I'm currently working on an app that offers multi selection (see attached image). Now I am wondering how to design the multi select "circle" in the toolbar.
- Should it be not marked while the user has not pressed it, and marked after the user pressed it? This would be similar to checkbox behavior on a computer (as on the image left and middle).
Should it behave like a pause/play button which shows the pause button while playing and the play button while being paused? Meaning: check icon in tool bar indicating that it will check all items when being pressed; and show unchecked when all items are checked, indicating that all items will be unchecked when pressing.
What about having used the "check all" button in the toolbar and deselecting one (or several) files manually again? Should this affect the visual appearance of the multi select button in the toolbar?