Page wheel

Pagination as a thumbwheel. A knurled wheel stands in a recess with a window in its face, and the page number rolls past it on a paper tape. A key either side steps by one. The keys are plain links, so it pages without any script; the wheel is what a script adds.

Drag the wheel up or right, scroll over it, or Tab to it and use the arrow keys. The keys either side step by one.

• The two keys are links to real pages, named “Previous page” and “Next page”. With no script they are the whole control, and the window still says which page you are on.
• The wheel is a spinbutton with a name, a minimum, a maximum and a value in words, so a screen reader says “Circuits, Page 3 of 12”, and the new value is spoken as it changes.
• The window and the printed “of 12” are hidden from assistive technology, because the value already says both.
• Every way of turning it (drag, scroll, keys) lands on whole page numbers and passes through none it should not; PageUp and PageDown are ten.
• Scrolling over the wheel turns it only while there is a page to turn to. At either end the scroll goes through to the page, so the wheel never traps it.
• With reduced motion the wheel jumps to the page: the tape and the ridges do not glide, and everything is still said.