[202_106] display the shortcut keys corresponding to the symbols in the right footer

devel/202_106.md

@@ -0,0 +1,40 @@
+# 2886 Display Symbol Shortcuts in Right Footer
+
+## How to Test
+1. Open a document in the editor.  
+2. Move the cursor to a position where a symbol is present.  
+3. Verify that the right footer displays the corresponding keyboard shortcut.  
+4. Move the cursor away from the symbol and confirm that the footer clears.
+
+---
+
+## 2026/02/28 Display corresponding symbol shortcut keys in the right
+
+### What  
+Display the keyboard shortcut of a symbol in the right footer when the editor cursor is positioned at or near that symbol.
+
+
+### How  
+
+**Shortcut lookup (Scheme)**  
+`kbd-find-inv-binding` – resolves a command string (e.g., `<symbol>`) to its inverse keyboard shortcut.
+
+**C++ integration**  
+`src/Edit/Interface/edit_footer.cpp` – two shortcut display paths:
+
+- **Symbol path:**  
+  `get_shortcut_suffix(cmd_s)` calls `kbd-find-inv-binding`, rewrites the keybinding via `kbd_system_rewrite`, formats it as `" [Shortcut]"`, and caches the result using a static `hashmap<string, tree>`.
+
+- **Operation path:**  
+  `compute_operation_footer()` retrieves the operation name via `drd->get_name(...)`, resolves its shortcut using `kbd_shortcut("(make '<op>)")`, and appends it as `" [Shortcut]"`.
+
+**Footer rendering logic**  
+In `compute_text_footer()`:
+- Detects symbol commands using `starts(r, "<")` (excluding `<#...>` internal commands).
+- Retrieves the shortcut suffix via `get_shortcut_suffix()`.
+- Appends the formatted shortcut to the displayed symbol in the footer.
+
+**Performance optimization**  
+A static `shortcut_cache` avoids repeated Scheme lookups during frequent cursor updates. Only the symbol resolution path uses caching.
+
+---

src/Edit/Interface/edit_footer.cpp

@@ -130,6 +130,24 @@ edit_interface_rep::set_middle_footer () {
  * Set right footer with information about cursor position
  ******************************************************************************/
 
+// Cache for keyboard shortcuts
+static hashmap<string, tree> shortcut_cache ("");
+
+tree
+edit_interface_rep::get_shortcut_suffix (string cmd_s) {
+  if (shortcut_cache->contains (cmd_s)) return shortcut_cache[cmd_s];
+
+  object result_obj= call ("kbd-find-inv-binding", object (cmd_s));
+  string binding   = as_string (result_obj);
+  tree   result    = "";
+  if (binding != "" && binding != "#f") {
+    tree shortcut_tree= sv->kbd_system_rewrite (binding);
+    result            = concat (" [", shortcut_tree, "]");
+  }
+  shortcut_cache (cmd_s)= result;
+  return result;
+}
+
 void
 edit_interface_rep::set_right_footer (tree r) {
   SERVER (
@@ -147,9 +165,12 @@ edit_interface_rep::compute_text_footer (tree st) {
   if (r == "") r= "start";
   if (r == " ") r= "space";
   if (r == "space" && get_env_string (MODE) == "math") r= "apply";
-  if (starts (r, "<") && !starts (r, "<#"))
+  if (starts (r, "<") && !starts (r, "<#")) {
+    tree suffix= get_shortcut_suffix (r);
     if (cork_to_utf8 (r) != r) r= r * " (" * r (1, N (r) - 1) * ")";
-  if (starts (r, "<")) return verbatim (r);
+    if (suffix != "") return concat (verbatim (r), suffix);
+    return verbatim (r);
+  }
   return r;
 }
 
@@ -327,6 +348,10 @@ edit_interface_rep::compute_operation_footer (tree st) {
     }
   }
   if (last_item (tp) == 0) r= concat ("before ", r);
+  string op_name   = drd->get_name (L (st));
+  tree   shortcut  = kbd_shortcut ("(make '" * op_name * ")");
+  string shortcut_s= as_string (shortcut);
+  if (shortcut_s != "") r= concat (r, " [", shortcut, "]");
   return r;
 }
 

src/Edit/Interface/edit_interface.hpp

@@ -259,6 +259,7 @@ class edit_interface_rep : virtual public editor_rep {
   bool      should_show_image_popup (tree t);
 
   /* the footer */
+  tree get_shortcut_suffix (string cmd_s);
   tree compute_text_footer (tree st);
   tree compute_operation_footer (tree st);
   tree compute_compound_footer (tree t, path p);