A tap needs immediate pressed-state feedback
Aliases: pressed state · press highlight · touch-down ripple
What it is
A tap happens while the finger still covers the target, so people cannot see whether they hit it. Pressed-state feedback pushes the object into a “being pressed” look or haptic at the start of contact, answering “the system received this, and this object is the one.” It is not confirmation of commit—that usually waits for lift—nor a loading indicator. Without that frame, a tap is a knock with no echo.
Why it happens
A touchscreen has no key travel and no mechanical click. Vision and a short haptic must arrive tens of milliseconds after contact, or people assume a miss and tap again, producing a double fire. The pressed state has to bind to the hit object: a full-screen flash or a buzz that names nobody cannot support “wrong target, slide off.” Feedback must appear on down, clear on exit from the hit region, and return on re-entry, so the pressed state can preview the lift commit. Delay comes from main-thread stalls, compositor lag, or press animations eased over hundreds of milliseconds—polish that turns the pressed state into decoration played after lift.
Studying it
Measure touch-down to first pixel of pressed appearance with a finger-to-photon setup, and log re-tap rate and slide-off cancel success. Independent variables include feedback delay, presence of haptics, magnitude of the press change (color, scale, shadow), and how much of the target the finger occludes; dependent measures include verbal “I thought it missed,” repeat clicks, and commits that still fire after a slide-off. On small, highly occluded icons, a color-only change often shows no measurable difference because it happens under the fingernail; the press cue then has to live around the target or move to haptics.
Where it stops holding
Fullscreen games and camera viewfinders cannot afford a press highlight that dirties the picture; they often switch to a reticle, a slight zoom, or haptics alone. On a low refresh rate or a power-saving frame cap, “immediate” feedback falls after the perceptible window. With haptics off, vision must carry the cue alone; haptics without object-level visuals cannot tell which of several adjacent buttons was hit. The same pressed state should still appear when a switch pointer or external keyboard activates the control, or only finger users get the preview.
Applying it
- Switch the pressed look on the touch-down frame or the next one; do not ease a long press animation past lift. Restore the default look as soon as the finger leaves the hit region.
- For small icons and list switches the pad easily covers, put the press change outside the silhouette or add a short haptic; do not merely darken the glyph under the finger.
- Frame-step recordings: how many frames from down to highlight, whether the highlight survives a slide-off, whether navigation waits for the press animation to finish. A single compensatory re-tap means the cue was late or too quiet.