Add debug property to safe guard ANGLE developer option UI.

Add a debug property to guard ANGLE developer option UI, only when the
debug property is enabled will ANGLE developer option UI be enabled.

Add further clarification in the text to indicate that this is an
experimental feature.

Bug: b/287909344
Test: atest -c GraphicsDriverEnableAngleAsSystemDriverControllerJUnitTest
Test: atest -c GraphicsDriverEnableAngleAsSystemDriverControllerTest
Change-Id: Ife31f4b0426f3ce107f86cfbaf3f1aeca567e250
diff --git a/res/values/strings.xml b/res/values/strings.xml
index f8b770f..4b8c39e 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -10618,9 +10618,9 @@
     </string-array>
 
     <!-- Debugging developer settings: enable angle as system driver? [CHAR LIMIT=50] -->
-    <string name="enable_angle_as_system_driver">Enable ANGLE</string>
+    <string name="enable_angle_as_system_driver">Experimental: 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 default OpenGL ES driver. Enabling it on incompatible devices may break some applications.</string>
+    <string name="enable_angle_as_system_driver_summary">Warning: Enable ANGLE as default OpenGL ES driver. This feature is in experiment and may not be compatible with some camera and video apps.</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>
 
diff --git a/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverController.java b/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverController.java
index b3af95e..95cf64c 100644
--- a/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverController.java
+++ b/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverController.java
@@ -57,6 +57,10 @@
     @VisibleForTesting
     static final String PROPERTY_PERSISTENT_GRAPHICS_EGL = "persist.graphics.egl";
 
+    @VisibleForTesting
+    static final String PROPERTY_DEBUG_ANGLE_DEVELOPER_OPTION =
+            "debug.graphics.angle.developeroption.enable";
+
     @VisibleForTesting static final String ANGLE_DRIVER_SUFFIX = "angle";
 
     @VisibleForTesting
@@ -72,6 +76,11 @@
                 public void set(String key, String val) {
                     SystemProperties.set(key, val);
                 }
+
+                @Override
+                public boolean getBoolean(String key, boolean def) {
+                    return SystemProperties.getBoolean(key, def);
+                }
             };
         }
     }
@@ -81,6 +90,13 @@
         this(context, fragment, new Injector());
     }
 
+    // Return true if the ANGLE developer option entry point is enabled.
+    // This can be enabled by calling:
+    //     `adb shell setprop debug.graphics.angle.developeroption.enable true`
+    private boolean isAngleDeveloperOptionEnabled() {
+        return mSystemProperties.getBoolean(PROPERTY_DEBUG_ANGLE_DEVELOPER_OPTION, false);
+    }
+
     private boolean isAngleSupported() {
         return TextUtils.equals(
                         mSystemProperties.get(PROPERTY_RO_GFX_ANGLE_SUPPORTED, ""), "true");
@@ -96,6 +112,10 @@
         // Exception is when user chooses to reboot now, the switch should keep its current value
         // and persist its' state over reboot.
         mShouldToggleSwitchBackOnRebootDialogDismiss = true;
+        final String persistGraphicsEglValue =
+                mSystemProperties.get(PROPERTY_PERSISTENT_GRAPHICS_EGL, "");
+        Log.v(TAG, "Value of " + PROPERTY_PERSISTENT_GRAPHICS_EGL + " is: "
+                + persistGraphicsEglValue);
     }
 
     @Override
@@ -149,6 +169,12 @@
             mPreference.setEnabled(false);
             ((SwitchPreference) mPreference).setChecked(false);
         }
+
+        // Regardless of whether ANGLE is enabled, disable the developer option UI
+        // as long as UI is not enabled via debug property.
+        if (!isAngleDeveloperOptionEnabled()) {
+            mPreference.setEnabled(false);
+        }
     }
 
     @Override
diff --git a/src/com/android/settings/development/graphicsdriver/GraphicsDriverSystemPropertiesWrapper.java b/src/com/android/settings/development/graphicsdriver/GraphicsDriverSystemPropertiesWrapper.java
index 549cd81..9684282 100644
--- a/src/com/android/settings/development/graphicsdriver/GraphicsDriverSystemPropertiesWrapper.java
+++ b/src/com/android/settings/development/graphicsdriver/GraphicsDriverSystemPropertiesWrapper.java
@@ -41,4 +41,13 @@
      * SELinux. libc will log the underlying reason.
      */
     void set(@NonNull String key, @Nullable String val);
+
+    /**
+     * Get the boolean value for the given {@code key}.
+     *
+     * @param key the key to lookup
+     * @param def the default value in case the property is not set or empty
+     * @return if the {@code key} isn't found, return {@code def}.
+     */
+    boolean getBoolean(@NonNull String key, @NonNull boolean def);
 }
diff --git a/tests/robotests/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverControllerTest.java b/tests/robotests/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverControllerTest.java
index 9210b87..249acf5 100644
--- a/tests/robotests/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverControllerTest.java
+++ b/tests/robotests/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverControllerTest.java
@@ -17,6 +17,7 @@
 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_DEBUG_ANGLE_DEVELOPER_OPTION;
 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;
 
@@ -67,6 +68,7 @@
     public void setUp() {
         MockitoAnnotations.initMocks(this);
         mContext = RuntimeEnvironment.application;
+        ShadowSystemProperties.override(PROPERTY_DEBUG_ANGLE_DEVELOPER_OPTION, "true");
         doReturn(mTransaction).when(mFragmentManager).beginTransaction();
         doReturn(mFragmentManager).when(mActivity).getSupportFragmentManager();
         doReturn(mActivity).when(mFragment).getActivity();
diff --git a/tests/unit/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverControllerJUnitTest.java b/tests/unit/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverControllerJUnitTest.java
index ae35431..4aa38ae 100644
--- a/tests/unit/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverControllerJUnitTest.java
+++ b/tests/unit/src/com/android/settings/development/graphicsdriver/GraphicsDriverEnableAngleAsSystemDriverControllerJUnitTest.java
@@ -18,12 +18,14 @@
 
 import static com.android.settings.development.graphicsdriver.GraphicsDriverEnableAngleAsSystemDriverController.ANGLE_DRIVER_SUFFIX;
 import static com.android.settings.development.graphicsdriver.GraphicsDriverEnableAngleAsSystemDriverController.Injector;
+import static com.android.settings.development.graphicsdriver.GraphicsDriverEnableAngleAsSystemDriverController.PROPERTY_DEBUG_ANGLE_DEVELOPER_OPTION;
 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.ArgumentMatchers.anyBoolean;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.when;
 
@@ -98,6 +100,8 @@
         }
 
         mContext = ApplicationProvider.getApplicationContext();
+        when(mSystemPropertiesMock.getBoolean(eq(PROPERTY_DEBUG_ANGLE_DEVELOPER_OPTION),
+                                              anyBoolean())).thenReturn(true);
 
         // Construct a GraphicsDriverEnableAngleAsSystemDriverController with two Overrides:
         // 1) Override the mSystemProperties with mSystemPropertiesMock,