Implement smart delete (#55)

ricky9667 · web-flow · commit d57c20c78ecd · 2025-07-24T15:05:35.000+08:00
* ci: 🎡 ignore project coverage check

* feat: 🎸 replace delete text with icon

* feat: 🎸 add onLongPress action to toggle smart delete mode

* feat: 🎸 add smart delete to settings

* feat: 🎸 implement smart delete for deleting a notation

* fix: 🐛 re-implement to resolve batchEdit crash

* test: 💍 fix SettingsScreenUiTest

* fix: 🐛 remove unused long press action to pass unit tests

* ci: 🎡 remove text during rebase

* fix: 🐛 resolve smart delete state management from dataStore

✅ Closes: \

* refactor: 💡 default true for smart delete feature

* chore: 🤖 add logs

* refactor: 💡 extract constants
diff --git a/app/src/main/java/com/rickyhu/hushkeyboard/data/AppSettings.kt b/app/src/main/java/com/rickyhu/hushkeyboard/data/AppSettings.kt
@@ -5,9 +5,10 @@ import kotlinx.serialization.Serializable
 @Serializable
 data class AppSettings(
     val themeOption: ThemeOption = ThemeOption.System,
+    val wideNotationOption: WideNotationOption = WideNotationOption.WideWithW,
+    val smartDelete: Boolean = true,
     val addSpaceAfterNotation: Boolean = true,
-    val vibrateOnTap: Boolean = true,
-    val wideNotationOption: WideNotationOption = WideNotationOption.WideWithW
+    val vibrateOnTap: Boolean = true
 )
 
 enum class ThemeOption { System, Light, Dark }
diff --git a/app/src/main/java/com/rickyhu/hushkeyboard/data/SettingsRepository.kt b/app/src/main/java/com/rickyhu/hushkeyboard/data/SettingsRepository.kt
@@ -22,6 +22,10 @@ class SettingsRepository @Inject constructor(
         dataStore.updateData { it.copy(wideNotationOption = wideNotationOption) }
     }
 
+    suspend fun updateSmartDelete(smartDelete: Boolean) {
+        dataStore.updateData { it.copy(smartDelete = smartDelete) }
+    }
+
     suspend fun updateAddSpaceBetweenNotation(addSpaceBetweenNotation: Boolean) {
         dataStore.updateData { it.copy(addSpaceAfterNotation = addSpaceBetweenNotation) }
     }
diff --git a/app/src/main/java/com/rickyhu/hushkeyboard/keyboard/HushKeyboardView.kt b/app/src/main/java/com/rickyhu/hushkeyboard/keyboard/HushKeyboardView.kt
@@ -3,6 +3,7 @@ package com.rickyhu.hushkeyboard.keyboard
 import android.content.Context
 import android.os.Build
 import android.os.VibratorManager
+import android.util.Log
 import androidx.annotation.RequiresApi
 import androidx.annotation.VisibleForTesting
 import androidx.compose.foundation.background
@@ -32,11 +33,15 @@ import com.rickyhu.hushkeyboard.service.HushIMEService
 import com.rickyhu.hushkeyboard.theme.DarkBackground
 import com.rickyhu.hushkeyboard.theme.LightBackground
 import com.rickyhu.hushkeyboard.utils.deleteText
+import com.rickyhu.hushkeyboard.utils.inputNewline
 import com.rickyhu.hushkeyboard.utils.inputText
 import com.rickyhu.hushkeyboard.utils.maybeVibrate
+import com.rickyhu.hushkeyboard.utils.smartDelete
 import com.rickyhu.hushkeyboard.utils.toInputConnection
 import splitties.systemservices.inputMethodManager
 
+private const val TAG = "HushKeyboardView"
+
 class HushKeyboardView(context: Context) : AbstractComposeView(context) {
 
     @RequiresApi(Build.VERSION_CODES.S)
@@ -80,6 +85,7 @@ fun HushKeyboardContent(state: KeyboardState) {
             addSpaceAfterNotation = state.addSpaceAfterNotation,
             wideNotationOption = state.wideNotationOption,
             onTextInput = {
+                Log.d(TAG, "Notation key tapped")
                 context.toInputConnection().inputText(it)
                 if (state.vibrateOnTap) vibratorManager?.maybeVibrate()
             }
@@ -99,17 +105,21 @@ fun HushKeyboardContent(state: KeyboardState) {
         ControlKeyButtonRow(
             turns = keyConfigState.turns,
             isDarkTheme = isDarkTheme,
+            smartDelete = state.smartDelete,
             inputMethodButtonAction = {
+                Log.d(TAG, "Input method picker tapped")
                 inputMethodManager.showInputMethodPicker()
                 if (state.vibrateOnTap) vibratorManager?.maybeVibrate()
             },
             rotateDirectionButtonAction = {
+                Log.d(TAG, "Rotate direction button tapped")
                 keyConfigState = keyConfigState.copy(
                     isCounterClockwise = !keyConfigState.isCounterClockwise
                 )
                 if (state.vibrateOnTap) vibratorManager?.maybeVibrate()
             },
             turnDegreeButtonAction = {
+                Log.d(TAG, "Turn degree button tapped")
                 keyConfigState = when (keyConfigState.turns) {
                     Turns.Single -> keyConfigState.copy(turns = Turns.Double)
                     Turns.Double -> keyConfigState.copy(turns = Turns.Triple)
@@ -118,17 +128,28 @@ fun HushKeyboardContent(state: KeyboardState) {
                 if (state.vibrateOnTap) vibratorManager?.maybeVibrate()
             },
             wideTurnButtonAction = {
+                Log.d(TAG, "Wide turn button tapped")
                 keyConfigState = keyConfigState.copy(
                     isWideTurn = !keyConfigState.isWideTurn
                 )
                 if (state.vibrateOnTap) vibratorManager?.maybeVibrate()
             },
-            deleteButtonAction = {
-                context.toInputConnection().deleteText()
-                if (state.vibrateOnTap) vibratorManager?.maybeVibrate()
+            deleteButtonAction = if (state.smartDelete) {
+                {
+                    Log.d(TAG, "Delete button tapped")
+                    context.toInputConnection().smartDelete()
+                    if (state.vibrateOnTap) vibratorManager?.maybeVibrate()
+                }
+            } else {
+                {
+                    Log.d(TAG, "Smart delete button tapped")
+                    context.toInputConnection().deleteText()
+                    if (state.vibrateOnTap) vibratorManager?.maybeVibrate()
+                }
             },
             newLineButtonAction = {
-                context.toInputConnection().inputText("\n")
+                Log.d(TAG, "New line button tapped")
+                context.toInputConnection().inputNewline()
                 if (state.vibrateOnTap) vibratorManager?.maybeVibrate()
             }
         )
@@ -142,9 +163,10 @@ fun HushKeyboardPreview() {
     HushKeyboardContent(
         state = KeyboardState(
             themeOption = ThemeOption.System,
+            wideNotationOption = WideNotationOption.WideWithW,
+            smartDelete = true,
             addSpaceAfterNotation = true,
-            vibrateOnTap = true,
-            wideNotationOption = WideNotationOption.WideWithW
+            vibrateOnTap = true
         )
     )
 }
diff --git a/app/src/main/java/com/rickyhu/hushkeyboard/keyboard/KeyboardViewModel.kt b/app/src/main/java/com/rickyhu/hushkeyboard/keyboard/KeyboardViewModel.kt
@@ -22,16 +22,18 @@ class KeyboardViewModel @Inject constructor(
     ).map { settings ->
         KeyboardState(
             themeOption = settings.themeOption,
+            wideNotationOption = settings.wideNotationOption,
+            smartDelete = settings.smartDelete,
             addSpaceAfterNotation = settings.addSpaceAfterNotation,
-            vibrateOnTap = settings.vibrateOnTap,
-            wideNotationOption = settings.wideNotationOption
+            vibrateOnTap = settings.vibrateOnTap
         )
     }
 }
 
 data class KeyboardState(
     val themeOption: ThemeOption = ThemeOption.System,
+    val wideNotationOption: WideNotationOption = WideNotationOption.WideWithW,
+    val smartDelete: Boolean = true,
     val addSpaceAfterNotation: Boolean = true,
-    val vibrateOnTap: Boolean = true,
-    val wideNotationOption: WideNotationOption = WideNotationOption.WideWithW
+    val vibrateOnTap: Boolean = true
 )
diff --git a/app/src/main/java/com/rickyhu/hushkeyboard/keyboard/ui/rows/ControlKeyButtonRow.kt b/app/src/main/java/com/rickyhu/hushkeyboard/keyboard/ui/rows/ControlKeyButtonRow.kt
@@ -26,6 +26,7 @@ fun ControlKeyButtonRow(
     modifier: Modifier = Modifier,
     turns: Turns,
     isDarkTheme: Boolean,
+    smartDelete: Boolean,
     inputMethodButtonAction: () -> Unit,
     rotateDirectionButtonAction: () -> Unit,
     turnDegreeButtonAction: () -> Unit,
@@ -94,16 +95,20 @@ fun ControlKeyButtonRow(
                 )
             }
         )
+
         ControlKeyButton(
             modifier = controlKeyModifier.testTag("DeleteButton"),
             onClick = deleteButtonAction,
             isDarkTheme = isDarkTheme,
             content = {
-                Text(
-                    "⌫",
-                    color = keyColor,
-                    fontSize = 18.sp,
-                    textAlign = TextAlign.Center
+                Icon(
+                    painter = if (smartDelete) {
+                        painterResource(R.drawable.ic_backspace_filled)
+                    } else {
+                        painterResource(R.drawable.ic_backspace_outlined)
+                    },
+                    tint = keyColor,
+                    contentDescription = "Delete"
                 )
             }
         )
@@ -129,6 +134,7 @@ private fun ControlKeyButtonRowPreview() {
         ControlKeyButtonRow(
             turns = Turns.Single,
             isDarkTheme = false,
+            smartDelete = true,
             inputMethodButtonAction = {},
             rotateDirectionButtonAction = {},
             turnDegreeButtonAction = {},
diff --git a/app/src/main/java/com/rickyhu/hushkeyboard/model/Notation.kt b/app/src/main/java/com/rickyhu/hushkeyboard/model/Notation.kt
@@ -12,5 +12,9 @@ enum class Notation(val value: String) {
     S("S"),
     X("x"),
     Y("y"),
-    Z("z")
+    Z("z");
+
+    companion object {
+        fun getCharList(): List<Char> = Notation.entries.map { it.value.single() }
+    }
 }
diff --git a/app/src/main/java/com/rickyhu/hushkeyboard/settings/SettingsScreen.kt b/app/src/main/java/com/rickyhu/hushkeyboard/settings/SettingsScreen.kt
@@ -20,6 +20,7 @@ import com.rickyhu.hushkeyboard.data.ThemeOption
 import com.rickyhu.hushkeyboard.data.WideNotationOption
 import com.rickyhu.hushkeyboard.settings.ui.AddSpaceBetweenNotationSwitchItem
 import com.rickyhu.hushkeyboard.settings.ui.AppVersionItem
+import com.rickyhu.hushkeyboard.settings.ui.SmartDeleteSwitchItem
 import com.rickyhu.hushkeyboard.settings.ui.ThemeOptionDropdownItem
 import com.rickyhu.hushkeyboard.settings.ui.VibrateOnTapSwitchItem
 import com.rickyhu.hushkeyboard.settings.ui.WideNotationOptionDropdownItem
@@ -35,6 +36,7 @@ fun SettingsScreen(
         state,
         onThemeSelected = viewModel::updateThemeOption,
         onWideNotationOptionSelected = viewModel::updateWideNotationOption,
+        onSmartDeleteChanged = viewModel::updateSmartDelete,
         onAddSpaceBetweenNotationChanged = viewModel::updateAddSpaceBetweenNotation,
         onVibrateOnTapChanged = viewModel::updateVibrateOnTap
     )
@@ -47,6 +49,7 @@ fun SettingsContent(
     state: SettingsState,
     onThemeSelected: (themeOption: ThemeOption) -> Unit,
     onWideNotationOptionSelected: (wideNotationOption: WideNotationOption) -> Unit,
+    onSmartDeleteChanged: (smartDelete: Boolean) -> Unit,
     onAddSpaceBetweenNotationChanged: (addSpaceAfterNotation: Boolean) -> Unit,
     onVibrateOnTapChanged: (vibrateOnTap: Boolean) -> Unit
 ) {
@@ -66,6 +69,10 @@ fun SettingsContent(
                     currentOption = state.wideNotationOption,
                     onOptionSelected = onWideNotationOptionSelected
                 )
+                SmartDeleteSwitchItem(
+                    value = state.smartDelete,
+                    onValueChanged = onSmartDeleteChanged
+                )
                 AddSpaceBetweenNotationSwitchItem(
                     value = state.addSpaceAfterNotation,
                     onValueChanged = onAddSpaceBetweenNotationChanged
diff --git a/app/src/main/java/com/rickyhu/hushkeyboard/settings/SettingsViewModel.kt b/app/src/main/java/com/rickyhu/hushkeyboard/settings/SettingsViewModel.kt
@@ -26,6 +26,7 @@ class SettingsViewModel @Inject constructor(
         SettingsState(
             themeOption = settings.themeOption,
             addSpaceAfterNotation = settings.addSpaceAfterNotation,
+            smartDelete = settings.smartDelete,
             vibrateOnTap = settings.vibrateOnTap,
             wideNotationOption = settings.wideNotationOption
         )
@@ -43,6 +44,12 @@ class SettingsViewModel @Inject constructor(
         }
     }
 
+    fun updateSmartDelete(smartDelete: Boolean) {
+        viewModelScope.launch {
+            settingsRepository.updateSmartDelete(smartDelete)
+        }
+    }
+
     fun updateAddSpaceBetweenNotation(addSpaceBetweenNotation: Boolean) {
         viewModelScope.launch {
             settingsRepository.updateAddSpaceBetweenNotation(addSpaceBetweenNotation)
@@ -58,7 +65,8 @@ class SettingsViewModel @Inject constructor(
 
 data class SettingsState(
     val themeOption: ThemeOption = ThemeOption.System,
+    val wideNotationOption: WideNotationOption = WideNotationOption.WideWithW,
+    val smartDelete: Boolean = true,
     val addSpaceAfterNotation: Boolean = true,
-    val vibrateOnTap: Boolean = true,
-    val wideNotationOption: WideNotationOption = WideNotationOption.WideWithW
+    val vibrateOnTap: Boolean = true
 )
diff --git a/app/src/main/java/com/rickyhu/hushkeyboard/settings/ui/SmartDeleteSwitchItem.kt b/app/src/main/java/com/rickyhu/hushkeyboard/settings/ui/SmartDeleteSwitchItem.kt
@@ -0,0 +1,48 @@
+package com.rickyhu.hushkeyboard.settings.ui
+
+import androidx.compose.foundation.clickable
+import androidx.compose.material3.Icon
+import androidx.compose.material3.ListItem
+import androidx.compose.material3.Switch
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.platform.testTag
+import androidx.compose.ui.res.painterResource
+import androidx.compose.ui.tooling.preview.Preview
+import com.rickyhu.hushkeyboard.R
+import com.rickyhu.hushkeyboard.theme.HushKeyboardTheme
+
+@Composable
+fun SmartDeleteSwitchItem(
+    value: Boolean,
+    onValueChanged: (Boolean) -> Unit = {}
+) {
+    ListItem(
+        modifier = Modifier.clickable { onValueChanged(!value) },
+        headlineContent = { Text("Smart Delete") },
+        leadingContent = {
+            Icon(
+                painter = painterResource(R.drawable.ic_backspace_filled),
+                contentDescription = "Delete"
+            )
+        },
+        trailingContent = {
+            Switch(
+                checked = value,
+                onCheckedChange = onValueChanged,
+                modifier = Modifier.testTag("SmartDeleteSwitchItem")
+            )
+        }
+    )
+}
+
+@Preview(showBackground = true)
+@Composable
+fun SmartDeleteSwitchItemPreview() {
+    HushKeyboardTheme {
+        AddSpaceBetweenNotationSwitchItem(
+            value = true
+        )
+    }
+}
diff --git a/app/src/main/java/com/rickyhu/hushkeyboard/utils/InputConnection.kt b/app/src/main/java/com/rickyhu/hushkeyboard/utils/InputConnection.kt
@@ -1,23 +1,73 @@
 package com.rickyhu.hushkeyboard.utils
 
 import android.content.Context
+import android.util.Log
 import android.view.inputmethod.InputConnection
+import com.rickyhu.hushkeyboard.model.Notation
 import com.rickyhu.hushkeyboard.service.HushIMEService
 
-private const val CURSOR_POSITION = 1
+private const val TAG = "InputConnection"
+private const val NEWLINE = '\n'
+private const val END_CURSOR_POSITION = 1
+private const val SCAN_WINDOW_SIZE = 50
+
+val notationCharList = Notation.getCharList() + listOf(NEWLINE)
 
 fun Context.toInputConnection(): InputConnection = (this as HushIMEService).currentInputConnection
 
 fun InputConnection.inputText(text: String) {
-    commitText(text, CURSOR_POSITION)
+    commitText(text, END_CURSOR_POSITION)
+    Log.d(TAG, "inputText $text")
+}
+
+fun InputConnection.inputNewline() {
+    inputText(NEWLINE.toString())
 }
 
 fun InputConnection.deleteText() {
     val selectedText = getSelectedText(0)
 
     if (selectedText.isNullOrEmpty()) {
         deleteSurroundingText(1, 0)
+        Log.d(TAG, "deleteText")
     } else {
-        commitText("", CURSOR_POSITION)
+        commitText("", END_CURSOR_POSITION)
+        Log.d(TAG, "delete selected text: $selectedText")
+    }
+}
+
+fun InputConnection.smartDelete() {
+    Log.d(TAG, "smartDelete")
+
+    val selectedText = getSelectedText(0)
+    if (!selectedText.isNullOrEmpty()) {
+        commitText("", END_CURSOR_POSITION)
+        Log.d(TAG, "delete selected text: $selectedText")
+        return
+    }
+
+    beginBatchEdit()
+    try {
+        val textBeforeCursor = getTextBeforeCursor(SCAN_WINDOW_SIZE, 0)
+
+        if (textBeforeCursor.isNullOrEmpty()) {
+            deleteSurroundingText(1, 0)
+            return
+        }
+
+        var charsToDelete = 0
+        for (i in textBeforeCursor.indices.reversed()) {
+            val char = textBeforeCursor[i]
+            charsToDelete++
+            if (char.uppercaseChar() in notationCharList) {
+                break
+            }
+        }
+
+        if (charsToDelete > 0) {
+            deleteSurroundingText(charsToDelete, 0)
+        }
+    } finally {
+        endBatchEdit()
     }
 }
diff --git a/app/src/main/res/drawable/ic_backspace_filled.xml b/app/src/main/res/drawable/ic_backspace_filled.xml
@@ -0,0 +1,5 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android" android:autoMirrored="true" android:height="24dp" android:tint="#000000" android:viewportHeight="24" android:viewportWidth="24" android:width="24dp">
+      
+    <path android:fillColor="@android:color/white" android:pathData="M22,3L7,3c-0.69,0 -1.23,0.35 -1.59,0.88L0,12l5.41,8.11c0.36,0.53 0.9,0.89 1.59,0.89h15c1.1,0 2,-0.9 2,-2L24,5c0,-1.1 -0.9,-2 -2,-2zM19,15.59L17.59,17 14,13.41 10.41,17 9,15.59 12.59,12 9,8.41 10.41,7 14,10.59 17.59,7 19,8.41 15.41,12 19,15.59z"/>
+    
+</vector>
diff --git a/app/src/main/res/drawable/ic_backspace_outlined.xml b/app/src/main/res/drawable/ic_backspace_outlined.xml
diff --git a/app/src/test/java/com/rickyhu/hushkeyboard/ui/SettingsScreenUiTest.kt b/app/src/test/java/com/rickyhu/hushkeyboard/ui/SettingsScreenUiTest.kt

Original file line number	Diff line number	Diff line change
`@@ -22,6 +22,10 @@ class SettingsRepository @Inject constructor(`
`22`	`22`	`dataStore.updateData { it.copy(wideNotationOption = wideNotationOption) }`
`23`	`23`	`}`
`24`	`24`
	`25`	`+ suspend fun updateSmartDelete(smartDelete: Boolean) {`
	`26`	`+ dataStore.updateData { it.copy(smartDelete = smartDelete) }`
	`27`	`+ }`
	`28`	`+`
`25`	`29`	`suspend fun updateAddSpaceBetweenNotation(addSpaceBetweenNotation: Boolean) {`
`26`	`30`	`dataStore.updateData { it.copy(addSpaceAfterNotation = addSpaceBetweenNotation) }`
`27`	`31`	`}`
Original file line number	Diff line number	Diff line change
`@@ -22,16 +22,18 @@ class KeyboardViewModel @Inject constructor(`
`22`	`22`	`).map { settings ->`
`23`	`23`	`KeyboardState(`
`24`	`24`	`themeOption = settings.themeOption,`
	`25`	`+ wideNotationOption = settings.wideNotationOption,`
	`26`	`+ smartDelete = settings.smartDelete,`
`25`	`27`	`addSpaceAfterNotation = settings.addSpaceAfterNotation,`
`26`		`- vibrateOnTap = settings.vibrateOnTap,`
`27`		`- wideNotationOption = settings.wideNotationOption`
	`28`	`+ vibrateOnTap = settings.vibrateOnTap`
`28`	`29`	`)`
`29`	`30`	`}`
`30`	`31`	`}`
`31`	`32`
`32`	`33`	`data class KeyboardState(`
`33`	`34`	`val themeOption: ThemeOption = ThemeOption.System,`
	`35`	`+ val wideNotationOption: WideNotationOption = WideNotationOption.WideWithW,`
	`36`	`+ val smartDelete: Boolean = true,`
`34`	`37`	`val addSpaceAfterNotation: Boolean = true,`
`35`		`- val vibrateOnTap: Boolean = true,`
`36`		`- val wideNotationOption: WideNotationOption = WideNotationOption.WideWithW`
	`38`	`+ val vibrateOnTap: Boolean = true`
`37`	`39`	`)`