Re: Displaying an NSArray of NSArray's in a Table view

FROM : Bruce Truax
DATE : Sun Dec 12 14:36:50 2004

I have implemented these methods in my datasource object.  When I have used
table views in the past I have always used bindings and I have bound each
column to the column of the table.  In this case I cannot do that because
the array is created dynamically and I do not have advance knowledge of the
columns.  It appears that I need to start with an empty table and then add
columns dynamically which I do as follows:

    for (i=0;i<10;i++)
    {
        NSTableColumn *theColumn = [[NSTableColumn alloc] init];
        [theColumn setIdentifier:[NSString stringWithFormat:@"i%",i]];
        [displayArrayTable addTableColumn:theColumn];
        [theColumn release];
    }
I set the identifier of each column as a string which is the same as the
column number.  This is also the key that I use in the dictionary
representing the objects in each row. (At your suggestion that table views
are really set up to deal with arrays of dictionaries.)

I then do the following:

    [self setDisplayArray:[[DLDDisplayArray alloc]
initWithCArray:outputArray
                                            withXDimension:xSize
                                          withYDimensiont:ySize]];
   
    [displayArray retain];
    [displayArrayTable setDataSource:displayArray];
    [displayArrayTable setNeedsDisplay:YES];

I end up with a table containing the correct number of columns (all with the
column header title "FIELD" but no data in the table.  I think some of the
problem is related to my column identifiers but the documentation is unclear
as to how these should be specified.  I appears that they should be the
strings representing the keys for each column but I am not sure.

Bruce


On 12/11/04 6:51 PM, "Jonathan Jackel" <<email_removed>> eloquently
wrote:

> Table views are really set up to deal with arrays of dictionaries, not
> arrays of arrays.  Also, to understand table views you need to
> understand table columns as well.  I would spend some time with the
> NSTableView and NSTableColumn docs (NSArray and NSMutableArray docs,
> too).
>
> I imagine that there is some clever way of making this work with
> bindings, but I don't know it.  I would use a data source and five
> lines of code.
>
> In the table datasource, implement this (written in Mail):
>
> - (int)numberOfRowsInTableView:(NSTableView *)aTableView
> {
>    return [rows count];
> }
>
> - (id)tableView:(NSTableView *)aTableView
>    objectValueForTableColumn:(NSTableColumn *)aTableColumn
>    row:(int)rowIndex
> {
> int columnIndex = [[aTableView tableColumns]
> indexOfObject:aTableColumn];
>        return [[rows objectAtIndex:rowIndex]
> objectAtIndex:columnIndex];
> }
>
> -  (void)tableView:(NSTableView *)aTableView
>    setObjectValue:anObject
>    forTableColumn:(NSTableColumn *)aTableColumn
>    row:(int)rowIndex
> {
> int columnIndex = [[aTableView tableColumns]
> indexOfObject:aTableColumn];
> [[rows objectAtIndex:rowIndex] replaceObjectAtIndex:columnIndex
> withObject:anObject];
> }
>
> Jonathan
>
> On Dec 10, 2004, at 8:57 PM, Bruce Truax wrote:
>

>> As some of you have seen from an earlier post, I have taken a two
>> dimensional C array of floats and created an NSMutableArray (rows) of
>> NSMutableArrays (columns) of NSNumbers which I created from the C
>> array of
>> floats.  It seems that this should be easy to display in a table view
>> but it
>> is not obvious how to do this.  Binding the content array of the table
>> view
>> to the NSMutableArray does not cause the display, neither does setting
>> the
>> data source.
>>
>> Suggestions are appreciated.
>>
>> Bruce
>> --