fixed panel scrolling

src/main/java/cz/kamma/kfmanager/ui/FilePanelTab.java

@@ -28,8 +28,10 @@ import java.io.InputStreamReader;
 import java.io.FileReader;
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
+import java.util.ArrayDeque;
 import java.util.Arrays;
 import java.util.Comparator;
+import java.util.Deque;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
@@ -90,6 +92,7 @@ public class FilePanelTab extends JPanel {
     private long archiveExtractTime = 0; // Track time of extraction to detect changes
     private File archiveReturnDirectory = null;
     private Point archiveReturnViewPosition = null;
+    private final Deque<ReturnNavigationState> navigationReturnStates = new ArrayDeque<>();
     private boolean inlineRenameActive = false;
     private boolean refreshDeferredWhileInlineRename = false;
     private boolean deferredRefreshRequestFocus = false;
@@ -105,6 +108,20 @@ public class FilePanelTab extends JPanel {
     private FtpProfile ftpProfile;
     private String ftpCurrentPath;
 
+    private static final class ReturnNavigationState {
+        private final File parentDirectory;
+        private final String itemName;
+        private final Point itemOffsetInView;
+        private final Point fallbackViewPosition;
+
+        private ReturnNavigationState(File parentDirectory, String itemName, Point itemOffsetInView, Point fallbackViewPosition) {
+            this.parentDirectory = parentDirectory;
+            this.itemName = itemName;
+            this.itemOffsetInView = itemOffsetInView;
+            this.fallbackViewPosition = fallbackViewPosition;
+        }
+    }
+
     public FilePanelTab(String initialPath) {
         this(initialPath, true);
     }
@@ -1520,6 +1537,125 @@ public class FilePanelTab extends JPanel {
         }
     }
 
+    private ReturnNavigationState rememberReturnStateForItem(FileItem item, int row, int column) {
+        if (item == null || item.getName() == null || currentDirectory == null || fileTable == null || row < 0) {
+            return null;
+        }
+
+        Rectangle cell = fileTable.getCellRect(row, Math.max(0, column), true);
+        Rectangle visible = fileTable.getVisibleRect();
+        Point offset = new Point(cell.x - visible.x, cell.y - visible.y);
+        Point fallback = visible.getLocation();
+
+        ReturnNavigationState state = new ReturnNavigationState(
+                currentDirectory,
+                item.getName(),
+                offset,
+                fallback
+        );
+        navigationReturnStates.push(state);
+        return state;
+    }
+
+    private void discardReturnState(ReturnNavigationState state) {
+        if (state == null) {
+            return;
+        }
+        navigationReturnStates.removeFirstOccurrence(state);
+    }
+
+    private ReturnNavigationState consumeReturnState(File parentDirectory, String itemName) {
+        if (parentDirectory == null || itemName == null) {
+            return null;
+        }
+
+        java.util.Iterator<ReturnNavigationState> it = navigationReturnStates.iterator();
+        while (it.hasNext()) {
+            ReturnNavigationState state = it.next();
+            if (parentDirectory.equals(state.parentDirectory) && itemName.equals(state.itemName)) {
+                it.remove();
+                return state;
+            }
+        }
+        return null;
+    }
+
+    private void restoreReturnState(ReturnNavigationState state, boolean requestFocus) {
+        if (state == null || fileTable == null || currentDirectory == null) {
+            return;
+        }
+        if (!currentDirectory.equals(state.parentDirectory)) {
+            return;
+        }
+
+        for (int i = 0; i < tableModel.items.size(); i++) {
+            FileItem item = tableModel.items.get(i);
+            if (item == null || !state.itemName.equalsIgnoreCase(item.getName())) {
+                continue;
+            }
+
+            if (viewMode == ViewMode.BRIEF) {
+                int column = i / tableModel.briefRowsPerColumn;
+                int row = i % tableModel.briefRowsPerColumn;
+                selectBriefItemWithoutAutoScroll(row, column);
+                restoreViewportForCell(row, column, state);
+                final int finalRow = row;
+                final int finalColumn = column;
+                SwingUtilities.invokeLater(() -> restoreViewportForCell(finalRow, finalColumn, state));
+            } else {
+                selectFullRowWithoutAutoScroll(i);
+                restoreViewportForCell(i, 0, state);
+                final int finalRow = i;
+                SwingUtilities.invokeLater(() -> restoreViewportForCell(finalRow, 0, state));
+            }
+
+            fileTable.repaint();
+            if (requestFocus) {
+                fileTable.requestFocusInWindow();
+            }
+            updateStatus();
+            return;
+        }
+    }
+
+    private void restoreViewportForCell(int row, int column, ReturnNavigationState state) {
+        if (fileTable == null || state == null) {
+            return;
+        }
+
+        Rectangle cell = fileTable.getCellRect(row, Math.max(0, column), true);
+        Container parent = fileTable.getParent();
+        if (parent instanceof JViewport viewport) {
+            if (state.fallbackViewPosition != null) {
+                viewport.setViewPosition(clampViewPosition(viewport, new Point(state.fallbackViewPosition)));
+            }
+
+            Rectangle visibleAfterFallback = viewport.getViewRect();
+            if (visibleAfterFallback.intersects(cell)) {
+                return;
+            }
+
+            Point target = (state.itemOffsetInView != null)
+                    ? new Point(cell.x - state.itemOffsetInView.x, cell.y - state.itemOffsetInView.y)
+                    : new Point(state.fallbackViewPosition != null ? state.fallbackViewPosition : new Point());
+            viewport.setViewPosition(clampViewPosition(viewport, target));
+        } else if (state.fallbackViewPosition != null) {
+            fileTable.scrollRectToVisible(new Rectangle(state.fallbackViewPosition.x, state.fallbackViewPosition.y, 1, 1));
+        }
+    }
+
+    private Point clampViewPosition(JViewport viewport, Point target) {
+        Dimension pref = fileTable.getPreferredSize();
+        int contentW = Math.max(fileTable.getWidth(), pref != null ? pref.width : 0);
+        int contentH = Math.max(fileTable.getHeight(), pref != null ? pref.height : 0);
+        int maxX = Math.max(0, contentW - viewport.getWidth());
+        int maxY = Math.max(0, contentH - viewport.getHeight());
+        return new Point(
+                Math.max(0, Math.min(target.x, maxX)),
+                Math.max(0, Math.min(target.y, maxY))
+        );
+    }
+
     private void scrollBriefCellToColumnStart(int row, int column) {
         if (fileTable == null || viewMode != ViewMode.BRIEF || row < 0 || column < 0
                 || column >= fileTable.getColumnModel().getColumnCount()) {
@@ -1659,6 +1795,8 @@ public class FilePanelTab extends JPanel {
         } else {
             SwingUtilities.invokeLater(() -> {
                 alignTableItemsToViewportStart();
+                fileTable.revalidate();
+                fileTable.repaint();
                 if (autoSelectFirst && fileTable.getRowCount() > 0) {
                     int startIndex = 0;
                     fileTable.setRowSelectionInterval(startIndex, startIndex);
@@ -2168,6 +2306,7 @@ public class FilePanelTab extends JPanel {
             if (item.getName().equals("..")) {
                 navigateUp();
             } else if (FileOperations.canOpenAsArchive(item.getFile())) {
+                ReturnNavigationState returnState = rememberReturnStateForItem(item, selectedRow, viewMode == ViewMode.BRIEF ? briefCurrentColumn : 0);
                 rememberArchiveReturnState(item.getFile());
                 final File archiveFile = item.getFile();
                 
@@ -2195,11 +2334,13 @@ public class FilePanelTab extends JPanel {
                         loadDirectory(temp.toFile());
                     },
                     error -> {
+                        discardReturnState(returnState);
                         clearArchiveReturnState();
                         JOptionPane.showMessageDialog(FilePanelTab.this, error, "Archive Error", JOptionPane.ERROR_MESSAGE);
                     }
                 );
             } else if (item.isDirectory()) {
+                rememberReturnStateForItem(item, selectedRow, viewMode == ViewMode.BRIEF ? briefCurrentColumn : 0);
                 loadDirectory(item.getFile());
             } else if (item.getFile() != null && item.getFile().isFile()) {
                 openFileNative(item.getFile());
@@ -2715,6 +2856,7 @@ public class FilePanelTab extends JPanel {
         if (item.getName().equals("..")) {
             navigateUp();
         } else if (FileOperations.canOpenAsArchive(item.getFile())) {
+            ReturnNavigationState returnState = rememberReturnStateForItem(item, row, viewMode == ViewMode.BRIEF ? col : 0);
             rememberArchiveReturnState(item.getFile());
             final File archiveFile = item.getFile();
             
@@ -2732,11 +2874,13 @@ public class FilePanelTab extends JPanel {
                     loadDirectory(temp.toFile(), true, true);
                 },
                 error -> {
+                    discardReturnState(returnState);
                     clearArchiveReturnState();
                     JOptionPane.showMessageDialog(FilePanelTab.this, error, "Archive Error", JOptionPane.ERROR_MESSAGE);
                 }
             );
         } else if (item.isDirectory()) {
+            rememberReturnStateForItem(item, row, viewMode == ViewMode.BRIEF ? col : 0);
             loadDirectory(item.getFile());
         } else if (item.getFile() != null && item.getFile().isFile()) {
             openFileNative(item.getFile());
@@ -3143,6 +3287,7 @@ public class FilePanelTab extends JPanel {
                     File parent = currentArchiveSourceFile.getParentFile();
                     if (parent != null) {
                         String archiveName = currentArchiveSourceFile.getName();
+                        ReturnNavigationState returnState = consumeReturnState(parent, archiveName);
                         
                         // Save any changes made to the archive before leaving (only if modified)
                         if (FileOperations.supportsArchiveRewrite(currentArchiveSourceFile)) {
@@ -3159,13 +3304,9 @@ public class FilePanelTab extends JPanel {
                         deleteTempDirRecursively(currentArchiveTempDir);
                         clearOpenedArchiveSession();
                         loadDirectory(parent, false, true, () -> {
-                            // Restore original viewport position and keep focus on archive item.
+                            restoreReturnState(returnState, true);
-                            // In BRIEF mode some selection listeners may still run later, so apply once more on EDT tail.
-                            restoreArchiveReturnPosition();
-                            selectItemByName(archiveName, true, false);
                             SwingUtilities.invokeLater(() -> {
-                                restoreArchiveReturnPosition();
+                                restoreReturnState(returnState, true);
-                                selectItemByName(archiveName, true, false);
                                 clearArchiveReturnState();
                             });
                         });
@@ -3178,10 +3319,18 @@ public class FilePanelTab extends JPanel {
         File parent = currentDirectory.getParentFile();
         if (parent != null) {
             String previousDirName = currentDirectory.getName();
-            loadDirectory(parent, false);
+            ReturnNavigationState returnState = consumeReturnState(parent, previousDirName);
+            loadDirectory(parent, false, true, () -> {
+                if (returnState != null) {
+                    restoreReturnState(returnState, true);
+                } else {
+                    selectItemByName(previousDirName);
+                }
+            });
             
-            // Select the directory we just left
+            if (returnState != null) {
-            SwingUtilities.invokeLater(() -> selectItemByName(previousDirName));
+                SwingUtilities.invokeLater(() -> restoreReturnState(returnState, true));
+            }
         }
     }