Add sttrace option dialog (#1109)

app/src/main/java/com/nutomic/syncthingandroid/activities/SettingsActivity.java

@@ -416,13 +416,7 @@ public class SettingsActivity extends SyncthingActivity {
                     mSyncOnlyOnSSIDs.setEnabled((Boolean) o);
                     break;
                 case KEY_STTRACE:
-                    if (((String) o).matches("[0-9a-z, ]*"))
                     mRequireRestart = true;
-                    else {
-                        Toast.makeText(getActivity(), R.string.toast_invalid_sttrace, Toast.LENGTH_SHORT)
-                                .show();
-                        return false;
-                    }
                     break;
                 case Constants.PREF_ENVIRONMENT_VARIABLES:
                     if (((String) o).matches("^(\\w+=[\\w:/\\.]+)?( \\w+=[\\w:/\\.]+)*$")) {

app/src/main/java/com/nutomic/syncthingandroid/service/SyncthingRunnable.java

@@ -27,6 +27,7 @@ import java.io.LineNumberReader;
 import java.security.InvalidParameterException;
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicReference;
@@ -437,7 +438,7 @@ public class SyncthingRunnable implements Runnable {
         HashMap<String, String> targetEnv = new HashMap<>();
         // Set home directory to data folder for web GUI folder picker.
         targetEnv.put("HOME", Environment.getExternalStorageDirectory().getAbsolutePath());
-        targetEnv.put("STTRACE", mPreferences.getString("sttrace", ""));
+        targetEnv.put("STTRACE", TextUtils.join(" ", mPreferences.getStringSet("sttrace", new HashSet<>())));
         File externalFilesDir = mContext.getExternalFilesDir(null);
         if (externalFilesDir != null)
             targetEnv.put("STGUIASSETS", externalFilesDir.getAbsolutePath() + "/gui");

app/src/main/java/com/nutomic/syncthingandroid/views/SttracePreference.java

@@ -0,0 +1,100 @@
+package com.nutomic.syncthingandroid.views;
+
+import android.Manifest;
+import android.content.Context;
+import android.os.Build;
+import android.os.Bundle;
+import android.preference.MultiSelectListPreference;
+import android.support.v4.app.ActivityCompat;
+import android.support.v4.content.ContextCompat;
+import android.util.AttributeSet;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.TreeSet;
+
+/**
+ * SttracePreference which allows the user to select which debug facilities
+ * are enabled.
+ *
+ * Setting can be "no debug facility" (none selected), or selecting individual  debug facilities.
+ *
+ * The preference is stored as Set<String> where an empty set represents
+ * "no debug facility".
+ *
+ * Debug facilities are documented in https://docs.syncthing.net/dev/debugging.html
+ *
+ */
+public class SttracePreference extends MultiSelectListPreference {
+
+    public SttracePreference(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        setDefaultValue(new TreeSet<String>());
+    }
+
+    public SttracePreference(Context context) {
+        this(context, null);
+    }
+
+    /**
+     * Show the dialog.
+     */
+    @Override
+    protected void showDialog(Bundle state) {
+        Set<String> selected = getSharedPreferences().getStringSet(getKey(), new HashSet<>());
+        // from JavaDoc: Note that you must not modify the set instance returned by this call.
+        // therefore required to make a defensive copy of the elements
+        selected = new HashSet<>(selected);
+        CharSequence[] all = getDebugFacilities();
+        filterRemovedDebugFacilities(selected, all);
+        setEntries(all);        // display without surrounding quotes
+        setEntryValues(all);    // the value of the entry is the debug facility "as is"
+        setValues(selected);    // the currently selected values
+        super.showDialog(state);
+    }
+
+    /**
+     * Removes any debug facility that is no longer present in the current syncthing version.
+     * Otherwise it will never be removed from the enabled facilities set by MultiSelectListPreference.
+     */
+    private void filterRemovedDebugFacilities(Set<String> selected, CharSequence[] all) {
+        HashSet<CharSequence> availableDebugFacilities = new HashSet<>(Arrays.asList(all));
+        selected.retainAll(availableDebugFacilities);
+    }
+
+    /**
+     * Returns all debug facilities available in the currently syncthing version.
+     */
+    private CharSequence[] getDebugFacilities() {
+        // Syncthing v0.14.47 debug facilities.
+        List<String> debugFacilities = new ArrayList<String>();
+        debugFacilities.add("beacon");
+        debugFacilities.add("config");
+        debugFacilities.add("connections");
+        debugFacilities.add("db");
+        debugFacilities.add("dialer");
+        debugFacilities.add("discover");
+        debugFacilities.add("events");
+        debugFacilities.add("fs");
+        debugFacilities.add("http");
+        debugFacilities.add("main");
+        debugFacilities.add("model");
+        debugFacilities.add("nat");
+        debugFacilities.add("pmp");
+        debugFacilities.add("protocol");
+        debugFacilities.add("scanner");
+        debugFacilities.add("sha256");
+        debugFacilities.add("stats");
+        debugFacilities.add("sync");
+        debugFacilities.add("upgrade");
+        debugFacilities.add("upnp");
+        debugFacilities.add("versioner");
+        debugFacilities.add("walkfs");
+        debugFacilities.add("watchaggregator");
+        return debugFacilities.toArray(new CharSequence[debugFacilities.size()]);
+    }
+
+}

app/src/main/res/xml/app_settings.xml

@@ -167,11 +167,9 @@
             android:title="@string/notify_crashes_title"
             android:summary="@string/notify_crashes_summary"/>
 
-        <EditTextPreference
+        <com.nutomic.syncthingandroid.views.SttracePreference
             android:key="sttrace"
-            android:title="@string/sttrace_title"
+            android:title="@string/sttrace_title" />
-            android:singleLine="true"
-            android:inputType="textNoSuggestions"/>
 
         <EditTextPreference
             android:key="environment_variables"