Add config for Wi-Fi Hotspot Settings hidden

- Add config_show_wifi_hotspot_settings for Settings customization

- Hide Wi-Fi Hotspot preference in Hotspot & tethering Settings

- Don't launch Wi-Fi Hotspot Settings (e.g long press on Hotspot in QS-tile)

Bug: 213426762
Test: manual test
atest -c com.android.settings.wifi.WifiUtilsTest
make RunSettingsRoboTests ROBOTEST_FILTER=WifiTetherPreferenceControllerTest
make RunSettingsRoboTests ROBOTEST_FILTER=WifiTetherSettingsTest

Merged-In: I11f88d0d15d6d5c2766b64b5847ac31ed0f34c25
Change-Id: I11f88d0d15d6d5c2766b64b5847ac31ed0f34c25
(cherry picked from commit 160b5078ed)

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

@@ -22,14 +22,20 @@ import android.content.ContentResolver;
 import android.content.Context;
 import android.content.pm.PackageManager;
 import android.net.NetworkCapabilities;
+import android.net.TetheringManager;
 import android.net.wifi.ScanResult;
 import android.net.wifi.SoftApConfiguration;
 import android.net.wifi.WifiConfiguration;
+import android.net.wifi.WifiManager;
 import android.os.UserHandle;
 import android.os.UserManager;
 import android.provider.Settings;
 import android.text.TextUtils;
+import android.util.Log;
 
+import androidx.annotation.VisibleForTesting;
+
+import com.android.settings.R;
 import com.android.settings.Utils;
 import com.android.wifitrackerlib.WifiEntry;
 
@@ -38,12 +44,16 @@ import java.nio.charset.StandardCharsets;
 /** A utility class for Wi-Fi functions. */
 public class WifiUtils extends com.android.settingslib.wifi.WifiUtils {
 
+    static final String TAG = "WifiUtils";
+
     private static final int SSID_ASCII_MIN_LENGTH = 1;
     private static final int SSID_ASCII_MAX_LENGTH = 32;
 
     private static final int PSK_PASSPHRASE_ASCII_MIN_LENGTH = 8;
     private static final int PSK_PASSPHRASE_ASCII_MAX_LENGTH = 63;
 
+    private static Boolean sCanShowWifiHotspotCached;
+
     public static boolean isSSIDTooLong(String ssid) {
         if (TextUtils.isEmpty(ssid)) {
             return false;
@@ -240,4 +250,62 @@ public class WifiUtils extends com.android.settingslib.wifi.WifiUtils {
 
         return WifiEntry.SECURITY_NONE;
     }
+
+    /**
+     * Check if Wi-Fi hotspot settings can be displayed.
+     *
+     * @param context Context of caller
+     * @return true if Wi-Fi hotspot settings can be displayed
+     */
+    public static boolean checkShowWifiHotspot(Context context) {
+        if (context == null) return false;
+
+        boolean showWifiHotspotSettings =
+                context.getResources().getBoolean(R.bool.config_show_wifi_hotspot_settings);
+        if (!showWifiHotspotSettings) {
+            Log.w(TAG, "config_show_wifi_hotspot_settings:false");
+            return false;
+        }
+
+        WifiManager wifiManager = context.getSystemService(WifiManager.class);
+        if (wifiManager == null) {
+            Log.e(TAG, "WifiManager is null");
+            return false;
+        }
+
+        TetheringManager tetheringManager = context.getSystemService(TetheringManager.class);
+        if (tetheringManager == null) {
+            Log.e(TAG, "TetheringManager is null");
+            return false;
+        }
+        String[] wifiRegexs = tetheringManager.getTetherableWifiRegexs();
+        if (wifiRegexs == null || wifiRegexs.length == 0) {
+            Log.w(TAG, "TetherableWifiRegexs is empty");
+            return false;
+        }
+        return true;
+    }
+
+    /**
+     * Return the cached result to see if Wi-Fi hotspot settings can be displayed.
+     *
+     * @param context Context of caller
+     * @return true if Wi-Fi hotspot settings can be displayed
+     */
+    public static boolean canShowWifiHotspot(Context context) {
+        if (sCanShowWifiHotspotCached == null) {
+            sCanShowWifiHotspotCached = checkShowWifiHotspot(context);
+        }
+        return sCanShowWifiHotspotCached;
+    }
+
+    /**
+     * Sets the sCanShowWifiHotspotCached for testing purposes.
+     *
+     * @param cached Cached value for #canShowWifiHotspot()
+     */
+    @VisibleForTesting
+    public static void setCanShowWifiHotspotCached(Boolean cached) {
+        sCanShowWifiHotspotCached = cached;
+    }
 }