add a helper function to build the formspec frame

fixes https://gitlab.com/4w/mtimer/issues/4

system/formspec_creation.lua

@@ -2,6 +2,29 @@ local m = mtimer
 local S = m.translator
 
 
+local build_frame = function (width, height, title)
+    local formspec_frame = [[
+    size[+width,+height] label[0,-0.125;+title]
+    container[0,+position]
+    button_exit[+exitpos,0;+bwidth,1;exit;]]..S('Exit')..[[]
+    button[+mainpos,0;+bwidth,1;main_menu;]]..S('Main Menu')..[[]
+    button[+defaultpos,0;+bwidth,1;default;]]..S('Default')..[[]
+    container_end[]
+    ]]
+
+    return formspec_frame:gsub('%+%a+', {
+        ['+width'] = width,
+        ['+height'] = height,
+        ['+title'] = title,
+        ['+position'] = height-0.6,
+        ['+bwidth'] = width/3,
+        ['+exitpos'] = 0,
+        ['+mainpos'] = width/3,
+        ['+defaultpos'] = (width/3)*2
+    })
+end
+
+
 mtimer.show_formspec.main_menu = function (player_name)
     minetest.show_formspec(player_name, 'mtimer:main_menu', [[
     size[4,8.25]
@@ -20,24 +43,17 @@ end
 
 
 mtimer.show_formspec.set_visibility = function (player_name)
-    minetest.show_formspec(player_name, 'mtimer:set_visibility', [[
-    size[6,2.25]
-    label[0,-0.125;]]..S('mTimer Visibility')..[[]
-
-    button[0,0.5;2,1;visible;]]..S('Visible')..[[]
-    button[2,0.5;2,1;invisible;]]..S('Invisible')..[[]
-    button[4,0.5;2,1;default;]]..S('Default')..[[]
-
-    button_exit[0,1.5;3,1;exit;]]..S('Exit')..[[]
-    button[3,1.5;3,1;back;]]..S('Main Menu')..[[]
+    minetest.show_formspec(player_name, 'mtimer:set_visibility',
+    build_frame(6, 2.25, S('mTimer Visibility'))..[[
+    button[0,0.5;3,1;visible;]]..S('Visible')..[[]
+    button[3,0.5;3,1;invisible;]]..S('Invisible')..[[]
     ]])
 end
 
 
 mtimer.show_formspec.set_position = function (player_name)
-    minetest.show_formspec(player_name, 'mtimer:set_position', [[
-    size[8,6.125]
-    label[0,-0.125;]]..S('mTimer Position')..[[]
+    minetest.show_formspec(player_name, 'mtimer:set_position',
+    build_frame(8, 6.125, S('mTimer Position'))..[[
 
     image_button[0,0.5;8,4.5 ;mtimer_positions_orientation.png;pos_xx;;;false]
 
@@ -54,10 +70,6 @@ mtimer.show_formspec.set_position = function (player_name)
     image_button[5.34,3.5;2.67,1.5;mtimer_transparent.png;pos_br;;;false]
 
     label[0,5;]]..S('Click the position you want to place the timer at.')..[[]
-
-    button_exit[0,5.5;2,1;exit;]]..S('Exit')..[[]
-    button[2,5.5;2,1;back;]]..S('Main Menu')..[[]
-    button[4,5.5;2,1;default;]]..S('Default')..[[]
     ]])
 end
 
@@ -74,18 +86,11 @@ mtimer.show_formspec.set_color = function (player_name)
         'AA'
     })
 
-    minetest.show_formspec(player_name, 'mtimer:set_color', [[
-    size[6.85,2.7]
-    label[0,-0.125;]]..S('mTimer Color')..[[]
+    minetest.show_formspec(player_name, 'mtimer:set_color',
+    build_frame(6, 2.7, S('mTimer Color'))..[[
     field_close_on_enter[color;false]
-
     field[0.25,0.75;3,1;color;;]]..color..[[]
     box[3,0.55;0.65,0.65;]]..color..[[]
-    button[3.85,0.45;3,1;default;]]..S('Default')..[[]
-
     label[-0.05,1.45;]]..S('Use `@1` format only!', hexcolor)..[[]
-
-    button_exit[-0.05,2;3.45,1;exit;]]..S('Exit')..[[]
-    button[3.44,2;3.4,1;back;]]..S('Main Menu')..[[]
     ]])
 end

system/on_receive_fields.lua

@@ -54,7 +54,7 @@ minetest.register_on_player_receive_fields(function(player, formname, fields)
 
 
     -- Back to menu from all formspecs
-    if fields.back then f.main_menu(name) end
+    if fields.main_menu then f.main_menu(name) end
 
 
     -- DEBUG: Print all player meta data