Add method to get first visible entry index and adjust selection logic for hidden default entries

src/hosts/main.py

@@ -176,6 +176,20 @@ class HostsManagerApp(App):
         
         return visible_entries
     
+    def get_first_visible_entry_index(self) -> int:
+        """Get the index of the first visible entry in the hosts file."""
+        show_defaults = self.config.should_show_default_entries()
+        
+        for i, entry in enumerate(self.hosts_file.entries):
+            canonical_hostname = entry.hostnames[0] if entry.hostnames else ""
+            # Skip default entries if configured to hide them
+            if not show_defaults and self.config.is_default_entry(entry.ip_address, canonical_hostname):
+                continue
+            return i
+        
+        # If no visible entries found, return 0
+        return 0
+    
     def display_index_to_actual_index(self, display_index: int) -> int:
         """Convert a display table index to the actual hosts file entry index."""
         visible_entries = self.get_visible_entries()
@@ -270,8 +284,8 @@ class HostsManagerApp(App):
             return
         
         if previous_entry is None:
-            # No previous selection, start at first entry
+            # No previous selection, start at first visible entry
-            self.selected_entry_index = 0
+            self.selected_entry_index = self.get_first_visible_entry_index()
         else:
             # Try to find the same entry in the reloaded file
             for i, entry in enumerate(self.hosts_file.entries):
@@ -281,8 +295,8 @@ class HostsManagerApp(App):
                     self.selected_entry_index = i
                     break
             else:
-                # Entry not found, default to first entry
+                # Entry not found, default to first visible entry
-                self.selected_entry_index = 0
+                self.selected_entry_index = self.get_first_visible_entry_index()
         
         # Update the DataTable cursor position using display index
         table = self.query_one("#entries-table", DataTable)
@@ -302,6 +316,27 @@ class HostsManagerApp(App):
             details_widget.update("No entries loaded")
             return
         
+        # Get visible entries to check if we need to adjust selection
+        visible_entries = self.get_visible_entries()
+        if not visible_entries:
+            details_widget.update("No visible entries")
+            return
+        
+        # If default entries are hidden and selected_entry_index points to a hidden entry,
+        # we need to find the corresponding visible entry
+        show_defaults = self.config.should_show_default_entries()
+        if not show_defaults:
+            # Check if the currently selected entry is a default entry (hidden)
+            if (self.selected_entry_index < len(self.hosts_file.entries) and 
+                self.hosts_file.entries[self.selected_entry_index].is_default_entry()):
+                # The selected entry is hidden, so we should show the first visible entry instead
+                if visible_entries:
+                    # Find the first visible entry in the hosts file
+                    for i, entry in enumerate(self.hosts_file.entries):
+                        if not entry.is_default_entry():
+                            self.selected_entry_index = i
+                            break
+        
         if self.selected_entry_index >= len(self.hosts_file.entries):
             self.selected_entry_index = 0