Add an option to invalidate the quest cache

app/src/main/java/de/westnordost/streetcomplete/Prefs.java

@@ -18,7 +18,8 @@ public class Prefs
 
 	// not shown anywhere directly
 	public static final String
-			QUEST_ORDER = "quests.order";
+			QUEST_ORDER = "quests.order",
+			QUEST_INVALIDATION = "quests.invalidation";
 
 	public enum Autosync
 	{

app/src/main/java/de/westnordost/streetcomplete/data/tiles/DownloadedTilesDao.java

@@ -70,6 +70,12 @@ public int remove(Point tile)
 				DownloadedTilesTable.Columns.Y + " = ?", whereArgs);
 	}
 
+	public void removeAll()
+	{
+		SQLiteDatabase db = dbHelper.getWritableDatabase();
+		db.execSQL("DELETE FROM " + DownloadedTilesTable.NAME);
+	}
+
 	/** @return a list of quest type names which have already been downloaded in every tile in the
 	 *          given tile range */
 	public List<String> get(Rect tiles, long ignoreOlderThan)

app/src/main/java/de/westnordost/streetcomplete/data/visiblequests/VisibleQuestTypeDao.java

@@ -96,7 +96,7 @@ public synchronized void setVisible(QuestType questType, boolean visible)
 
 	public synchronized void clear()
 	{
-		SQLiteDatabase db = dbHelper.getReadableDatabase();
+		SQLiteDatabase db = dbHelper.getWritableDatabase();
 		db.execSQL("DELETE FROM " + QuestVisibilityTable.NAME);
 		questTypeVisibilities = null;
 	}

app/src/main/java/de/westnordost/streetcomplete/settings/SettingsFragment.java

@@ -1,23 +1,32 @@
 package de.westnordost.streetcomplete.settings;
 
+import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
+import android.graphics.Point;
 import android.os.Bundle;
 import android.support.v4.app.DialogFragment;
+import android.support.v7.app.AlertDialog;
 import android.support.v7.preference.Preference;
 import android.support.v7.preference.PreferenceFragmentCompat;
 import android.support.v7.preference.PreferenceManager;
 
 import javax.inject.Inject;
 import javax.inject.Provider;
 
+import de.westnordost.osmapi.map.data.OsmLatLon;
+import de.westnordost.streetcomplete.ApplicationConstants;
 import de.westnordost.streetcomplete.FragmentContainerActivity;
 import de.westnordost.streetcomplete.Injector;
 import de.westnordost.streetcomplete.IntentListener;
 import de.westnordost.streetcomplete.Prefs;
+import de.westnordost.streetcomplete.data.tiles.DownloadedTilesDao;
 import de.westnordost.streetcomplete.oauth.OAuthPrefs;
 import de.westnordost.streetcomplete.R;
 import de.westnordost.streetcomplete.oauth.OsmOAuthDialogFragment;
+import de.westnordost.streetcomplete.tangram.MapFragment;
+import de.westnordost.streetcomplete.util.SlippyMapMath;
+import de.westnordost.streetcomplete.view.dialogs.AlertDialogBuilder;
 
 public class SettingsFragment extends PreferenceFragmentCompat
 		implements SharedPreferences.OnSharedPreferenceChangeListener, IntentListener
@@ -27,6 +36,7 @@ public class SettingsFragment extends PreferenceFragmentCompat
 	@Inject SharedPreferences prefs;
 	@Inject OAuthPrefs oAuth;
 	@Inject Provider<ApplyNoteVisibilityChangedTask> applyNoteVisibilityChangedTask;
+	@Inject DownloadedTilesDao downloadedTilesDao;
 
 	@Override public void onCreatePreferences(Bundle savedInstanceState, String rootKey)
 	{
@@ -47,6 +57,21 @@ public class SettingsFragment extends PreferenceFragmentCompat
 			getFragmentActivity().setCurrentFragment(new QuestSelectionFragment());
 			return true;
 		});
+
+		Preference questsInvalidation = getPreferenceScreen().findPreference("quests.invalidation");
+		questsInvalidation.setOnPreferenceClickListener(preference ->
+		{
+			new AlertDialogBuilder(getContext())
+					.setMessage(R.string.invalidation_dialog_message)
+					.setPositiveButton(R.string.invalidate_confirmation, (dialog, which) -> {
+						downloadedTilesDao.removeAll();
+					})
+					.setNegativeButton(android.R.string.cancel, (dialog, which) -> {})
+					.create()
+					.show();
+
+			return true;
+		});
 	}
 
 	@Override

app/src/main/java/de/westnordost/streetcomplete/tangram/MapFragment.java

@@ -525,7 +525,7 @@ private float meters2Pixels(LngLat at, float meters) {
 		);
 	}
 
-	private static final String
+	public static final String
 			PREF_ROTATION = "map_rotation",
 			PREF_TILT = "map_tilt",
 			PREF_ZOOM = "map_zoom",

app/src/main/res/values/strings.xml

@@ -440,4 +440,8 @@ Otherwise, you can download another keyboard in the app store. Popular keyboards
     <string name="quest_housenumber_conscription_number_required">A conscription number must be specified</string>
     <string name="quest_cycleway_answer_contraflow_cycleway">Also cycleway on other side</string>
     <string name="need_specify_both_sides">You need to specify both sides</string>
+    <string name="pref_title_quests_invalidation">Invalidate Quest Cache</string>
+    <string name="pref_title_quests_invalidation_summary">Useful if you think that some quests are outdated</string>
+    <string name="invalidate_confirmation">Invalidate</string>
+    <string name="invalidation_dialog_message">Invalidating the cache causes the quests to be updated next time they are downloaded each. The quest cache is invalidated automatically after one week and immediately when a quest you solved turns out to be already answered by someone else.</string>
 </resources>

app/src/main/res/xml/preferences.xml

@@ -76,6 +76,12 @@
             android:widgetLayout="@layout/widget_image_next"
             />
 
+        <Preference
+            android:key="quests.invalidation"
+            android:title="@string/pref_title_quests_invalidation"
+            android:summary="@string/pref_title_quests_invalidation_summary"
+            />
+
     </PreferenceCategory>
 
 </PreferenceScreen>