add comments to necessary functions and classes.

Author: johnnzhou

app/src/main/java/com/lcl/lclmeasurementtool/MainActivity.java

@@ -98,7 +98,7 @@ public void onCellularNetworkChanged(boolean isConnected) {
                 Log.e(TAG, "on connection lost");
                 if (!isConnected) {
                     updateSignalStrengthTexts(SignalStrengthLevel.NONE, 0);
-                    updateFAB(isConnected);
+                    updateFAB(false);
                 }
             }
         });

app/src/main/java/com/lcl/lclmeasurementtool/Managers/CellularChangeListener.java

@@ -2,6 +2,15 @@
 
 import com.lcl.lclmeasurementtool.Utils.SignalStrengthLevel;
 
+/**
+ * Listen to the cellular network changes from the device.
+ */
 public interface CellularChangeListener {
+
+    /**
+     * Callback function when the cellular network changes.
+     * @param level  the Signal Strength level.
+     * @param dBm    the signal strength in dBm.
+     */
     void onChange(SignalStrengthLevel level, int dBm);
 }

app/src/main/java/com/lcl/lclmeasurementtool/Managers/LocationServiceManager.java

@@ -91,6 +91,7 @@ public void getLastLocation() {
                     if (task.isSuccessful() && task.getResult() != null) {
                         mLastLocation = task.getResult();
 
+                        // TODO: log the location latitude and longitude
                         Log.i(TAG, String.valueOf(mLastLocation.getLatitude()));
                         Log.i(TAG, String.valueOf(mLastLocation.getLongitude()));
                     } else {

app/src/main/java/com/lcl/lclmeasurementtool/Managers/NetworkChangeListener.java

@@ -1,8 +1,29 @@
 package com.lcl.lclmeasurementtool.Managers;
 
+/**
+ * An interface that listens to the changes in the network status.
+ */
 public interface NetworkChangeListener {
+
+    /**
+     * callback function when the cellular network becomes available.
+     */
     void onAvailable();
+
+    /**
+     * callback function when the cellular network becomes unavailable.
+     */
     void onUnavailable();
+
+    /**
+     * callback function when the cellular network gets lost.
+     */
     void onLost();
+
+    /**
+     * callback function when the cellular network status gets changed.
+     *
+     * @param isConnected boolean parameter indicating whether there is cellular connection.
+     */
     void onCellularNetworkChanged(boolean isConnected);
 }

app/src/main/java/com/lcl/lclmeasurementtool/Managers/NetworkManager.java

@@ -141,6 +141,11 @@ public boolean isCellularConnected() {
                 this.capabilities.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR);
     }
 
+    /**
+     * Retrieve the downstream bandwidth in Kbps
+     *
+     * @return the downstream bandwidth in Kbps as an integer. If no cellular capability, return 0.
+     */
     public int getLinkDownstreamBandwidthKbps() {
         if (this.capabilities != null) {
             return this.capabilities.getLinkDownstreamBandwidthKbps();
@@ -149,6 +154,11 @@ public int getLinkDownstreamBandwidthKbps() {
         return 0;
     }
 
+    /**
+     * Retrieve the upstream bandwidth in Kbps
+     *
+     * @return the upstream bandwidth in Kbps as an integer. If no cellular capability, return 0.
+     */
     public int getLinkUpstreamBandwidthKbps() {
         if (this.capabilities != null) {
             return this.capabilities.getLinkUpstreamBandwidthKbps();

app/src/main/java/com/lcl/lclmeasurementtool/Utils/SignalStrengthLevel.java

@@ -62,6 +62,11 @@ public String toString() {
                 "levelCode=" + levelCode;
     }
 
+    /**
+     * Retrieve the name of the signal strength.
+     *
+     * @return the string representation of the signal strength level.
+     */
     public String getName() {
         switch (this) {
             case NONE:
@@ -81,6 +86,11 @@ public String getName() {
         return "";
     }
 
+    /**
+     * Retrieve the color representation of the signal strength.
+     * @param context the context of the application/activity
+     * @return the color representation of the signal strength.
+     */
     public int getColor(Context context) {
         switch (this) {
             case GREAT:

app/src/main/java/com/lcl/lclmeasurementtool/Utils/UnitUtils.java

@@ -5,6 +5,9 @@
  */
 public class UnitUtils {
 
+    /** the signal strength unit */
     public static final String SIGNAL_STRENGTH_UNIT = "dBm";
+
+    /** the ping test unit */
     public static final String PING_UNIT = "ms";
 }