source/blender/editors/include/UI_interface.h

@@ -8,6 +8,11 @@
 
 #pragma once
 
+#ifdef __cplusplus
+#  include <functional>
+#  include <string>
+#endif
+
 #include "BLI_compiler_attrs.h"
 #include "BLI_string_utf8_symbols.h"
 #include "BLI_sys_types.h" /* size_t */
@@ -289,8 +294,11 @@ enum {
   UI_BUT_TEXT_RIGHT = 1 << 3,
   /** Prevent the button to show any tooltip. */
   UI_BUT_NO_TOOLTIP = 1 << 4,
+  /** Always show a tooltip label (the short tooltip that appears faster than the full one and only
+   * shows the label) even the label may already be visible. */
+  UI_BUT_FORCE_TOOLTIP_LABEL = 1 << 5,
   /** Do not add the usual horizontal padding for text drawing. */
-  UI_BUT_NO_TEXT_PADDING = 1 << 5,
+  UI_BUT_NO_TEXT_PADDING = 1 << 6,
 
   /* Button align flag, for drawing groups together.
    * Used in 'uiBlock.flag', take care! */
@@ -1386,6 +1394,8 @@ typedef enum uiStringInfoType {
   BUT_GET_RNASTRUCT_IDENTIFIER,
   BUT_GET_RNAENUM_IDENTIFIER,
   BUT_GET_LABEL,
+  /** Sometimes the button doesn't have a label itself, but provides one for the tooltip. */
+  BUT_GET_TIP_LABEL,
   BUT_GET_RNA_LABEL,
   BUT_GET_RNAENUM_LABEL,
   BUT_GET_RNA_LABEL_CONTEXT, /* Context specified in CTX_XXX_ macros are just unreachable! */
@@ -1746,6 +1756,10 @@ void UI_but_func_drawextra_set(
 
 void UI_but_func_menu_step_set(uiBut *but, uiMenuStepFunc func);
 
+#ifdef __cplusplus
+void UI_but_func_tooltip_label_set(uiBut *but, std::function<std::string(const uiBut *but)> func);
+#endif
+
 void UI_but_func_tooltip_set(uiBut *but, uiButToolTipFunc func, void *arg, uiFreeArgFunc free_arg);
 /**
  * Recreate tool-tip (use to update dynamic tips)

source/blender/editors/interface/interface.cc

@@ -856,7 +856,7 @@ static void ui_but_update_old_active_from_new(uiBut *oldbut, uiBut *but)
 
   /* flags from the buttons we want to refresh, may want to add more here... */
   const int flag_copy = UI_BUT_REDALERT | UI_HAS_ICON | UI_SELECT_DRAW;
-  const int drawflag_copy = 0; /* None currently. */
+  const int drawflag_copy = UI_BUT_FORCE_TOOLTIP_LABEL;
 
   /* still stuff needs to be copied */
   oldbut->rect = but->rect;
@@ -878,6 +878,7 @@ static void ui_but_update_old_active_from_new(uiBut *oldbut, uiBut *but)
   std::swap(oldbut->tip_func, but->tip_func);
   std::swap(oldbut->tip_arg, but->tip_arg);
   std::swap(oldbut->tip_arg_free, but->tip_arg_free);
+  std::swap(oldbut->tip_label_func, but->tip_label_func);
 
   oldbut->flag = (oldbut->flag & ~flag_copy) | (but->flag & flag_copy);
   oldbut->drawflag = (oldbut->drawflag & ~drawflag_copy) | (but->drawflag & drawflag_copy);
@@ -6076,6 +6077,11 @@ void UI_but_func_menu_step_set(uiBut *but, uiMenuStepFunc func)
   but->menu_step_func = func;
 }
 
+void UI_but_func_tooltip_label_set(uiBut *but, std::function<std::string(const uiBut *but)> func)
+{
+  but->tip_label_func = func;
+}
+
 void UI_but_func_tooltip_set(uiBut *but, uiButToolTipFunc func, void *arg, uiFreeArgFunc free_arg)
 {
   but->tip_func = func;
@@ -6577,6 +6583,17 @@ void UI_but_string_info_get(bContext *C, uiBut *but, ...)
     uiStringInfoType type = si->type;
     char *tmp = nullptr;
 
+    if (type == BUT_GET_TIP_LABEL) {
+      if (but->tip_label_func) {
+        const std::string tooltip_label = but->tip_label_func(but);
+        tmp = BLI_strdupn(tooltip_label.c_str(), tooltip_label.size());
+      }
+      /* Fallback to the regular label. */
+      else {
+        type = BUT_GET_LABEL;
+      }
+    }
+
     if (type == BUT_GET_LABEL) {
       if (but->str && but->str[0]) {
         const char *str_sep;

source/blender/editors/interface/interface_intern.hh

@@ -219,6 +219,7 @@ struct uiBut {
   uiButToolTipFunc tip_func = nullptr;
   void *tip_arg = nullptr;
   uiFreeArgFunc tip_arg_free = nullptr;
+  std::function<std::string(const uiBut *)> tip_label_func;
 
   /** info on why button is disabled, displayed in tooltip */
   const char *disabled_info = nullptr;

source/blender/editors/interface/interface_query.cc

@@ -144,11 +144,19 @@ bool UI_but_is_tool(const uiBut *but)
 
 bool UI_but_has_tooltip_label(const uiBut *but)
 {
+  if (but->drawflag & UI_BUT_FORCE_TOOLTIP_LABEL) {
+    return true;
+  }
+
   /* No tooltip label if the button itself shows a label already. */
   if (but->drawstr[0] != '\0') {
     return false;
   }
 
+  if (but->tip_label_func) {
+    return true;
+  }
+
   if (UI_but_is_tool(but)) {
     return !ui_block_is_popover(but->block);
   }

source/blender/editors/interface/interface_region_tooltip.cc

@@ -751,6 +751,7 @@ static uiTooltipData *ui_tooltip_data_from_button_or_extra_icon(bContext *C,
                                                                 const bool is_label)
 {
   uiStringInfo but_label = {BUT_GET_LABEL, nullptr};
+  uiStringInfo but_tip_label = {BUT_GET_TIP_LABEL, nullptr};
   uiStringInfo but_tip = {BUT_GET_TIP, nullptr};
   uiStringInfo enum_label = {BUT_GET_RNAENUM_LABEL, nullptr};
   uiStringInfo enum_tip = {BUT_GET_RNAENUM_TIP, nullptr};
@@ -770,20 +771,22 @@ static uiTooltipData *ui_tooltip_data_from_button_or_extra_icon(bContext *C,
 
   if (extra_icon) {
     if (is_label) {
-      UI_but_extra_icon_string_info_get(C, extra_icon, &but_label, &enum_label, nullptr);
+      UI_but_extra_icon_string_info_get(C, extra_icon, &but_tip_label, &enum_label, nullptr);
     }
     else {
-      UI_but_extra_icon_string_info_get(C, extra_icon, &but_label, &but_tip, &op_keymap, nullptr);
+      UI_but_extra_icon_string_info_get(
+          C, extra_icon, &but_label, &but_tip_label, &but_tip, &op_keymap, nullptr);
     }
   }
   else {
     if (is_label) {
-      UI_but_string_info_get(C, but, &but_label, &enum_label, nullptr);
+      UI_but_string_info_get(C, but, &but_tip_label, &enum_label, nullptr);
     }
     else {
       UI_but_string_info_get(C,
                              but,
                              &but_label,
+                             &but_tip_label,
                              &but_tip,
                              &enum_label,
                              &enum_tip,
@@ -799,11 +802,14 @@ static uiTooltipData *ui_tooltip_data_from_button_or_extra_icon(bContext *C,
    * Check prefix instead of comparing because the button may include the shortcut.
    * Buttons with dynamic tool-tips also don't get their default label here since they
    * can already provide more accurate and specific tool-tip content. */
-  if (but_label.strinfo && !STRPREFIX(but->drawstr, but_label.strinfo) && !but->tip_func) {
+  const bool force_tip_label = but->drawflag & UI_BUT_FORCE_TOOLTIP_LABEL;
+  if (but_tip_label.strinfo &&
+      (force_tip_label || (!STRPREFIX(but->drawstr, but_tip_label.strinfo) && !but->tip_func)))
+  {
     uiTooltipField *field = text_field_add(
         data, uiTooltipFormat::Style::Header, uiTooltipFormat::ColorID::Normal);
 
-    field->text = BLI_strdup(but_label.strinfo);
+    field->text = BLI_strdup(but_tip_label.strinfo);
   }
 
   /* Tip */
@@ -986,6 +992,9 @@ static uiTooltipData *ui_tooltip_data_from_button_or_extra_icon(bContext *C,
   if (but_label.strinfo) {
     MEM_freeN(but_label.strinfo);
   }
+  if (but_tip_label.strinfo) {
+    MEM_freeN(but_tip_label.strinfo);
+  }
   if (but_tip.strinfo) {
     MEM_freeN(but_tip.strinfo);
   }