focus fixes

src/main/java/com/kfmanager/ui/FilePanel.java

@@ -155,6 +155,42 @@ public class FilePanel extends JPanel {
         });
         
         add(tabbedPane, BorderLayout.CENTER);
+
+        // Click on panel background or empty areas should focus the table
+        addMouseListenerToComponents(this);
+    }
+
+    /**
+     * Recursively adds a mouse listener to all components (except buttons/combos)
+     * to request focus for the active table when clicked.
+     */
+    private void addMouseListenerToComponents(Component comp) {
+        if (comp == null) return;
+        
+        // Components that should NOT steal focus back to the table when clicked
+        boolean isInteractive = comp instanceof JButton || 
+                                comp instanceof JComboBox || 
+                                comp instanceof JTextField || 
+                                comp instanceof JTable;
+                                
+        if (!isInteractive) {
+            comp.addMouseListener(new java.awt.event.MouseAdapter() {
+                @Override
+                public void mousePressed(java.awt.event.MouseEvent e) {
+                    FilePanelTab tab = getCurrentTab();
+                    if (tab != null) {
+                        tab.getFileTable().requestFocusInWindow();
+                        tab.selectLastItem();
+                    }
+                }
+            });
+        }
+        
+        if (comp instanceof Container) {
+            for (Component child : ((Container) comp).getComponents()) {
+                addMouseListenerToComponents(child);
+            }
+        }
     }
 
     /**
@@ -196,6 +232,9 @@ public class FilePanel extends JPanel {
         tabbedPane.addTab(tabTitle, tab);
         tabbedPane.setSelectedComponent(tab);
         
+        // Ensure clicking on empty areas of the tab/scrollpane focuses the table
+        addMouseListenerToComponents(tab);
+        
         // Update path field
         updatePathField();
         updateTabStyles();
@@ -225,6 +264,9 @@ public class FilePanel extends JPanel {
         tabbedPane.addTab(tabTitle, tab);
         tabbedPane.setSelectedComponent(tab);
 
+        // Ensure clicking on empty areas of the tab/scrollpane focuses the table
+        addMouseListenerToComponents(tab);
+
         updatePathField();
         updateTabStyles();
 

src/main/java/com/kfmanager/ui/FilePanelTab.java

@@ -42,7 +42,10 @@ public class FilePanelTab extends JPanel {
     // Sorting state for FULL mode header clicks
     private int sortColumn = -1; // 0=name,1=size,2=date
     private boolean sortAscending = true;
-        private com.kfmanager.config.AppConfig persistedConfig;
+    private com.kfmanager.config.AppConfig persistedConfig;
+    // Track last selection to restore it if focus is requested on empty area
+    private int lastValidRow = 0;
+    private int lastValidBriefColumn = 0;
     // If an archive was opened, we may extract it to a temp directory; track it so
     // we can cleanup older temp directories when navigation changes.
     private Path currentArchiveTempDir = null;
@@ -239,10 +242,14 @@ public class FilePanelTab extends JPanel {
                         repaint();
                     }
 
+                    // Request focus on table even if clicking on empty area
+                    fileTable.requestFocusInWindow();
+
                     // Single left-click should focus/select the item under cursor but
                     // should NOT toggle its marked state. This preserves keyboard
                     // marking (Insert) while making mouse clicks act as simple focus.
                     if (e.getClickCount() == 1 && javax.swing.SwingUtilities.isLeftMouseButton(e)) {
+                        boolean selected = false;
                         if (row >= 0) {
                             // Convert brief layout coordinates to absolute index where needed
                             if (viewMode == ViewMode.BRIEF) {
@@ -255,17 +262,23 @@ public class FilePanelTab extends JPanel {
                                         briefCurrentColumn = selCol;
                                         fileTable.setRowSelectionInterval(selRow, selRow);
                                         fileTable.scrollRectToVisible(fileTable.getCellRect(selRow, selCol, true));
+                                        selected = true;
                                     }
                                 }
                             } else {
                                 // FULL mode: rows map directly
                                 fileTable.setRowSelectionInterval(row, row);
                                 fileTable.scrollRectToVisible(fileTable.getCellRect(row, 0, true));
+                                selected = true;
                             }
-                            fileTable.requestFocusInWindow();
-                            repaint();
-                            updateStatus();
                         }
+                        
+                        if (!selected) {
+                            // Clicked on empty area (row < 0 or empty cell in BRIEF): select the last item in the panel
+                            selectLastItem();
+                        }
+                        repaint();
+                        updateStatus();
                     }
 
                     // Double-click opens the item under cursor (directories)
@@ -281,9 +294,11 @@ public class FilePanelTab extends JPanel {
                 // Allow MOUSE_PRESSED for drag initiating gestures, but block standard selection change.
                 // We'll process selection manually in MOUSE_CLICKED above.
                 if (e.getID() == java.awt.event.MouseEvent.MOUSE_PRESSED) {
+                    fileTable.requestFocusInWindow();
                     // Start selection logic on press to support DnD initiate
                     int col = columnAtPoint(e.getPoint());
                     int row = rowAtPoint(e.getPoint());
+                    boolean selected = false;
                     if (row >= 0) {
                         if (viewMode == ViewMode.BRIEF) {
                             FileItem item = tableModel.getItemFromBriefLayout(row, col);
@@ -293,14 +308,25 @@ public class FilePanelTab extends JPanel {
                                     int selRow = index % tableModel.briefRowsPerColumn;
                                     fileTable.setRowSelectionInterval(selRow, selRow);
                                     briefCurrentColumn = index / tableModel.briefRowsPerColumn;
+                                    selected = true;
                                 }
                             }
                         } else {
                             fileTable.setRowSelectionInterval(row, row);
+                            selected = true;
                         }
-                        fileTable.requestFocusInWindow();
-                        repaint();
                     }
+                    
+                    if (!selected) {
+                        // Clicked on empty area of the table: select the last item
+                        selectLastItem();
+                        // For empty area, we MUST consume the event to prevent JTable from clearing selection
+                        e.consume();
+                        return;
+                    }
+                    repaint();
+                    // If we are on a row, we let it pass to super so Drag and Drop can be initiated,
+                    // but since we already set selection, JTable will just confirm it.
                 }
 
                 if (e.getID() == java.awt.event.MouseEvent.MOUSE_RELEASED) {
@@ -308,7 +334,9 @@ public class FilePanelTab extends JPanel {
                     return;
                 }
 
-                super.processMouseEvent(e);
+                if (!e.isConsumed()) {
+                    super.processMouseEvent(e);
+                }
             }
             @Override
             protected void processMouseMotionEvent(java.awt.event.MouseEvent e) {
@@ -433,6 +461,40 @@ public class FilePanelTab extends JPanel {
         fileTable.setBackground(this.getBackground());
         fileTable.setOpaque(true);
         
+        fileTable.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
+        // Enforce that at least one item is always active (selected) if the table is not empty.
+        fileTable.getSelectionModel().addListSelectionListener(e -> {
+            int row = fileTable.getSelectedRow();
+            if (row >= 0) {
+                if (!e.getValueIsAdjusting()) {
+                    lastValidRow = row;
+                    lastValidBriefColumn = briefCurrentColumn;
+                }
+            } else {
+                // Selection became empty. Attempt to restore it.
+                // We do this even if e.getValueIsAdjusting() is true to prevent temporary selection loss.
+                if (fileTable.getRowCount() > 0) {
+                    int targetRow = Math.min(lastValidRow, fileTable.getRowCount() - 1);
+                    if (targetRow < 0) targetRow = 0;
+                    
+                    final int finalRow = targetRow;
+                    final int finalCol = lastValidBriefColumn;
+                    
+                    // Use invokeLater to avoid potential re-entrancy issues with selection model
+                    SwingUtilities.invokeLater(() -> {
+                        if (fileTable != null && fileTable.getSelectionModel().isSelectionEmpty() && fileTable.getRowCount() > 0) {
+                            briefCurrentColumn = finalCol;
+                            fileTable.setRowSelectionInterval(finalRow, finalRow);
+                            // Ensure the restored selection is visible
+                            try {
+                                fileTable.scrollRectToVisible(fileTable.getCellRect(finalRow, finalCol, true));
+                            } catch (Exception ignore) {}
+                        }
+                    });
+                }
+            }
+        });
+        
     JScrollPane scrollPane = new JScrollPane(fileTable);
     // Enable horizontal scrollbar when needed so BRIEF mode can scroll left-right
     scrollPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
@@ -728,6 +790,8 @@ public class FilePanelTab extends JPanel {
         
         this.currentDirectory = directory;
         briefCurrentColumn = 0;
+        lastValidRow = 0;
+        lastValidBriefColumn = 0;
         
         File[] files = directory.listFiles();
         List<FileItem> items = new ArrayList<>();
@@ -1293,6 +1357,28 @@ public class FilePanelTab extends JPanel {
         }
         return null;
     }
+
+    /**
+     * Mark/Select the very last item in the list
+     */
+    public void selectLastItem() {
+        int count = tableModel.getRowCount();
+        if (count > 0) {
+            if (viewMode == ViewMode.BRIEF) {
+                int lastIndex = tableModel.items.size() - 1;
+                briefCurrentColumn = lastIndex / tableModel.briefRowsPerColumn;
+                int row = lastIndex % tableModel.briefRowsPerColumn;
+                fileTable.setRowSelectionInterval(row, row);
+                fileTable.scrollRectToVisible(fileTable.getCellRect(row, briefCurrentColumn, true));
+            } else {
+                int last = count - 1;
+                fileTable.setRowSelectionInterval(last, last);
+                fileTable.scrollRectToVisible(fileTable.getCellRect(last, 0, true));
+            }
+            repaint();
+            updateStatus();
+        }
+    }
     
     public void setViewMode(ViewMode mode) {
         if (this.viewMode != mode) {

src/main/java/com/kfmanager/ui/MainWindow.java

@@ -144,20 +144,33 @@ public class MainWindow extends JFrame {
             // ignore and keep default
         }
         
-    // Focus listeners to track active panel
+        // Global focus listener to track which panel is active based on focused component
+        KeyboardFocusManager.getCurrentKeyboardFocusManager().addPropertyChangeListener("permanentFocusOwner", evt -> {
+            Component focused = (Component) evt.getNewValue();
+            if (focused != null) {
+                if (SwingUtilities.isDescendingFrom(focused, leftPanel)) {
+                    activePanel = leftPanel;
+                    updateActivePanelBorder();
+                    leftPanel.getFileTable().repaint();
+                    rightPanel.getFileTable().repaint();
+                } else if (SwingUtilities.isDescendingFrom(focused, rightPanel)) {
+                    activePanel = rightPanel;
+                    updateActivePanelBorder();
+                    leftPanel.getFileTable().repaint();
+                    rightPanel.getFileTable().repaint();
+                }
+            }
+        });
+
+    // Focus listeners to track active panel and ensure selection
         leftPanel.getFileTable().addFocusListener(new FocusAdapter() {
             @Override
             public void focusGained(FocusEvent e) {
-                activePanel = leftPanel;
-                updateActivePanelBorder();
                 // Ensure some row is selected
                 JTable leftTable = leftPanel.getFileTable();
                 if (leftTable.getSelectedRow() == -1 && leftTable.getRowCount() > 0) {
                     leftTable.setRowSelectionInterval(0, 0);
                 }
-                // Repaint both panels
-                leftPanel.getFileTable().repaint();
-                rightPanel.getFileTable().repaint();
             }
             
             @Override
@@ -170,16 +183,11 @@ public class MainWindow extends JFrame {
         rightPanel.getFileTable().addFocusListener(new FocusAdapter() {
             @Override
             public void focusGained(FocusEvent e) {
-                activePanel = rightPanel;
-                updateActivePanelBorder();
                 // Ensure some row is selected
                 JTable rightTable = rightPanel.getFileTable();
                 if (rightTable.getSelectedRow() == -1 && rightTable.getRowCount() > 0) {
                     rightTable.setRowSelectionInterval(0, 0);
                 }
-                // Repaint both panels
-                leftPanel.getFileTable().repaint();
-                rightPanel.getFileTable().repaint();
             }
             
             @Override