Display warning if users does not provide CA cert in EAP config

Display an explicit warning in the WiFi configuration menu if
the user selects the option to not validate the EAP server (i.e.
does not provide a CA certificate) in an EAP configuration.

BUG: 26686071
Change-Id: I73620b60defdcf40865f8c67d5de24b5dad636f8
TEST: Warning appears when the abovementioned option is selected.

res/layout/wifi_dialog.xml

@@ -145,6 +145,18 @@
                             android:prompt="@string/wifi_eap_ca_cert" />
                 </LinearLayout>
 
+                <LinearLayout android:id="@+id/no_ca_cert_warning"
+                        android:layout_width="match_parent"
+                        android:layout_height="wrap_content"
+                        android:visibility="gone"
+                        style="@style/wifi_item" >
+                    <TextView
+                            android:layout_width="wrap_content"
+                            android:layout_height="wrap_content"
+                            style="@style/wifi_item_warning"
+                            android:text="@string/wifi_do_not_validate_eap_server_warning" />
+                </LinearLayout>
+
                 <LinearLayout android:id="@+id/l_user_cert"
                         android:layout_width="match_parent"
                         android:layout_height="wrap_content"

res/values/strings.xml

@@ -1588,6 +1588,8 @@
     <string name="wifi_do_not_provide_eap_user_cert">Do not provide</string>
     <!-- Menu option for not validating the EAP server -->
     <string name="wifi_do_not_validate_eap_server">Do not validate</string>
+    <!-- Warning message displayed if user choses not to validate the EAP server -->
+    <string name="wifi_do_not_validate_eap_server_warning">No certificate specified. Your connection will not be private.</string>
     <!-- Substring of status line when Wi-Fi Protected Setup (WPS) is available and
          string is listed first [CHAR LIMIT=20]-->
     <string name="wifi_wps_available_first_item">WPS available</string>

res/values/styles.xml

@@ -204,6 +204,14 @@
         <item name="android:textColor">?android:attr/textColorSecondary</item>
     </style>
 
+    <style name="wifi_item_warning">
+        <item name="android:paddingStart">8dip</item>
+        <item name="android:textSize">12sp</item>
+        <item name="android:textAlignment">viewStart</item>
+        <item name="android:textAppearance">@android:style/TextAppearance.Material.Body1</item>
+        <item name="android:textColor">@color/warning</item>
+    </style>
+
     <style name="wifi_item_content">
         <item name="android:textAlignment">viewStart</item>
         <item name="android:textAppearance">@android:style/TextAppearance.Material.Subhead</item>

src/com/android/settings/wifi/WifiConfigController.java

@@ -393,6 +393,18 @@ public class WifiConfigController
         submit.setEnabled(enabled);
     }
 
+    void showWarningMessageIfAppropriate() {
+        mView.findViewById(R.id.no_ca_cert_warning).setVisibility(View.GONE);
+        if (mEapCaCertSpinner != null
+                && mView.findViewById(R.id.l_ca_cert).getVisibility() != View.GONE
+                && ((String) mEapCaCertSpinner.getSelectedItem())
+                       .equals(mDoNotValidateEapServerString)) {
+            // Display warning if user chooses not to validate the EAP server with a user-supplied
+            // CA certificate in an EAP network configuration.
+            mView.findViewById(R.id.no_ca_cert_warning).setVisibility(View.VISIBLE);
+        }
+    }
+
     /* package */ WifiConfiguration getConfig() {
         if (!mEdit) {
             return null;
@@ -1077,6 +1089,7 @@ public class WifiConfigController
         } else {
             showIpConfigFields();
         }
+        showWarningMessageIfAppropriate();
         enableSubmitIfAppropriate();
     }