Add force SmartDark dev setting

Bug: 118348733
Test: toggled it
Change-Id: I43b8ddaada9f8fc0a2a1fb4144fd4a53141bdb2e

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

@@ -445,6 +445,7 @@ public class DevelopmentSettingsDashboardFragment extends RestrictedDashboardFra
         controllers.add(new HardwareLayersUpdatesPreferenceController(context));
         controllers.add(new DebugGpuOverdrawPreferenceController(context));
         controllers.add(new DebugNonRectClipOperationsPreferenceController(context));
+        controllers.add(new ForceDarkPreferenceController(context));
         controllers.add(new ForceMSAAPreferenceController(context));
         controllers.add(new HardwareOverlaysPreferenceController(context));
         controllers.add(new SimulateColorSpacePreferenceController(context));

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

@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2018 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.os.SystemProperties;
+import android.view.ThreadedRenderer;
+
+import androidx.preference.Preference;
+import androidx.preference.SwitchPreference;
+
+import com.android.settings.core.PreferenceControllerMixin;
+import com.android.settingslib.development.DeveloperOptionsPreferenceController;
+import com.android.settingslib.development.SystemPropPoker;
+
+public class ForceDarkPreferenceController extends DeveloperOptionsPreferenceController
+        implements Preference.OnPreferenceChangeListener, PreferenceControllerMixin {
+
+    private static final String HWUI_FORCE_DARK = "hwui_force_dark";
+
+    public ForceDarkPreferenceController(Context context) {
+        super(context);
+    }
+
+    @Override
+    public String getPreferenceKey() {
+        return HWUI_FORCE_DARK;
+    }
+
+    @Override
+    public boolean onPreferenceChange(Preference preference, Object newValue) {
+        final boolean isEnabled = (Boolean) newValue;
+        SystemProperties.set(ThreadedRenderer.DEBUG_FORCE_DARK,
+                isEnabled ? "true" : null);
+        SystemPropPoker.getInstance().poke();
+        return true;
+    }
+
+    @Override
+    public void updateState(Preference preference) {
+        final boolean isEnabled = SystemProperties.getBoolean(
+                ThreadedRenderer.DEBUG_FORCE_DARK, false /* default */);
+        ((SwitchPreference) mPreference).setChecked(isEnabled);
+    }
+
+    @Override
+    protected void onDeveloperOptionsSwitchDisabled() {
+        super.onDeveloperOptionsSwitchDisabled();
+        SystemProperties.set(ThreadedRenderer.DEBUG_FORCE_DARK, null);
+        ((SwitchPreference) mPreference).setChecked(false);
+    }
+}