feat: toggleable incrementer for "Learn ahead limit" and "Timebox time limit"

AnkiDroid/src/main/java/com/ichi2/preferences/ToggleableIncrementerNumberRangePreferenceCompat.kt

@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+package com.ichi2.preferences
+
+import android.content.Context
+import android.util.AttributeSet
+import androidx.preference.PreferenceViewHolder
+import com.google.android.material.materialswitch.MaterialSwitch
+import com.ichi2.anki.R
+
+/**
+ * A [NumberRangePreferenceCompat] with a [MaterialSwitch] widget on the preference row.
+ *
+ * The switch reflects whether the value is non-zero (enabled) or zero (disabled).
+ * Tapping the switch toggles between enabled/disabled without opening the dialog.
+ * Tapping the title area opens the incrementer dialog only when enabled.
+ *
+ * No separate preference key is needed — the existing value `0` represents "disabled".
+ */
+class ToggleableIncrementerNumberRangePreferenceCompat :
+    NumberRangePreferenceCompat,
+    DialogFragmentProvider {
+    @Suppress("unused")
+    constructor(
+        context: Context,
+        attrs: AttributeSet?,
+        defStyleAttr: Int,
+        defStyleRes: Int,
+    ) : super(context, attrs, defStyleAttr, defStyleRes)
+
+    @Suppress("unused")
+    constructor(context: Context, attrs: AttributeSet?, defStyleAttr: Int) : super(context, attrs, defStyleAttr)
+
+    @Suppress("unused")
+    constructor(context: Context, attrs: AttributeSet?) : super(context, attrs)
+
+    @Suppress("unused")
+    constructor(context: Context) : super(context)
+
+    init {
+        widgetLayoutResource = R.layout.preference_widget_switch_with_separator
+    }
+
+    override fun onBindViewHolder(holder: PreferenceViewHolder) {
+        super.onBindViewHolder(holder)
+
+        val switch = holder.findViewById(R.id.switch_widget) as MaterialSwitch
+        switch.setOnCheckedChangeListener(null)
+        switch.isChecked = getValue() != 0
+        switch.setOnCheckedChangeListener { _, isChecked ->
+            val newValue = if (isChecked) maxOf(1, min) else 0
+            if (callChangeListener(newValue)) {
+                setValue(newValue)
+                notifyChanged()
+            } else {
+                switch.isChecked = !isChecked
+            }
+        }
+    }
+
+    override fun onClick() {
+        if (getValue() == 0) return
+        super.onClick()
+    }
+
+    override fun makeDialogFragment() = IncrementerNumberRangePreferenceCompat.IncrementerNumberRangeDialogFragmentCompat()
+}

AnkiDroid/src/main/res/xml/preferences_reviewing.xml

@@ -35,13 +35,13 @@
             android:title="@string/day_offset_with_description"
             app:persistent="false"
             app:summaryFormat="@plurals/day_offset_summ"/>
-        <com.ichi2.preferences.IncrementerNumberRangePreferenceCompat
+        <com.ichi2.preferences.ToggleableIncrementerNumberRangePreferenceCompat
             android:key="@string/learn_cutoff_preference"
             android:title="@string/learn_cutoff"
             app:max="999"
             app:min="0"
             app:summaryFormat="@plurals/pref_summ_minutes"/>
-        <com.ichi2.preferences.IncrementerNumberRangePreferenceCompat
+        <com.ichi2.preferences.ToggleableIncrementerNumberRangePreferenceCompat
             android:key="@string/time_limit_preference"
             android:title="@string/time_limit"
             app:max="999"

AnkiDroid/src/test/java/com/ichi2/preferences/ToggleableIncrementerNumberRangePreferenceCompatTest.kt

@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+package com.ichi2.preferences
+
+import com.ichi2.preferences.IncrementerNumberRangePreferenceCompat.Companion.ValidationResult
+import com.ichi2.preferences.IncrementerNumberRangePreferenceCompat.Companion.validate
+import org.hamcrest.MatcherAssert.assertThat
+import org.hamcrest.core.IsEqual
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.robolectric.RobolectricTestRunner
+
+@RunWith(RobolectricTestRunner::class)
+class ToggleableIncrementerNumberRangePreferenceCompatTest {
+    @Test
+    fun `validation logic works with toggleable min of 0`() {
+        val min = 0
+        val max = 999
+
+        assertThat(
+            "0 should be VALID (represents disabled state)",
+            validate("0", 0, min, max),
+            IsEqual(ValidationResult.VALID),
+        )
+
+        assertThat(
+            "A number within range should be VALID",
+            validate("20", 20, min, max),
+            IsEqual(ValidationResult.VALID),
+        )
+
+        assertThat(
+            "Max boundary should be VALID",
+            validate("999", 999, min, max),
+            IsEqual(ValidationResult.VALID),
+        )
+
+        assertThat(
+            "A number greater than max should return OVERFLOW",
+            validate("1000", 1000, min, max),
+            IsEqual(ValidationResult.OVERFLOW),
+        )
+
+        assertThat(
+            "An empty string should return EMPTY",
+            validate("", null, min, max),
+            IsEqual(ValidationResult.EMPTY),
+        )
+
+        assertThat(
+            "A number exceeding Integer limits should return INVALID",
+            validate("9999999999", null, min, max),
+            IsEqual(ValidationResult.INVALID),
+        )
+    }
+
+    @Test
+    fun `toggle on default value is 1 when min is 0`() {
+        val min = 0
+        val defaultValue = maxOf(1, min)
+        assertThat(
+            "Default value when toggling ON from disabled should be 1",
+            defaultValue,
+            IsEqual(1),
+        )
+    }
+
+    @Test
+    fun `toggle on default value respects min when min is positive`() {
+        val min = 5
+        val defaultValue = maxOf(1, min)
+        assertThat(
+            "Default value when toggling ON should be at least min",
+            defaultValue,
+            IsEqual(5),
+        )
+    }
+}