UI: Add highlight arguments to tab buttons

This adds arguments to `uiLayout.prop_tabs_enum` and the C equivalent
(`uiItemTabsEnumR_prop`) to gray out tabs based on a boolean array.

For property search in multiple tabs, we need a way to show which tabs
have a search result, but we still need to show which tab is active.

Differential Revision: https://developer.blender.org/D8858

source/blender/editors/include/UI_interface.h

@@ -2429,6 +2429,8 @@ void uiItemTabsEnumR_prop(uiLayout *layout,
                           struct bContext *C,
                           struct PointerRNA *ptr,
                           PropertyRNA *prop,
+                          struct PointerRNA *ptr_highlight,
+                          PropertyRNA *prop_highlight,
                           bool icon_only);
 
 /* Only for testing, inspecting layouts. */

source/blender/editors/interface/interface_layout.c

@@ -886,6 +886,8 @@ static void ui_item_enum_expand_tabs(uiLayout *layout,
                                      uiBlock *block,
                                      PointerRNA *ptr,
                                      PropertyRNA *prop,
+                                     PointerRNA *ptr_highlight,
+                                     PropertyRNA *prop_highlight,
                                      const char *uiname,
                                      const int h,
                                      const bool icon_only)
@@ -894,9 +896,24 @@ static void ui_item_enum_expand_tabs(uiLayout *layout,
 
   ui_item_enum_expand_exec(layout, block, ptr, prop, uiname, h, UI_BTYPE_TAB, icon_only);
   BLI_assert(last != block->buttons.last);
+
   for (uiBut *tab = last ? last->next : block->buttons.first; tab; tab = tab->next) {
     UI_but_drawflag_enable(tab, ui_but_align_opposite_to_area_align_get(CTX_wm_region(C)));
   }
+
+  const bool use_custom_highlight = (prop_highlight != NULL);
+
+  if (use_custom_highlight) {
+    const int highlight_array_len = RNA_property_array_length(ptr_highlight, prop_highlight);
+    bool *highlight_array = alloca(sizeof(bool) * highlight_array_len);
+    RNA_property_boolean_get_array(ptr_highlight, prop_highlight, highlight_array);
+    int i = 0;
+    for (uiBut *tab_but = last ? last->next : block->buttons.first;
+         (tab_but != NULL) && (i < highlight_array_len);
+         tab_but = tab_but->next, i++) {
+      SET_FLAG_FROM_TEST(tab_but->flag, !highlight_array[i], UI_BUT_INACTIVE);
+    }
+  }
 }
 
 /* callback for keymap item change button */
@@ -3474,13 +3491,19 @@ void uiItemMenuEnumR(
   uiItemMenuEnumR_prop(layout, ptr, prop, name, icon);
 }
 
-void uiItemTabsEnumR_prop(
-    uiLayout *layout, bContext *C, PointerRNA *ptr, PropertyRNA *prop, bool icon_only)
+void uiItemTabsEnumR_prop(uiLayout *layout,
+                          bContext *C,
+                          PointerRNA *ptr,
+                          PropertyRNA *prop,
+                          PointerRNA *ptr_highlight,
+                          PropertyRNA *prop_highlight,
+                          bool icon_only)
 {
   uiBlock *block = layout->root->block;
 
   UI_block_layout_set_current(block, layout);
-  ui_item_enum_expand_tabs(layout, C, block, ptr, prop, NULL, UI_UNIT_Y, icon_only);
+  ui_item_enum_expand_tabs(
+      layout, C, block, ptr, prop, ptr_highlight, prop_highlight, NULL, UI_UNIT_Y, icon_only);
 }
 
 /** \} */

source/blender/makesrna/intern/rna_ui_api.c

@@ -216,8 +216,13 @@ static void rna_uiItemMenuEnumR(uiLayout *layout,
   uiItemMenuEnumR_prop(layout, ptr, prop, name, icon);
 }
 
-static void rna_uiItemTabsEnumR(
-    uiLayout *layout, bContext *C, struct PointerRNA *ptr, const char *propname, bool icon_only)
+static void rna_uiItemTabsEnumR(uiLayout *layout,
+                                bContext *C,
+                                struct PointerRNA *ptr,
+                                const char *propname,
+                                struct PointerRNA *ptr_highlight,
+                                const char *propname_highlight,
+                                bool icon_only)
 {
   PropertyRNA *prop = RNA_struct_find_property(ptr, propname);
 
@@ -230,7 +235,31 @@ static void rna_uiItemTabsEnumR(
     return;
   }
 
-  uiItemTabsEnumR_prop(layout, C, ptr, prop, icon_only);
+  /* Get the highlight property used to gray out some of the tabs. */
+  PropertyRNA *prop_highlight = NULL;
+  if (!RNA_pointer_is_null(ptr_highlight)) {
+    prop_highlight = RNA_struct_find_property(ptr_highlight, propname_highlight);
+    if (!prop_highlight) {
+      RNA_warning("property not found: %s.%s",
+                  RNA_struct_identifier(ptr_highlight->type),
+                  propname_highlight);
+      return;
+    }
+    if (RNA_property_type(prop_highlight) != PROP_BOOLEAN) {
+      RNA_warning("property is not a boolean: %s.%s",
+                  RNA_struct_identifier(ptr_highlight->type),
+                  propname_highlight);
+      return;
+    }
+    if (!RNA_property_array_check(prop_highlight)) {
+      RNA_warning("property is not an array: %s.%s",
+                  RNA_struct_identifier(ptr_highlight->type),
+                  propname_highlight);
+      return;
+    }
+  }
+
+  uiItemTabsEnumR_prop(layout, C, ptr, prop, ptr_highlight, prop_highlight, icon_only);
 }
 
 static void rna_uiItemEnumR_string(uiLayout *layout,
@@ -929,6 +958,11 @@ void RNA_api_ui_layout(StructRNA *srna)
   func = RNA_def_function(srna, "prop_tabs_enum", "rna_uiItemTabsEnumR");
   RNA_def_function_flag(func, FUNC_USE_CONTEXT);
   api_ui_item_rna_common(func);
+  parm = RNA_def_pointer(
+      func, "data_highlight", "AnyType", "", "Data from which to take highlight property");
+  RNA_def_parameter_flags(parm, PROP_NEVER_NULL, PARM_RNAPTR);
+  parm = RNA_def_string(
+      func, "property_highlight", NULL, 0, "", "Identifier of highlight property in data");
   RNA_def_boolean(func, "icon_only", false, "", "Draw only icons in tabs, no text");
 
   func = RNA_def_function(srna, "prop_enum", "rna_uiItemEnumR_string");