How can I make NSCollectionView finish drawing before the view containing it is made visible?

Question

Hello,

I'm trying to clean up the UI on my application (built for 10.5) and one thing that's rather annoying is that when I swap to the library I reload the contents and the nscollectionview that displays the items fades the old content out before fading the new ones in. I don't mind the fade in/out of old/new items, but the way i've programmed the view swapping should make the library reload happen before the the nsview that contains the nscollectionview is inserted into the main window.

Anyone had this sort of problem before?

Here's an abridged version of how the swap between different parts of the application to the library goes:

In the main controller:

-(void)setMainPaneToLibrary {
    if(viewState == VIEW_STATE_LIBRARY)
        return;
    [libraryController refreshDevices:self];
    [libraryController refreshLibraryContents];

    [menuController setSelectionToIndex:0];
    viewState = VIEW_STATE_LIBRARY;

    [self removeSubview]; //clear the area
    [mainPane addSubview:[libraryController view]];
}

In the library controller:

-(void)refreshLibraryContents {
    [self loadLibraryContents:[rootDir stringByAppendingPathComponent:currentDir]];
}

-(void)loadLibraryContents:(NSString *)folderToLoad {

    int i;
    int currentSelection = [libraryArrayController selectionIndex]; //used to preserve selection and smooth folder changing

    [libraryArrayController setContent:nil];

    //expand the path to load
    folderToLoad = [folderToLoad stringByExpandingTildeInPath];

    NSFileManager * fileManager = [NSFileManager defaultManager]; 
    //load the files in the folder
    NSArray * contents = [fileManager directoryContentsAtPath:folderToLoad];

    //create two seperate arrays for actual files and folders - allows us to add them in order
    NSMutableArray * directories = [[NSMutableArray alloc] init];
    NSMutableArray * musicFiles = [[NSMutableArray alloc] init];

//... a load of stuff filling the file arrays ...

    for(i=0;i<[directories count];i++) {
    [libraryArrayController addObject:[directories objectAtIndex:i]];
    }
    for(i=0;i<[musicFiles count];i++) {
    [libraryArrayController addObject:[musicFiles objectAtIndex:i]];
    }

    if(currentSelection >= 0) {
    [libraryArrayController setSelectionIndex:currentSelection];
    }

    [directories release];
    [musicFiles release];   
}

Answer 1

The issue is not that the collection view hasn't finished drawing, it's that it animates the adding and removal of the subviews. It may be possible to create a transaction that disables layer actions while you're reloading the collection view's content. Listing 2 (temporarily disabling a layer's actions) shows how to do this. I haven't tested this, so I don't know if this will do what you want, but this is where I'd start.