Having a table and outline work togethor

FROM : Coleman Nitroy
DATE : Mon Dec 20 21:33:29 2004

I have been working for a bit on getting a proper data source working
for a outline view. I am aware that an outline view cannot use
bindings, but a table can. I have a leaf/node style structure to
contain all of my data. Each and every node and leaf has a dictionary
in it. Basically I want to make it so if the user selects something
from the outline view, the tableview shows the dictionary in two
columns, keys and values. So i only want one node displayed at a time.
This also needs to be editable, and I would love to do this with
bindings but am not sure how to go about doing so. The first problem I
have is getting the outline view to work at all. Here is what I am
currently doing. Being new to cocoa and its been awhile since I last
coded I am having some troubles coming up with good "kosher" ways to
have the data thrown around in the application. All suggestions are
greatly appreciated. Begin the fun code:

MapNode.m
   ((I wont display this code because its long complex and tested to
work))
   MapNode basically takes in an NSData object and creates a root node
and builds the node tree structure. I have a debugging function after
its all loaded climbing the newly created tree and NSLogging everything
in the tree and it is all in tact.

MapDataSource.m
- (void) initWithContents: (NSData *) data
{
   //  Each node has a NSString as an identifier for debugging
    [rootNode setNodeName: @"Root"];
   // Build a tree with the data
    [rootNode createTree: data];
   // Debugging function that spits out the entire tree
    [rootNode printNodeChildren:rootNode];
}
   ((I wrote my own then got frustrated and tossed in the code from
OutlineMe from Hillegass's example and modified it))
- (id)outlineView:(NSOutlineView *)ov child:(int)index ofItem:(id)item
{
    if (item)
        // Return the child
        return [item childAtIndex:index];
    else
        // Else return the root
        return rootNode;
}

// Called repeatedly to find out if there should be an
// "expand triangle" next to the label
- (BOOL)outlineView:(NSOutlineView *)ov isItemExpandable:(id)item
{
    // Returns YES if the node has children
    return [item expandable];
}

// Called repeatedly when the table view is displaying itself
- (int)outlineView:(NSOutlineView *)ov numberOfChildrenOfItem:(id)item
{
    if (item == nil) {
        // The root object;
        return 1;
    }
    return [item childrenCount];
}

// This method gets called repeatedly when the outline view is trying
// to display it self.
- (id)outlineView:(NSOutlineView *)ov
    objectValueForTableColumn:(NSTableColumn *)tableColumn
     byItem:(id)item
{

    return [item nodeName];
}

// This method gets called when the user edits the field.
- (void)outlineView:(NSOutlineView *)ov     
      setObjectValue:(id)object
      forTableColumn:(NSTableColumn *)tableColumn
       byItem:(id)item
{
    [item setNodeName:object];

    [outlineView reloadItem:rootNode reloadChildren:YES];
}

MapDocument.m
   ((has a MapDataSource object and passes it the data loaded from an
open dialog))

TreeviewController.m
   ((controller for the particular nib file that the outline view is in,
contains code to load the nib thats it))
   ((I am not sure what class this particular nib's file owner should
be?))
IntrerfaceBuilder Stuff:
   The outlineview is connected to MapDataSource as its data source.

Sorry if this is rather complex or not very verbose. Ill gladly answer
any questions about this, anything to get this up and running properly.

Thanks in advance,

---
Coleman Nitroy
<email_removed>
nitroy.com/cole