UI: Add padding to items in ui lists and tree views

Add a utility function to add horizontal padding to the left and right
of items in UI lists and tree views to make them more consistent with
other buttons like menu entries.

Pull Request: https://projects.blender.org/blender/blender/pulls/125498

scripts/startup/bl_ui/properties_data_armature.py

@@ -378,7 +378,6 @@ class POSE_PT_selection_sets(Panel):
 class POSE_UL_selection_set(UIList):
     def draw_item(self, context, layout, data, item, icon, active_data, active_propname, index):
         row = layout.row()
-        row.separator()
         row.prop(item, "name", text="", emboss=False)
         if self.layout_type in ('DEFAULT', 'COMPACT'):
             row.prop(item, "is_selected", text="")

source/blender/editors/include/UI_interface_c.hh

@@ -2331,6 +2331,9 @@ bool uiLayoutGetPropDecorate(uiLayout *layout);
 Panel *uiLayoutGetRootPanel(uiLayout *layout);
 float uiLayoutGetSearchWeight(uiLayout *layout);
 
+int uiLayoutListItemPaddingWidth();
+void uiLayoutListItemAddPadding(uiLayout *layout);
+
 /* Layout create functions. */
 
 uiLayout *uiLayoutRow(uiLayout *layout, bool align);

source/blender/editors/interface/interface_layout.cc

@@ -5396,6 +5396,24 @@ eUIEmbossType uiLayoutGetEmboss(uiLayout *layout)
   return layout->emboss;
 }
 
+int uiLayoutListItemPaddingWidth()
+{
+  return 5 * UI_SCALE_FAC;
+}
+
+void uiLayoutListItemAddPadding(uiLayout *layout)
+{
+  uiBlock *block = uiLayoutGetBlock(layout);
+  uiLayout *row = uiLayoutRow(layout, true);
+  uiLayoutSetFixedSize(row, true);
+
+  uiDefBut(
+      block, UI_BTYPE_SEPR, 0, "", 0, 0, uiLayoutListItemPaddingWidth(), 0, nullptr, 0.0, 0.0, "");
+
+  /* Restore. */
+  UI_block_layout_set_current(block, layout);
+}
+
 /** \} */
 
 /* -------------------------------------------------------------------- */

source/blender/editors/interface/templates/interface_template_list.cc

@@ -794,8 +794,11 @@ static void ui_template_list_layout_draw(const bContext *C,
             UI_but_func_tooltip_set(but, uilist_item_tooltip_func, dyntip_data, MEM_freeN);
           }
 
-          sub = uiLayoutRow(overlap, false);
+          uiLayout *item_row = uiLayoutRow(overlap, true);
 
+          uiLayoutListItemAddPadding(item_row);
+
+          sub = uiLayoutRow(item_row, false);
           icon = UI_icon_from_rnaptr(C, itemptr, rnaicon, false);
           if (icon == ICON_DOT) {
             icon = ICON_NONE;
@@ -820,6 +823,7 @@ static void ui_template_list_layout_draw(const bContext *C,
             ui_layout_list_set_labels_active(sub);
           }
 
+          uiLayoutListItemAddPadding(item_row);
           UI_block_flag_disable(subblock, UI_BLOCK_LIST_ITEM);
         }
       }

source/blender/editors/interface/templates/interface_templates.cc

@@ -2962,7 +2962,6 @@ static void draw_exporter_item(uiList * /*ui_list*/,
   RNA_string_get(itemptr, "name", name);
 
   uiLayout *row = uiLayoutRow(layout, false);
-  uiItemS(row);
   uiItemL(row, name, ICON_NONE);
 }
 

source/blender/editors/interface/views/tree_view.cc

@@ -171,9 +171,10 @@ void AbstractTreeView::draw_hierarchy_lines_recursive(const ARegion &region,
     rcti last_child_rect;
     ui_but_to_pixelrect(&last_child_rect, &region, block, &last_child_but);
 
-    const float x = first_child_rect.xmin + ((first_descendant->indent_width() -
-                                              (0.5f * UI_ICON_SIZE) + U.pixelsize + UI_SCALE_FAC) /
-                                             aspect);
+    const float x = first_child_rect.xmin +
+                    ((first_descendant->indent_width() + uiLayoutListItemPaddingWidth() -
+                      (0.5f * UI_ICON_SIZE) + U.pixelsize) /
+                     aspect);
     const int first_child_top = first_child_rect.ymax - (2.0f * UI_SCALE_FAC / aspect);
     const int last_child_bottom = last_child_rect.ymin + (4.0f * UI_SCALE_FAC / aspect);
     immBegin(GPU_PRIM_LINES, 2);
@@ -695,6 +696,8 @@ void TreeViewLayoutBuilder::build_row(AbstractTreeViewItem &item) const
     uiDefBut(&block_, UI_BTYPE_LABEL, 0, "", 0, 0, UI_UNIT_X, margin_top, nullptr, 0, 0, "");
   }
   row = uiLayoutRow(content_col, true);
+
+  uiLayoutListItemAddPadding(row);
   item.add_indent(*row);
   item.add_collapse_chevron(block_);
 
@@ -705,6 +708,8 @@ void TreeViewLayoutBuilder::build_row(AbstractTreeViewItem &item) const
     item.build_row(*row);
   }
 
+  uiLayoutListItemAddPadding(row);
+
   UI_block_emboss_set(&block_, previous_emboss);
   UI_block_layout_set_current(&block_, &prev_layout);
 }