1 files changed, 102 insertions, 0 deletions
diff --git a/com/android/server/location/GnssSatelliteBlacklistHelper.java b/com/android/server/location/GnssSatelliteBlacklistHelper.java
new file mode 100644
index 00000000..77951aa7
--- /dev/null
+++ b/com/android/server/location/GnssSatelliteBlacklistHelper.java
@@ -0,0 +1,102 @@
+package com.android.server.location;
+
+import android.content.ContentResolver;
+import android.content.Context;
+import android.database.ContentObserver;
+import android.os.Handler;
+import android.os.Looper;
+import android.os.UserHandle;
+import android.provider.Settings;
+import android.util.Log;
+
+import com.android.internal.annotations.VisibleForTesting;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Detects blacklist change and updates the blacklist.
+ */
+class GnssSatelliteBlacklistHelper {
+
+    private static final String TAG = "GnssBlacklistHelper";
+    private static final boolean DEBUG = Log.isLoggable(TAG, Log.DEBUG);
+    private static final String BLACKLIST_DELIMITER = ",";
+
+    private final Context mContext;
+    private final GnssSatelliteBlacklistCallback mCallback;
+
+    interface GnssSatelliteBlacklistCallback {
+        void onUpdateSatelliteBlacklist(int[] constellations, int[] svids);
+    }
+
+    GnssSatelliteBlacklistHelper(Context context, Looper looper,
+            GnssSatelliteBlacklistCallback callback) {
+        mContext = context;
+        mCallback = callback;
+        ContentObserver contentObserver = new ContentObserver(new Handler(looper)) {
+            @Override
+            public void onChange(boolean selfChange) {
+                updateSatelliteBlacklist();
+            }
+        };
+        mContext.getContentResolver().registerContentObserver(
+                Settings.Global.getUriFor(
+                        Settings.Global.GNSS_SATELLITE_BLACKLIST),
+                true,
+                contentObserver, UserHandle.USER_ALL);
+    }
+
+    void updateSatelliteBlacklist() {
+        ContentResolver resolver = mContext.getContentResolver();
+        String blacklist = Settings.Global.getString(
+                resolver,
+                Settings.Global.GNSS_SATELLITE_BLACKLIST);
+        if (blacklist == null) {
+            blacklist = "";
+        }
+        if (DEBUG) {
+            Log.d(TAG, String.format("Update GNSS satellite blacklist: %s", blacklist));
+        }
+
+        List<Integer> blacklistValues;
+        try {
+            blacklistValues = parseSatelliteBlacklist(blacklist);
+        } catch (NumberFormatException e) {
+            Log.e(TAG, "Exception thrown when parsing blacklist string.", e);
+            return;
+        }
+
+        if (blacklistValues.size() % 2 != 0) {
+            Log.e(TAG, "blacklist string has odd number of values."
+                    + "Aborting updateSatelliteBlacklist");
+            return;
+        }
+
+        int length = blacklistValues.size() / 2;
+        int[] constellations = new int[length];
+        int[] svids = new int[length];
+        for (int i = 0; i < length; i++) {
+            constellations[i] = blacklistValues.get(i * 2);
+            svids[i] = blacklistValues.get(i * 2 + 1);
+        }
+        mCallback.onUpdateSatelliteBlacklist(constellations, svids);
+    }
+
+    @VisibleForTesting
+    static List<Integer> parseSatelliteBlacklist(String blacklist) throws NumberFormatException {
+        String[] strings = blacklist.split(BLACKLIST_DELIMITER);
+        List<Integer> parsed = new ArrayList<>(strings.length);
+        for (String string : strings) {
+            string = string.trim();
+            if (!"".equals(string)) {
+                int value = Integer.parseInt(string);
+                if (value < 0) {
+                    throw new NumberFormatException("Negative value is invalid.");
+                }
+                parsed.add(value);
+            }
+        }
+        return parsed;
+    }
+}