fixes

src/main/java/com/kfmanager/config/AppConfig.java

@@ -244,6 +244,37 @@ public class AppConfig {
         }
     }
 
+    // --- File Associations ---
+    /** Returns a map of pattern (extension or wildcard) -> command */
+    public java.util.Map<String, String> getFileAssociations() {
+        java.util.Map<String, String> map = new java.util.HashMap<>();
+        for (String key : properties.stringPropertyNames()) {
+            if (key.startsWith("assoc.")) {
+                String pattern = key.substring(6);
+                map.put(pattern, properties.getProperty(key));
+            }
+        }
+        return map;
+    }
+
+    public void setFileAssociations(java.util.Map<String, String> associations) {
+        // Remove all current associations first
+        for (String key : properties.stringPropertyNames()) {
+            if (key.startsWith("assoc.")) {
+                properties.remove(key);
+            }
+        }
+        // Add new ones
+        if (associations != null) {
+            for (java.util.Map.Entry<String, String> entry : associations.entrySet()) {
+                String pattern = entry.getKey().trim();
+                if (!pattern.isEmpty()) {
+                    properties.setProperty("assoc." + pattern, entry.getValue());
+                }
+            }
+        }
+    }
+
     // --- Appearance (global) settings ---
     public String getGlobalFontName() {
         return properties.getProperty("global.font.name", "Monospaced");

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

@@ -891,10 +891,87 @@ public class FilePanelTab extends JPanel {
                 }
             } else if (item.isDirectory()) {
                 loadDirectory(item.getFile());
+            } else if (item.getFile().isFile()) {
+                openFileNative(item.getFile());
             }
         }
     }
 
+    private void openFileNative(File file) {
+        try {
+            // 1. Check custom associations from config (wildcard matching)
+            if (persistedConfig != null) {
+                java.util.Map<String, String> associations = persistedConfig.getFileAssociations();
+                String name = file.getName();
+                String command = null;
+
+                // Sort associations by length descending to match more specific patterns first (e.g. *.tar.gz before *.gz)
+                java.util.List<String> patterns = new java.util.ArrayList<>(associations.keySet());
+                patterns.sort((a, b) -> Integer.compare(b.length(), a.length()));
+
+                for (String pattern : patterns) {
+                    String glob = pattern;
+                    // If user just provided an extension like "txt", convert to "*.txt"
+                    if (!glob.contains("*") && !glob.contains("?")) {
+                        glob = "*." + glob;
+                    }
+
+                    try {
+                        java.nio.file.PathMatcher matcher = java.nio.file.FileSystems.getDefault().getPathMatcher("glob:" + glob);
+                        if (matcher.matches(java.nio.file.Paths.get(name))) {
+                            command = associations.get(pattern);
+                            break;
+                        }
+                    } catch (Exception ignore) {
+                        // Fallback for simple extension match if glob is invalid
+                        if (name.toLowerCase().endsWith("." + pattern.toLowerCase())) {
+                            command = associations.get(pattern);
+                            break;
+                        }
+                    }
+                }
+
+                if (command != null && !command.trim().isEmpty()) {
+                    String fullPath = file.getAbsolutePath();
+                    String fileName = file.getName();
+                    String trimmedCmd = command.trim();
+                    boolean hasPlaceholder = trimmedCmd.contains("%f") || trimmedCmd.contains("%n");
+
+                    java.util.List<String> cmdList = new java.util.ArrayList<>();
+                    String[] parts = trimmedCmd.split("\\s+");
+                    for (String part : parts) {
+                        String processed = part.replace("%f", fullPath).replace("%n", fileName);
+                        if (processed.startsWith("\"") && processed.endsWith("\"") && processed.length() >= 2) {
+                            processed = processed.substring(1, processed.length() - 1);
+                        }
+                        cmdList.add(processed);
+                    }
+
+                    if (!hasPlaceholder) {
+                        cmdList.add(fullPath);
+                    }
+
+                    new ProcessBuilder(cmdList).directory(file.getParentFile()).start();
+                    return;
+                }
+            }
+
+            // 2. If executable, start it directly
+            if (file.canExecute() && !file.isDirectory()) {
+                new ProcessBuilder(file.getAbsolutePath())
+                    .directory(file.getParentFile())
+                    .start();
+            } else if (Desktop.isDesktopSupported() && Desktop.getDesktop().isSupported(Desktop.Action.OPEN)) {
+                // 3. Fallback to system default
+                Desktop.getDesktop().open(file);
+            }
+        } catch (Exception ex) {
+            try {
+                JOptionPane.showMessageDialog(this, "Error opening file: " + ex.getMessage(), "Error", JOptionPane.ERROR_MESSAGE);
+            } catch (Exception ignore) {}
+        }
+    }
+
     /**
      * Open the item located at the given point (used for double-clicks while
      * mouse-driven selection is blocked). This mirrors the behavior of
@@ -931,6 +1008,8 @@ public class FilePanelTab extends JPanel {
             }
         } else if (item.isDirectory()) {
             loadDirectory(item.getFile());
+        } else if (item.getFile().isFile()) {
+            openFileNative(item.getFile());
         }
     }
 
@@ -949,13 +1028,7 @@ public class FilePanelTab extends JPanel {
             if (item.isDirectory()) {
                 loadDirectory(item.getFile());
             } else {
-                try {
-                    if (Desktop.isDesktopSupported()) {
-                        Desktop.getDesktop().open(item.getFile());
-                    }
-                } catch (Exception ex) {
-                    try { JOptionPane.showMessageDialog(FilePanelTab.this, "Cannot open: " + ex.getMessage()); } catch (Exception ignore) {}
-                }
+                openFileNative(item.getFile());
             }
         });
         menu.add(openItem);

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

@@ -3,6 +3,7 @@ package com.kfmanager.ui;
 import com.kfmanager.config.AppConfig;
 
 import javax.swing.*;
+import javax.swing.table.DefaultTableModel;
 import java.awt.*;
 import java.io.File;
 import java.util.HashMap;
@@ -29,6 +30,7 @@ public class SettingsDialog extends JDialog {
     private final String originalExternalEditorPath;
     private final int originalToolbarButtonSize;
     private final int originalToolbarIconSize;
+    private final java.util.Map<String, String> originalFileAssociations;
 
     // Appearance controls
     private JButton appearanceFontBtn;
@@ -58,6 +60,7 @@ public class SettingsDialog extends JDialog {
         this.originalExternalEditorPath = config.getExternalEditorPath();
         this.originalToolbarButtonSize = config.getToolbarButtonSize();
         this.originalToolbarIconSize = config.getToolbarIconSize();
+        this.originalFileAssociations = new java.util.HashMap<>(config.getFileAssociations());
 
         setDefaultCloseOperation(DISPOSE_ON_CLOSE);
         setSize(700, 420);
@@ -69,6 +72,7 @@ public class SettingsDialog extends JDialog {
     model.addElement("Editor");
     model.addElement("Sorting");
     model.addElement("Toolbar");
+    model.addElement("Associations");
         categoryList = new JList<>(model);
         categoryList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
         categoryList.setSelectedIndex(0);
@@ -81,6 +85,7 @@ public class SettingsDialog extends JDialog {
     cards.add(buildEditorPanel(), "Editor");
     cards.add(buildSortingPanel(), "Sorting");
     cards.add(buildToolbarPanel(), "Toolbar");
+    cards.add(buildAssociationsPanel(), "Associations");
 
         categoryList.addListSelectionListener(e -> {
             if (!e.getValueIsAdjusting()) {
@@ -169,6 +174,25 @@ public class SettingsDialog extends JDialog {
                     if (is != null) config.setToolbarIconSize((Integer) is.getValue());
                 } catch (Exception ignore) {}
             }
+
+            // Collect Associations settings
+            JPanel assocHolder = (JPanel) panels.get("Associations");
+            if (assocHolder != null) {
+                try {
+                    DefaultTableModel assocModel = (DefaultTableModel) assocHolder.getClientProperty("tableModel");
+                    if (assocModel != null) {
+                        java.util.Map<String, String> map = new java.util.HashMap<>();
+                        for (int i = 0; i < assocModel.getRowCount(); i++) {
+                            String ext = (String) assocModel.getValueAt(i, 0);
+                            String cmd = (String) assocModel.getValueAt(i, 1);
+                            if (ext != null && !ext.trim().isEmpty() && cmd != null && !cmd.trim().isEmpty()) {
+                                map.put(ext.trim(), cmd.trim());
+                            }
+                        }
+                        config.setFileAssociations(map);
+                    }
+                } catch (Exception ignore) {}
+            }
             
             // Save external editor path
             if (externalEditorField != null) {
@@ -192,6 +216,7 @@ public class SettingsDialog extends JDialog {
             config.setExternalEditorPath(originalExternalEditorPath);
             config.setToolbarButtonSize(originalToolbarButtonSize);
             config.setToolbarIconSize(originalToolbarIconSize);
+            config.setFileAssociations(originalFileAssociations);
             
             // Notify UI to revert changes
             if (onChange != null) onChange.run();
@@ -517,6 +542,44 @@ public class SettingsDialog extends JDialog {
         return p;
     }
 
+    private JPanel buildAssociationsPanel() {
+        JPanel p = new JPanel(new BorderLayout(8, 8));
+        p.setBorder(BorderFactory.createEmptyBorder(12, 12, 12, 12));
+
+        JLabel hint = new JLabel("<html>Use <b>wildcards</b> (e.g. *.tar.gz) or plain extension (e.g. txt).<br>" +
+                                "Use <b>%f</b> for full path, <b>%n</b> for filename. " +
+                                "If no placeholder is used, path is appended to the end.</html>");
+        p.add(hint, BorderLayout.NORTH);
+
+        DefaultTableModel model = new DefaultTableModel(new String[]{"Pattern", "Command"}, 0);
+        java.util.Map<String, String> current = config.getFileAssociations();
+        for (java.util.Map.Entry<String, String> entry : current.entrySet()) {
+            model.addRow(new Object[]{entry.getKey(), entry.getValue()});
+        }
+
+        JTable table = new JTable(model);
+        p.add(new JScrollPane(table), BorderLayout.CENTER);
+
+        JPanel btnPanel = new JPanel(new FlowLayout(FlowLayout.LEFT));
+        JButton addBtn = new JButton("Add");
+        addBtn.addActionListener(e -> model.addRow(new Object[]{"", ""}));
+        JButton removeBtn = new JButton("Remove");
+        removeBtn.addActionListener(e -> {
+            int row = table.getSelectedRow();
+            if (row >= 0) model.removeRow(row);
+        });
+        btnPanel.add(addBtn);
+        btnPanel.add(removeBtn);
+        p.add(btnPanel, BorderLayout.SOUTH);
+
+        // Save reference for OK action
+        JPanel holder = new JPanel();
+        holder.putClientProperty("tableModel", model);
+        panels.put("Associations", holder);
+
+        return p;
+    }
+
     private static String capitalize(String s) {
         if (s == null || s.isEmpty()) return s;
         return s.substring(0,1).toUpperCase() + s.substring(1).toLowerCase();