DisplayCutout: Add emulation option to DeveloperSettings

Bug: 65689439
Test: Go to Developer Settings > Toggle "Emulate display with a cutout"
Change-Id: Id3387c026df9868d42e0a7b0d7e623115f41452b

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

@@ -0,0 +1,122 @@
+/*
+ * 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.content.om.IOverlayManager;
+import android.content.om.OverlayInfo;
+import android.os.RemoteException;
+import android.os.ServiceManager;
+import android.os.UserHandle;
+import android.support.annotation.VisibleForTesting;
+import android.support.v7.preference.Preference;
+import android.support.v7.preference.PreferenceScreen;
+import android.support.v7.preference.TwoStatePreference;
+
+import com.android.settings.core.PreferenceControllerMixin;
+import com.android.settingslib.development.DeveloperOptionsPreferenceController;
+
+public class EmulateDisplayCutoutPreferenceController extends
+        DeveloperOptionsPreferenceController implements Preference.OnPreferenceChangeListener,
+        PreferenceControllerMixin {
+
+    private static final String EMULATION_OVERLAY = "com.android.internal.display.cutout.emulation";
+    private static final String KEY = "display_cutout_emulation";
+
+    private final IOverlayManager mOverlayManager;
+    private final boolean mAvailable;
+
+    private TwoStatePreference mPreference;
+
+    @VisibleForTesting
+    EmulateDisplayCutoutPreferenceController(Context context, IOverlayManager overlayManager) {
+        super(context);
+        mOverlayManager = overlayManager;
+        mAvailable = overlayManager != null && getEmulationOverlayInfo() != null;
+    }
+
+    public EmulateDisplayCutoutPreferenceController(Context context) {
+        this(context, IOverlayManager.Stub.asInterface(
+                ServiceManager.getService(Context.OVERLAY_SERVICE)));
+    }
+
+    @Override
+    public boolean isAvailable() {
+        return mAvailable;
+    }
+
+    @Override
+    public String getPreferenceKey() {
+        return KEY;
+    }
+
+    @Override
+    public void displayPreference(PreferenceScreen screen) {
+        super.displayPreference(screen);
+        setPreference((TwoStatePreference) screen.findPreference(getPreferenceKey()));
+    }
+
+    @VisibleForTesting
+    void setPreference(TwoStatePreference preference) {
+        mPreference = preference;
+    }
+
+    @Override
+    public boolean onPreferenceChange(Preference preference, Object newValue) {
+        return writeEnabled((boolean) newValue);
+    }
+
+    private boolean writeEnabled(boolean newValue) {
+        OverlayInfo current = getEmulationOverlayInfo();
+        if (current == null || current.isEnabled() == newValue) {
+            return false;
+        }
+        try {
+            return mOverlayManager.setEnabled(EMULATION_OVERLAY, newValue, UserHandle.USER_SYSTEM);
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
+
+    @Override
+    public void updateState(Preference preference) {
+        OverlayInfo overlayInfo = getEmulationOverlayInfo();
+        mPreference.setChecked(overlayInfo != null && overlayInfo.isEnabled());
+    }
+
+    private OverlayInfo getEmulationOverlayInfo() {
+        OverlayInfo overlayInfo = null;
+        try {
+            overlayInfo = mOverlayManager.getOverlayInfo(EMULATION_OVERLAY, UserHandle.USER_SYSTEM);
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+        return overlayInfo;
+    }
+
+    @Override
+    protected void onDeveloperOptionsSwitchEnabled() {
+        mPreference.setEnabled(true);
+    }
+
+    @Override
+    protected void onDeveloperOptionsSwitchDisabled() {
+        writeEnabled(false);
+        mPreference.setChecked(false);
+        mPreference.setEnabled(false);
+    }
+}