Select text (content) instead of cell with NSCell

Question

I'm currently working in a project with a NSOutlineView...

I use, of course, NSCell(s) and I need to let the ability to select text inside the cell... Or at least... prevent the selection (and highlight) of the cells...

I search all options on IB, but can't found the right one...

Is there a way, programmatically or not, to prevent selection/highlighting of cell, nor let user select cell content ?

Thanks =)

Answer 1

That's not much NSCell related, maybe you're looking to implementing outlineView:shouldSelectItem: in your delegate.

On the NSCell, setEnabled:NO, may help too. From the documentation:

setEnabled:(BOOL)flag

The text of disabled cells is changed to gray. If a cell is disabled, it cannot be highlighted, does not support mouse tracking (and thus cannot participate in target/action functionality), and cannot be edited. However, you can still alter many attributes of a disabled cell programmatically. (The setState: method, for instance, still works.)

Answer 2

Try setting:

cell.selectionStyle = UITableViewCellSelectionStyleNone;

You could also try overriding highlightSelectionInClipRect:, but I'm not totally sure this will work.

Answer 3

Let's take a quick example like the outline view below. There are 3 columns: firstName, lastName, and fullName.

In this particular example, let's say we want to only allow firstName and lastName to be editable while fullName (which is potentially derived from firstName and lastName) is not. You could set this up in Interface Builder by checking or unchecking the editable checkbox for the table column. To do that, click 3 times on one of the table columns (not the header, but inside the outline view); this first selects the NSScrollView, then the NSOutlineView, then an NSTableColumn:

You'd set the attributes like the following:

That provides a start by setting a default editable value for the entire column. If you need more control over whether a particular row's item value should be editable or not, you can use the outlineView:shouldEditTableColumn:item: delegate method:

#pragma mark -
#pragma mark <NSOutlineViewDelegate>

- (BOOL)outlineView:(NSOutlineView *)anOutlineView
    shouldEditTableColumn:(NSTableColumn *)tableColumn
               item:(id)item {

    if ([[tableColumn identifier] isEqualToString:@"firstName"] ||
        [[tableColumn identifier] isEqualToString:@"lastName"]) {

        return YES;

    } else if ([[tableColumn identifier] isEqualToString:@"fullName"]) {

        return NO;
    }
    return YES;
}

If you want to control whether a particular row in the outline view is selectable (for example, you could prevent selection of a group item), you can use outlineView:shouldSelectItem:.

 - (BOOL)outlineView:(NSOutlineView *)anOutlineView shouldSelectItem:(id)item {
    // if self knows whether it should be selected
    // call its fictional isItemSelectable:method:

    if ([self isItemSelectable:item]) {
        return YES;
    }

    /* if the item itself knows know whether it should be selectable
     call the item's fictional isSelectable method. Here we
     are assuming that all items are of a fictional
      MDModelItem class and we cast `item` to (MDModelItem *)
      to prevent compiler warning */

    if ([(MDModelItem *)item isSelectable]) {
        return YES;
    }

    return NO;
}