macOS Best way of display lengthy strings.

If you're ok with bigger cells, you could always expand the height of the row when a mouse hovers over the cell with a nice simple animation, and then shrink it back when the mouse is outside the frame. If you want to go this route, take a look at the docs and sample code that deals with view-based tables. Alternatively, you could explode out the cell to a larger size, instead of the whole row. I suspect this would be too annoying though.

Marimuthu said:

...But, as stated earlier, to maintain consistency, cells are of predetermined dimensions hence Increasing the dimensions is not an option.

Click to expand...

UX design is all about making decisions based on constraints. It may actually be more useable for the user to hover over a truncated cell and have it's row animate open to reveal the text, and then have the row return to the consistent size when the mouse exits the frame. I think this would be a better experience than them trying to squint at a tooltip, furthermore, the user is not going to be able to select and copy text from the tooltip like they could with using the approach I proposed. I think it would be worth mocking up.

Build and run Apple's TableViewPlayground sample code. Take a look at the Complex Cell TableView window, and check/uncheck the "Use Small Row Height" box to see kind of what I'm talking about. I think the appropriate animation would only apply to 1 row and the animation would be much faster, possibly with the ease in/ease out parameter set so it has a bit of a popping or snapping effect. I think users might find this classy, and an elegant way to solve a tricky problem.

Obviously you have your own constraints you have to deal with, but I think it might be worth considering. Consistency for it's own sake is often detrimental to usability.

Out of context I would suggest just sticking with the truncation scheme, it may not be worth the effort to expand the feature. This of course is predicated on the assumption that the full text is available elsewhere. Add the full feature when the entire app is done and ready to go and you've decided that it is worth it. If the full text is not available elsewhere, I would support the animation method suggested by Marinuthu.