sloposk

iPad-style floating on-screen keyboard for Plasma Wayland. Qt 6, C++ core, QML UI.

• Flick a key down for its secondary symbol; long-press for accented alternates
• iOS shift: tap = one letter, double-tap = caps lock, hold = shift while held
• Works everywhere, not just in text fields: with none focused, keys reach the focused window like a hardware keyboard (shortcuts, terminals, the desktop); "Always Show" in ⚙ keeps it up
• "Hold Keys" (⚙): keys stay down while touched, like a hardware keyboard (games, Shift+click, system key repeat); modifiers are plain keys, dead keys compose in the app; touch conveniences off
• Letters follow the system keyboard layout; the globe key switches it
• Auto-capitalization, double-space → ". " (both optional, ⚙ on the bottom bar), backspace repeat → word delete
• Long-press space = trackpad; slide from .?123 onto a symbol and release
• Compact (iPad) or full (iPad Pro) keyboard: number row, punctuation, tab, caps lock, ctrl/alt/super, dead keys
• Ctrl/Alt/Super stick like shift (tap, double-tap, hold) and turn keys into shortcuts; a tapped or held shift joins them (Shift+F5, Shift+Tab, Shift+arrows), auto-shift and caps lock don't
• Optional PC key blocks: function row, navigation (ins/home/pg up, del/end/pg dn, arrows), numeric keypad; any mix, typing keys included (⚙)
• Floating: drag the bottom bar, resize from the corner; geometry is remembered per screen
• See-through background (opacity slider in ⚙) with optional blur behind it (KWin's blur effect)

Build & test

cmake -B build -G Ninja && cmake --build build
ctest --test-dir build

Needs Qt ≥ 6.8 (Quick, WaylandClient, DBus, Test), KF6 WindowSystem, KF6 Config, xkbcommon, wayland-protocols.

Run

KWin only offers the input-method protocol to the process it launches itself.

Where	How
Nested session (safe)	kwin_wayland --no-lockscreen --socket sloposk-dev --width 1400 --height 900 --inputmethod $PWD/build/src/sloposk kwrite
Desktop	cmake --install build --prefix ~/.local, then System Settings → Keyboard → Virtual Keyboard → sloposk
UI only	build/src/sloposk (stays visible, types nowhere)

Show/hide, e.g. from a global shortcut: qdbus org.sloposk.Keyboard /Keyboard org.sloposk.Keyboard.Toggle

Dev hooks: SLOPOSK_AUTOTYPE=text commits on focus; SLOPOSK_SCREENSHOT=file.png saves the window and quits.

Layouts

Letters come from the system keymap (what KWin sends to every client): its Q/A/Z rows become the three letter rows. Letters elsewhere, e.g. Slovak ľščťž on the number row, become long-press alternates. The globe key switches the system layout over org.kde.keyboard, so the physical keyboard follows.

In full mode every typing key comes from the keymap (number row, [ ] \ ; ' , . / or the layout's equivalents), with the shifted symbol shown above. Dead keys compose with the locale's XKB compose table.

Everything else is layouts/template.json; ~/.local/share/sloposk/template.json replaces it.

{"type": "letters", "row": 0, "flicks": ["1", "2", "3"]},
{"type": "backspace", "width": 1.5, "stretch": true}

• Key: a string, or an object with type (char space backspace enter shift layer globe dismiss spacer letters keysym), label, shifted, flick, alternates, width (key units), target (for layer), stretch
• keysym: sends the XKB keysym named by keysym (Home, F5, Left...) on press; repeat auto-repeats while held
• letters: the keymap's letters in row row (0–2), with flicks handed out left to right
• keys: every typing key in keymap row row (0 = number row … 3 = bottom)
• modifier: "modifier": "ctrl" | "alt" | "super"; capslock
• Layer full: rows used instead of rows in full-keyboard mode
• stretch: the key grows so its row is as wide as the layer's widest (letter counts vary by layout)
• Top-level alternates: long-press choices per letter, after the keymap's own
• Top-level sections: optional blocks, {"id", "name", "placement": "above" | "right", "fillHeight", "rows"}; the user picks which show; fillHeight stretches a right-hand block over the full keyboard height

Settings

~/.config/sloposk/sloposk.conf, also editable from the ⚙ panel: typing/autoCapitalize, typing/doubleSpacePeriod, typing/holdKeys, layout/visibleSections (main plus section ids), layout/fullKeyboard, window/alwaysVisible, appearance/backgroundOpacity (0.1–1), appearance/blurBackground.

Architecture

qml/        view only
input/      touch → PointerTracker gestures → KeyboardController rules
engine/     key output → text ops (DirectEngine; prediction/swipe later)
backend/    text ops → compositor (KWin input-method-v1, or fake input with no text field); the compositor's keymap
layout/     template JSON + keymap letters → Layout → LayoutModel (geometry, hit testing)
window/     floating window (KWin rule: on top, no focus), visibility, saved geometry
app/        D-Bus control and system layouts, dev hooks
settings/   persisted user preferences

sloposk_core (everything compositor-independent, plus the Sloposk QML module) is a static library shared by the app and the tests.

protocols/fake-input.xml is KDE's org_kde_kwin_fake_input (LGPL-2.1-or-later), vendored from plasma-wayland-protocols.