make color of the flag item configurable

Only changes the look of the item.

Original intention was to use dye to change colors (craft from
different colored wool, etc), but probably not worth it.

init.lua

@@ -197,15 +197,28 @@ minetest.register_chatcommand(ANNOUNCE_COMMAND_NAME, {
 local flag_dialog_context = {}
 local function show_flag_config_dialog(itemstack, player)
     local meta = itemstack:get_meta()
-    local formspec_head = "formspec_version[4]size[8,3]set_focus[close;]"
+    local formspec_head = "formspec_version[4]size[8,4]set_focus[close;]"
     local message = meta:get_string("message") or "Flag point"
-    local field_message = ("field[0.5,0.6;7,0.8;message;Message;%s]"):format(minetest.formspec_escape(message))
+    local field_message = ("field[0.5,0.6;7,0.7;message;Message;%s]"):format(minetest.formspec_escape(message))
+    local color_str = meta:get_string("color_str")
+    if color_str == "" then
+        color_str = meta:get_string("color")
+        if color_str == "" then
+            -- probably an old flag, provide default color
+            color_str = "red"
+        end
+    end
+    -- strip alpha (it should never appear here anyway)
+    color_str = string.match(color_str, "#[0-9A-F][0-9A-F][0-9A-F][0-9A-F][0-9A-F][0-9A-F]") or color_str
+    local field_color = ("field[0.5,1.75;4,0.7;color;Color;%s]"):format(
+        minetest.formspec_escape(color_str))
     minetest.show_formspec(player:get_player_name(), "waypoint_announce:flag_edit",
                            formspec_head ..
                            field_message ..
-                           --field_color ..
-                           "button_exit[0.5,1.7;3,0.8;save;save]" ..
-                           "button_exit[4.5,1.7;3,0.8;close;close]")
+                           field_color ..
+                           --field_time .. -- TODO set time too? (within limits)
+                           "button_exit[0.5,2.7;3,0.8;save;save]" ..
+                           "button_exit[4.5,2.7;3,0.8;close;close]")
     flag_dialog_context[player:get_player_name()] = itemstack
 end
 
@@ -214,6 +227,7 @@ minetest.register_on_player_receive_fields(function(player, formname, fields)
     if formname ~= "waypoint_announce:flag_edit" then
         return
     end
+    -- FIXME has same wielded item swapping problems as compass had
     if fields.save or (fields.key_enter_field and fields.quit) then
         local flag_item = flag_dialog_context[player:get_player_name()]
         if not flag_item then
@@ -228,6 +242,21 @@ minetest.register_on_player_receive_fields(function(player, formname, fields)
         local message = fields.message
         meta:set_string("message", message)
 
+
+        if fields.color and #(fields.color) < 20 then
+            local colorstring = minetest.colorspec_to_colorstring(fields.color)
+            if colorstring then
+                -- strip alpha
+                colorstring = string.match(colorstring, "#[0-9A-F][0-9A-F][0-9A-F][0-9A-F][0-9A-F][0-9A-F]") or colorstring
+                meta:set_string("color", colorstring)
+                -- preserve original color name for editing
+                meta:set_string("color_str", fields.color)
+            end
+        -- else
+        --     -- something sus is going on, don't set it
+        --     meta:set_string("color_str", "")
+        end
+
         local success = player:set_wielded_item(flag_item)
         if not success then
             -- no idea why this can happen