KeyboardLayoutPickerFragment uses DashboardFragment

- Build a controller to generate a list of preferences and add to screen.
- Move some logic to controller.
- Add some test cases for controller.

Test: manual
Test: make RunSettingsRoboTests -j ROBOTEST_FILTER=com.android.settings.inputmethod
      make RunSettingsRoboTests -j ROBOTEST_FILTER=com.android.settings.core
      make RunSettingsRoboTests -j ROBOTEST_FILTER=com.android.settings.dashboard
      atest UniquePreferenceTest
Change-Id: I4ebe486ade3439b9814b11866c402dcf881f21a7

src/com/android/settings/inputmethod/KeyboardLayoutPickerController.java

@@ -0,0 +1,162 @@
+/*
+ * 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.inputmethod;
+
+
+import android.app.Fragment;
+import android.content.Context;
+import android.hardware.input.InputDeviceIdentifier;
+import android.hardware.input.InputManager;
+import android.hardware.input.KeyboardLayout;
+import android.support.v14.preference.SwitchPreference;
+import android.support.v7.preference.Preference;
+import android.support.v7.preference.PreferenceScreen;
+import android.view.InputDevice;
+
+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;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+
+
+public class KeyboardLayoutPickerController extends BasePreferenceController implements
+        InputManager.InputDeviceListener, LifecycleObserver, OnStart, OnStop {
+
+    private final InputManager mIm;
+    private final Map<SwitchPreference, KeyboardLayout> mPreferenceMap;
+
+    private Fragment mParent;
+    private int mInputDeviceId;
+    private InputDeviceIdentifier mInputDeviceIdentifier;
+    private KeyboardLayout[] mKeyboardLayouts;
+    private PreferenceScreen mScreen;
+
+
+    public KeyboardLayoutPickerController(Context context, String key) {
+        super(context, key);
+        mIm = (InputManager) context.getSystemService(Context.INPUT_SERVICE);
+        mInputDeviceId = -1;
+        mPreferenceMap = new HashMap<>();
+    }
+
+    public void initialize(Fragment parent, InputDeviceIdentifier inputDeviceIdentifier) {
+        mParent = parent;
+        mInputDeviceIdentifier = inputDeviceIdentifier;
+        mKeyboardLayouts = mIm.getKeyboardLayoutsForInputDevice(mInputDeviceIdentifier);
+        Arrays.sort(mKeyboardLayouts);
+    }
+
+    @Override
+    public void onStart() {
+        mIm.registerInputDeviceListener(this, null);
+
+        final InputDevice inputDevice =
+                mIm.getInputDeviceByDescriptor(mInputDeviceIdentifier.getDescriptor());
+        if (inputDevice == null) {
+            mParent.getActivity().finish();
+            return;
+        }
+        mInputDeviceId = inputDevice.getId();
+
+        updateCheckedState();
+    }
+
+    @Override
+    public void onStop() {
+        mIm.unregisterInputDeviceListener(this);
+        mInputDeviceId = -1;
+    }
+
+    @Override
+    public void displayPreference(PreferenceScreen screen) {
+        super.displayPreference(screen);
+        mScreen = screen;
+        createPreferenceHierarchy();
+    }
+
+    @Override
+    public int getAvailabilityStatus() {
+        return AVAILABLE;
+    }
+
+    @Override
+    public boolean handlePreferenceTreeClick(Preference preference) {
+        if (!(preference instanceof SwitchPreference)) {
+            return false;
+        }
+
+        final SwitchPreference switchPref = (SwitchPreference) preference;
+        final KeyboardLayout layout = mPreferenceMap.get(switchPref);
+        if (layout != null) {
+            final boolean checked = switchPref.isChecked();
+            if (checked) {
+                mIm.addKeyboardLayoutForInputDevice(mInputDeviceIdentifier,
+                        layout.getDescriptor());
+            } else {
+                mIm.removeKeyboardLayoutForInputDevice(mInputDeviceIdentifier,
+                        layout.getDescriptor());
+            }
+        }
+        return true;
+    }
+
+    @Override
+    public void onInputDeviceAdded(int deviceId) {
+
+    }
+
+    @Override
+    public void onInputDeviceRemoved(int deviceId) {
+        if (mInputDeviceId >= 0 && deviceId == mInputDeviceId) {
+            mParent.getActivity().finish();
+        }
+    }
+
+    @Override
+    public void onInputDeviceChanged(int deviceId) {
+        if (mInputDeviceId >= 0 && deviceId == mInputDeviceId) {
+            updateCheckedState();
+        }
+    }
+
+    private void updateCheckedState() {
+        final String[] enabledKeyboardLayouts = mIm.getEnabledKeyboardLayoutsForInputDevice(
+                mInputDeviceIdentifier);
+        Arrays.sort(enabledKeyboardLayouts);
+
+        for (Map.Entry<SwitchPreference, KeyboardLayout> entry : mPreferenceMap.entrySet()) {
+            entry.getKey().setChecked(Arrays.binarySearch(enabledKeyboardLayouts,
+                    entry.getValue().getDescriptor()) >= 0);
+        }
+    }
+
+    private void createPreferenceHierarchy() {
+        for (KeyboardLayout layout : mKeyboardLayouts) {
+            final SwitchPreference pref = new SwitchPreference(mScreen.getContext());
+            pref.setTitle(layout.getLabel());
+            pref.setSummary(layout.getCollection());
+            pref.setKey(layout.getDescriptor());
+            mScreen.addPreference(pref);
+            mPreferenceMap.put(pref, layout);
+        }
+    }
+}
+