Having problems using NSMutableArray with NSTableView (Cocoa)

Question

I'm having a problem trying to use an NSMutableArray with a NSTableView controller in my simple ToDo list application. Adding items does not work and trying to delete items gives me the error -[NSCFArray removeObjectAtIndex:]: index (0) beyond bounds (0). I can't seem to find the cause of my problem as trying to add an item returns no error and the error in removing one leads to no obvious solution. My code is as follow:

AppController.h

//
//  AppController.h
//  ToDo
//
//  Created by Rhys Powell on 10/01/11.
//

#import <Cocoa/Cocoa.h>
#import <BWToolkitFramework/BWToolkitFramework.h>

@interface AppController : NSObject {
    IBOutlet BWAnchoredButton *addButton;
    IBOutlet BWAnchoredButton *removeButton;
    IBOutlet NSMenuItem *clearAll;
    IBOutlet NSTableView *tableView;
    NSMutableArray *toDoList;
}
- (IBAction)addToDo:(id)sender;
- (IBAction)removeToDo:(id)sender;
- (IBAction)clearAllToDos:(id)sender;
@end

AppController.m

//
//  AppController.m
//  ToDo
//
//  Created by Rhys Powell on 10/01/11.
//

#import "AppController.h"


@implementation AppController

- (id)init
{
    [super init];

    NSLog(@"Initialising...");

    toDoList = [[NSMutableArray arrayWithObject:@"Add a ToDo with the '+' button"] retain];

    return self;
}

- (IBAction)addToDo:(id)sender
{
    NSLog(@"Added a ToDo");
    [toDoList addObject:@"Test"];
}

- (IBAction)removeToDo:(id)sender
{
    [toDoList removeObjectAtIndex:[tableView selectedRow]];
}

- (IBAction)clearAllToDos:(id)sender
{
    [toDoList removeAllObjects];
}

- (int)numberOfRowsInTableView:(NSTableView *)tv
{
    return [toDoList count];
}

- (id)tableView:(NSTableView *)tv objectValueForTableColumn:(NSTableColumn *)tableColumn row:(int)row
{
    return [toDoList objectAtIndex:row];
}

@end

I should also note that the initial string I initialise the array with displays, but I cannot delete it or add new strings.

Show the calling code. Do you update the table view parallel to that? — Eiko
– Eiko, Commented Jan 10, 2011 at 10:28

mrbaboo · Accepted Answer · 2011-01-10 10:29:13Z

3

Not sure of the underlying problem, but the first thing I see is you're deleting/adding the rows from the underlying array but not telling the table about this. Make sure you call [tableView reloadData] from within addToDo, removeToDo and clearAllToDos.

The [NSMutableArray arrayWithObject;...] call is fine as you also subsequently call retain.

edited Jan 10, 2011 at 10:29

answered Jan 10, 2011 at 10:23

mrbaboo

4733 silver badges6 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

rpowell Over a year ago

Thank you so much, I'd only worked with static tables prior to this point so I didn't know I had to do this.

Neilvert Noval · Accepted Answer · 2011-01-10 10:20:36Z

2

I have checked you code. And it seems that the toDoList = [[NSMutableArray arrayWithObject:@"Add a ToDo with the '+' button"] retain]; and the [toDoList removeObjectAtIndex:[tableView selectedRow]]; are doing well.
My perception on your problem is with regards to the table view. Make sure your table view always contains a selection. You can set that up in the Interface Builder or programmatically. This is to make sure that [toDoList removeObjectAtIndex: will always recieve a value from table view.

answered Jan 10, 2011 at 10:20

Neilvert Noval

1,7153 gold badges16 silver badges21 bronze badges

1 Comment

JeremyP Over a year ago

Yes, if there is no selection, -selectedRow returns -1.

Robin · Accepted Answer · 2011-01-11 03:34:17Z

0

In AppController.m you are creating the array with method arrayWithObject: this will create an autorelease array which will be released after something. so instead use initWithObjects: method

edited Jan 11, 2011 at 3:34

answered Jan 10, 2011 at 9:37

Robin

10k5 gold badges51 silver badges76 bronze badges

2 Comments

rpowell Over a year ago

Xcode is telling me that there's no such method as initWithObject:.

Robin Over a year ago

NSArray *temp = [[NSArray alloc] initWithObjects:object, nil]; i am very sorry that i forgot to write 's' after Object.

Collectives™ on Stack Overflow

Having problems using NSMutableArray with NSTableView (Cocoa)

3 Answers 3

1 Comment

1 Comment

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

1 Comment

1 Comment

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related