Change Input Settings UI flow.

1. Introduces new UI components as per the new flow
2. Temporarily disables components in the old flow that are to be
   replaced by the new flow. This is done so we can neatly revert
   to the old flow if there are issues with the new flow
3. AvailableVirtualKeyboardActivity now responds to
   android.settings.INPUT_METHOD_SETTINGS intents instead of
   InputMethodAndLanguageSettingsActivity

Bug: 25752812
Change-Id: I728d7ee185827ed328c16cb7abce244557a26518

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

@@ -0,0 +1,116 @@
+/*
+ * Copyright (C) 2016 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.Activity;
+import android.app.admin.DevicePolicyManager;
+import android.content.Context;
+import android.content.res.Configuration;
+import android.os.Bundle;
+import android.support.v7.preference.PreferenceScreen;
+import android.view.inputmethod.InputMethodInfo;
+import android.view.inputmethod.InputMethodManager;
+
+import com.android.settings.R;
+import com.android.settings.InstrumentedFragment;
+import com.android.settings.SettingsPreferenceFragment;
+
+import java.text.Collator;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.List;
+
+public final class AvailableVirtualKeyboardFragment extends SettingsPreferenceFragment
+        implements InputMethodPreference.OnSavePreferenceListener {
+
+    private final ArrayList<InputMethodPreference> mInputMethodPreferenceList = new ArrayList<>();
+    private InputMethodSettingValuesWrapper mInputMethodSettingValues;
+    private InputMethodManager mImm;
+    private DevicePolicyManager mDpm;
+
+    @Override
+    public void onCreatePreferences(Bundle bundle, String s) {
+        Activity activity = getActivity();
+        PreferenceScreen screen = getPreferenceManager().createPreferenceScreen(activity);
+        screen.setTitle(activity.getString(R.string.available_virtual_keyboard_category));
+        setPreferenceScreen(screen);
+        mInputMethodSettingValues = InputMethodSettingValuesWrapper.getInstance(activity);
+        mImm = activity.getSystemService(InputMethodManager.class);
+        mDpm = activity.getSystemService(DevicePolicyManager.class);
+    }
+
+    @Override
+    public void onResume() {
+        super.onResume();
+        // Refresh internal states in mInputMethodSettingValues to keep the latest
+        // "InputMethodInfo"s and "InputMethodSubtype"s
+        mInputMethodSettingValues.refreshAllInputMethodAndSubtypes();
+        updateInputMethodPreferenceViews();
+    }
+
+    @Override
+    public void onSaveInputMethodPreference(final InputMethodPreference pref) {
+        final boolean hasHardwareKeyboard = getResources().getConfiguration().keyboard
+                == Configuration.KEYBOARD_QWERTY;
+        InputMethodAndSubtypeUtil.saveInputMethodSubtypeList(this, getContentResolver(),
+                mImm.getInputMethodList(), hasHardwareKeyboard);
+        // Update input method settings and preference list.
+        mInputMethodSettingValues.refreshAllInputMethodAndSubtypes();
+        for (final InputMethodPreference p : mInputMethodPreferenceList) {
+            p.updatePreferenceViews();
+        }
+    }
+
+    @Override
+    protected int getMetricsCategory() {
+        return InstrumentedFragment.ENABLE_VIRTUAL_KEYBOARDS;
+    }
+
+    private void updateInputMethodPreferenceViews() {
+        mInputMethodSettingValues.refreshAllInputMethodAndSubtypes();
+        // Clear existing "InputMethodPreference"s
+        mInputMethodPreferenceList.clear();
+        List<String> permittedList = mDpm.getPermittedInputMethodsForCurrentUser();
+        final Context context = getPrefContext();
+        final List<InputMethodInfo> imis = mInputMethodSettingValues.getInputMethodList();
+        final int N = (imis == null ? 0 : imis.size());
+        for (int i = 0; i < N; ++i) {
+            final InputMethodInfo imi = imis.get(i);
+            final boolean isAllowedByOrganization = permittedList == null
+                    || permittedList.contains(imi.getPackageName());
+            final InputMethodPreference pref = new InputMethodPreference(
+                    context, imi, true, isAllowedByOrganization, this);
+            mInputMethodPreferenceList.add(pref);
+        }
+        final Collator collator = Collator.getInstance();
+        Collections.sort(mInputMethodPreferenceList, new Comparator<InputMethodPreference>() {
+            @Override
+            public int compare(InputMethodPreference lhs, InputMethodPreference rhs) {
+                return lhs.compareTo(rhs, collator);
+            }
+        });
+        getPreferenceScreen().removeAll();
+        for (int i = 0; i < N; ++i) {
+            final InputMethodPreference pref = mInputMethodPreferenceList.get(i);
+            pref.setOrder(i);
+            getPreferenceScreen().addPreference(pref);
+            InputMethodAndSubtypeUtil.removeUnnecessaryNonPersistentPreference(pref);
+            pref.updatePreferenceViews();
+        }
+    }
+}