Is it more appropriate to use "Deselect All" or "Select None" or some other phrase to indicate the opposite of "Select All"?
Context: A toggle button in an iOS app UIToolbar that will select all items on screen, then change title to indicate it will clear the selected state of all items. Note that space is limited as there will be multiple buttons in the toolbar (so I wouldn't use "Clear Selection").
One option could be to only use "All" then change it to "None" but users may not know it'll modify selection state. Another complexity is there is also a "Range" button which allows selecting a range of items. So it too is related to selection state yet it's not titled "Select Range" due to the limited space. Could these be replaced with icons instead of text? I could add a non-interactive label that reads "Select:" but I've never seen that on a toolbar I don't believe.
Is there anything on iOS that implements this functionality? Being consistent with the system would be best.