Base implementation of WFC disclaimer UI

Test: manual - Check that no error occurred when changing the wifi
calling settings to turn on.
Test: auto - Passed WifiCallingSettingsForSubTest,
WifiCallingDisclaimerFragmentTest and DisclaimerItemListAdapterTest.
Bug: 67872298

Change-Id: I789f530d3e16baa6e56feaa4269f6696976f747e
Merged-In: I789f530d3e16baa6e56feaa4269f6696976f747e

src/com/android/settings/wifi/calling/DisclaimerItem.java

@@ -0,0 +1,137 @@
+/*
+ * 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.wifi.calling;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.os.PersistableBundle;
+import android.telephony.CarrierConfigManager;
+import android.util.Log;
+
+import com.android.internal.annotations.VisibleForTesting;
+
+/**
+ * Interface to control disclaimer item from {@link WifiCallingDisclaimerFragment}.
+ */
+@VisibleForTesting
+public abstract class DisclaimerItem {
+    private static final String SHARED_PREFERENCES_NAME = "wfc_disclaimer_prefs";
+
+    protected final Context mContext;
+    protected final int mSubId;
+    private final CarrierConfigManager mCarrierConfigManager;
+
+    DisclaimerItem(Context context, int subId) {
+        mContext = context;
+        mSubId = subId;
+        mCarrierConfigManager = mContext.getSystemService(CarrierConfigManager.class);
+    }
+
+    /**
+     * Called by the {@link WifiCallingDisclaimerFragment} when a user has clicked the agree button.
+     */
+    void onAgreed() {
+        setBooleanSharedPrefs(getPrefKey(), true);
+    }
+
+    /**
+     * Checks whether the disclaimer item need to be displayed or not.
+     *
+     * @return Returns {@code true} if disclaimer item need to be displayed,
+     * {@code false} if not displayed.
+     */
+    boolean shouldShow() {
+        if (getBooleanSharedPrefs(getPrefKey(), false)) {
+            logd("shouldShow: false due to a user has already agreed.");
+            return false;
+        }
+        logd("shouldShow: true");
+        return true;
+    }
+
+    /**
+     * Gets the configuration values for a particular sub id.
+     *
+     * @return The {@link PersistableBundle} instance containing the config value for a
+     * particular phone id, or default values.
+     */
+    protected PersistableBundle getCarrierConfig() {
+        PersistableBundle config = mCarrierConfigManager.getConfigForSubId(mSubId);
+        if (config != null) {
+            return config;
+        }
+        // Return static default defined in CarrierConfigManager.
+        return CarrierConfigManager.getDefaultConfig();
+    }
+
+    protected void logd(String msg) {
+        Log.d(getName(), "[" + mSubId +  "] " + msg);
+    }
+
+    /**
+     * Gets a title id for disclaimer item.
+     *
+     * @return Title id for disclaimer item.
+     */
+    protected abstract int getTitleId();
+
+    /**
+     * Gets a message id for disclaimer item.
+     *
+     * @return Message id for disclaimer item.
+     */
+    protected abstract int getMessageId();
+
+    /**
+     * Gets a name of disclaimer item.
+     *
+     * @return Name of disclaimer item.
+     */
+    protected abstract String getName();
+
+    /**
+     * Gets a preference key to keep user's consent.
+     *
+     * @return Preference key to keep user's consent.
+     */
+    protected abstract String getPrefKey();
+
+    /**
+     * Gets the boolean value from shared preferences.
+     *
+     * @param key The key for the preference item.
+     * @param defValue Value to return if this preference does not exist.
+     * @return The boolean value of corresponding key, or defValue.
+     */
+    private boolean getBooleanSharedPrefs(String key, boolean defValue) {
+        SharedPreferences prefs = mContext.getSharedPreferences(SHARED_PREFERENCES_NAME,
+                Context.MODE_PRIVATE);
+        return prefs.getBoolean(key + mSubId, defValue);
+    }
+
+    /**
+     * Sets the boolean value to shared preferences.
+     *
+     * @param key The key for the preference item.
+     * @param value The value to be set for shared preferences.
+     */
+    private void setBooleanSharedPrefs(String key, boolean value) {
+        SharedPreferences prefs = mContext.getSharedPreferences(SHARED_PREFERENCES_NAME,
+                Context.MODE_PRIVATE);
+        prefs.edit().putBoolean(key + mSubId, value).apply();
+    }
+}