#pragma mark - TABLE DELEGATES AND DATA SOURCE

- (NSInteger)outlineView:(NSOutlineView *)outlineView numberOfChildrenOfItem:(id)item {
    if (item == nil) // root folder
        return [self.projectDocument.loader countObjectsWithParentID:VIEWS_ROOT];
    else { // folder items
        MKObjectID itemID = [[((NSDictionary*)item) objectForKey:@MKPROPERTY_ID] intValue];
        return [self.projectDocument.loader countObjectsWithParentID:itemID];
    }
}

- (id)outlineView:(NSOutlineView *)outlineView child:(NSInteger)index ofItem:(id)item {
    MKObjectID itemID = (item == nil ? VIEWS_ROOT : [[((NSDictionary*)item) objectForKey:@MKPROPERTY_ID] intValue]);
    return [[self.projectDocument.loader objectsForParentID:itemID] objectAtIndex: index];
}

- (BOOL)outlineView:(NSOutlineView *)outlineView isItemExpandable:(id)item {
    MKObjectID itemID = [[((NSDictionary*)item) objectForKey:@MKPROPERTY_ID] intValue];
    BOOL isFolder = [self.projectDocument.loader isFolder:itemID];
    return isFolder;
}

- (NSView *)outlineView:(NSOutlineView *)outlineView viewForTableColumn:(NSTableColumn *)tableColumn item:(id)item {
    MKViewThumbCell *cell = (MKViewThumbCell*)[outlineView makeViewWithIdentifier:kMKViewThumbCellIdentifier owner:self];
    if (cell == nil) { // If we have not a cached version of our view we will make a new one
        cell = [[MKViewThumbCell alloc] initWithFrame:CGRectZero identifier:kMKViewThumbCellIdentifier];
    }

    NSDictionary *viewItem = (NSDictionary*)item;
    cell.title = [viewItem objectForKey:@MKPROPERTY_NAME];
    cell.previewImage = [NSImage imageNamed:@"preview_sample"];

    return cell;
}

- (CGFloat)outlineView:(NSOutlineView *)outlineView heightOfRowByItem:(id)item {
    NSImage *previewImage = [NSImage imageNamed:@"preview_sample"];
    return [MKViewThumbCell heightForRowWithPreview:previewImage smallSize:useSmallPreviews];
}