Ruby: use core methods for finding selected item and building

Similar to c3d566332, the core methods have become more complicated (and are also checked at compile-time). This will give a more consistent experience across scripts.

Fixes #1563

plugins/ruby/building.rb

@@ -2,16 +2,7 @@ module DFHack
     class << self
         def building_find(what=:selected, y=nil, z=nil)
             if what == :selected
-                case ui.main.mode
+                return world.buildings.all.binsearch(df.get_selected_building_id)
-                when :LookAround
-                    k = ui_look_list.items[ui_look_cursor]
-                    k.building if k.type == :Building
-                when :BuildingItems, :QueryBuilding
-                    world.selected_building
-                when :Zones, :ZonesPenInfo, :ZonesPitInfo, :ZonesHospitalInfo
-                    ui_sidebar_menus.zone.selected
-                end
-
             elsif what.kind_of?(Integer)
                 # search by building.id
                 return world.buildings.all.binsearch(what) if not z

plugins/ruby/item.rb

@@ -4,41 +4,7 @@ module DFHack
         # arg similar to unit.rb/unit_find; no arg = 'k' menu
         def item_find(what=:selected, y=nil, z=nil)
             if what == :selected
-                case curview._rtti_classname
+                return world.items.all.binsearch(df.get_selected_item_id)
-                when :viewscreen_itemst
-                    if ref = curview.entry_ref[curview.cursor_pos]
-                        ref.item_tg if ref.kind_of?(GeneralRefItem)
-                    else
-                        # not a container
-                        curview.item
-                    end
-                when :viewscreen_storesst   # z/stocks
-                    if curview.in_group_mode == 0 and curview.in_right_list == 1
-                        curview.items[curview.item_cursor]
-                    end
-                else
-                    case ui.main.mode
-                    when :LookAround
-                        k = ui_look_list.items[ui_look_cursor]
-                        case k.type
-                        when :Item
-                            k.item
-                        when :Building
-                            # hilight a constructed bed/coffer
-                            mats = k.building.contained_items.find_all { |i| i.use_mode == 2 }
-                            mats[0].item if mats.length == 1
-                        end
-                    when :BuildingItems
-                        bld = world.selected_building
-                        bld.contained_items[ui_building_item_cursor].item if bld
-                    when :ViewUnits
-                        u = world.units.active[ui_selected_unit]
-                        u.inventory[ui_look_cursor].item if u and u.pos.z == cursor.z and
-                                ui_unit_view_mode.value == :Inventory and u.inventory[ui_look_cursor]
-                    else
-                        ui.follow_item_tg if ui.follow_item != -1
-                    end
-                end
             elsif what.kind_of?(Integer)
                 # search by id
                 return world.items.all.binsearch(what) if not z

plugins/ruby/ruby.cpp

@@ -9,6 +9,8 @@
 
 #include "modules/Gui.h"
 #include "df/global_objects.h"
+#include "df/building.h"
+#include "df/item.h"
 #include "df/unit.h"
 
 #include "tinythread.h"
@@ -630,6 +632,18 @@ static VALUE rb_dfget_vtable_ptr(VALUE self, VALUE objptr)
     return rb_uint2inum(*(uintptr_t*)rb_num2ulong(objptr));
 }
 
+static VALUE rb_dfget_selected_building_id(VALUE self)
+{
+    df::building *b = Gui::getAnyBuilding(Core::getTopViewscreen());
+    return rb_int2inum(b ? b->id : -1);
+}
+
+static VALUE rb_dfget_selected_item_id(VALUE self)
+{
+    df::item *i = Gui::getAnyItem(Core::getTopViewscreen());
+    return rb_int2inum(i ? i->id : -1);
+}
+
 static VALUE rb_dfget_selected_unit_id(VALUE self)
 {
     df::unit *u = Gui::getAnyUnit(Core::getTopViewscreen());
@@ -1147,6 +1161,8 @@ static void ruby_bind_dfhack(void) {
     rb_define_singleton_method(rb_cDFHack, "get_vtable", RUBY_METHOD_FUNC(rb_dfget_vtable), 1);
     rb_define_singleton_method(rb_cDFHack, "get_rtti_classname", RUBY_METHOD_FUNC(rb_dfget_rtti_classname), 1);
     rb_define_singleton_method(rb_cDFHack, "get_vtable_ptr", RUBY_METHOD_FUNC(rb_dfget_vtable_ptr), 1);
+    rb_define_singleton_method(rb_cDFHack, "get_selected_building_id", RUBY_METHOD_FUNC(rb_dfget_selected_building_id), 0);
+    rb_define_singleton_method(rb_cDFHack, "get_selected_item_id", RUBY_METHOD_FUNC(rb_dfget_selected_item_id), 0);
     rb_define_singleton_method(rb_cDFHack, "get_selected_unit_id", RUBY_METHOD_FUNC(rb_dfget_selected_unit_id), 0);
     rb_define_singleton_method(rb_cDFHack, "dfhack_run", RUBY_METHOD_FUNC(rb_dfhack_run), 1);
     rb_define_singleton_method(rb_cDFHack, "print_str", RUBY_METHOD_FUNC(rb_dfprint_str), 1);