From 25b270c0f83e96fd33cd5c43dd077bc28905e73b Mon Sep 17 00:00:00 2001
From: Yuxin Hu <yuxinhu@google.com>
Date: Wed, 19 Apr 2023 02:40:13 +0000
Subject: [PATCH] Add developer option switch to set ANGLE as the default
 system driver

This change adds a new developer option switch called
"Enable ANGLE". It defaults to off. User can choose
to toggle it on and off, and the value of the system
property "persist.graphics.egl" is changed accordingly:

switch off: persist.graphics.egl=""
switch on: persist.graphics.egl="angle"

When user toggles the switch, a reboot window is
popped up asking user to reboot now to make the change
takes effect. If user chooses to cancel the reboot,
the switch is toggled back. This enforces that a reboot
is required whenever the "persis.graphics.egl" value
changes.

Upon reboot, we will load either ANGLE or native
GLES driver as the system driver, based on the value of
"persist.graphics.egl".

The switch is disabled if ANGLE is not installed
in /vendor partition. We use the system property
"ro.gfx.angle.supported" as an indicator. We set the
two conditions together in angle.mk file. Any device
mk file that inherits angle.mk file will result in
ANGLE libs installed in /vendor and "ro.gfx.angle.supported"
set to true.

Bug: b/270994705
Test: m; flash and check Pixel 7 boots fine
atest SettingsRoboTests:GraphicsDriverEnableAngleAsSystemDriverControllerTest

Change-Id: I565eff614472bb6ba50742e7dfa49b50dca2809f
---
 res/values/strings.xml                        |   7 +
 res/xml/development_settings.xml              |   5 +
 .../DesktopModePreferenceController.java      |   7 -
 .../DevelopmentSettingsDashboardFragment.java |   2 +
 .../FreeformWindowsPreferenceController.java  |   7 -
 .../RebootConfirmationDialogFragment.java     |  23 ++-
 .../RebootConfirmationDialogHost.java         |  17 +-
 ...erEnableAngleAsSystemDriverController.java | 139 +++++++++++++++
 ...ableAngleAsSystemDriverControllerTest.java | 164 ++++++++++++++++++
 9 files changed, 351 insertions(+), 20 deletions(-)
 create mode 100644 src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverController.java
 create mode 100644 tests/robotests/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverControllerTest.java

diff --git a/res/values/strings.xml b/res/values/strings.xml
index e02d2a75762..10fd86ffc41 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -10440,6 +10440,13 @@
         <item>@string/graphics_driver_app_preference_system</item>
     </string-array>
 
+    <!-- Debugging developer settings: enable angle as system driver? [CHAR LIMIT=50] -->
+    <string name="enable_angle_as_system_driver">Enable ANGLE</string>
+    <!-- Debugging developer settings: enable angle as system driver summary [CHAR LIMIT=NONE] -->
+    <string name="enable_angle_as_system_driver_summary">Enable ANGLE as system OpenGL ES driver</string>
+    <!--Dialog body text used to explain a reboot is required after changing ANGLE as system GLES driver setting-->
+    <string name="reboot_dialog_enable_angle_as_system_driver">A reboot is required to change the system OpenGL ES driver</string>
+
     <!-- Title for App Compatibility Changes dashboard where developers can configure per-app overrides for compatibility changes [CHAR LIMIT=50] -->
     <string name="platform_compat_dashboard_title">App Compatibility Changes</string>
     <!-- Summary for App Compatibility Changes dashboard [CHAR LIMIT=NONE] -->
diff --git a/res/xml/development_settings.xml b/res/xml/development_settings.xml
index b5ce57eb605..eb17fbf0828 100644
--- a/res/xml/development_settings.xml
+++ b/res/xml/development_settings.xml
@@ -243,6 +243,11 @@
             android:title="@string/enable_gpu_debug_layers"
             android:summary="@string/enable_gpu_debug_layers_summary" />
 
+        <SwitchPreference
+            android:key="enable_angle_as_system_driver"
+            android:title="@string/enable_angle_as_system_driver"
+            android:summary="@string/enable_angle_as_system_driver_summary" />
+
         <Preference
             android:key="graphics_driver_dashboard"
             android:title="@string/graphics_driver_dashboard_title"
diff --git a/src/com/android/settings/development/DesktopModePreferenceController.java b/src/com/android/settings/development/DesktopModePreferenceController.java
index 912809c0a56..0e257f69dd6 100644
--- a/src/com/android/settings/development/DesktopModePreferenceController.java
+++ b/src/com/android/settings/development/DesktopModePreferenceController.java
@@ -19,7 +19,6 @@ package com.android.settings.development;
 import static android.provider.Settings.Global.DEVELOPMENT_FORCE_DESKTOP_MODE_ON_EXTERNAL_DISPLAYS;
 
 import android.content.Context;
-import android.content.Intent;
 import android.os.Build;
 import android.provider.Settings;
 
@@ -83,12 +82,6 @@ public class DesktopModePreferenceController extends DeveloperOptionsPreferenceC
         ((SwitchPreference) mPreference).setChecked(false);
     }
 
-    @Override
-    public void onRebootConfirmed() {
-        final Intent intent = new Intent(Intent.ACTION_REBOOT);
-        mContext.startActivity(intent);
-    }
-
     @VisibleForTesting
     String getBuildType() {
         return Build.TYPE;
diff --git a/src/com/android/settings/development/DevelopmentSettingsDashboardFragment.java b/src/com/android/settings/development/DevelopmentSettingsDashboardFragment.java
index 194a13a500b..f8ce97531d6 100644
--- a/src/com/android/settings/development/DevelopmentSettingsDashboardFragment.java
+++ b/src/com/android/settings/development/DevelopmentSettingsDashboardFragment.java
@@ -66,6 +66,7 @@ import com.android.settings.development.bluetooth.BluetoothCodecDialogPreference
 import com.android.settings.development.bluetooth.BluetoothHDAudioPreferenceController;
 import com.android.settings.development.bluetooth.BluetoothQualityDialogPreferenceController;
 import com.android.settings.development.bluetooth.BluetoothSampleRateDialogPreferenceController;
+import com.android.settings.development.graphicsdriver.GraphicsDriverEnableAngleAsSystemDriverController;
 import com.android.settings.development.qstile.DevelopmentTiles;
 import com.android.settings.development.storage.SharedDataPreferenceController;
 import com.android.settings.overlay.FeatureFactory;
@@ -640,6 +641,7 @@ public class DevelopmentSettingsDashboardFragment extends RestrictedDashboardFra
         controllers.add(new SelectDebugAppPreferenceController(context, fragment));
         controllers.add(new WaitForDebuggerPreferenceController(context));
         controllers.add(new EnableGpuDebugLayersPreferenceController(context));
+        controllers.add(new GraphicsDriverEnableAngleAsSystemDriverController(context, fragment));
         controllers.add(new ForcePeakRefreshRatePreferenceController(context));
         controllers.add(new EnableVerboseVendorLoggingPreferenceController(context));
         controllers.add(new VerifyAppsOverUsbPreferenceController(context));
diff --git a/src/com/android/settings/development/FreeformWindowsPreferenceController.java b/src/com/android/settings/development/FreeformWindowsPreferenceController.java
index 47b648565d4..8bb2b1c4feb 100644
--- a/src/com/android/settings/development/FreeformWindowsPreferenceController.java
+++ b/src/com/android/settings/development/FreeformWindowsPreferenceController.java
@@ -17,7 +17,6 @@
 package com.android.settings.development;
 
 import android.content.Context;
-import android.content.Intent;
 import android.os.Build;
 import android.provider.Settings;
 
@@ -81,12 +80,6 @@ public class FreeformWindowsPreferenceController extends DeveloperOptionsPrefere
         ((SwitchPreference) mPreference).setChecked(false);
     }
 
-    @Override
-    public void onRebootConfirmed() {
-        final Intent intent = new Intent(Intent.ACTION_REBOOT);
-        mContext.startActivity(intent);
-    }
-
     @VisibleForTesting
     String getBuildType() {
         return Build.TYPE;
diff --git a/src/com/android/settings/development/RebootConfirmationDialogFragment.java b/src/com/android/settings/development/RebootConfirmationDialogFragment.java
index 84409d1b45a..2fa07476878 100644
--- a/src/com/android/settings/development/RebootConfirmationDialogFragment.java
+++ b/src/com/android/settings/development/RebootConfirmationDialogFragment.java
@@ -37,22 +37,33 @@ public class RebootConfirmationDialogFragment extends InstrumentedDialogFragment
     private static final String TAG = "FreeformPrefRebootDlg";
 
     private final int mMessageId;
+    private final int mCancelButtonId;
     private final RebootConfirmationDialogHost mHost;
 
     /**
      * Show an instance of this dialog.
      */
     public static void show(Fragment fragment, int messageId, RebootConfirmationDialogHost host) {
+        show(fragment, messageId, R.string.reboot_dialog_reboot_later, host);
+    }
+
+    /**
+     * Show an instance of this dialog with cancel button string set as cancelButtonId
+     */
+    public static void show(Fragment fragment, int messageId,
+            int cancelButtonId, RebootConfirmationDialogHost host) {
         final FragmentManager manager = fragment.getActivity().getSupportFragmentManager();
         if (manager.findFragmentByTag(TAG) == null) {
             final RebootConfirmationDialogFragment dialog =
-                    new RebootConfirmationDialogFragment(messageId, host);
+                    new RebootConfirmationDialogFragment(messageId, cancelButtonId, host);
             dialog.show(manager, TAG);
         }
     }
 
-    private RebootConfirmationDialogFragment(int messageId, RebootConfirmationDialogHost host) {
+    private RebootConfirmationDialogFragment(int messageId,
+            int cancelButtonId, RebootConfirmationDialogHost host) {
         mMessageId = messageId;
+        mCancelButtonId = cancelButtonId;
         mHost = host;
     }
 
@@ -66,12 +77,16 @@ public class RebootConfirmationDialogFragment extends InstrumentedDialogFragment
         return new AlertDialog.Builder(getActivity())
                 .setMessage(mMessageId)
                 .setPositiveButton(R.string.reboot_dialog_reboot_now, this)
-                .setNegativeButton(R.string.reboot_dialog_reboot_later, null)
+                .setNegativeButton(mCancelButtonId, this)
                 .create();
     }
 
     @Override
     public void onClick(DialogInterface dialog, int which) {
-        mHost.onRebootConfirmed();
+        if (which == DialogInterface.BUTTON_POSITIVE) {
+            mHost.onRebootConfirmed(getContext());
+        } else {
+            mHost.onRebootCancelled();
+        }
     }
 }
diff --git a/src/com/android/settings/development/RebootConfirmationDialogHost.java b/src/com/android/settings/development/RebootConfirmationDialogHost.java
index 6eb9f2fd111..65ffbed0aa3 100644
--- a/src/com/android/settings/development/RebootConfirmationDialogHost.java
+++ b/src/com/android/settings/development/RebootConfirmationDialogHost.java
@@ -16,13 +16,26 @@
 
 package com.android.settings.development;
 
+import android.content.Context;
+import android.content.Intent;
+
 /**
  * Host of {@link RebootConfirmationDialogFragment} that provides callback when user
  * interacts with the UI.
  */
 public interface RebootConfirmationDialogHost {
     /**
-     * Called when user made a decision on whether to reboot the device.
+     * Called when user made a decision to reboot the device.
      */
-    void onRebootConfirmed();
+    default void onRebootConfirmed(Context context) {
+        // user presses button "Reboot now", reboot the device
+        final Intent intent = new Intent(Intent.ACTION_REBOOT);
+        context.startActivity(intent);
+    }
+
+    /**
+     * Called when user made a decision to cancel the reboot
+     * Default to do nothing
+     */
+    default void onRebootCancelled() {}
 }
diff --git a/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverController.java b/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverController.java
new file mode 100644
index 00000000000..b9f34137111
--- /dev/null
+++ b/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverController.java
@@ -0,0 +1,139 @@
+/*
+ * Copyright (C) 2023 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.graphicsdriver;
+
+import android.content.Context;
+import android.os.GraphicsEnvironment;
+import android.os.SystemProperties;
+import android.text.TextUtils;
+import android.util.Log;
+
+import androidx.annotation.VisibleForTesting;
+import androidx.preference.Preference;
+import androidx.preference.SwitchPreference;
+
+import com.android.settings.R;
+import com.android.settings.core.PreferenceControllerMixin;
+import com.android.settings.development.DevelopmentSettingsDashboardFragment;
+import com.android.settings.development.RebootConfirmationDialogFragment;
+import com.android.settings.development.RebootConfirmationDialogHost;
+import com.android.settingslib.development.DeveloperOptionsPreferenceController;
+
+/**
+ * Controller to handle the events when user toggles this developer option switch: Enable ANGLE
+ */
+public class GraphicsDriverEnableAngleAsSystemDriverController
+        extends DeveloperOptionsPreferenceController
+        implements Preference.OnPreferenceChangeListener,
+                PreferenceControllerMixin,
+                RebootConfirmationDialogHost {
+
+    private static final String TAG = "GraphicsEnableAngleCtrl";
+
+    private static final String ENABLE_ANELE_AS_SYSTEM_DRIVER_KEY = "enable_angle_as_system_driver";
+
+    private final DevelopmentSettingsDashboardFragment mFragment;
+
+    @VisibleForTesting
+    static final String PROPERTY_RO_GFX_ANGLE_SUPPORTED = "ro.gfx.angle.supported";
+
+    @VisibleForTesting
+    static final String PROPERTY_PERSISTENT_GRAPHICS_EGL = "persist.graphics.egl";
+
+    @VisibleForTesting
+    static final String ANGLE_DRIVER_SUFFIX = "angle";
+
+
+    public GraphicsDriverEnableAngleAsSystemDriverController(
+            Context context, DevelopmentSettingsDashboardFragment fragment) {
+        super(context);
+        mFragment = fragment;
+    }
+
+    @Override
+    public String getPreferenceKey() {
+        return ENABLE_ANELE_AS_SYSTEM_DRIVER_KEY;
+    }
+
+    @Override
+    public boolean onPreferenceChange(Preference preference, Object newValue) {
+        final boolean enableAngleAsSystemDriver = (Boolean) newValue;
+        // set "persist.graphics.egl" to "angle" if enableAngleAsSystemDriver is true
+        // set "persist.graphics.egl" to "" if enableAngleAsSystemDriver is false
+        GraphicsEnvironment.getInstance().toggleAngleAsSystemDriver(enableAngleAsSystemDriver);
+        // pop up a window asking user to reboot to make the new "persist.graphics.egl" take effect
+        RebootConfirmationDialogFragment.show(
+                mFragment, R.string.reboot_dialog_enable_angle_as_system_driver,
+                R.string.cancel, this);
+        return true;
+    }
+
+    @Override
+    public void updateState(Preference preference) {
+        // set switch on if "persist.graphics.egl" is "angle" and angle is built in /vendor
+        // set switch off otherwise.
+        final String currentGlesDriver = SystemProperties.get(PROPERTY_PERSISTENT_GRAPHICS_EGL);
+        final boolean isAngle = TextUtils.equals(ANGLE_DRIVER_SUFFIX, currentGlesDriver);
+        final boolean isAngleSupported =
+                TextUtils.equals(SystemProperties.get(PROPERTY_RO_GFX_ANGLE_SUPPORTED), "true");
+        ((SwitchPreference) mPreference).setChecked(isAngle && isAngleSupported);
+        ((SwitchPreference) mPreference).setEnabled(isAngleSupported);
+    }
+
+    @Override
+    protected void onDeveloperOptionsSwitchEnabled() {
+        // only enable the switch if ro.gfx.angle.supported is true
+        // we use ro.gfx.angle.supported to indicate if ANGLE libs are installed under /vendor
+        final boolean isAngleSupported =
+                TextUtils.equals(SystemProperties.get(PROPERTY_RO_GFX_ANGLE_SUPPORTED), "true");
+        ((SwitchPreference) mPreference).setEnabled(isAngleSupported);
+    }
+
+    @Override
+    protected void onDeveloperOptionsSwitchDisabled() {
+        // 1) set the persist.graphics.egl empty string
+        GraphicsEnvironment.getInstance().toggleAngleAsSystemDriver(false);
+        // 2) reset the switch
+        ((SwitchPreference) mPreference).setChecked(false);
+        // 3) disable switch
+        ((SwitchPreference) mPreference).setEnabled(false);
+    }
+
+    @Override
+    public void onRebootCancelled() {
+        // if user presses button "Cancel", do not reboot the device, and toggles switch back
+        final String currentGlesDriver = SystemProperties.get(PROPERTY_PERSISTENT_GRAPHICS_EGL);
+        if (TextUtils.equals(ANGLE_DRIVER_SUFFIX, currentGlesDriver)) {
+            // if persist.graphics.egl = "angle", set the property value back to ""
+            GraphicsEnvironment.getInstance().toggleAngleAsSystemDriver(false);
+            // toggle switch off
+            ((SwitchPreference) mPreference).setChecked(false);
+            return;
+        }
+
+        if (TextUtils.isEmpty(currentGlesDriver)) {
+            // if persist.graphicx.egl = "", set the persist.graphics.egl back to "angle"
+            GraphicsEnvironment.getInstance().toggleAngleAsSystemDriver(true);
+            // toggle switch on
+            ((SwitchPreference) mPreference).setChecked(true);
+            return;
+        }
+
+        // if persist.graphics.egl holds values other than the above two, log error message
+        Log.e(TAG, "Invalid persist.graphics.egl property value");
+    }
+}
diff --git a/tests/robotests/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverControllerTest.java b/tests/robotests/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverControllerTest.java
new file mode 100644
index 00000000000..314f8c38091
--- /dev/null
+++ b/tests/robotests/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverControllerTest.java
@@ -0,0 +1,164 @@
+/*
+ * Copyright 2023 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.graphicsdriver;
+
+import static com.android.settings.development.graphicsdriver.GraphicsDriverEnableAngleAsSystemDriverController.ANGLE_DRIVER_SUFFIX;
+import static com.android.settings.development.graphicsdriver.GraphicsDriverEnableAngleAsSystemDriverController.PROPERTY_PERSISTENT_GRAPHICS_EGL;
+import static com.android.settings.development.graphicsdriver.GraphicsDriverEnableAngleAsSystemDriverController.PROPERTY_RO_GFX_ANGLE_SUPPORTED;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.any;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import android.content.Context;
+import android.os.SystemProperties;
+
+import androidx.fragment.app.FragmentActivity;
+import androidx.fragment.app.FragmentManager;
+import androidx.fragment.app.FragmentTransaction;
+import androidx.preference.PreferenceScreen;
+import androidx.preference.SwitchPreference;
+
+import com.android.settings.development.DevelopmentSettingsDashboardFragment;
+import com.android.settings.development.RebootConfirmationDialogFragment;
+
+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;
+import org.robolectric.shadows.ShadowSystemProperties;
+
+@RunWith(RobolectricTestRunner.class)
+public class GraphicsDriverEnableAngleAsSystemDriverControllerTest {
+    private static final String TAG = "GraphicsDriverEnableAngleAsSystemDriverControllerTest";
+    @Mock private PreferenceScreen mScreen;
+    @Mock private SwitchPreference mPreference;
+    @Mock private DevelopmentSettingsDashboardFragment mFragment;
+    @Mock private FragmentActivity mActivity;
+    @Mock private FragmentManager mFragmentManager;
+    @Mock private FragmentTransaction mTransaction;
+
+    private GraphicsDriverEnableAngleAsSystemDriverController mController;
+
+    private Context mContext;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        mContext = RuntimeEnvironment.application;
+        doReturn(mTransaction).when(mFragmentManager).beginTransaction();
+        doReturn(mFragmentManager).when(mActivity).getSupportFragmentManager();
+        doReturn(mActivity).when(mFragment).getActivity();
+        mController = new GraphicsDriverEnableAngleAsSystemDriverController(mContext, mFragment);
+        when(mScreen.findPreference(mController.getPreferenceKey())).thenReturn(mPreference);
+        mController.displayPreference(mScreen);
+    }
+
+    @Test
+    public void onPreferenceChange_switchOn_shouldEnableAngleAsSystemDriver() {
+        ShadowSystemProperties.override(PROPERTY_RO_GFX_ANGLE_SUPPORTED, "true");
+        // since GraphicsEnvironment is mocked in Robolectric test environment,
+        // we will override the system property persist.graphics.egl as if it is changed by
+        // mGraphicsEnvironment.toggleAngleAsSystemDriver(true).
+        // TODO: b/270994705 yuxinhu:
+        // add test coverage to test mGraphicsEnvironment.toggleAngleAsSystemDriver()
+        // works properly on Android devices / emulators.
+        ShadowSystemProperties.override(PROPERTY_PERSISTENT_GRAPHICS_EGL, ANGLE_DRIVER_SUFFIX);
+        mController.onPreferenceChange(mPreference, true);
+        final String systemEGLDriver = SystemProperties.get(PROPERTY_PERSISTENT_GRAPHICS_EGL);
+        assertThat(systemEGLDriver).isEqualTo(ANGLE_DRIVER_SUFFIX); // empty
+        verify(mTransaction).add(any(RebootConfirmationDialogFragment.class), any());
+    }
+
+    @Test
+    public void onPreferenceChange_switchOff_shouldDisableAngleAsSystemDriver() {
+        ShadowSystemProperties.override(PROPERTY_RO_GFX_ANGLE_SUPPORTED, "true");
+        // since GraphicsEnvironment is mocked in Robolectric test environment,
+        // we will override the system property persist.graphics.egl as if it is changed by
+        // mGraphicsEnvironment.toggleAngleAsSystemDriver(false).
+        // TODO: b/270994705 yuxinhu:
+        // add test coverage to test mGraphicsEnvironment.toggleAngleAsSystemDriver()
+        // works properly on Android devices / emulators.
+        ShadowSystemProperties.override(PROPERTY_PERSISTENT_GRAPHICS_EGL, "");
+        mController.onPreferenceChange(mPreference, false);
+        final String systemEGLDriver = SystemProperties.get(PROPERTY_PERSISTENT_GRAPHICS_EGL);
+        assertThat(systemEGLDriver).isEqualTo("");
+        verify(mTransaction).add(any(RebootConfirmationDialogFragment.class), any());
+    }
+
+    @Test
+    public void updateState_angleNotSupported_preferenceShouldNotBeChecked() {
+        ShadowSystemProperties.override(PROPERTY_RO_GFX_ANGLE_SUPPORTED, "");
+        mController.updateState(mPreference);
+        verify(mPreference).setChecked(false);
+    }
+
+    @Test
+    public void updateState_angleNotSupported_preferenceShouldNotBeEnabled() {
+        ShadowSystemProperties.override(PROPERTY_RO_GFX_ANGLE_SUPPORTED, "");
+        mController.updateState(mPreference);
+        verify(mPreference).setEnabled(false);
+    }
+
+    @Test
+    public void updateState_angleSupported_angleUsed_preferenceShouldBeChecked() {
+        ShadowSystemProperties.override(PROPERTY_RO_GFX_ANGLE_SUPPORTED, "true");
+        // TODO: b/270994705 yuxinhu:
+        // add test coverage to test mGraphicsEnvironment.toggleAngleAsSystemDriver()
+        // works properly on Android devices / emulators.
+        ShadowSystemProperties.override(PROPERTY_PERSISTENT_GRAPHICS_EGL, ANGLE_DRIVER_SUFFIX);
+        mController.updateState(mPreference);
+        verify(mPreference).setChecked(true); //false
+    }
+
+    @Test
+    public void updateState_angleSupported_angleNotUsed_preferenceShouldNotBeChecked() {
+        ShadowSystemProperties.override(PROPERTY_RO_GFX_ANGLE_SUPPORTED, "true");
+        // TODO: b/270994705 yuxinhu:
+        // add test coverage to test mGraphicsEnvironment.toggleAngleAsSystemDriver(false)
+        // works properly on Android devices / emulators.
+        ShadowSystemProperties.override(PROPERTY_PERSISTENT_GRAPHICS_EGL, "");
+        mController.updateState(mPreference);
+        verify(mPreference).setChecked(false);
+    }
+
+    @Test
+    public void onDeveloperOptionSwitchDisabled_shouldDisableAngleAsSystemDriver() {
+        mController.onDeveloperOptionsSwitchDisabled();
+        final String systemEGLDriver = SystemProperties.get(PROPERTY_PERSISTENT_GRAPHICS_EGL);
+        assertThat(systemEGLDriver).isEqualTo("");
+    }
+
+    @Test
+    public void onDeveloperOptionSwitchDisabled_preferenceShouldNotBeChecked() {
+        mController.onDeveloperOptionsSwitchDisabled();
+        verify(mPreference).setChecked(false);
+    }
+
+    @Test
+    public void onDeveloperOptionsSwitchDisabled_preferenceShouldNotBeEnabled() {
+        mController.onDeveloperOptionsSwitchDisabled();
+        verify(mPreference).setEnabled(false);
+    }
+}