Convert VibrationSettings to DashboardFragment.

- DashboardFragment integrates Slices and settings search better than
  SettingsPreferenceFragment, and is more testable.

Test: robotests
Change-Id: I5f73836f94712c03521eac6b3f67964524381078

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

@@ -0,0 +1,114 @@
+/*
+ * 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.accessibility;
+
+import android.content.Context;
+import android.database.ContentObserver;
+import android.net.Uri;
+import android.os.Handler;
+import android.os.Looper;
+import android.os.Vibrator;
+import android.provider.Settings;
+import android.support.v7.preference.Preference;
+import android.support.v7.preference.PreferenceScreen;
+
+import com.android.settings.R;
+import com.android.settings.core.BasePreferenceController;
+import com.android.settingslib.core.lifecycle.LifecycleObserver;
+import com.android.settingslib.core.lifecycle.events.OnStart;
+import com.android.settingslib.core.lifecycle.events.OnStop;
+
+public abstract class VibrationIntensityPreferenceController extends BasePreferenceController
+        implements LifecycleObserver, OnStart, OnStop {
+
+    protected final Vibrator mVibrator;
+    private final SettingObserver mSettingsContentObserver;
+    private final String mSettingKey;
+
+    private Preference mPreference;
+
+    public VibrationIntensityPreferenceController(Context context, String prefkey,
+            String settingKey) {
+        super(context, prefkey);
+        mVibrator = mContext.getSystemService(Vibrator.class);
+        mSettingKey = settingKey;
+        mSettingsContentObserver = new SettingObserver(settingKey) {
+            @Override
+            public void onChange(boolean selfChange, Uri uri) {
+                updateState(null);
+            }
+        };
+    }
+
+    @Override
+    public void onStart() {
+        mContext.getContentResolver().registerContentObserver(
+                mSettingsContentObserver.uri,
+                false /* notifyForDescendants */,
+                mSettingsContentObserver);
+    }
+
+    @Override
+    public void onStop() {
+        mContext.getContentResolver().unregisterContentObserver(mSettingsContentObserver);
+    }
+
+    @Override
+    public void displayPreference(PreferenceScreen screen) {
+        super.displayPreference(screen);
+        mPreference = screen.findPreference(getPreferenceKey());
+    }
+
+    @Override
+    public void updateState(Preference preference) {
+        if (mPreference == null) {
+            return;
+        }
+        mPreference.setSummary(getSummary());
+    }
+
+    @Override
+    public String getSummary() {
+        final int intensity = Settings.System.getInt(mContext.getContentResolver(),
+                mSettingKey, getDefaultIntensity());
+
+        switch (intensity) {
+            case Vibrator.VIBRATION_INTENSITY_OFF:
+                return mContext.getString(R.string.accessibility_vibration_intensity_off);
+            case Vibrator.VIBRATION_INTENSITY_LOW:
+                return mContext.getString(R.string.accessibility_vibration_intensity_low);
+            case Vibrator.VIBRATION_INTENSITY_MEDIUM:
+                return mContext.getString(R.string.accessibility_vibration_intensity_medium);
+            case Vibrator.VIBRATION_INTENSITY_HIGH:
+                return mContext.getString(R.string.accessibility_vibration_intensity_high);
+            default:
+                return "";
+        }
+    }
+
+    protected abstract int getDefaultIntensity();
+
+    private static class SettingObserver extends ContentObserver {
+
+        public final Uri uri;
+
+        public SettingObserver(String settingKey) {
+            super(new Handler(Looper.getMainLooper()));
+            uri = Settings.System.getUriFor(settingKey);
+        }
+    }
+}