Pull out a PreferenceController of lock screen from accessibility

To reduce the complexity of AccessibilitySettings, we are planning to
create a bunch of preference controllers. First of all, we are converting
lock screen preference to a preference controller. The rest part will be
uploaded soon.

Bug: 135056871
Test: robotest, manual
Change-Id: I6079136f3d08934c9a5363eb4d0e0ade29f8ba99

src/com/android/settings/accessibility/LockScreenRotationPreferenceController.java

@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2019 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.accessibility;
+
+import android.content.Context;
+
+import androidx.preference.Preference;
+import androidx.preference.PreferenceScreen;
+
+import com.android.internal.view.RotationPolicy;
+import com.android.internal.view.RotationPolicy.RotationPolicyListener;
+import com.android.settings.core.TogglePreferenceController;
+import com.android.settingslib.core.lifecycle.LifecycleObserver;
+import com.android.settingslib.core.lifecycle.events.OnPause;
+import com.android.settingslib.core.lifecycle.events.OnResume;
+
+public class LockScreenRotationPreferenceController extends TogglePreferenceController implements
+        LifecycleObserver, OnPause, OnResume {
+
+    private Preference mPreference;
+    private RotationPolicyListener mRotationPolicyListener;
+
+    public LockScreenRotationPreferenceController(Context context, String preferenceKey) {
+        super(context, preferenceKey);
+    }
+
+    /**
+     * Returns true if rotation lock is enabled.
+     */
+    @Override
+    public boolean isChecked() {
+        return !RotationPolicy.isRotationLocked(mContext);
+    }
+
+    /**
+     * Enables or disables screen rotation lock from Accessibility settings. If rotation is locked
+     * for accessibility, the toggle in Display settings is hidden to avoid confusion.
+     */
+    @Override
+    public boolean setChecked(boolean isChecked) {
+        RotationPolicy.setRotationLockForAccessibility(mContext, !isChecked);
+        return true;
+    }
+
+    @Override
+    public int getAvailabilityStatus() {
+        return RotationPolicy.isRotationSupported(mContext) ? AVAILABLE : UNSUPPORTED_ON_DEVICE;
+    }
+
+    @Override
+    public void onPause() {
+        if (mRotationPolicyListener != null) {
+            RotationPolicy.unregisterRotationPolicyListener(mContext, mRotationPolicyListener);
+        }
+    }
+
+    @Override
+    public void onResume() {
+        if (mRotationPolicyListener == null) {
+            mRotationPolicyListener = new RotationPolicyListener() {
+                @Override
+                public void onChange() {
+                    if (mPreference != null) {
+                        updateState(mPreference);
+                    }
+                }
+            };
+        }
+        RotationPolicy.registerRotationPolicyListener(mContext, mRotationPolicyListener);
+    }
+
+    @Override
+    public void displayPreference(PreferenceScreen screen) {
+        mPreference = screen.findPreference(getPreferenceKey());
+        super.displayPreference(screen);
+    }
+}