feat: user-selectable touch calibration profiles (v1.9.46)

Expose the previously-hardcoded touch-resolution knobs as Conservative /
Normal / Rescue-heavy calibration profiles (Settings -> Typing). Each
profile tunes the gap-rescue dead-zone factor (TextKeyboard) and the
adaptive spatial model's neighbour tolerances + minimum learned-sample
threshold (AdaptiveTouchModel).

NORMAL reproduces the historic constants exactly and is the default, so
hit-testing behaviour is unchanged unless the user opts into another
profile. getNearestKeyForPos and AdaptiveTouchModel.refine gained
defaulted parameters so existing call sites and tests are unaffected.
Profile invariants covered by JVM tests; full unit suite green.

Author: SysAdminDoc

README.md

@@ -1,6 +1,6 @@
 # SwiftFloris
 
-![Version](https://img.shields.io/badge/version-v1.9.45-blue) ![License](https://img.shields.io/badge/license-Apache%202.0-green) ![Platform](https://img.shields.io/badge/platform-Android%208.0+-orange) ![Network](https://img.shields.io/badge/network-none-lightgrey) ![Dictionary imports](https://img.shields.io/badge/dictionary%20imports-local%20files-green)
+![Version](https://img.shields.io/badge/version-v1.9.46-blue) ![License](https://img.shields.io/badge/license-Apache%202.0-green) ![Platform](https://img.shields.io/badge/platform-Android%208.0+-orange) ![Network](https://img.shields.io/badge/network-none-lightgrey) ![Dictionary imports](https://img.shields.io/badge/dictionary%20imports-local%20files-green)
 
 **SwiftFloris** is a privacy-first Android keyboard, forked from FlorisBoard and pushed toward SwiftKey-class multilingual typing without the cloud. It ships under Apache-2.0, holds no `INTERNET` permission, and binds zero accounts.
 
@@ -37,7 +37,7 @@
 
 ## Highlights
 
-| Area | What's in v1.9.45 | Privacy posture |
+| Area | What's in v1.9.46 | Privacy posture |
 |------|-------------------|-----------------|
 | **Autocorrect / prediction** | SCOWL 117k English dictionary, heap-bounded SymSpell d1+d2, bigram + trigram next-word, capitalization-aware completions, contraction handling, instant-remember user-dictionary overlay | On-device |
 | **Multilingual typing** | Bilingual subtype presets (EN+ES / EN+FR / EN+DE), per-token Latin language identification, top-two straddle guard, sentence-local context scoring, opt-in remembered keyboard language per app, and stale-id-safe manual subtype switching | On-device |
@@ -304,6 +304,7 @@ Current SM-S938B / Android 16 baselines record `am start -W` first-render median
 
 The full public release stream lives on [GitHub Releases](https://github.com/SysAdminDoc/SwiftFloris/releases).
 
+- **v1.9.46** (2026-06-14) — New "Touch calibration" setting (Settings → Typing) exposes Conservative / Normal / Rescue-heavy profiles that tune gap-rescue dead zones and adaptive-touch neighbour correction. Normal reproduces the previously-hardcoded behaviour exactly, so the default is unchanged.
 - **v1.9.45** (2026-06-14) — New optional "CJK mixed-script spacing" setting inserts a boundary space between Han characters and adjacent Latin words or digits (安装 App, 第 3 章). Preference-gated, off by default; the Han boundary requirement keeps Latin/digit-only typing untouched and existing whitespace is respected.
 - **v1.9.44** (2026-06-13) — Locale script heuristics now use runtime Unicode character-property detection instead of hardcoded language lists, covering all scripts automatically. Release workflow gains SLSA Build Level 2 provenance attestation and SPDX SBOM generation.
 - **v1.9.43** (2026-06-13) — Translate quick-action now reads the user's preferred target locale instead of hardcoding English. Sticker bitmap LRU cache now trims on system memory pressure. Composer WithRules case conversion now preserves character count under CAPS_LOCK.
@@ -511,7 +512,7 @@ limitations under the License.
 
 ## Status
 
-🚀 **Active development.** Current release: **v1.9.45** (2026-06-14). The SwiftKey account export window closed on **2026-05-31**; local/on-device migration paths remain documented above.
+🚀 **Active development.** Current release: **v1.9.46** (2026-06-14). The SwiftKey account export window closed on **2026-05-31**; local/on-device migration paths remain documented above.
 
 ---
 

app/src/main/kotlin/dev/patrickgold/florisboard/app/EnumDisplayEntries.kt

@@ -43,6 +43,7 @@ import dev.patrickgold.florisboard.ime.text.gestures.GlideTrailTheme
 import dev.patrickgold.florisboard.ime.text.gestures.SwipeAction
 import dev.patrickgold.florisboard.ime.text.key.KeyHintMode
 import dev.patrickgold.florisboard.ime.text.key.UtilityKeyAction
+import dev.patrickgold.florisboard.ime.text.keyboard.TouchCalibrationProfile
 import dev.patrickgold.florisboard.ime.theme.ThemeMode
 import dev.patrickgold.florisboard.ime.voice.VoiceModelPreference
 import dev.patrickgold.florisboard.ime.voice.VoiceRecognitionEnginePreference
@@ -97,6 +98,28 @@ private val ENUM_DISPLAY_ENTRIES = mapOf<Pair<KClass<*>, String>, @Composable ()
             )
         }
     },
+    TouchCalibrationProfile::class to DEFAULT to {
+        listPrefEntries {
+            entry(
+                key = TouchCalibrationProfile.CONSERVATIVE,
+                label = stringRes(R.string.enum__touch_calibration_profile__conservative),
+                description = stringRes(R.string.enum__touch_calibration_profile__conservative__description),
+                showDescriptionOnlyIfSelected = true,
+            )
+            entry(
+                key = TouchCalibrationProfile.NORMAL,
+                label = stringRes(R.string.enum__touch_calibration_profile__normal),
+                description = stringRes(R.string.enum__touch_calibration_profile__normal__description),
+                showDescriptionOnlyIfSelected = true,
+            )
+            entry(
+                key = TouchCalibrationProfile.RESCUE_HEAVY,
+                label = stringRes(R.string.enum__touch_calibration_profile__rescue_heavy),
+                description = stringRes(R.string.enum__touch_calibration_profile__rescue_heavy__description),
+                showDescriptionOnlyIfSelected = true,
+            )
+        }
+    },
     CandidatesDisplayMode::class to DEFAULT to {
         listPrefEntries {
             entry(

app/src/main/kotlin/dev/patrickgold/florisboard/app/prefs/CorrectionPrefs.kt

@@ -48,6 +48,7 @@ import dev.patrickgold.florisboard.ime.smartbar.quickaction.QuickAction
 import dev.patrickgold.florisboard.ime.smartbar.quickaction.QuickActionArrangement
 import dev.patrickgold.florisboard.ime.smartbar.quickaction.QuickActionJsonConfig
 import dev.patrickgold.florisboard.ime.text.gestures.GlideTrailTheme
+import dev.patrickgold.florisboard.ime.text.keyboard.TouchCalibrationProfile
 import dev.patrickgold.florisboard.ime.text.gestures.SwipeAction
 import dev.patrickgold.florisboard.ime.text.key.KeyCode
 import dev.patrickgold.florisboard.ime.text.key.KeyHintConfiguration
@@ -104,6 +105,10 @@ open class CorrectionPrefs : PreferenceModel() {
         key = "correction__adaptive_touch_model",
         default = true,
     )
+    val touchCalibrationProfile = enum(
+        key = "correction__touch_calibration_profile",
+        default = TouchCalibrationProfile.Default,
+    )
     val multilingualSuggestions = boolean(
         key = "correction__multilingual_suggestions",
         default = true,

app/src/main/kotlin/dev/patrickgold/florisboard/app/settings/typing/TypingScreen.kt

@@ -38,6 +38,7 @@ import dev.patrickgold.florisboard.app.enumDisplayEntriesOf
 import dev.patrickgold.florisboard.ime.keyboard.IncognitoMode
 import dev.patrickgold.florisboard.ime.nlp.AutoCorrectCommitMode
 import dev.patrickgold.florisboard.ime.nlp.SpellingLanguageMode
+import dev.patrickgold.florisboard.ime.text.keyboard.TouchCalibrationProfile
 import dev.patrickgold.florisboard.lib.compose.FlorisHyperlinkText
 import dev.patrickgold.florisboard.lib.compose.FlorisScreen
 import dev.patrickgold.jetpref.datastore.model.collectAsState
@@ -148,6 +149,12 @@ fun TypingScreen() = FlorisScreen {
                 title = stringRes(R.string.pref__correction__adaptive_touch_model__label),
                 summary = stringRes(R.string.pref__correction__adaptive_touch_model__summary),
             )
+            ListPreference(
+                prefs.correction.touchCalibrationProfile,
+                title = stringRes(R.string.pref__correction__touch_calibration_profile__label),
+                entries = enumDisplayEntriesOf(TouchCalibrationProfile::class),
+                enabledIf = { prefs.correction.adaptiveTouchModel isEqualTo true },
+            )
             SwitchPreference(
                 prefs.suggestion.nextWordPrediction,
                 title = stringRes(R.string.pref__suggestion__next_word_prediction__label),

app/src/main/kotlin/dev/patrickgold/florisboard/ime/text/keyboard/AdaptiveTouchModel.kt

@@ -166,15 +166,23 @@ internal object AdaptiveTouchModel {
      * distribution. Returns [primary] when there is not enough learned data.
      */
     @Synchronized
-    fun refine(keyboard: TextKeyboard, primary: TextKey, touchX: Float, touchY: Float): TextKey {
+    fun refine(
+        keyboard: TextKeyboard,
+        primary: TextKey,
+        touchX: Float,
+        touchY: Float,
+        minSamples: Int = MIN_SAMPLES_PER_KEY,
+        horizontalTolerance: Float = NEIGHBOUR_HORIZONTAL_TOLERANCE,
+        verticalTolerance: Float = NEIGHBOUR_VERTICAL_TOLERANCE,
+    ): TextKey {
         if (!isLearnableKey(primary)) return primary
         val bucketStats = statsBySubtype[activeBucket] ?: return primary
         // Key by touchModelCode() to match recordTap() and the candidate branch
         // below. computedData.code can be UNSPECIFIED for keys whose code only
         // lives on `data`; using it here meant the lookup missed and refinement
         // silently no-op'd for exactly those keys.
         val primaryStats = bucketStats[primary.touchModelCode()] ?: return primary
-        if (primaryStats.count < MIN_SAMPLES_PER_KEY) return primary
+        if (primaryStats.count < minSamples) return primary
 
         val pBounds = primary.visibleBounds
         if (pBounds.isEmpty()) return primary
@@ -202,10 +210,10 @@ internal object AdaptiveTouchModel {
             // Restrict the candidate set to actual neighbours of the primary
             // hit (same row + immediately adjacent column, give or take key
             // size). Keys far away can never legitimately win.
-            if (kotlin.math.abs(rawDx) > pHalfW + cHalfW + NEIGHBOUR_HORIZONTAL_TOLERANCE * pHalfW) continue
-            if (kotlin.math.abs(rawDy) > pHalfH + cHalfH + NEIGHBOUR_VERTICAL_TOLERANCE * pHalfH) continue
+            if (kotlin.math.abs(rawDx) > pHalfW + cHalfW + horizontalTolerance * pHalfW) continue
+            if (kotlin.math.abs(rawDy) > pHalfH + cHalfH + verticalTolerance * pHalfH) continue
             val candStats = bucketStats[candidate.touchModelCode()] ?: continue
-            if (candStats.count < MIN_SAMPLES_PER_KEY) continue
+            if (candStats.count < minSamples) continue
             val cNx = (rawDx / cHalfW).coerceIn(-2f, 2f)
             val cNy = (rawDy / cHalfH).coerceIn(-2f, 2f)
             val score = candStats.logLikelihood(cNx, cNy)

app/src/main/kotlin/dev/patrickgold/florisboard/ime/text/keyboard/TextKeyboard.kt

@@ -57,7 +57,11 @@ class TextKeyboard(
         return null
     }
 
-    fun getNearestKeyForPos(pointerX: Float, pointerY: Float): TextKey? {
+    fun getNearestKeyForPos(
+        pointerX: Float,
+        pointerY: Float,
+        gapRescueDistanceFactor: Float = GapRescueDistanceFactor,
+    ): TextKey? {
         if (layoutStyle == TextKeyboardLayoutStyle.Honeycomb) {
             return honeycombKeyForPos(pointerX, pointerY)
         }
@@ -69,7 +73,7 @@ class TextKeyboard(
                 continue
             }
             val bounds = key.visibleBounds
-            val maxRescueDistance = min(bounds.width, bounds.height) * GapRescueDistanceFactor
+            val maxRescueDistance = min(bounds.width, bounds.height) * gapRescueDistanceFactor
             val dx = when {
                 pointerX < bounds.left -> bounds.left - pointerX
                 pointerX >= bounds.right -> pointerX - bounds.right

app/src/main/kotlin/dev/patrickgold/florisboard/ime/text/keyboard/TextKeyboardLayout.kt

@@ -916,16 +916,25 @@ private class TextKeyboardLayoutController(
         val canCaptureTextTap = keyboard.mode == KeyboardMode.CHARACTERS &&
             keyboardManager.activeState.keyVariation != KeyVariation.PASSWORD
         val adaptiveTouchEnabled = prefs.correction.adaptiveTouchModel.get() && canCaptureTextTap
+        val calibration = prefs.correction.touchCalibrationProfile.get()
         val touchDecoderEnabled = prefs.correction.autoCorrect.get() &&
             canCaptureTextTap &&
             !keyboardManager.activeState.isIncognitoMode
         val initialKey = keyboard.getKeyForPos(touchX, touchY) ?: if (adaptiveTouchEnabled) {
-            keyboard.getNearestKeyForPos(touchX, touchY)
+            keyboard.getNearestKeyForPos(touchX, touchY, calibration.gapRescueDistanceFactor)
         } else {
             null
         }
         val key = if (initialKey != null && adaptiveTouchEnabled) {
-            AdaptiveTouchModel.refine(keyboard, initialKey, touchX, touchY)
+            AdaptiveTouchModel.refine(
+                keyboard = keyboard,
+                primary = initialKey,
+                touchX = touchX,
+                touchY = touchY,
+                minSamples = calibration.minSamplesPerKey,
+                horizontalTolerance = calibration.neighbourHorizontalTolerance,
+                verticalTolerance = calibration.neighbourVerticalTolerance,
+            )
         } else {
             initialKey
         }

app/src/main/kotlin/dev/patrickgold/florisboard/ime/text/keyboard/TouchCalibrationProfile.kt

@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2026 SwiftFloris Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package dev.patrickgold.florisboard.ime.text.keyboard
+
+/**
+ * User-selectable touch-resolution calibration profile.
+ *
+ * Adjacent-key false hits are a recurring FOSS-keyboard complaint (HeliBoard
+ * #2549). SwiftFloris resolves taps through two cooperating mechanisms:
+ *
+ *  - **Gap rescue** ([TextKeyboard.getNearestKeyForPos]) snaps a tap that
+ *    lands in the dead zone *between* keys onto the closest key within
+ *    [gapRescueDistanceFactor] × min(key width, key height).
+ *  - **Spatial model** ([AdaptiveTouchModel.refine]) re-attributes a tap to a
+ *    learned neighbour when the user's accumulated offset distribution makes
+ *    the neighbour the better fit, bounded by the neighbour tolerances and a
+ *    minimum learned-sample count.
+ *
+ * A calibration profile exposes those previously-hardcoded knobs so users can
+ * trade off between "never steal my tap" (conservative — narrow dead zones,
+ * reluctant neighbour correction, lots of evidence required) and "fix my fat
+ * fingers" (rescue-heavy — wide dead zones, eager correction, low evidence
+ * threshold). [NORMAL] reproduces the historically-shipped constants exactly,
+ * so the default behaviour is unchanged.
+ *
+ * The profile is consulted per touch-down; values are plain immutable data so
+ * the policy is trivially unit-testable.
+ */
+enum class TouchCalibrationProfile(
+    /** Multiplied by min(key width, key height) to bound gap-rescue distance. */
+    val gapRescueDistanceFactor: Float,
+    /** Horizontal neighbour-candidate window, in primary-key half-widths. */
+    val neighbourHorizontalTolerance: Float,
+    /** Vertical neighbour-candidate window, in primary-key half-heights. */
+    val neighbourVerticalTolerance: Float,
+    /** Minimum learned taps on a key before the spatial model may act on it. */
+    val minSamplesPerKey: Int,
+) {
+    /** Tight: prefers the geometric hit, rarely rescues or re-attributes. */
+    CONSERVATIVE(
+        gapRescueDistanceFactor = 0.18f,
+        neighbourHorizontalTolerance = 0.28f,
+        neighbourVerticalTolerance = 0.45f,
+        minSamplesPerKey = 45,
+    ),
+
+    /** Shipped default — identical to the pre-calibration hardcoded values. */
+    NORMAL(
+        gapRescueDistanceFactor = 0.32f,
+        neighbourHorizontalTolerance = 0.40f,
+        neighbourVerticalTolerance = 0.60f,
+        minSamplesPerKey = 30,
+    ),
+
+    /** Loose: wide dead zones and eager neighbour correction for heavy thumbs. */
+    RESCUE_HEAVY(
+        gapRescueDistanceFactor = 0.48f,
+        neighbourHorizontalTolerance = 0.55f,
+        neighbourVerticalTolerance = 0.75f,
+        minSamplesPerKey = 20,
+    );
+
+    companion object {
+        val Default = NORMAL
+    }
+}

app/src/main/res/values/strings.xml

@@ -920,6 +920,7 @@
     <string name="pref__correction__double_space_period__summary" comment="Preference summary">Tapping twice on spacebar inserts a period followed by a space</string>
     <string name="pref__correction__adaptive_touch_model__label" comment="Preference title">Adaptive touch model</string>
     <string name="pref__correction__adaptive_touch_model__summary" comment="Preference summary">Learn how you actually tap each key and bias hit-tests toward your tap pattern. All on-device.</string>
+    <string name="pref__correction__touch_calibration_profile__label" comment="Preference title">Touch calibration</string>
     <string name="pref__suggestion__next_word_prediction__label" comment="Preference title">Predict the next word</string>
     <string name="pref__suggestion__next_word_prediction__summary" comment="Preference summary">Show predicted next words in the suggestion strip after a space. Learns from your typing history, all on-device.</string>
     <string name="pref__correction__multilingual_suggestions__label" comment="Preference title">Multilingual suggestions</string>
@@ -2076,6 +2077,13 @@
     <string name="enum__auto_correct_commit_mode__high_confidence" comment="Enum value label">Cautious</string>
     <string name="enum__auto_correct_commit_mode__high_confidence__description" comment="Enum value description">Keep lower-confidence corrections as suggestions; auto-replace only when confidence is high.</string>
 
+    <string name="enum__touch_calibration_profile__conservative" comment="Enum value label">Conservative</string>
+    <string name="enum__touch_calibration_profile__conservative__description" comment="Enum value description">Prefer the key you actually touched. Narrow dead zones and rarely re-attribute a tap to a neighbour.</string>
+    <string name="enum__touch_calibration_profile__normal" comment="Enum value label">Normal</string>
+    <string name="enum__touch_calibration_profile__normal__description" comment="Enum value description">Balanced gap rescue and neighbour correction. The default.</string>
+    <string name="enum__touch_calibration_profile__rescue_heavy" comment="Enum value label">Rescue-heavy</string>
+    <string name="enum__touch_calibration_profile__rescue_heavy__description" comment="Enum value description">Wide dead zones and eager neighbour correction for heavier thumbs and more frequent adjacent-key misses.</string>
+
     <string name="enum__spelling_language_mode__use_system_languages" comment="Enum value label">Use system languages</string>
     <string name="enum__spelling_language_mode__use_keyboard_subtypes" comment="Enum value label">Use keyboard subtypes</string>