Adding Settings preference for single finger panning feature

Test: Locally tested on device +
MagnificationOneFingerPanningPreferenceControllerTest
Bug: 282039824

Change-Id: I1d1a649060cba862c8f333e6e76184fade2dcdce
diff --git a/res/values/strings.xml b/res/values/strings.xml
index 7ae9074..8b0cd67 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -4760,6 +4760,14 @@
     <string name="accessibility_magnification_triple_tap_warning_negative_button">Cancel</string>
     <!-- Title for the accessibility preference screen to enable screen magnification settings. [CHAR LIMIT=35] -->
     <string name="accessibility_magnification_service_settings_title">Magnification settings</string>
+    <!-- Title for accessibility magnification preference where user can move the magnification area by dragging one finger instead of two. [CHAR LIMIT=60] -->
+    <string name="accessibility_magnification_one_finger_panning_title">One-finger panning</string>
+    <!-- Summary for accessibility magnification preference when one finger panning feature is turned on.
+         The feature when enabled allows user to move the magnification area by dragging one finger instead of two. [CHAR LIMIT=60] -->
+    <string name="accessibility_magnification_one_finger_panning_summary_on">Move the magnification area by dragging one finger.</string>
+    <!-- Summary for accessibility magnification preference when one finger panning feature is turned off.
+         The feature when disabled, allows user to move the magnification area by dragging two fingers instead of one. [CHAR LIMIT=60] -->
+    <string name="accessibility_magnification_one_finger_panning_summary_off">Move the magnification area by dragging two fingers.</string>
     <!-- Title for the accessibility preference screen to enable navigation bar screen magnification. [CHAR LIMIT=35] -->
     <string name="accessibility_screen_magnification_navbar_title">Magnify with shortcut</string>
     <!-- Summary for the accessibility magnification setting indicating both "Magnify with button" and "Magnify with triple-tap" are enabled [CHAR LIMIT=50] -->
diff --git a/src/com/android/settings/accessibility/MagnificationOneFingerPanningPreferenceController.java b/src/com/android/settings/accessibility/MagnificationOneFingerPanningPreferenceController.java
new file mode 100644
index 0000000..a2ce948
--- /dev/null
+++ b/src/com/android/settings/accessibility/MagnificationOneFingerPanningPreferenceController.java
@@ -0,0 +1,102 @@
+/*
+ * Copyright (C) 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.accessibility;
+
+import static com.android.settings.accessibility.AccessibilityUtil.State.OFF;
+import static com.android.settings.accessibility.AccessibilityUtil.State.ON;
+
+import android.content.Context;
+import android.content.res.Resources;
+import android.provider.Settings;
+
+import androidx.annotation.Nullable;
+import androidx.annotation.VisibleForTesting;
+import androidx.preference.PreferenceScreen;
+import androidx.preference.TwoStatePreference;
+
+import com.android.server.accessibility.Flags;
+import com.android.settings.R;
+import com.android.settings.core.TogglePreferenceController;
+
+public class MagnificationOneFingerPanningPreferenceController
+        extends TogglePreferenceController {
+    static final String PREF_KEY = Settings.Secure.ACCESSIBILITY_SINGLE_FINGER_PANNING_ENABLED;
+
+    @Nullable
+    private TwoStatePreference mSwitchPreference;
+
+    @VisibleForTesting
+    final boolean mDefaultValue;
+
+    public MagnificationOneFingerPanningPreferenceController(Context context) {
+        super(context, PREF_KEY);
+        boolean defaultValue;
+        try {
+            defaultValue = context.getResources().getBoolean(
+                    com.android.internal.R.bool.config_enable_a11y_magnification_single_panning);
+        } catch (Resources.NotFoundException e) {
+            defaultValue = false;
+        }
+        mDefaultValue = defaultValue;
+    }
+
+    @Override
+    public int getAvailabilityStatus() {
+        return (Flags.enableMagnificationOneFingerPanningGesture())
+                ? AVAILABLE : DISABLED_FOR_USER;
+    }
+
+    @Override
+    public boolean isChecked() {
+        return Settings.Secure.getInt(
+                mContext.getContentResolver(),
+                PREF_KEY,
+                (mDefaultValue) ? ON : OFF) == ON;
+    }
+
+    @Override
+    public boolean setChecked(boolean isChecked) {
+        var toReturn = Settings.Secure.putInt(mContext.getContentResolver(),
+                PREF_KEY,
+                (isChecked ? ON : OFF));
+        if (mSwitchPreference != null) {
+            refreshSummary(mSwitchPreference);
+        }
+        return toReturn;
+    }
+
+    @Override
+    public CharSequence getSummary() {
+        return (isChecked())
+                ? mContext.getString(
+                        R.string.accessibility_magnification_one_finger_panning_summary_on)
+                : mContext.getString(
+                        R.string.accessibility_magnification_one_finger_panning_summary_off);
+    }
+
+    @Override
+    public int getSliceHighlightMenuRes() {
+        return R.string.menu_key_accessibility;
+    }
+
+    @Override
+    public void displayPreference(PreferenceScreen screen) {
+        super.displayPreference(screen);
+        mSwitchPreference = screen.findPreference(getPreferenceKey());
+        refreshSummary(mSwitchPreference);
+    }
+}
diff --git a/src/com/android/settings/accessibility/ToggleScreenMagnificationPreferenceFragment.java b/src/com/android/settings/accessibility/ToggleScreenMagnificationPreferenceFragment.java
index d9baa03..985d45d 100644
--- a/src/com/android/settings/accessibility/ToggleScreenMagnificationPreferenceFragment.java
+++ b/src/com/android/settings/accessibility/ToggleScreenMagnificationPreferenceFragment.java
@@ -200,6 +200,7 @@
         final PreferenceCategory generalCategory = findPreference(KEY_GENERAL_CATEGORY);
         generalCategory.addPreference(mSettingsPreference);
 
+        addOneFingerPanningSetting(generalCategory);
         final MagnificationModePreferenceController magnificationModePreferenceController =
                 new MagnificationModePreferenceController(getContext(),
                         MagnificationModePreferenceController.PREF_KEY);
@@ -283,6 +284,24 @@
         addPreferenceController(alwaysOnPreferenceController);
     }
 
+    private void addOneFingerPanningSetting(PreferenceCategory generalCategory) {
+        if (!Flags.enableMagnificationOneFingerPanningGesture()) {
+            return;
+        }
+
+        var oneFingerPanningPreference = new SwitchPreferenceCompat(getPrefContext());
+        oneFingerPanningPreference.setTitle(
+                R.string.accessibility_magnification_one_finger_panning_title);
+        oneFingerPanningPreference.setKey(
+                MagnificationOneFingerPanningPreferenceController.PREF_KEY);
+        generalCategory.addPreference(oneFingerPanningPreference);
+
+        var oneFingerPanningPreferenceController =
+                new MagnificationOneFingerPanningPreferenceController(getContext());
+        oneFingerPanningPreferenceController.displayPreference(getPreferenceScreen());
+        addPreferenceController(oneFingerPanningPreferenceController);
+    }
+
     private void addJoystickSetting(PreferenceCategory generalCategory) {
         if (!DeviceConfig.getBoolean(
                 DeviceConfig.NAMESPACE_WINDOW_MANAGER,
diff --git a/tests/robotests/src/com/android/settings/accessibility/MagnificationOneFingerPanningPreferenceControllerTest.java b/tests/robotests/src/com/android/settings/accessibility/MagnificationOneFingerPanningPreferenceControllerTest.java
new file mode 100644
index 0000000..326a7a0
--- /dev/null
+++ b/tests/robotests/src/com/android/settings/accessibility/MagnificationOneFingerPanningPreferenceControllerTest.java
@@ -0,0 +1,187 @@
+/*
+ * Copyright (C) 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.accessibility;
+
+import static com.android.server.accessibility.Flags.enableMagnificationOneFingerPanningGesture;
+import static com.android.settings.accessibility.AccessibilityUtil.State.OFF;
+import static com.android.settings.accessibility.AccessibilityUtil.State.ON;
+import static com.android.settings.core.BasePreferenceController.AVAILABLE;
+import static com.android.settings.core.BasePreferenceController.DISABLED_FOR_USER;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
+
+import android.content.Context;
+import android.platform.test.flag.junit.SetFlagsRule;
+import android.provider.Settings;
+
+import androidx.preference.PreferenceManager;
+import androidx.preference.PreferenceScreen;
+import androidx.preference.SwitchPreference;
+import androidx.test.core.app.ApplicationProvider;
+
+import com.android.server.accessibility.Flags;
+import com.android.settings.R;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RobolectricTestRunner;
+
+@RunWith(RobolectricTestRunner.class)
+public class MagnificationOneFingerPanningPreferenceControllerTest {
+    private static final String ONE_FINGER_PANNING_KEY =
+            Settings.Secure.ACCESSIBILITY_SINGLE_FINGER_PANNING_ENABLED;
+
+    @Rule public final SetFlagsRule mSetFlagsRule =
+            new SetFlagsRule(SetFlagsRule.DefaultInitValueType.DEVICE_DEFAULT);
+
+    private final Context mContext = ApplicationProvider.getApplicationContext();
+    private final SwitchPreference mSwitchPreference = spy(new SwitchPreference(mContext));
+    private final MagnificationOneFingerPanningPreferenceController mController =
+            new MagnificationOneFingerPanningPreferenceController(mContext);
+
+    private PreferenceScreen mScreen;
+
+    @Before
+    public void setUp() {
+        final PreferenceManager preferenceManager = new PreferenceManager(mContext);
+        mScreen = preferenceManager.createPreferenceScreen(mContext);
+        mSwitchPreference.setKey(MagnificationOneFingerPanningPreferenceController.PREF_KEY);
+        mScreen.addPreference(mSwitchPreference);
+        mController.displayPreference(mScreen);
+    }
+
+    @After
+    public void cleanup() {
+        // Can't use resetToDefaults as it NPE with
+        // "Cannot invoke "android.content.IContentProvider.call"
+        Settings.Secure.putInt(
+                mContext.getContentResolver(),
+                MagnificationOneFingerPanningPreferenceController.PREF_KEY,
+                (mController.mDefaultValue) ? ON : OFF);
+    }
+
+    @Test
+    public void displayPreference_defaultState_correctSummarySet() {
+        assertThat(mSwitchPreference.getSummary())
+                .isEqualTo(mContext.getString(
+                        R.string.accessibility_magnification_one_finger_panning_summary_off));
+    }
+
+    @Test
+    public void getAvailabilityStatus_defaultState_disabled() {
+        int status = mController.getAvailabilityStatus();
+
+        assertThat(status).isEqualTo(DISABLED_FOR_USER);
+    }
+
+    @Test
+    public void getAvailabilityStatus_featureFlagEnabled_enabled() {
+        enableFlag();
+
+        int status = mController.getAvailabilityStatus();
+
+        assertThat(status).isEqualTo(AVAILABLE);
+    }
+
+    @Test
+    public void isChecked_defaultState_returnFalse() {
+        assertThat(mController.isChecked()).isFalse();
+        assertThat(mSwitchPreference.isChecked()).isFalse();
+    }
+
+    @Test
+    public void isChecked_settingsEnabled_returnTrue() {
+        Settings.Secure.putInt(mContext.getContentResolver(), ONE_FINGER_PANNING_KEY, ON);
+
+        assertThat(mController.isChecked()).isTrue();
+    }
+
+    @Test
+    public void isChecked_settingsDisabled_returnTrue() {
+        Settings.Secure.putInt(mContext.getContentResolver(), ONE_FINGER_PANNING_KEY, OFF);
+
+        assertThat(mController.isChecked()).isFalse();
+    }
+
+    @Test
+    public void setChecked_enabled_enabledSummarySet() {
+        mController.setChecked(true);
+
+        assertThat(mSwitchPreference.getSummary()).isEqualTo(enabledSummary());
+        assertThat(mController.isChecked()).isTrue();
+    }
+
+    @Test
+    public void setChecked_disabled_disabledSummarySet() {
+        mController.setChecked(false);
+
+        assertThat(mController.isChecked()).isFalse();
+        assertThat(mSwitchPreference.getSummary()).isEqualTo(disabledSummary());
+    }
+
+    @Test
+    public void getSummary_disable_disableSummaryTextUsed() {
+        Settings.Secure.putInt(mContext.getContentResolver(), ONE_FINGER_PANNING_KEY, OFF);
+
+        var summary = mController.getSummary();
+
+        assertThat(summary).isEqualTo(disabledSummary());
+    }
+
+    @Test
+    public void getSummary_enable_enabledSummaryTextUsed() {
+        Settings.Secure.putInt(mContext.getContentResolver(), ONE_FINGER_PANNING_KEY, ON);
+
+        var summary = mController.getSummary();
+
+        assertThat(summary).isEqualTo(enabledSummary());
+    }
+
+    @Test
+    public void performClick_switchDefaultState_shouldReturnTrue() {
+        enableFlag();
+
+        mSwitchPreference.performClick();
+
+        verify(mSwitchPreference).setChecked(true);
+        assertThat(mController.isChecked()).isTrue();
+        assertThat(mSwitchPreference.isChecked()).isTrue();
+    }
+
+    private void enableFlag() {
+        mSetFlagsRule.enableFlags(Flags.FLAG_ENABLE_MAGNIFICATION_ONE_FINGER_PANNING_GESTURE);
+        assertThat(enableMagnificationOneFingerPanningGesture()).isTrue();
+        // This ensures that preference change listeners are added correctly.
+        mController.displayPreference(mScreen);
+    }
+
+    private String enabledSummary() {
+        return mContext.getString(
+                R.string.accessibility_magnification_one_finger_panning_summary_on);
+    }
+
+    private String disabledSummary() {
+        return mContext.getString(
+                R.string.accessibility_magnification_one_finger_panning_summary_off);
+    }
+}