private
}
#end
#import "PrefWindowController.h"
#implementation PrefWindowController
- (id)init {
self = [super initWithWindowNibName: #"PrefWindow"];
return self;
}
- (void)dealloc {
// Clean-up code here.
[super dealloc];
}
- (void)windowDidLoad {
[super windowDidLoad];
// Implement this method to handle any initialization after your window controller's window has been loaded from its nib file.
}
#end
5. created new xib file named PrefWindow window IBOutlet connected to window from its controller (also controller set to PrefWindowController) Option "Visible At Launch" UNCHECKED! i want to see this window on buttonclick.
6. implemented window2AppDelegate
#import "window2AppDelegate.h"
#implementation window2AppDelegate
#synthesize window;
- (id) init {
if ((self = [super init])) {
ctrl = [[PrefWindowController alloc] init];
if ([ctrl window] == nil)
NSLog(#"Seems the window is nil!\n");
}
return self;
}
- (BOOL)applicationShouldTerminateAfterLastWindowClosed:(NSApplication *)sender {
return YES;
}
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
// Insert code here to initialize your application
}
- (IBAction) buttonClick:(id)sender {
// [[ctrl window] makeKeyAndOrderFront:self]; this doesn't work too :(
NSLog(#"it is here");
[ctrl showWindow:sender];
}
- (IBAction) buttonCloseClick:(id)sender {
[window close];
}
#end
7. After I build and run app: closebutton closes the app but buttonclick - won't show me PrefWindow!? Why and what am i doing wrong? Don't dell me that to show other window in cocoa objective-c is more difficult than in "stupid" Java or C#?
Finally i've managed the problem! In the nib editor for PrefWindow I had to do: Set File's owner class to: NSWindowController then connect window IBOutlet from File's owner to my (preferneces) window. After 6 days of unsuccessful attempts, google works.
Anyway, thanks for all your responses and time!
I'd suggest you move the creation of the PrefWindowController to applicationDidFinishLaunching:
I am not sure the application delegate's init method is called. Probably only initWithCoder: gets called when unarchiving the object from the NIB.
- (id) init {
if ((self = [super init])) {
ctrl = [[PrefWindowController alloc] init];
if ([ctrl window] == nil)
NSLog(#"Seems the window is nil!\n");
}
return self;
}
init is way too early in the scheme of things to be trying to test IBOutlets. They will still be nil yet. Not until later on in the object creation process will the nib outlets be "hooked up". The standard method where you can know that everything in the nib file has been hooked up is:
- (void)awakeFromNib {
}
At that point, all of your IBOutlets should be valid (provided they're not purposely referencing an object in a separate, yet-unloaded nib).
If PrefWindowController is a class that will only be used after the user chooses Preferences from the app menu, I would have to disagree with the others and say that I would not create the instance of the PrefsWindowController at all during the initial load. (Your main controller should be able to function independently from the prefs window). If you have a method that is meant to load the preferences window, then when that method is called, you should check to see if the PrefsWindowController instance is nil, and if it is, create it, then proceed to show the prefs window.
I'm realizing what a newbie I still am with this problem I have. I am trying to present a modal window in a project I am working on and it's not appearing. My solution was then to create an absolute basic project and get it working there first, so I would clearly understand my problem, but I can't get even this working :(
I add a ViewController to the MainWindow at applicationDidFinishLaunching. In this ViewControllers XIB, I have a button. The ViewController has the following header:
#import <UIKit/UIKit.h>
#import "ModalView.h"
#interface ViewBasedViewController : UIViewController {
ModalView *modalView;
}
- (IBAction)dooooIt :(id)sender;
#property (nonatomic, retain, readonly) ModalView *modalView;
#end
And methods:
#import "ViewBasedViewController.h"
#implementation ViewBasedViewController
#synthesize modalView;
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
}
- (void)viewDidUnload {
}
- (void)dealloc {
[super dealloc];
[modalView release];
}
- (ModalView *)modalView {
if (modalView == nil) {
modalView = [[ModalView alloc] initWithNibName:#"ModalView" bundle:nil];
}
return modalView;
}
- (IBAction)dooooIt :(id)sender {
[self.navigationController presentModalViewController:modalView animated:YES];
}
#end
I'm obviously missing something very simple and I believe it's between my ears at this stage :)
Does anyone want to put a poor fella out of his misery?
Many Thanks
Chris
Have you connected the button to the IBAction? Control-drag in Interface Builder from your button to the "File's Owner" icon in your XIB file, and select the "dooooIt" method there. Recompile and your code should execute as expected.
For those that may come across this problem and were as baffled as I was, I fell over the solution. There was two problems in the dooooIt method:
- (IBAction)dooooIt :(id)sender {
[self presentModalViewController:self.modalView animated:YES];
}
I should have included 'self' when referring to the modalView property (otherwise it's nil) and I shouldn't have referred to the navigationController as I had none hooked up.
Hope this helps any of you (amazing what a glass of wine can do! :)