source/blender/editors/interface/interface_handlers.cc

@@ -3660,6 +3660,61 @@ static void ui_textedit_prev_but(uiBlock *block, uiBut *actbut, uiHandleButtonDa
   }
 }
 
+/**
+ * Allow holding Alt, enter Unicode character code, release alt, to get special characters.
+ */
+
+static char unicode_input[10] = {0};
+
+static int ui_handle_unicode_input(uiBut *but,
+                                   uiHandleButtonData *data,
+                                   const wmEvent *event,
+                                   bool *changed)
+{
+  if (ELEM(event->type, EVT_LEFTALTKEY, EVT_RIGHTALTKEY)) {
+    if (event->val == KM_PRESS) {
+      /* Alt first held down, so clear any saved input. */
+      unicode_input[0] = 0;
+      return WM_UI_HANDLER_CONTINUE;
+    }
+    else if (event->val == KM_RELEASE && unicode_input[0]) {
+      /* Alt released so deal with any previous entry. */
+      uint val = strtoul(unicode_input, NULL, 16);
+      if (val > 31 && val < 0x10FFFF) {
+        char utf8[10] = {0};
+        char32_t utf32[2] = {val, 0};
+        const int utf8_buf_len = BLI_str_utf32_as_utf8(utf8, utf32, 5);
+        *changed = ui_textedit_insert_buf(but, data, utf8, utf8_buf_len);
+        return *changed ? WM_UI_HANDLER_BREAK : WM_UI_HANDLER_CONTINUE;
+      }
+    }
+  }
+
+  if (event->modifier & KM_ALT && event->val == KM_PRESS) {
+    /* Holding Alt while pressing a key. */
+    char ch = 0;
+    if ((event->type >= EVT_ZEROKEY && event->type <= EVT_NINEKEY) ||
+        (event->type >= EVT_AKEY && event->type <= EVT_FKEY))
+    {
+      ch = event->type;
+    }
+    else if (event->type >= EVT_PAD0 && event->type <= EVT_PAD9) {
+      ch = event->type - 102;
+    }
+
+    if (ch) {
+      int len = BLI_strnlen(unicode_input, ARRAY_SIZE(unicode_input));
+      if (len < ARRAY_SIZE(unicode_input) - 1) {
+        unicode_input[len] = ch;
+        unicode_input[len + 1] = 0;
+        return WM_UI_HANDLER_BREAK;
+      }
+    }
+  }
+
+  return WM_UI_HANDLER_CONTINUE;
+}
+
 /**
  * Return the jump type used for cursor motion & back-space/delete actions.
  */
@@ -3818,6 +3873,8 @@ static void ui_do_but_textedit(
     }
   }
 
+  retval = ui_handle_unicode_input(but, data, event, &changed);
+
   if (event->val == KM_PRESS && !is_ime_composing) {
     switch (event->type) {
       case EVT_VKEY: