Introduce developer option for Stylus handwriting

Introduce a new developer option for Input Method:
Stylus handwriting: when this setting is enabled, currently selected
input method receives stylus events after focus on editor.

Bug: 219777744
Test: atest StylusHandwritingPreferenceControllerTest
Change-Id: Ia6335df60aae56973ed54bec1a243ea1de3aa6ad

res/values/strings.xml

@@ -12277,6 +12277,14 @@
     <!-- Location setting: preference summary - describes the behavior of forcing full raw GNSS satellite measurements [CHAR LIMIT=NONE] -->
     <string name="enable_gnss_raw_meas_full_tracking_summary">Track all GNSS constellations and frequencies with no duty cycling</string>
 
+    <!-- Developer options Input method category strings -->
+    <!-- Title for input method category [CHAR LIMIT=30]-->
+    <string name="input_method_category">Input Method</string>
+    <!-- [CHAR LIMIT=30] Title for Stylus handwriting settings -->
+    <string name="stylus_handwriting">Stylus handwriting</string>
+    <!-- [CHAR LIMIT=130] Summary for Stylus handwriting toggle -->
+    <string name="stylus_handwriting_summary">When enabled, current Input method receives stylus MotionEvent if an Editor is focused.</string>
+
     <!-- Name of setting for switching device theme [CHAR LIMIT=60] -->
     <string name="device_theme">Device theme</string>
     <!-- Name of default device theme [CHAR LIMIT=60] -->

res/xml/development_settings.xml

@@ -709,4 +709,15 @@
             android:key="location_indicator_settings"
             settings:controller="com.android.settings.location.LocationIndicatorsPreferenceController"/>
     </PreferenceCategory>
+
+    <PreferenceCategory
+        android:key="input_method_category"
+        android:title="@string/input_method_category"
+        android:order="1400">
+
+        <SwitchPreference
+            android:key="stylus_handwriting"
+            android:title="@string/stylus_handwriting"
+            android:summary="@string/stylus_handwriting_summary" />
+    </PreferenceCategory>
 </PreferenceScreen>

src/com/android/settings/development/DevelopmentSettingsDashboardFragment.java

@@ -582,6 +582,7 @@ public class DevelopmentSettingsDashboardFragment extends RestrictedDashboardFra
                 bluetoothA2dpConfigStore, fragment));
         controllers.add(new SharedDataPreferenceController(context));
         controllers.add(new OverlaySettingsPreferenceController(context));
+        controllers.add(new StylusHandwritingPreferenceController(context));
 
         return controllers;
     }

src/com/android/settings/development/StylusHandwritingPreferenceController.java

@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2022 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.development;
+
+import android.content.Context;
+import android.provider.Settings;
+
+import androidx.preference.Preference;
+import androidx.preference.SwitchPreference;
+
+import com.android.settings.core.PreferenceControllerMixin;
+import com.android.settingslib.development.DeveloperOptionsPreferenceController;
+
+class StylusHandwritingPreferenceController extends DeveloperOptionsPreferenceController
+        implements Preference.OnPreferenceChangeListener, PreferenceControllerMixin {
+
+    static final int SETTING_VALUE_ON = 1;
+    static final int SETTING_VALUE_OFF = 0;
+
+    private static final String STYLUS_HANDWRITING_OPTIONS_KEY = "stylus_handwriting";
+
+    StylusHandwritingPreferenceController(Context context) {
+        super(context);
+    }
+
+    @Override
+    public String getPreferenceKey() {
+        return STYLUS_HANDWRITING_OPTIONS_KEY;
+    }
+
+    @Override
+    public boolean onPreferenceChange(Preference preference, Object newValue) {
+        final boolean isEnabled = (Boolean) newValue;
+        Settings.Global.putInt(mContext.getContentResolver(),
+                Settings.Global.STYLUS_HANDWRITING_ENABLED,
+                isEnabled ? SETTING_VALUE_ON : SETTING_VALUE_OFF);
+
+        return true;
+    }
+
+    @Override
+    public void updateState(Preference preference) {
+        final int enable = Settings.Global.getInt(mContext.getContentResolver(),
+                Settings.Global.STYLUS_HANDWRITING_ENABLED, SETTING_VALUE_OFF);
+        ((SwitchPreference) mPreference).setChecked(enable != SETTING_VALUE_OFF);
+    }
+
+    @Override
+    protected void onDeveloperOptionsSwitchDisabled() {
+        super.onDeveloperOptionsSwitchDisabled();
+        Settings.Global.putInt(mContext.getContentResolver(),
+                Settings.Global.STYLUS_HANDWRITING_ENABLED, SETTING_VALUE_OFF);
+        ((SwitchPreference) mPreference).setChecked(false);
+    }
+}

tests/robotests/src/com/android/settings/development/StylusHandwritingPreferenceControllerTest.java

@@ -0,0 +1,111 @@
+/*
+ * Copyright (C) 2022 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.development;
+
+import static com.android.settings.development.StylusHandwritingPreferenceController.SETTING_VALUE_OFF;
+import static com.android.settings.development.StylusHandwritingPreferenceController.SETTING_VALUE_ON;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import android.content.Context;
+import android.provider.Settings;
+
+import androidx.preference.PreferenceScreen;
+import androidx.preference.SwitchPreference;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.RuntimeEnvironment;
+
+@RunWith(RobolectricTestRunner.class)
+public class StylusHandwritingPreferenceControllerTest {
+
+    @Mock
+    private SwitchPreference mPreference;
+    @Mock
+    private PreferenceScreen mPreferenceScreen;
+
+    private Context mContext;
+    private StylusHandwritingPreferenceController mController;
+
+    @Before
+    public void setup() {
+        MockitoAnnotations.initMocks(this);
+        mContext = RuntimeEnvironment.application;
+        mController = new StylusHandwritingPreferenceController(mContext);
+        when(mPreferenceScreen.findPreference(mController.getPreferenceKey()))
+            .thenReturn(mPreference);
+        mController.displayPreference(mPreferenceScreen);
+    }
+
+    @Test
+    public void onPreferenceChange_settingEnabled_stylusHandwritingShouldBeOn() {
+        mController.onPreferenceChange(mPreference, true /* new value */);
+
+        final int mode = Settings.Global.getInt(mContext.getContentResolver(),
+                Settings.Global.STYLUS_HANDWRITING_ENABLED, -1 /* default */);
+
+        assertThat(mode).isEqualTo(SETTING_VALUE_ON);
+    }
+
+    @Test
+    public void onPreferenceChange_settingEnabled_stylusHandwritingShouldBeOff() {
+        mController.onPreferenceChange(mPreference, false /* new value */);
+
+        final int mode = Settings.Global.getInt(mContext.getContentResolver(),
+                Settings.Global.STYLUS_HANDWRITING_ENABLED, -1 /* default */);
+
+        assertThat(mode).isEqualTo(SETTING_VALUE_OFF);
+    }
+
+    @Test
+    public void updateState_settingDisabled_preferenceShouldNotBeChecked() {
+        Settings.Global.putInt(mContext.getContentResolver(),
+                Settings.Global.STYLUS_HANDWRITING_ENABLED, SETTING_VALUE_OFF);
+        mController.updateState(mPreference);
+
+        verify(mPreference).setChecked(false);
+    }
+
+    @Test
+    public void updateState_settingEnabled_preferenceShouldBeChecked() {
+        Settings.Global.putInt(mContext.getContentResolver(),
+                Settings.Global.STYLUS_HANDWRITING_ENABLED, SETTING_VALUE_ON);
+        mController.updateState(mPreference);
+
+        verify(mPreference).setChecked(true);
+    }
+
+    @Test
+    public void onDeveloperOptionsSwitchDisabled_shouldDisablePreference() {
+        mController.onDeveloperOptionsSwitchDisabled();
+
+        final int mode = Settings.Global.getInt(mContext.getContentResolver(),
+                Settings.Global.STYLUS_HANDWRITING_ENABLED, -1 /* default */);
+
+        assertThat(mode).isEqualTo(SETTING_VALUE_OFF);
+        verify(mPreference).setChecked(false);
+        verify(mPreference).setEnabled(false);
+    }
+}