[Settings] Code refactor - SIM slot UI preference key

Avoid from controlling Preference key separately in different places.

Bug: 261374879
Test: local & auto
Change-Id: I0a777c3f2511a25e8f619deba964bc343183c3cc

src/com/android/settings/deviceinfo/simstatus/SlotSimStatus.java

@@ -0,0 +1,100 @@
+/*
+ * Copyright (C) 2022 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.deviceinfo.simstatus;
+
+import android.content.Context;
+import android.telephony.TelephonyManager;
+import android.telephony.SubscriptionManager;
+import android.util.Log;
+
+/**
+ * A class for showing a summary of status of sim slots.
+ */
+public class SlotSimStatus {
+
+    private static final String TAG = "SlotSimStatus";
+
+    private int mNumberOfSlots;
+    private int mBasePreferenceOrdering;
+
+    private static final String KEY_SIM_STATUS = "sim_status";
+
+    /**
+     * Construct of class.
+     * @param context Context
+     */
+    public SlotSimStatus(Context context) {
+        TelephonyManager telMgr = context.getSystemService(TelephonyManager.class);
+        if (telMgr == null) {
+            return;
+        }
+        mNumberOfSlots = telMgr.getPhoneCount();
+    }
+
+    /**
+     * Set base ordering of Preference.
+     * @param baseOrdering the base ordering for SIM Status within "About Phone".
+     */
+    public void setBasePreferenceOrdering(int baseOrdering) {
+        mBasePreferenceOrdering = baseOrdering;
+    }
+
+    /**
+     * Number of slots available.
+     * @return number of slots
+     */
+    public int size() {
+        return mNumberOfSlots;
+    }
+
+    /**
+     * Get ordering of Preference based on index of slot.
+     * @param slotIndex index of slot
+     * @return Preference ordering.
+     */
+    public int getPreferenceOrdering(int slotIndex) {
+        return mBasePreferenceOrdering + 1 + slotIndex;
+    }
+
+    /**
+     * Get key of Preference and PreferenceController based on index of slot.
+     * @param slotIndex index of slot
+     * @return Preference key.
+     */
+    public String getPreferenceKey(int slotIndex) {
+        if (slotIndex == SubscriptionManager.INVALID_SIM_SLOT_INDEX) {
+            return KEY_SIM_STATUS;
+        }
+        return KEY_SIM_STATUS + (1 + slotIndex);
+    }
+
+    /**
+     * Get slot index based on Preference key
+     * @param prefKey is the preference key
+     * @return slot index.
+     */
+    public int findSlotIndexByKey(String prefKey) {
+        int simSlotIndex = SubscriptionManager.INVALID_SIM_SLOT_INDEX + 1;
+        try {
+            simSlotIndex = Integer.parseInt(prefKey.substring(KEY_SIM_STATUS.length()));
+        } catch (Exception exception) {
+            Log.w(TAG, "Preference key invalid: " + prefKey +
+                       ". Error Msg: " + exception.getMessage());
+        }
+        return simSlotIndex - 1;
+    }
+}