Touchpad: add tap dragging setting

Screenshot: go/ag-26012379-screenshot

Bug: 321978150
Bug: 324058706
Test: with the flag disabled, check the new entry doesn't appear
Test: with the flag enabled, toggle the setting and check that it
    enables and disables tap dragging (tapping then immediately putting
    your finger back on the touchpad and moving it)
Test: with the flag enabled, check the setting appears in search results
Test: atest SettingsRoboTests:com.android.settings.inputmethod
Change-Id: Iccfbe842ff655ea295edc764cfc400709948df7d

res/values/strings.xml

@@ -4362,6 +4362,8 @@
 
     <!-- Title text for 'Tap to click'. [CHAR LIMIT=35] -->
     <string name="trackpad_tap_to_click">Tap to click</string>
+    <!-- TODO(b/321978150): mark as translatable once we have finalized text from UX. -->
+    <string name="trackpad_tap_dragging" translatable="false">Tap dragging</string>
     <!-- Title text for 'Touchpad gestures' [CHAR LIMIT=35] -->
     <string name="trackpad_touchpad_gesture_title">Touchpad gestures</string>
     <!-- Summary text for 'Touchpad gestures' [CHAR LIMIT=60] -->

res/xml/trackpad_settings.xml

@@ -52,6 +52,13 @@
         android:order="30"
         settings:keywords="@string/keywords_trackpad_bottom_right_tap"/>
 
+    <!-- TODO(b/321978150): add a summary line once we have finalized text from UX. -->
+    <SwitchPreferenceCompat
+        android:key="trackpad_tap_dragging"
+        android:title="@string/trackpad_tap_dragging"
+        settings:controller="com.android.settings.inputmethod.TrackpadTapDraggingPreferenceController"
+        android:order="35"/>
+
     <com.android.settings.widget.SeekBarPreference
         android:key="trackpad_pointer_speed"
         android:title="@string/trackpad_pointer_speed"

src/com/android/settings/inputmethod/TrackpadTapDraggingPreferenceController.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2024 The Android Open Source Project
+ *
+ * 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 com.android.settings.inputmethod;
+
+import android.content.Context;
+import android.hardware.input.InputSettings;
+
+import com.android.settings.R;
+import com.android.settings.core.TogglePreferenceController;
+
+public class TrackpadTapDraggingPreferenceController extends TogglePreferenceController {
+
+    public TrackpadTapDraggingPreferenceController(Context context, String key) {
+        super(context, key);
+    }
+
+    @Override
+    public boolean isChecked() {
+        return InputSettings.useTouchpadTapDragging(mContext);
+    }
+
+    @Override
+    public boolean setChecked(boolean isChecked) {
+        InputSettings.setTouchpadTapDragging(mContext, isChecked);
+        // TODO(b/321978150): add a metric for tap dragging settings changes.
+        return true;
+    }
+
+    @Override
+    public int getAvailabilityStatus() {
+        return InputSettings.isTouchpadTapDraggingFeatureFlagEnabled()
+                ? AVAILABLE : CONDITIONALLY_UNAVAILABLE;
+    }
+
+    @Override
+    public int getSliceHighlightMenuRes() {
+        return R.string.menu_key_system;
+    }
+}