implement recommendations from code analysis

app/src/androidTest/java/com/nononsenseapps/notepad/test/DBProviderTest.java

@@ -45,6 +45,7 @@ private void assertUriReturnsResult(final Uri uri, final String[] fields, final
 										final String[] whereArgs, final int count) {
 		final Cursor c = mResolver
 				.query(uri, fields, where, whereArgs, null);
+		assertNotNull(c);
 		if (count == 6 && c.getCount() == 7) {
 			// TODO sometimes tests on github (not on a fast PC) crash here. Investigate why
 			NnnLogger.debug(DBProviderTest.class, "cursor info:");

app/src/main/java/com/nononsenseapps/notepad/database/Task.java

@@ -616,7 +616,7 @@ public String getText() {
 			result += title;
 		}
 		if (note != null && !note.isEmpty()) {
-			if (result.length() > 0) {
+			if (!result.isEmpty()) {
 				result += "\n";
 			}
 			result += note;

app/src/main/java/com/nononsenseapps/notepad/fragments/TaskListFragment.java

@@ -682,12 +682,15 @@ String getShareText() {
 				return sb.toString();
 			}
 
+			// when sharing many notes from the list view,
+			// we send a list of their titles as subject
 			String getShareSubject() {
-				String result = "";
+				StringBuilder result = new StringBuilder();
 				for (Task t : tasks.values()) {
-					result += ", " + t.title;
+					result.append(", ").append(t.title);
 				}
-				return result.length() > 0 ? result.substring(2) : result;
+				// if necessary, remove the first ", "
+				return (result.length() == 0) ? "" : result.substring(2);
 			}
 
 			/**

app/src/main/java/com/nononsenseapps/notepad/prefs/NotificationPrefs.java

@@ -107,7 +107,7 @@ public boolean onPreferenceTreeClick(Preference preference) {
 					.getDefaultSharedPreferences(this.getContext())
 					.getString(ringtonePrefKey, null);
 			if (existingValue != null) {
-				Uri existing = existingValue.length() == 0
+				Uri existing = existingValue.isEmpty()
 						? null // Select "Silent"
 						: Uri.parse(existingValue);
 				intent.putExtra(RingtoneManager.EXTRA_RINGTONE_EXISTING_URI, existing);

app/src/main/java/com/nononsenseapps/notepad/sync/orgsync/DBSyncBase.java

@@ -344,7 +344,7 @@ protected boolean wasRenamed(final TaskList list, final OrgFile file) {
 	 */
 	protected void renameFile(final TaskList list,
 							  final RemoteTaskList dbEntry, final OrgFile file) {
-		if (list.title != null && list.title.length() > 0) {
+		if (list.title != null && !list.title.isEmpty()) {
 			file.setFilename(OrgConverter.getTitleAsFilename(list));
 		}
 		dbEntry.remoteId = file.getFilename();

app/src/main/java/com/nononsenseapps/ui/TitleNoteTextView.java

@@ -116,7 +116,7 @@ public static CharSequence getStyledText(final String title,
 											 final String rest, final float titleRelSize, final int face,
 											 final int font) {
 		final StringBuilder textBuilder = new StringBuilder(title);
-		if (rest.length() > 0) {
+		if (!rest.isEmpty()) {
 			textBuilder.append("\n").append(rest);
 		}
 		return getStyledText(textBuilder.toString(), titleRelSize, face, font);
@@ -371,7 +371,7 @@ public void setTextRest(final String rest) {
 		if (rest != null) {
 			this.mRest = rest;
 			// Make sure it starts with a new line
-			if (mRest.length() > 0) {
+			if (!mRest.isEmpty()) {
 				mRest = (rest.startsWith("\n") ? "" : "\n") + rest;
 			}