NSOutlineView: how to make parent items bold?

Question

I have a NSOutlineView with a list of parents item and children.

What's the easiest way to make the parent items (those ones with the opening arrow) in bold text?

thanks

Answer 1

If you are using a cell-based outline view, you can use this delegate method to bold parent items:

// Assuming you use NSTextFieldCell
- (void)outlineView:(NSOutlineView *)outlineView willDisplayCell:(id)cell forTableColumn:(NSTableColumn *)tableColumn item:(id)item {
    if ([self outlineView:outlineView numberOfChildrenOfItem:item] > 0) {
        [(NSCell *)cell setFont: [NSFont boldSystemFontOfSize: ((NSCell *)cell).font.pointSize]];
    } else {
        [(NSCell *)cell setFont: [NSFont systemFontOfSize: ((NSCell *)cell).font.pointSize]];
    }
}

Otherwise, in a view-based outline view you can do the following:

- (NSView *)outlineView:(NSOutlineView *)outlineView viewForTableColumn:(NSTableColumn *)tableColumn item:(id)item {
    NSTableCellView *cellView = [outlineView makeViewWithIdentifier:@"MyIdentifier" owner:self];
    if ([self outlineView:outlineView numberOfChildrenOfItem:item] > 0) {
        [cellView.textField setFont: [NSFont boldSystemFontOfSize: cellView.textField.font.pointSize]];
    } else {
        [cellView.textField setFont: [NSFont systemFontOfSize: cellView.textField.font.pointSize]];
    }

    // do whatever else you do
    return cellView;
}

Alternatively, NSOutlineViewDelegate's -outlineView:isGroupItem: might be what you're actually looking for: https://developer.apple.com/library/mac/documentation/cocoa/reference/NSOutlineViewDelegate_Protocol/Reference/Reference.html#//apple_ref/occ/intfm/NSOutlineViewDelegate/outlineView:isGroupItem: