Googlebook Keyboards Bring Back Android's Triangle, Circle and Square as Window Keys

Every Googlebook keyboard prints Android's triangle, circle and square icons on the F1, F2 and F3 keycaps, according to The Verge. The legends are standard across Googlebook hardware, not an optional layout or vendor skin.

Those three glyphs date to Android 5.0 Lollipop. For several generations they were the system back, home and app-switcher controls, first as capacitive keys below the screen and later as an on-screen bar, before gesture-based navigation replaced them on phones and tablets.

On Googlebook OS the same glyphs are reused for windowed operation. The triangle key performs back navigation. The circle key performs home by minimizing all open apps at once. The square key tiles open apps into an overview grid, in the style of Mission Control on macOS and Task View on Windows.

System navigation stays at the far left of the function row. On Lenovo's Googlebook keyboard the three keys sit next to Escape, beside the screenshot controls, per 9to5Google. That puts back, home and overview under the left hand without a modifier chord, with no need to hold Ctrl or Alt.

The keycodes matter more than the icons. F1 through F3 remain ordinary function keys at the HID layer, the low-level keyboard signal the computer sees. The legends show a default binding in the window manager, not dedicated hardware buttons in the Android handset sense. Users get physical travel and a fixed position for operations that previously needed a pointer click or a shortcut.

The broader context here is continuity of input vocabulary across form factors. Phone users learned triangle for back, circle for home and square for recents. Googlebook OS preserves that mapping while changing what home and recents mean when multiple windows share a display. Minimizing all windows is a plain translation of home. A tiled overview is a plain translation of the app-switcher.

In my view, the trade concerns scarce function-row space. F1 to F3 were historically application-defined, or bound to help and search. Reserving them for window-manager navigation favors focus movement, back-stack traversal and workspace overview over per-app shortcuts. For users who live in terminals, browsers and IDEs, that reduces clashes with Ctrl, Alt and Super combinations and keeps navigation discoverable for people who never open a shortcut sheet.

Looking at what this means in practice, physical keys lower the effort of frequent window operations. Back becomes a single keypress rather than a pointer hit on a chrome control. Home becomes deterministic, with all windows minimizing together. Overview stays available in the same location. That consistency supports muscle memory when input shifts between touch, trackpad and keyboard in one session. Triangle still means retreat one step in the focus order. Circle still means leave the current surface. Square still means survey open surfaces. The implementation differs. The mental model carries over, which is what a converged input system across phone and laptop should allow.