That is a somewhat cryptic notation. Sure, it tells you exactly what you want to know "if" you know that's what it's telling you.
On the other hand, anything longer might be too long.

Just curious, would it be possible to display it within the bar itself in a tiny font? Then one of the following notations:

• 6/60 GiB
• 6 GiB free (of 60)

Or something else...

I agree that the presentation isn't ideal. Is this better?

Actually I like this better, and now it matches the Properties window, too:

While I recognize this implements a wish from bugzilla, I'm not yet convinced this is something Dolphin should add by default, as for a lot of users this might just be clutter and is not "Simple by default, powerful when needed".

I'm wondering what is the root cause for wanting to see this information: Is it because it is not clear on which partition or device the current folder is located? If so, there might be better ways to solve this. I'd suggest to open an new task on Dolphin's workboard (or a bugzilla issue) to brainstorm, even if this patch goes in.

Now for something tangible. In split mode with the default window size, it looks problematic with this patch, but even in normal mode (see F5338350) the space bar is just too small in relation to the long text (before vs. after):

Ideas:

• show less information if space is constrained (e.g. 3 steps: only space bar, space bar + free, space bar + free + total)
• use KSqueezedTextLabel
• different width distribution: instead of "zoom slider | space bar+text" do "zoom slider | space bar | space text" (with "|" separating segments of equal width)
• never show any text by default, on mouse over completely replace space bar with full text
• add it as a third option to the context menu
• show it as a tooltip

Ideally all of these ideas could be combined, but this might be too much work for a single patch. However, at least something should be done before this patch goes in.

I think there are a few root causes for wanting this:

1. it's not obvious how to find the capacity of a disk. There's no Properties menu item when you right-click on a device. You have to find this information at the bottom of the Properties dialog for individual items stored on the disk, which probably isn't what people expect. This is tracked by https://bugs.kde.org/show_bug.cgi?id=181880

2. As mentioned in the bug, the reporter wants this feature to make it easier to tell disks apart, since he has a lot of them. And Dolphin doesn't let you rename disks. This is tracked by https://bugs.kde.org/show_bug.cgi?id=216425

Even if those were addressed (and they should be) IMHO this is still worthwhile if we can address the issue of a lack of space in the bottom bar. I like your space-constrained idea of 3 steps: only space bar, space bar + free, space bar + free + total). I'll see if I can make that happen.

Maybe this information could be added to the information sidebar:

Otherwise I like Henrik's idea of using a tooltip to show additional information when hovering the free space widget.

Yes, I've been meaning to add a real space calculation to the Information Panel. "Size: 68 items" is kind of useless, or at least much less useful than a real readout of on-disk space used.

In D8227#156817, @anthonyfieroni wrote:

%1%% free

That's what the progressbar already shows.

Let's take a step back and think about who will need what:

• casual user who does not know what a "GiB" is and only checks to see if the disk is "nearly full" → relative disk usage, i.e. progressbar (graphical, intuitive) or percentage (text, not intuitive)
• advanced user who cares about how many more docs/photos/... he has space for → absolute disk usage ("1.4 GiB free"), because a percentage is not meaningful in terms of docs/photos/...
• expert user who wants to know everything → add more information (but which?)

IMHO this also determines the order in which Dolphin should hide items if the horizontal space becomes restricted. You may also notice Dolphin already provides quite good usability for the first two users, no need to change that. Therefore, adding things for the third type of user should be done quite carefully.

Great observations, @rkflx. Agree 100%. I'll have a think on this.