feat(study-screen): nosuggest:type field filter

This removes suggestions from the IME, so a language learner can learn
an orthography without hints. It also removes the 'swipe' operation on
the keyboard without showing the incognito icon.

This input mode (TYPE_NULL) will not be for all users: it makes Mandarin
 Chinese keyboards output in QWERTY only mode, and likely will disable
 voice input.

It is to be treated as an advanced feature, and is currently a hidden
feature, planned to be exposed by the FieldFilter class.

`nosuggest` needs to come before `type` in the field filter list: `type`
 is  processed by the backend, and AnkiDroid processes the remaining
 'custom' filters

so: `{{nosuggest:type:Field}}` becomes [[type:nosuggest:Field]] which is
 exposed by TypeAnswer, and implemented by the study screen

----

The following were considered:

TYPE_TEXT_FLAG_AUTO_COMPLETE = false
TYPE_TEXT_FLAG_AUTO_CORRECT = false
TYPE_TEXT_FLAG_AUTO_CORRECT = false
TYPE_TEXT_VARIATION_FILTER = true
IME_FLAG_NO_PERSONALIZED_LEARNING = true

The above are not sufficient for GBoard - incognito shows, and the strip
 showing suggested words is still visible

`TYPE_TEXT_VARIATION_VISIBLE_PASSWORD` removed suggestions, but with an
in-IME hint to open the password manager and a monospaced font on the
field

Fixes 10352

https://developer.android.com/reference/android/text/InputType#TYPE_NULL

Assisted-by: Claude Opus 4.7 - the code and a lot of bad research

Author: david-allison

.idea/dictionaries/project.xml

@@ -0,0 +1,7 @@
+<component name="ProjectDictionaryState">
+  <dictionary name="project">
+    <words>
+      <w>nosuggest</w>
+    </words>
+  </dictionary>
+</component>

AnkiDroid/src/main/java/com/ichi2/anki/AbstractFlashcardViewer.kt

@@ -36,6 +36,7 @@ import android.os.Bundle
 import android.os.Handler
 import android.os.Looper
 import android.os.SystemClock
+import android.text.InputType
 import android.view.GestureDetector
 import android.view.GestureDetector.SimpleOnGestureListener
 import android.view.KeyEvent
@@ -71,6 +72,7 @@ import androidx.annotation.IdRes
 import androidx.annotation.RequiresApi
 import androidx.annotation.VisibleForTesting
 import androidx.appcompat.app.AlertDialog
+import androidx.core.content.getSystemService
 import androidx.core.net.toFile
 import androidx.core.net.toUri
 import androidx.core.view.WindowInsetsCompat
@@ -127,6 +129,7 @@ import com.ichi2.anki.libanki.SoundOrVideoTag
 import com.ichi2.anki.libanki.TTSTag
 import com.ichi2.anki.libanki.TtsPlayer
 import com.ichi2.anki.model.CardStateFilter
+import com.ichi2.anki.model.FieldFilters.NoSuggestFilter
 import com.ichi2.anki.multimedia.getAvTag
 import com.ichi2.anki.noteeditor.NoteEditorLauncher
 import com.ichi2.anki.observability.ChangeManager
@@ -245,6 +248,10 @@ abstract class AbstractFlashcardViewer :
     private var cardFrame: FrameLayout? = null
     private var touchLayer: FrameLayout? = null
     protected var answerField: FixedEditText? = null
+
+    /** Layout-provided default `inputType` for [answerField], captured once and used to restore
+     *  state when moving off a card that used `{{nosuggest:type:}}`. See issue #10352. */
+    private var defaultAnswerFieldInputType: Int? = null
     protected var flipCardLayout: FrameLayout? = null
     private var easeButtonsLayout: LinearLayout? = null
 
@@ -569,6 +576,7 @@ abstract class AbstractFlashcardViewer :
         shortAnimDuration = resources.getInteger(android.R.integer.config_shortAnimTime)
         gestureDetectorImpl = LinkDetectingGestureDetector()
         TtsVoicesFieldFilter.ensureApplied()
+        NoSuggestFilter.ensureApplied()
     }
 
     override fun setupBackPressedCallbacks() {
@@ -737,6 +745,20 @@ abstract class AbstractFlashcardViewer :
 
     protected open fun answerFieldIsFocused(): Boolean = answerField != null && answerField!!.isFocused
 
+    /**
+     * Apply or restore the `{{nosuggest:type:}}` flag set on [answerField].
+     */
+    private fun applyTypeAnswerSuggestionFlags(noSuggest: Boolean) {
+        val field = answerField ?: return
+        // see ReviewerFragment for why `TYPE_NULL` was selected
+        val targetInputType =
+            if (noSuggest) InputType.TYPE_NULL else (defaultAnswerFieldInputType ?: field.inputType)
+        if (field.inputType != targetInputType) {
+            field.inputType = targetInputType
+            getSystemService<InputMethodManager>()?.restartInput(field)
+        }
+    }
+
     val deckOptionsLauncher =
         registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { _ ->
             Timber.i("Returned from deck options -> Restarting activity")
@@ -971,7 +993,10 @@ abstract class AbstractFlashcardViewer :
             val params = flipCardLayout!!.layoutParams
             params.height = initialFlipCardHeight * 2
         }
-        answerField = findViewById(R.id.answer_field)
+        answerField =
+            findViewById<FixedEditText>(R.id.answer_field).also { answerField ->
+                defaultAnswerFieldInputType = answerField.inputType
+            }
         initControls()
 
         // Position answer buttons
@@ -1333,6 +1358,7 @@ abstract class AbstractFlashcardViewer :
             // Show text entry based on if the user wants to write the answer
             answerField?.visibility = View.VISIBLE
             answerField?.applyLanguageHint(typeAnswer?.languageHint)
+            applyTypeAnswerSuggestionFlags(typeAnswer?.noSuggest == true)
         } else {
             answerField?.visibility = View.GONE
         }
@@ -1978,6 +2004,7 @@ abstract class AbstractFlashcardViewer :
                 // Show text entry based on if the user wants to write the answer
                 answerField?.visibility = View.VISIBLE
                 answerField?.applyLanguageHint(typeAnswer?.languageHint)
+                applyTypeAnswerSuggestionFlags(typeAnswer?.noSuggest == true)
             } else {
                 answerField?.visibility = View.GONE
             }

AnkiDroid/src/main/java/com/ichi2/anki/AnkiDroidApp.kt

@@ -51,6 +51,7 @@ import com.ichi2.anki.logging.FragmentLifecycleLogger
 import com.ichi2.anki.logging.LogType
 import com.ichi2.anki.logging.ProductionCrashReportingTree
 import com.ichi2.anki.logging.RobolectricDebugTree
+import com.ichi2.anki.model.FieldFilters.NoSuggestFilter
 import com.ichi2.anki.observability.ChangeManager
 import com.ichi2.anki.preferences.SharedPreferencesProvider
 import com.ichi2.anki.preferences.sharedPrefs
@@ -267,8 +268,20 @@ open class AnkiDroidApp :
 
         activityAgnosticDialogs = ActivityAgnosticDialogs.register(this)
         TtsVoices.launchBuildLocalesJob()
+        applyCustomFieldFilters()
+    }
+
+    /**
+     * Applies AnkiDroid-specific implementations of field filters
+     *
+     * @see com.ichi2.anki.model.FieldFilter
+     * @see com.ichi2.anki.model.FieldFilters
+     */
+    private fun applyCustomFieldFilters() {
         // enable {{tts-voices:}} field filter
         TtsVoicesFieldFilter.ensureApplied()
+        // enable {{nosuggest:type:}} field filter (issue #10352)
+        NoSuggestFilter.ensureApplied()
     }
 
     /**

AnkiDroid/src/main/java/com/ichi2/anki/cardviewer/TypeAnswer.kt

@@ -1,18 +1,4 @@
-/*
- *  Copyright (c) 2021 David Allison <davidallisongithub@gmail.com>
- *
- *  This program is free software; you can redistribute it and/or modify it under
- *  the terms of the GNU General Public License as published by the Free Software
- *  Foundation; either version 3 of the License, or (at your option) any later
- *  version.
- *
- *  This program is distributed in the hope that it will be useful, but WITHOUT ANY
- *  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
- *  PARTICULAR PURPOSE. See the GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License along with
- *  this program.  If not, see <http://www.gnu.org/licenses/>.
- */
+// SPDX-License-Identifier: GPL-3.0-or-later
 
 package com.ichi2.anki.cardviewer
 
@@ -31,6 +17,8 @@ import java.util.regex.Matcher
 import java.util.regex.Pattern
 
 /**
+ * Handles 'Type the answer' for the old study screen
+ *
  * @param useInputTag use an `<input>` tag to allow for HTML styling
  * @param autoFocus Whether the user wants to focus "type in answer"
  */
@@ -45,6 +33,14 @@ class TypeAnswer(
     var combining: Boolean = true
         private set
 
+    /**
+     * Whether keyboard suggestions, swiping and autocorrect should be disabled (#10352).
+     *
+     * @see com.ichi2.anki.model.FieldFilters.NoSuggestFilter
+     */
+    var noSuggest: Boolean = false
+        private set
+
     /** What the learner actually typed (externally mutable) */
     var input = ""
 
@@ -86,24 +82,18 @@ class TypeAnswer(
         res: Resources,
     ) {
         combining = true
+        noSuggest = false
         correct = null
         val q = card.question(col)
         val m = PATTERN.matcher(q)
-        var clozeIdx = 0
         if (!m.find()) {
             return
         }
-        var fldTag = m.group(1)!!
-        // if it's a cloze, extract data
-        if (fldTag.startsWith("cloze:")) {
-            // get field and cloze position
-            clozeIdx = card.ord + 1
-            fldTag = fldTag.split(":").toTypedArray()[1]
-        }
-        if (fldTag.startsWith("nc:")) {
-            combining = false
-            fldTag = fldTag.split(":").toTypedArray()[1]
-        }
+        val parsed = TypeAnswerModifiers.parse(m.group(1)!!)
+        combining = parsed.combining
+        noSuggest = parsed.noSuggest
+        val fldTag = parsed.fieldName
+        val clozeIdx = if (parsed.cloze) card.ord + 1 else 0
         // loop through fields for a match
         for (fld in card.noteType(col).fields) {
             val name = fld.name

AnkiDroid/src/main/java/com/ichi2/anki/cardviewer/TypeAnswerModifiers.kt

@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package com.ichi2.anki.cardviewer
+
+/**
+ * Represents modifiers for `[[type:...]]`
+ *
+ * Examples:
+ * - `[[type:nosuggest:nc:Field]]`
+ * - `[[type:cloze:Field]]`
+ */
+internal data class TypeAnswerModifiers(
+    val fieldName: String,
+    val combining: Boolean,
+    val cloze: Boolean,
+    val noSuggest: Boolean,
+) {
+    companion object {
+        /**
+         * Represents the known modifiers in a [[type: ]] declaration, and remaining data
+         */
+        fun parse(rawField: String): TypeAnswerModifiers {
+            var remaining = rawField
+            var combining = true
+            var cloze = false
+            var noSuggest = false
+            while (true) {
+                when {
+                    remaining.startsWith("nosuggest:") -> {
+                        noSuggest = true
+                        remaining = remaining.removePrefix("nosuggest:")
+                    }
+                    remaining.startsWith("cloze:") -> {
+                        cloze = true
+                        remaining = remaining.removePrefix("cloze:")
+                    }
+                    remaining.startsWith("nc:") -> {
+                        combining = false
+                        remaining = remaining.removePrefix("nc:")
+                    }
+                    else -> return TypeAnswerModifiers(
+                        fieldName = remaining,
+                        combining = combining,
+                        cloze = cloze,
+                        noSuggest = noSuggest,
+                    )
+                }
+            }
+        }
+    }
+}

AnkiDroid/src/main/java/com/ichi2/anki/model/FieldFilters.kt

@@ -1,23 +1,10 @@
-/*
- *  Copyright (c) 2026 David Allison <davidallisongithub@gmail.com>
- *
- *  This program is free software; you can redistribute it and/or modify it under
- *  the terms of the GNU General Public License as published by the Free Software
- *  Foundation; either version 3 of the License, or (at your option) any later
- *  version.
- *
- *  This program is distributed in the hope that it will be useful, but WITHOUT ANY
- *  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
- *  PARTICULAR PURPOSE. See the GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License along with
- *  this program.  If not, see <http://www.gnu.org/licenses/>.
- */
+// SPDX-License-Identifier: GPL-3.0-or-later
 
 package com.ichi2.anki.model
 
 import androidx.annotation.CheckResult
 import com.ichi2.anki.libanki.NotetypeJson
+import com.ichi2.anki.libanki.TemplateManager
 
 // Classes relating to a chain of field filters: {{type:cloze:Front}}
 
@@ -34,7 +21,7 @@ import com.ichi2.anki.libanki.NotetypeJson
  * only be used to validate inserting new filters in the AnkiDroid editor.
  *
  * @see FieldFilter
- * @see com.ichi2.anki.libanki.TemplateManager.FieldFilter
+ * @see TemplateManager.FieldFilter
  */
 data class FilterContext(
     /**
@@ -69,6 +56,10 @@ data class FilterContext(
      * Applying more filters to these outputs would corrupt them.
      */
     val isTerminal: Boolean = false,
+    /**
+     * Whether the chain produces a `[[type:...]]` marker (via the `type:` field filter)
+     */
+    val producesTypeMarker: Boolean = false,
 )
 
 /**
@@ -133,6 +124,7 @@ object FieldFilters {
             HintFilter,
             TypeTheAnswerFilter,
             TypeTheAnswerNonCombiningFilter,
+            NoSuggestFilter,
             TextToSpeechFilter(),
             FuriganaFilter,
             KanaFilter,
@@ -240,7 +232,7 @@ object FieldFilters {
     object TypeTheAnswerFilter : FieldFilter {
         override val name: String = "type"
 
-        override fun updateContext(input: FilterContext) = input.copy(isTerminal = true)
+        override fun updateContext(input: FilterContext) = input.copy(isTerminal = true, producesTypeMarker = true)
     }
 
     /**
@@ -263,7 +255,49 @@ object FieldFilters {
     object TypeTheAnswerNonCombiningFilter : FieldFilter {
         override val name: String = "type:nc"
 
-        override fun updateContext(input: FilterContext) = input.copy(isTerminal = true)
+        override fun updateContext(input: FilterContext) = input.copy(isTerminal = true, producesTypeMarker = true)
+    }
+
+    /**
+     * `{{nosuggest:type:Field}}`: disables keyboard suggestions, swiping and autocorrect
+     *
+     * AnkiDroid-only.
+     *
+     * Converts the rendered `[[type:abc]]` to `[[type:nosuggest:abc]]`, which is then consumed
+     * by the `TypeAnswer` parser.
+     *
+     * See [#10352](https://github.com/ankidroid/Anki-Android/issues/10352).
+     * @see com.ichi2.anki.previewer.TypeAnswer.noSuggest
+     */
+    object NoSuggestFilter :
+        FieldFilter,
+        TemplateManager.FieldFilter {
+        override val name: String = "nosuggest"
+
+        /**
+         * May only be applied to `type:` or `type:nc` filter which are both terminal chains,
+         * therefore, do not check 'super.canApplyTo'
+         */
+        override fun canApplyTo(context: FilterContext): Boolean = context.producesTypeMarker
+
+        override fun updateContext(input: FilterContext): FilterContext = input
+
+        override fun apply(
+            fieldText: String,
+            fieldName: String,
+            filterName: String,
+            ctx: TemplateManager.TemplateRenderContext,
+        ): String {
+            if (filterName != name) return fieldText
+            if (!fieldText.contains("[[type:")) return fieldText
+            if (fieldText.contains("[[type:nosuggest:")) return fieldText
+            return fieldText.replace("[[type:", "[[type:nosuggest:")
+        }
+
+        /** Registers this filter as a runtime transformer with the [TemplateManager]. */
+        fun ensureApplied() {
+            TemplateManager.fieldFilters.putIfAbsent(name, this)
+        }
     }
 
     /**