From 54cf7b9a5da05f8da46ea410cf6d485acedf5046 Mon Sep 17 00:00:00 2001
From: rdb <git@rdb.name>
Date: Sun, 23 Feb 2020 14:04:42 +0100
Subject: [PATCH] x11: add labels to various buttons returned from
 get_keyboard_map()
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This allows identifying, eg. the é button on French keyboard (which is at the location where 2 is on QWERTY)

This is not intended to be complete.  One must still choose what to display depending on the label and the mapped button handle (if any).
---
 panda/src/x11display/x11GraphicsWindow.cxx | 24 ++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/panda/src/x11display/x11GraphicsWindow.cxx b/panda/src/x11display/x11GraphicsWindow.cxx
index 1454346aa4..7dbd7c53dc 100644
--- a/panda/src/x11display/x11GraphicsWindow.cxx
+++ b/panda/src/x11display/x11GraphicsWindow.cxx
@@ -2014,11 +2014,31 @@ get_keyboard_map() const {
 
     KeySym sym = XkbKeycodeToKeysym(_display, k, 0, 0);
     ButtonHandle button = map_button(sym);
-    if (button == ButtonHandle::none()) {
+    std::string label;
+
+    // Compose a label for some keys; I have not yet been able to find an API
+    // that does this effectively.
+    if (sym >= XK_a && sym <= XK_z) {
+      label = toupper((char)sym);
+    }
+    else if (sym >= XK_F1 && sym <= XK_F35) {
+      label = "F" + format_string(sym - XK_F1 + 1);
+    }
+    else if (sym >= XK_exclamdown && sym <= XK_ydiaeresis) {
+      // A latin-1 symbol.  Translate this to the label.
+      char buffer[255];
+      int nbytes = XkbTranslateKeySym(_display, &sym, 0, buffer, 255, 0);
+      if (nbytes > 0) {
+        label.assign(buffer, nbytes);
+      }
+    }
+
+    if (button == ButtonHandle::none() && label.empty()) {
+      // No label and no mapping; this is useless.
       continue;
     }
 
-    map->map_button(raw_button, button);
+    map->map_button(raw_button, button, label);
   }
 
   return map;