refactor: rename method findParentlLuhmann to findParentLuhmann

for consistency and clarity.

- Updated all references to `findParentlLuhmann` in various classes to `findParentLuhmann`.
- Fixed typo in comments from "stringbuffer" to "string buffer" and "searchresults" to "search results".
- Renamed method `goToFirstTopOfTopic` to `goToFirstParentEntry` to better reflect its functionality.
- Updated unit tests to reflect method name changes and ensured consistency across the code base.

src/main/java/de/danielluedecke/zettelkasten/ZettelkastenView.java

@@ -6749,7 +6749,7 @@ public void run() {
 	private EntryID getRootEntryForLuhmannTree() {
 		int rootEntry = -1;
 		if (settings.getShowAllLuhmann()) {
-			rootEntry = data.findParentlLuhmann(data.getActivatedEntryNumber(), /* firstParent= */false);
+			rootEntry = data.findParentLuhmann(data.getActivatedEntryNumber(), /* firstParent= */false);
 
 		}
 		if (rootEntry == -1) {

src/main/java/de/danielluedecke/zettelkasten/database/Daten.java

@@ -5072,8 +5072,8 @@ public void lastEntry() {
 	 * 
 	 * It adds a the new entry (first parent entry) to the history.
 	 */
-	public void goToFirstTopOfTopic() { // was: goToFirstParentEntry ; cf. "Inhaltlich-logische Navigation" in https://niklas-luhmann-archiv.de/bestand/zettelkasten/tutorial
-		int firstParentEntry = findParentlLuhmann(activatedEntryNumber, /* firstParent= */true);
+	public void goToFirstParentEntry() { // See:  "Inhaltlich-logische Navigation" in https://niklas-luhmann-archiv.de/bestand/zettelkasten/tutorial
+		int firstParentEntry = findParentLuhmann(activatedEntryNumber, /* firstParent= */true);
 		if (firstParentEntry == -1) {
 			// No valid parent entry, do nothing.
 			return;
@@ -7456,7 +7456,7 @@ public boolean isTopLevelLuhmann(int nr) {
 		if (!hasLuhmannNumbers(nr)) {
 			return false;
 		}
-		return (-1 == findParentlLuhmann(nr, true));
+		return (-1 == findParentLuhmann(nr, true));
 	}
 
 	/**

src/main/java/de/danielluedecke/zettelkasten/tasks/ShowTitleListTask.java

@@ -47,7 +47,7 @@ public class ShowTitleListTask extends org.jdesktop.application.Task<Object, Voi
     /**
      * Reference to the data class
      */
-    private final Daten dataObj;
+    private final Daten data;
     /**
      * the table model from the main window's jtable, passed as parameter
      */
@@ -69,7 +69,7 @@ public class ShowTitleListTask extends org.jdesktop.application.Task<Object, Voi
         // doInBackground() depends on from parameters
         // to ImportFileTask fields, here.
         super(app);
-        dataObj = d;
+        data = d;
         tableModel = tm;
         parentDialog = parent;
         msgLabel = label;
@@ -83,7 +83,7 @@ protected Object doInBackground() {
         // the Swing GUI from here.
 
         // check whether we have any keywords at all
-        if (dataObj.getCount(Daten.ZKNCOUNT) < 1) {
+        if (data.getCount(Daten.ZKNCOUNT) < 1) {
             // reset list
             list = null;
             // leave thread
@@ -92,18 +92,18 @@ protected Object doInBackground() {
         // create new instance of that variable
         list = new LinkedList<>();
         // reset progress counter
-        int total_count = dataObj.getCount(Daten.ZKNCOUNT);
+        int total_count = data.getCount(Daten.ZKNCOUNT);
         // start loop
-        for (int cnt = 1; cnt <= dataObj.getCount(Daten.ZKNCOUNT); cnt++) {
+        for (int cnt = 1; cnt <= data.getCount(Daten.ZKNCOUNT); cnt++) {
             // is entry deleted?
-            if (dataObj.isDeleted(cnt)) {
+            if (data.isDeleted(cnt)) {
                 // skip entry
                 continue;
             }
             // get zettel-title
-            String title = dataObj.getZettelTitle(cnt);
+            String title = data.getZettelTitle(cnt);
             // get timestamp
-            String[] timestamp = dataObj.getTimestamp(cnt);
+            String[] timestamp = data.getTimestamp(cnt);
             // init timestamp variables.
             String created = "";
             String edited = "";
@@ -118,10 +118,10 @@ protected Object doInBackground() {
 
             // Make Note Sequences column sortable.
             String luhmannindex = "0";
-            if (dataObj.isTopLevelLuhmann(cnt)) {
+            if (data.isTopLevelLuhmann(cnt)) {
                 luhmannindex = "3";
-            } else if (dataObj.findParentlLuhmann(cnt, true) != -1) {
-                if (dataObj.hasLuhmannNumbers(cnt)) {
+            } else if (data.findParentLuhmann(cnt, true) != -1) {
+                if (data.hasLuhmannNumbers(cnt)) {
                     luhmannindex = "2";
                 } else {
                     luhmannindex = "1";
@@ -134,7 +134,7 @@ protected Object doInBackground() {
             ob[1] = title;
             ob[2] = created;
             ob[3] = edited;
-            ob[4] = dataObj.getZettelRating(cnt);
+            ob[4] = data.getZettelRating(cnt);
             ob[5] = luhmannindex;
             // and add it to the table
             list.add(ob);
@@ -164,7 +164,7 @@ protected void succeeded(Object result) {
                 tableModel.setRowCount(0);
             }
         }
-        dataObj.setTitlelistUpToDate(true);
+        data.setTitlelistUpToDate(true);
     }
 
     @Override

src/main/java/de/danielluedecke/zettelkasten/tasks/StartSearchTask.java

@@ -674,7 +674,7 @@ private void doSearchForTopLevelLuhman() {
 	private void doSearchForLuhmanParent() {
 		// get the amount of entries
 		int len = searchEntries.length;
-		// init a stringbuffer that temporarily stores the found entry-numbers
+		// init a string buffer that temporarily stores the found entry-numbers
 		List<Integer> finalresults = new ArrayList<>();
 		// iterate all entries where the search should be applied to...
 		// this may differ. a search request from the main-window usually searches
@@ -687,19 +687,19 @@ private void doSearchForLuhmanParent() {
 			// get the number of the entry which we want to search through...
 			int searchnr = searchEntries[counter];
 			// find first parent
-			int lp = dataObj.findParentlLuhmann(searchnr, true);
+			int lp = dataObj.findParentLuhmann(searchnr, true);
 			// check whether entry is a follower and has a first-level parent
 			if (lp != -1) {
-				// check if entry is not already in searchresults
+				// check if entry is not already in search results
 				// if not, add search result
 				if (!finalresults.contains(searchnr)) {
 					finalresults.add(searchnr);
 				}
 			}
-			// update progressbar
+			// update progress bar
 			setProgress(counter, 0, len);
 		}
-		// finally, check whether we have any searchresults at all...
+		// finally, check whether we have any search results at all...
 		if (finalresults.size() > 0) {
 			// create search results array, create search description and
 			// add search results to the search-data-class.

src/main/java/de/danielluedecke/zettelkasten/util/classes/TitleTableCellRenderer.java

@@ -64,7 +64,7 @@ public Component getTableCellRendererComponent(
             // get note
             if (dataObj.isTopLevelLuhmann(nr)) {
                 returnLabel = this.iconLabelParentLuhmann;
-            } else if (dataObj.findParentlLuhmann(nr, true) != -1) {
+            } else if (dataObj.findParentLuhmann(nr, true) != -1) {
                 if (dataObj.hasLuhmannNumbers(nr)) {
                     returnLabel = this.iconLabelMiddleLuhmann;
                 } else {

src/test/java/de/danielluedecke/zettelkasten/database/DatenTest.java

@@ -38,16 +38,16 @@ public void setUp() throws JDOMException, IOException {
 	}
 
 	@Test
-	void testGoToFirstTopOfTopic() {
+	void testGoToFirstParentEntry() {
 		// data by default has current entry == 1.
 		Daten data = new Daten(document);
 
 		// The first (and only) parent of entry 1 is entry 2.
-		data.goToFirstTopOfTopic();
+		data.goToFirstParentEntry();
 		assertEquals(data.getActivatedEntryNumber(), 2);
 
 		// Entry 2 doesn't have a parent. Keep at the same Zettel number.
-		data.goToFirstTopOfTopic();
+		data.goToFirstParentEntry();
 		assertEquals(data.getActivatedEntryNumber(), 2);
 	}