feat(snippet): add system-wide text snippet expansion with configurable prefix (#1743)

app/src/main/java/com/sameerasw/essentials/data/repository/SettingsRepository.kt

@@ -36,7 +36,10 @@ import com.sameerasw.essentials.domain.model.NotificationLightingSweepPosition
 import com.sameerasw.essentials.domain.model.PowerChoice
 import com.sameerasw.essentials.domain.model.RemapSlot
 import com.sameerasw.essentials.domain.model.ScaleAnimationsProfile
+import com.sameerasw.essentials.domain.model.Snippet
 import com.sameerasw.essentials.domain.model.SystemShortcutsState
+import com.sameerasw.essentials.services.tiles.ScreenOffAccessibilityService
+import java.util.UUID
 import com.sameerasw.essentials.domain.model.TrackedRepo
 import com.sameerasw.essentials.domain.model.github.GitHubUser
 import com.sameerasw.essentials.utils.RootUtils
@@ -198,6 +201,12 @@ class SettingsRepository(
     companion object {
         const val PREFS_NAME = "essentials_prefs"
 
+        @Volatile
+        private var cachedSnippets: List<Snippet>? = null
+
+        @Volatile
+        private var cachedPrefix: String? = null
+
         // Keys
         const val KEY_DEBUGGING_TILE_TAP_ACTION = "debugging_tile_tap_action"
         const val KEY_GENAI_AUTOMATION_ENABLED = "genai_automation_enabled"
@@ -403,6 +412,9 @@ class SettingsRepository(
         const val KEY_KEYBOARD_CLIPBOARD_ENABLED = "keyboard_clipboard_enabled"
         const val KEY_KEYBOARD_LONG_PRESS_SYMBOLS = "keyboard_long_press_symbols"
         const val KEY_KEYBOARD_ACCENTED_CHARACTERS = "keyboard_accented_characters"
+        const val KEY_KEYBOARD_TEXT_SNIPPETS_ENABLED = "keyboard_text_snippets_enabled"
+        const val KEY_KEYBOARD_SNIPPET_PREFIX = "keyboard_snippet_prefix"
+        const val KEY_KEYBOARD_SNIPPETS_DATA = "keyboard_snippets_data"
 
         // Essentials-AirSync Bridge
         const val KEY_AIRSYNC_CONNECTION_ENABLED = "airsync_connection_enabled"
@@ -4883,4 +4895,46 @@ class SettingsRepository(
         } ?: emptyMap()
 
     fun setAppVolumeLevels(levels: Map<String, Float>) = putString(KEY_APP_VOLUME_LEVELS, gson.toJson(levels))
+
+    fun isTextSnippetsEnabled(): Boolean = getBoolean(KEY_KEYBOARD_TEXT_SNIPPETS_ENABLED, false)
+    fun setTextSnippetsEnabled(enabled: Boolean) {
+        putBoolean(KEY_KEYBOARD_TEXT_SNIPPETS_ENABLED, enabled)
+        ScreenOffAccessibilityService.updateSnippetTextListening(enabled)
+    }
+
+    fun getSnippetPrefix(): String {
+        cachedPrefix?.let { return it }
+        val prefix = getString(KEY_KEYBOARD_SNIPPET_PREFIX, ";") ?: ";"
+        cachedPrefix = prefix
+        return prefix
+    }
+
+    fun setSnippetPrefix(prefix: String) {
+        cachedPrefix = prefix
+        putString(KEY_KEYBOARD_SNIPPET_PREFIX, prefix)
+    }
+
+    fun getTextSnippets(): List<Snippet> {
+        cachedSnippets?.let { return it }
+        val json = getString(KEY_KEYBOARD_SNIPPETS_DATA, null) ?: return defaultSnippets().also { cachedSnippets = it }
+        val list =
+            try {
+                val type = object : TypeToken<List<Snippet>>() {}.type
+                gson.fromJson<List<Snippet>>(json, type) ?: defaultSnippets()
+            } catch (_: Exception) {
+                defaultSnippets()
+            }
+        cachedSnippets = list
+        return list
+    }
+
+    fun saveTextSnippets(snippets: List<Snippet>) {
+        cachedSnippets = snippets
+        putString(KEY_KEYBOARD_SNIPPETS_DATA, gson.toJson(snippets))
+    }
+
+    fun defaultSnippets(): List<Snippet> =
+        listOf(
+            Snippet(id = UUID.randomUUID().toString(), keyword = "shrug", title = "Shrug", content = "¯\\_(ツ)_/¯"),
+        )
 }

app/src/main/java/com/sameerasw/essentials/domain/model/Snippet.kt

@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2026 sameerasw.com
+ * License: MIT License
+ *
+ * Feature Module: Domain Model Layer
+ * File: Snippet.kt
+ * Description: Data class representing an expandable text snippet with trigger keyword.
+ */
+
+package com.sameerasw.essentials.domain.model
+
+import java.util.UUID
+
+data class Snippet(
+    val id: String = UUID.randomUUID().toString(),
+    val keyword: String,
+    val title: String = "",
+    val content: String,
+)

app/src/main/java/com/sameerasw/essentials/domain/registry/PermissionRegistry.kt

@@ -62,6 +62,7 @@ fun initPermissionRegistry() {
     PermissionRegistry.register("ACCESSIBILITY", R.string.feat_status_glance_title)
     PermissionRegistry.register("READ_CALENDAR", R.string.feat_status_glance_title)
     PermissionRegistry.register("ACCESSIBILITY", R.string.feat_conscious_gate_title)
+    PermissionRegistry.register("ACCESSIBILITY", R.string.feat_text_snippets_title)
 
     // Write secure settings permission
     PermissionRegistry.register("WRITE_SECURE_SETTINGS", R.string.feat_statusbar_icons_title)

app/src/main/java/com/sameerasw/essentials/ime/EssentialsInputMethodService.kt

@@ -71,6 +71,16 @@ class EssentialsInputMethodService :
     // Undo Manager
     private val undoRedoManager = UndoRedoManager()
 
+    // Settings & Snippet Expansion Engine
+    private val settingsRepository by lazy { SettingsRepository(this) }
+    private val snippetEngine by lazy {
+        SnippetExpansionEngine(
+            getSnippets = { settingsRepository.getTextSnippets() },
+            getPrefix = { settingsRepository.getSnippetPrefix() },
+            isEnabled = { settingsRepository.isTextSnippetsEnabled() },
+        )
+    }
+
     // Suggestion Lookup Job
     private var lookupJob: Job? = null
 
@@ -470,8 +480,21 @@ class EssentialsInputMethodService :
                         onType = { text ->
                             undoRedoManager.recordInsert(text)
                             currentInputConnection?.commitText(text, 1)
-                            if (isUserDictionaryEnabled && text.length == 1 && !text[0].isLetterOrDigit()) {
-                                val ic = currentInputConnection
+
+                            val ic = currentInputConnection
+                            var expanded = false
+                            if (ic != null) {
+                                val textBefore = ic.getTextBeforeCursor(100, 0)?.toString() ?: ""
+                                expanded =
+                                    snippetEngine.checkAndExpand(textBefore) { deleteCount, replacement ->
+                                        undoRedoManager.recordDelete(textBefore.takeLast(deleteCount))
+                                        ic.deleteSurroundingText(deleteCount, 0)
+                                        undoRedoManager.recordInsert(replacement)
+                                        ic.commitText(replacement, 1)
+                                    }
+                            }
+
+                            if (!expanded && isUserDictionaryEnabled && text.length == 1 && !text[0].isLetterOrDigit()) {
                                 if (ic != null) {
                                     val textBefore = ic.getTextBeforeCursor(50, 0)?.toString()
                                     if (!textBefore.isNullOrEmpty()) {
@@ -618,6 +641,7 @@ class EssentialsInputMethodService :
         restarting: Boolean,
     ) {
         super.onStartInputView(info, restarting)
+        isInputActive = true
         // Ensure lifecycle is in RESUMED state when view becomes visible
         if (lifecycleRegistry.currentState != Lifecycle.State.RESUMED) {
             lifecycleRegistry.handleLifecycleEvent(Lifecycle.Event.ON_RESUME)
@@ -628,12 +652,14 @@ class EssentialsInputMethodService :
 
     override fun onFinishInputView(finishingInput: Boolean) {
         super.onFinishInputView(finishingInput)
+        isInputActive = false
         lifecycleRegistry.handleLifecycleEvent(Lifecycle.Event.ON_PAUSE)
         kbdResetTrigger.value++
     }
 
     override fun onDestroy() {
         super.onDestroy()
+        isInputActive = false
         lifecycleRegistry.handleLifecycleEvent(Lifecycle.Event.ON_STOP)
         lifecycleRegistry.handleLifecycleEvent(Lifecycle.Event.ON_DESTROY)
         if (::clipboardManager.isInitialized) {
@@ -758,4 +784,10 @@ class EssentialsInputMethodService :
             _clipboardHistory.value = current
         }
     }
+
+    companion object {
+        @Volatile
+        var isInputActive: Boolean = false
+            internal set
+    }
 }

app/src/main/java/com/sameerasw/essentials/ime/SnippetExpansionEngine.kt

@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) 2026 sameerasw.com
+ * License: MIT License
+ *
+ * Feature Module: Ime
+ * File: SnippetExpansionEngine.kt
+ * Description: Engine for detecting snippet prefixes/keywords and expanding text.
+ */
+
+package com.sameerasw.essentials.ime
+
+import com.sameerasw.essentials.domain.model.Snippet
+
+class SnippetExpansionEngine(
+    private val getSnippets: () -> List<Snippet>,
+    private val getPrefix: () -> String,
+    private val isEnabled: () -> Boolean,
+) {
+    fun checkAndExpand(
+        textBeforeCursor: String,
+        onExpand: (deleteCount: Int, replacement: String) -> Unit,
+    ): Boolean {
+        if (!isEnabled() || textBeforeCursor.isEmpty()) return false
+        val prefix = getPrefix()
+        val snippets = getSnippets()
+        if (snippets.isEmpty()) return false
+
+        val sorted = snippets.sortedByDescending { it.keyword.length }
+
+        for (snippet in sorted) {
+            if (snippet.keyword.isEmpty()) continue
+
+            if (prefix.isNotEmpty()) {
+                val trigger = "$prefix${snippet.keyword}"
+                val hasDelimiter = textBeforeCursor.endsWith(" ") || textBeforeCursor.endsWith("\t")
+                val candidate = if (hasDelimiter) textBeforeCursor.dropLast(1) else textBeforeCursor
+
+                if (candidate.endsWith(trigger, ignoreCase = true)) {
+                    val triggerStart = candidate.length - trigger.length
+                    val isBoundary = triggerStart == 0 || candidate[triggerStart - 1].isWhitespace()
+                    if (!isBoundary) continue
+
+                    if (!hasDelimiter) {
+                        val hasLongerSibling = sorted.any {
+                            it.keyword.length > snippet.keyword.length &&
+                                it.keyword.startsWith(snippet.keyword, ignoreCase = true)
+                        }
+                        if (hasLongerSibling) continue
+                    }
+
+                    val matchLen = if (hasDelimiter) trigger.length + 1 else trigger.length
+                    val replacement = if (hasDelimiter) snippet.content + " " else snippet.content
+                    onExpand(matchLen, replacement)
+                    return true
+                }
+            } else {
+                val lastChar = textBeforeCursor.last()
+                if (lastChar.isWhitespace()) {
+                    val trimmed = textBeforeCursor.dropLast(1)
+                    if (trimmed.endsWith(snippet.keyword, ignoreCase = true)) {
+                        val beforeIndex = trimmed.length - snippet.keyword.length - 1
+                        val isBoundary = beforeIndex < 0 || trimmed[beforeIndex].isWhitespace()
+                        if (isBoundary) {
+                            onExpand(snippet.keyword.length + 1, snippet.content + lastChar)
+                            return true
+                        }
+                    }
+                }
+            }
+        }
+        return false
+    }
+}

app/src/main/java/com/sameerasw/essentials/services/handlers/SnippetExpansionHandler.kt

@@ -0,0 +1,101 @@
+/*
+ * Copyright (c) 2026 sameerasw.com
+ * License: MIT License
+ *
+ * Feature Module: Background Services & Receivers
+ * File: SnippetExpansionHandler.kt
+ * Description: Accessibility event handler for expanding text snippets across any input method or app.
+ */
+
+package com.sameerasw.essentials.services.handlers
+
+import android.accessibilityservice.AccessibilityService
+import android.os.Build
+import android.os.Bundle
+import android.text.InputType
+import android.view.accessibility.AccessibilityEvent
+import android.view.accessibility.AccessibilityNodeInfo
+import com.sameerasw.essentials.data.repository.SettingsRepository
+import com.sameerasw.essentials.ime.EssentialsInputMethodService
+import com.sameerasw.essentials.ime.SnippetExpansionEngine
+
+class SnippetExpansionHandler(
+    private val service: AccessibilityService,
+) {
+    private val settings = SettingsRepository(service)
+    @Volatile private var expectedSelfText: String? = null
+
+    private val snippetEngine =
+        SnippetExpansionEngine(
+            getSnippets = { settings.getTextSnippets() },
+            getPrefix = { settings.getSnippetPrefix() },
+            isEnabled = { settings.isTextSnippetsEnabled() },
+        )
+
+    fun onTextChanged(event: AccessibilityEvent) {
+        if (!settings.isTextSnippetsEnabled()) return
+        if (EssentialsInputMethodService.isInputActive) return
+        if (event.isPassword) return
+
+        val source = event.source ?: return
+        if (source.isPassword || !source.isEditable) return
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O && source.isShowingHintText) return
+
+        val inputType = source.inputType
+        val isPasswordType =
+            (inputType and InputType.TYPE_MASK_VARIATION) == InputType.TYPE_TEXT_VARIATION_PASSWORD ||
+                (inputType and InputType.TYPE_MASK_VARIATION) == InputType.TYPE_TEXT_VARIATION_VISIBLE_PASSWORD ||
+                (inputType and InputType.TYPE_MASK_VARIATION) == InputType.TYPE_TEXT_VARIATION_WEB_PASSWORD ||
+                ((inputType and InputType.TYPE_MASK_CLASS) == InputType.TYPE_CLASS_NUMBER &&
+                    (inputType and InputType.TYPE_MASK_VARIATION) == InputType.TYPE_NUMBER_VARIATION_PASSWORD)
+        if (isPasswordType) return
+
+        val text = source.text?.toString() ?: return
+        if (text.isEmpty()) return
+
+        if (expectedSelfText != null) {
+            if (text == expectedSelfText) {
+                expectedSelfText = null
+                return
+            }
+        }
+
+        var cursor = source.textSelectionEnd
+        if (cursor < 0 || cursor > text.length) {
+            cursor = text.length
+        }
+
+        val textBeforeCursor = text.substring(0, cursor)
+
+        snippetEngine.checkAndExpand(textBeforeCursor) { deleteCount, replacement ->
+            val start = cursor - deleteCount
+            if (start < 0) return@checkAndExpand
+
+            val newText = text.substring(0, start) + replacement + text.substring(cursor)
+            val newCursor = start + replacement.length
+
+            val supportsSetText = source.actionList.any { it.id == AccessibilityNodeInfo.ACTION_SET_TEXT }
+            if (!supportsSetText) return@checkAndExpand
+
+            expectedSelfText = newText
+            val args =
+                Bundle().apply {
+                    putCharSequence(
+                        AccessibilityNodeInfo.ACTION_ARGUMENT_SET_TEXT_CHARSEQUENCE,
+                        newText,
+                    )
+                }
+            val setSuccess = source.performAction(AccessibilityNodeInfo.ACTION_SET_TEXT, args)
+            if (setSuccess) {
+                val selArgs =
+                    Bundle().apply {
+                        putInt(AccessibilityNodeInfo.ACTION_ARGUMENT_SELECTION_START_INT, newCursor)
+                        putInt(AccessibilityNodeInfo.ACTION_ARGUMENT_SELECTION_END_INT, newCursor)
+                    }
+                source.performAction(AccessibilityNodeInfo.ACTION_SET_SELECTION, selArgs)
+            } else {
+                expectedSelfText = null
+            }
+        }
+    }
+}