Display, add and delete data from an NSTableView Implement NSTableView.

http://juliuspaintings.co.uk/cgi-bin/paint_css/animatedPaint/025-NSTableView.pl

Problem: To create a 3 collumn NSTableView, with ability to edit entries, insert rows and delete rows.

Implementation.

Create a new project in XCode: File->New Project->Cocoa Application

Call it: 025-NSTableView

Now create the classes: MyDataObject of type NSObject, MyTableController of type NSControl.

(Note it need not be of type NSControl!)

Code these as shown below and save.

Note that MyTableController is the Data Source for the NSTableView which expects to find there the methods:

- (int)numberOfRowsInTableView:

- (id) tableView:objectValueForTableColumn:row:

- (void)tableView:setObjectValue:forTableColumn:row:

Note also that although I have made MyTableController not only the Data Source for the NSTableView but also its Delegate, I have not used any of its delegate methods.

The following links I found useful:

CocoaDev: NSTableView

CocoaDev: NSTableViewTutorial

CocoaDev: AnotherNSTableViewTutorial

O'Reilley MacDevCenter: Understanding the NSTableView Class

Rixstep: NSTableView

Quickies for NSTableView

And ofcourse NSTableView Class Reference

// MyTableController.h

// 025-NSTableView

//

#import <Cocoa/Cocoa.h>

#import "MyDataObject.h"

//@interface MyTableController : NSControl {
@interface MyTableController :
NSObject {
NSMutableArray * nsMutaryDataObj;
IBOutlet
NSTableView * idTableView;

}
@property (assign)
NSMutableArray * nsMutaryDataObj;
@property (assign)
NSTableView * idTableView;

- (IBAction)addAtSelectedRow:(id)pId;
- (IBAction)deleteSelectedRow:(id)pId;

- (void)addRow:(MyDataObject *)pDataObj;

- (int)numberOfRowsInTableView:(NSTableView *)pTableViewObj;

- (id) tableView:(NSTableView *)pTableViewObj
objectValueForTableColumn:(NSTableColumn *)pTableColumn
row:(int)pRowIndex;

- (void)tableView:(NSTableView *)pTableViewObj
setObjectValue:(id)pObject
forTableColumn:(NSTableColumn *)pTableColumn
row:(int)pRowIndex;

@end

// MyTableController.m

// 025-NSTableView

//

#import "MyTableController.h"

@implementation MyTableController
@synthesize nsMutaryDataObj;
@synthesize idTableView;

- (void)awakeFromNib {

self.nsMutaryDataObj = [[NSMutableArray
alloc]init];
int i;
for (i =
0; i < 10; i ++) {
NSString * zStr1 = [[NSString
alloc]initWithFormat:@"%d",(i+1)*10];
NSString * zStr2 = [[NSString
alloc]initWithFormat:@"%d",(i+1)*100];
NSString * zStr3 = [[NSString
alloc]initWithFormat:@"%d",(i+1)*1000];
MyDataObject * zDataObject = [[MyDataObject
alloc]initWithString1:zStr1

andString2:zStr2

andString3:zStr3];
[self.nsMutaryDataObj
addObject:zDataObject];

} // end for

[idTableView
reloadData];

} // end awakeFromNib

- (IBAction)addAtSelectedRow:(id)pId {
if ([idTableView
selectedRow] > -1) {
NSString * zStr1 =
@"Text Cell 1";
NSString * zStr2 =
@"Text Cell 2";
NSString * zStr3 =
@"Text Cell 3";
MyDataObject * zDataObject = [[MyDataObject
alloc]initWithString1:zStr1

andString2:zStr2

andString3:zStr3];
[self.nsMutaryDataObj
insertObject:zDataObject

atIndex:[idTableView
selectedRow]];

[idTableView
reloadData];

} // end if

} // end deleteSelectedRow

- (IBAction)deleteSelectedRow:(id)pId {
if ([idTableView
selectedRow] > -1) {

[self.nsMutaryDataObj
removeObjectAtIndex:[idTableView
selectedRow]];

[idTableView
reloadData];

} // end if

} // end deleteSelectedRow

- (void)addRow:(MyDataObject *)pDataObj {
[self.nsMutaryDataObj
addObject:pDataObj];

[idTableView
reloadData];

} // end addRow

- (int)numberOfRowsInTableView:(NSTableView *)pTableViewObj {

return [self.nsMutaryDataObj
count];

} // end numberOfRowsInTableView

- (id) tableView:(NSTableView *)pTableViewObj
objectValueForTableColumn:(NSTableColumn *)pTableColumn
row:(int)pRowIndex {

MyDataObject * zDataObject = (MyDataObject *)
[self.nsMutaryDataObj
objectAtIndex:pRowIndex];
if (! zDataObject) {

NSLog(@"tableView: objectAtIndex:%d = NULL",pRowIndex);

return
NULL;

} // end if

NSLog(@"pTableColumn identifier = %@",[pTableColumn
identifier]);

if ([[pTableColumn
identifier] isEqualToString:@"Col_ID1"]) {
return [zDataObject
nsStrName1];
}

if ([[pTableColumn
identifier] isEqualToString:@"Col_ID2"]) {
return [zDataObject
nsStrName2];
}

if ([[pTableColumn
identifier] isEqualToString:@"Col_ID3"]) {
return [zDataObject
nsStrName3];
}

NSLog(@"***ERROR** dropped through pTableColumn identifiers");

return
NULL;

} // end tableView:objectValueForTableColumn:row:

- (void)tableView:(NSTableView *)pTableViewObj
setObjectValue:(id)pObject
forTableColumn:(NSTableColumn *)pTableColumn
row:(int)pRowIndex {

MyDataObject * zDataObject = (MyDataObject *)
[self.nsMutaryDataObj
objectAtIndex:pRowIndex];

if ([[pTableColumn
identifier] isEqualToString:@"Col_ID1"]) {
[zDataObject
setNsStrName1:(NSString *)pObject];
}

if ([[pTableColumn
identifier] isEqualToString:@"Col_ID2"]) {
[zDataObject
setNsStrName2:(NSString *)pObject];
}

if ([[pTableColumn
identifier] isEqualToString:@"Col_ID3"]) {
[zDataObject
setNsStrName3:(NSString *)pObject];
}

} // end tableView:setObjectValue:forTableColumn:row:

Bring up Interface Builder by double clicking on MainMenu.nib.

Drag a NSTableView and two buttons onto the window and name them as shown.

Note: to insert the third collumn go to the Attributes panel of the Inspector and set the number of collumns to three.

Note: to make the collumns of equal size select the NSScrollView, go into the Size panel of the Inspector and set the width of the view to 3n + 26, where n is the required width of each collumn and 26 is for the rhs scroll bar.

Next, select each collumn in turn and set its width to n. In my example n = 95.

Interface Builder: Do the layout

Set the number of NSTableView collumns to 3

Select each collumn in turn and in the Attributes panel of the Inspector give it an identifier by which to identify it in the code. Here the identifier is Col_ID1.

Interface Builder: Set the collumn identifier to Col_ID1

Drag an NSObject onto the MainMenu.xib and set the object to MyTableController.

Interface Builder: set NSObject to MyTableController

Select the NSTableView and in the Connections panel of the Inspector set the DataSource and Delegate outlets to MyTableController.

Interface Builder: set DataSource and delegate to be MyTableController

Link the idTableViewOutlet of MyTableController to the NSTableView.

Interface Builder: Link MyTableController to the NSTableView

Link the two buttons to their respective IBActions in MyTableController.

Save everything and Run.

the working NSTableView Application

If you want to download the code

Click the Download Link to obtain 025-NSTableView.zip file of this whole OS X 10.5 Leopard program.

Download 025-NSTableView.zip (2.3 MB)