source/blender/editors/include/ED_util.hh

@@ -104,6 +104,9 @@ void ED_slider_allow_increments_set(tSlider *slider, bool value);
 void ED_slider_mode_set(tSlider *slider, SliderMode mode);
 SliderMode ED_slider_mode_get(const tSlider *slider);
 void ED_slider_unit_set(tSlider *slider, const char *unit);
+/* Set a name that will show next to the slider to indicate which property is modified currently.
+ * To clear, set to an empty string. */
+void ED_slider_property_label_set(tSlider *slider, const char *prop_name);
 
 /* ************** XXX OLD CRUFT WARNING ************* */
 

source/blender/editors/space_graph/graph_slider_ops.cc

@@ -1030,6 +1030,7 @@ static int ease_modal(bContext *C, wmOperator *op, const wmEvent *event)
         ED_slider_unit_set(gso->slider, "%");
         gso->factor_prop = RNA_struct_find_property(op->ptr, "factor");
       }
+      ED_slider_property_label_set(gso->slider, RNA_property_ui_name(gso->factor_prop));
       ease_modal_update(C, op);
       break;
     }
@@ -1055,6 +1056,7 @@ static int ease_invoke(bContext *C, wmOperator *op, const wmEvent *event)
   ED_slider_allow_overshoot_set(gso->slider, false, false);
   ED_slider_factor_bounds_set(gso->slider, -1, 1);
   ED_slider_factor_set(gso->slider, 0.0f);
+  ED_slider_property_label_set(gso->slider, RNA_property_ui_name(gso->factor_prop));
 
   return invoke_result;
 }

source/blender/editors/util/ed_draw.cc

@@ -81,6 +81,10 @@ struct tSlider {
   /* How the factor number is drawn. When drawing percent it is factor*100. */
   SliderMode slider_mode;
 
+  /* Optional string that will display next to the slider to indicate which property is modified
+   * right now. */
+  std::string property_label;
+
   /* What unit to add to the slider. */
   char unit_string[SLIDER_UNIT_STRING_SIZE];
 
@@ -224,19 +228,28 @@ static void draw_backdrop(const int fontid,
                           const rctf *main_line_rect,
                           const uint8_t color_bg[4],
                           const short region_y_size,
-                          const float base_tick_height)
+                          const float base_tick_height,
+                          const std::string &property_label)
 {
-  float string_pixel_size[2];
+  float percent_string_pixel_size[2];
   const char *percentage_string_placeholder = "000%%";
   BLF_width_and_height(fontid,
                        percentage_string_placeholder,
                        sizeof(percentage_string_placeholder),
-                       &string_pixel_size[0],
-                       &string_pixel_size[1]);
-  const float pad[2] = {(region_y_size - base_tick_height) / 2, 2.0f * U.pixelsize};
+                       &percent_string_pixel_size[0],
+                       &percent_string_pixel_size[1]);
+
+  float property_name_pixel_size[2];
+  BLF_width_and_height(fontid,
+                       property_label.c_str(),
+                       property_label.size(),
+                       &property_name_pixel_size[0],
+                       &property_name_pixel_size[1]);
+  const float pad[2] = {(region_y_size - base_tick_height) / 2 + 12.0f * U.pixelsize,
+                        2.0f * U.pixelsize};
   rctf backdrop_rect{};
-  backdrop_rect.xmin = main_line_rect->xmin - string_pixel_size[0] - pad[0];
-  backdrop_rect.xmax = main_line_rect->xmax + pad[0];
+  backdrop_rect.xmin = main_line_rect->xmin - property_name_pixel_size[0] - pad[0];
+  backdrop_rect.xmax = main_line_rect->xmax + percent_string_pixel_size[0] + pad[0];
   backdrop_rect.ymin = pad[1];
   backdrop_rect.ymax = region_y_size - pad[1];
   UI_draw_roundbox_3ub_alpha(&backdrop_rect, true, 4.0f, color_bg, color_bg[3]);
@@ -304,7 +317,12 @@ static void slider_draw(const bContext * /*C*/, ARegion *region, void *arg)
     handle_pos_x = main_line_rect.xmin + SLIDE_PIXEL_DISTANCE * range_factor;
   }
 
-  draw_backdrop(fontid, &main_line_rect, color_bg, slider->region_header->winy, base_tick_height);
+  draw_backdrop(fontid,
+                &main_line_rect,
+                color_bg,
+                slider->region_header->winy,
+                base_tick_height,
+                slider->property_label);
 
   draw_main_line(&main_line_rect, slider->factor, slider->overshoot, color_overshoot, color_line);
 
@@ -356,11 +374,25 @@ static void slider_draw(const bContext * /*C*/, ARegion *region, void *arg)
                        &factor_string_pixel_size[0],
                        &factor_string_pixel_size[1]);
 
-  BLF_position(fontid,
-               main_line_rect.xmin - 12.0 * U.pixelsize - factor_string_pixel_size[0],
-               (region->winy / 2) - factor_string_pixel_size[1] / 2,
-               0.0f);
+  const float text_padding = 12.0 * U.pixelsize;
+  const float factor_string_pos_x = main_line_rect.xmax + text_padding;
+  BLF_position(
+      fontid, factor_string_pos_x, (region->winy / 2) - factor_string_pixel_size[1] / 2, 0.0f);
   BLF_draw(fontid, factor_string, sizeof(factor_string));
+
+  if (!slider->property_label.empty()) {
+    float property_name_pixel_size[2];
+    BLF_width_and_height(fontid,
+                         slider->property_label.c_str(),
+                         slider->property_label.length(),
+                         &property_name_pixel_size[0],
+                         &property_name_pixel_size[1]);
+    BLF_position(fontid,
+                 main_line_rect.xmin - text_padding - property_name_pixel_size[0],
+                 (region->winy / 2) - property_name_pixel_size[1] / 2,
+                 0.0f);
+    BLF_draw(fontid, slider->property_label.c_str(), slider->property_label.length());
+  }
 }
 
 static void slider_update_factor(tSlider *slider, const wmEvent *event)
@@ -584,6 +616,11 @@ void ED_slider_unit_set(tSlider *slider, const char *unit)
   STRNCPY(slider->unit_string, unit);
 }
 
+void ED_slider_property_label_set(tSlider *slider, const char *property_label)
+{
+  slider->property_label.assign(property_label);
+}
+
 /** \} */
 
 void ED_region_draw_mouse_line_cb(const bContext *C, ARegion *region, void *arg_info)