[Dwarf Fortress] PatrikLundell's regionmanipulator.lua

--Manipulates the parameters of the region in focus pre embark. Use ? for help.
--NOTE: Manipulations made are NOT permanent. They will be applied to the embark if the user embarks while
--the region is still in focus, but they will be discarded as soon as the focus is shifted. They are also
--lost for any subsequent embarks in the same region (but the previous embark will still retain the effects
--of the changes in place when it was embarked upon). It is unknown what effects manipulations have on
--Adventure Mode, but weird discontinuities are likely at the border between an abandoned/retired embark
--generated while under manipulation influence and the region itself (which is back to its original state).
--[====[

regionmanipulator
========
]====]

local gui = require 'gui'
local dialog = require 'gui.dialogs'
local widgets =require 'gui.widgets'
local guiScript = require 'gui.script'

local Main_Page = {}

--================================================================
--  The Grid widget defines an pen supporting X/Y character display grid supporting display of
--  a grid larger than the frame allows through a panning viewport. The init function requires
--  the specification of the width and height attributes that defines the grid dimensions.
--  The grid coordinates are 0 based.
--
Grid = defclass (Grid, widgets.Widget)
Grid.ATTRS =
  {width = DEFAULT_NIL,
   height = DEFAULT_NIL}

--================================================================

function Grid:init ()
  if type (self.width) ~= 'number' or
     type (self.height) ~= 'number' or
     self.width < 0 or
     self.height < 0 then
    error ("Grid widgets have to have their width and height set permanently on initiation")
    return
  end

  self.grid = dfhack.penarray.new (self.width, self.height)

  self.viewport = {x1 = 0,
                   x2 = self.frame.r - self.frame.l,
                   y1 = 0,
                   y2 = self.frame.b - self.frame.t}
end

--================================================================
--  Pans the viewport in the X and Y dimensions the number of steps specified by the parameters.
--  It will stop the panning at 0, however, and will not pan outside of the grid (a grid smaller)
--  than the frame will still have non grid parts in the frame, of course).
--
function Grid:pan (x, y)
  local x_size = self.viewport.x2 - self.viewport.x1 + 1
  local y_size = self.viewport.y2 - self.viewport.y1 + 1

  self.viewport.x1 = self.viewport.x1 + x

  if self.viewport.x1 + x_size > self.width then
    self.viewport.x1 = self.width - x_size
  end

  if self.viewport.x1 < 0 then
    self.viewport.x1 = 0
  end

  self.viewport.x2 = self.viewport.x1 + x_size - 1

  self.viewport.y1 = self.viewport.y1 + y

  if self.viewport.y1 + y_size > self.height then
    self.viewport.y1 = self.height - y_size
  end

  if self.viewport.y1 < 0 then
    self.viewport.y1 = 0
  end

  self.viewport.y2 = self.viewport.y1 + y_size - 1
end

--================================================================
--  Assigns a value to the specified grid (not frame) coordinates. The 'pen'
--  parameter has to be a DFHack 'pen' table or object.
--
function Grid:set (x, y, pen)
  if x < 0 or x >= self.width then
    error ("Grid:set error: x out of bounds " .. tostring (x) .. " vs 0 - " .. tostring (self.width - 1))
    return

  elseif y < 0 or y >= self.height then
    error ("Grid:set error: y out of bounds " .. tostring (y) .. " vs 0 - " .. tostring (self.height - 1))
    return
  end

  self.grid:set_tile (x, y, pen)
end

--================================================================
--  Returns the data at position x, y in the grid.
--
function Grid:get (x, y)
  if x < 0 or x >= self.width then
    error ("Grid:set error: x out of bounds " .. tostring (x) .. " vs 0 - " .. tostring (self.width - 1))
    return

  elseif y < 0 or y >= self.height then
    error ("Grid:set error: y out of bounds " .. tostring (y) .. " vs 0 - " .. tostring (self.height - 1))
    return
  else
    return self.grid:get_tile (x, y)
  end
end

--================================================================
--  Renders the contents within the viewport into the frame.
--
function Grid:onRenderBody (dc)
  self.grid:draw (self.frame.l,
                  self.frame.t,
                  self.viewport.x2 - self.viewport.x1 + 1,
                  self.viewport.y2 - self.viewport.y1 + 1,
                  self.viewport.x1,
                  self.viewport.y1)
end

--================================================================
--
--  An EditField widget that shows whether the value has been modified but not commited.
--  Only works properly if the setText operation is used rather than setting the text
--  field directly. Isn't based on the EditField class because both its operations have
--  to be overridden.
--
MarkEditField = defclass (MarkEditField, widgets.Widget)

MarkEditField.ATTRS =
  {text = '',
   text_pen = DEFAULT_NIL,
   on_char = DEFAULT_NIL,
   on_change = DEFAULT_NIL,
   on_submit = DEFAULT_NIL,
   modified_pen = DEFAULT_NIL,
   modified = false}

--================================================================

function MarkEditField:setText (str)
  self.text = str
  self.modified = false
end

--================================================================

function MarkEditField:onRenderBody (dc)
  if self.modified then
    dc:pen (self.modified_pen or COLOR_YELLOW):fill (0, 0, dc.width - 1, 0)
  else
    dc:pen (self.text_pen or COLOR_LIGHTCYAN):fill (0, 0, dc.width - 1, 0)
  end

  local cursor = '_'
  if not self.active or gui.blink_visible(300) then
    cursor = ' '
  end

  local txt = self.text .. cursor
  if #txt > dc.width then
    txt = string.char(27) .. string.sub (txt, #txt - dc.width + 2)
  end

  dc:string (txt)
end

--================================================================

function MarkEditField:onInput (keys)
  if self.on_submit and keys.SELECT then
    self.on_submit (self.text)
    self.modified = false
    return true

  elseif keys._STRING then
    local old = self.text

    if keys._STRING == 0 then
      self.text = string.sub (old, 1, #old - 1)

    else
      local cv = string.char (keys._STRING)
      if not self.on_char or self.on_char (cv, old) then
        self.text = old .. cv
      end
    end

    if self.text ~= old then
      self.modified = true
    end

    if self.on_change and self.text ~= old then
      self.on_change(self.text, old)
    end

    return true
  end
end

--================================================================
--================================================================

function regionmanipulator ()
  if not dfhack.isWorldLoaded () then
    dfhack.color (COLOR_RED)
    dfhack.print("Error: This script requires a world to be loaded.")
    dfhack.color(COLOR_RESET)
    dfhack.println()
    return
  end

  if dfhack.isMapLoaded() then
    dfhack.color (COLOR_RED)
    dfhack.print("Error: This script requires a world to be loaded, but not a map.")
    dfhack.color(COLOR_RESET)
    dfhack.println()
    return
  end

  local map_width = df.global.world.world_data.world_width
  local map_height = df.global.world.world_data.world_height
  local x = 0
  local y = 0
  local max_x = 16
  local max_y = 16
  local region = df.global.world.world_data.region_details [0]
  local Edit_Focus
  local Focus = "Main"

  local Vertical_River_Image = {[-1] = "North",
                                [0] = "None",
                                [1] = "South"}

  local Horizontal_River_Image = {[-1] = "East",
                                  [0] = "None",
                                  [1] = "West"}

  local keybindings = {
    next_edit = {key = "CHANGETAB",
                 desc = "Go to next edit field"},
    prev_edit = {key = "SEC_CHANGETAB",
                 desc = "Go to previous edit field"},
    elevation = {key = "CUSTOM_ALT_E",
                 desc = "Change display to region elevation"},
    biome = {key = "CUSTOM_ALT_B",
             desc = "Change display to region biome"},
    rivers = {key = "CUSTOM_ALT_R",
              desc = "Change display to rivers"},
    flatten = {key = "CUSTOM_ALT_F",
               desc = "Flatten the region to the elevation of the current region tile"},
    up = {key = "CURSOR_UP",
          desc = "Shifts focus 1 step upwards"},
    down = {key = "CURSOR_DOWN",
            desc = "Shifts focus 1 step downwards"},
    left = {key = "CURSOR_LEFT",
            desc = "Shifts focus 1 step to the left"},
    right = {key = "CURSOR_RIGHT",
             desc = "Shift focus 1 step to the right"},
    upleft = {key = "CURSOR_UPLEFT",
              desc = "Shifts focus 1 step up to the left"},
    upright = {key = "CURSOR_UPRIGHT",
               desc = "Shifts focus 1 step up to the right"},
    downleft = {key = "CURSOR_DOWNLEFT",
                desc = "Shifts focus 1 step down to the left"},
    downright = {key = "CURSOR_DOWNRIGHT",
                 desc = "Shifts focus 1 step down to the right"},
    help = {key = "HELP",
            desc= " Show this help/info"}}

  --============================================================

  function Range_Color (arg)
    if arg < 100 then
      return COLOR_WHITE
    elseif arg < 110 then
      return COLOR_LIGHTCYAN
    elseif arg < 120 then
      return COLOR_CYAN
    elseif arg < 130 then
      return COLOR_LIGHTBLUE
    elseif arg < 140 then
      return COLOR_BLUE
    elseif arg < 150 then
      return COLOR_LIGHTGREEN
    elseif arg < 160 then
      return COLOR_GREEN
    elseif arg < 170 then
      return COLOR_YELLOW
    elseif arg < 180 then
      return COLOR_LIGHTMAGENTA
    elseif arg < 190 then
      return COLOR_LIGHTRED
    elseif arg < 200 then
      return COLOR_RED
    elseif arg < 210 then
      return COLOR_GREY
    else
      return COLOR_DARKGREY
    end
  end

  --============================================================

  function River_Elevation_Image (x, y)
    if region.rivers_vertical.active [x] [y] ~= 0 then
      return tostring (region.rivers_vertical.elevation [x] [y])

    elseif region.rivers_horizontal.active [x] [y] ~= 0 then
      return tostring (region.rivers_horizontal.elevation [x] [y])

    else
      return ""
    end
  end

  --============================================================

  function Make_Elevation (x, y)
    local end_x = #region.elevation - 1
    local end_y = #region.elevation [0] - 1
    local fg
    local bg
    local tile_color

    for k = 0, end_y do
      for i = 0, end_x do
        if i == x and k == y then
          fg = COLOR_BLACK
          bg = Range_Color (region.elevation [i] [k])
          tile_color = true

        else
          fg = Range_Color (region.elevation [i] [k])
          bg = COLOR_BLACK
          tile_color = false
        end

        Main_Page.elevationGrid:set (i, k, {ch = tostring (math.abs (region.elevation [i] [k] % 10)),
                                            fg = fg,
                                            bg = bg,
                                            bold = false,
                                            tile = nil,
                                            tile_color = tile_color,
                                            tile_fg = nil,
                                            tile_bg = nil})
      end
    end
  end

  --============================================================

  function Make_Biome (x, y)
    local end_x = #region.biome - 1
    local end_y = #region.biome [0] - 1
    local fg
    local bg
    local tile_color

    for k = 0, end_y do
      for i = 0, end_x do
        if i == x and k == y then
          fg = COLOR_BLACK
          bg = Range_Color (region.biome [i] [k] * 10 + 100)
          tile_color = true

        else
          fg = Range_Color (region.biome [i] [k] * 10 + 100)
          bg = COLOR_BLACK
          tile_color = false
        end

        Main_Page.biomeGrid:set (i, k, {ch = tostring (region.biome [i] [k]),
                                        fg = fg,
                                        bg = bg,
                                        bold = false,
                                        tile = nil,
                                        tile_color = tile_color,
                                        tile_fg = nil,
                                        tile_bg = nil})
      end
    end
  end

  --============================================================

  function Fit (Item, Size)
    if string.len (Item) > Size then
      return string.rep ('#', Size)
    else
      return Item .. string.rep (' ', Size - string.len (Item))
    end
  end

  --===========================================================================

  function Fit_Right (Item, Size)
    if string.len (Item) > Size then
      return string.rep ('#', Size)
    else
      return string.rep (' ', Size - string.len (Item)) .. Item
    end
  end

  --===========================================================================

  function Make_Rivers (x, y)
    local last = #region.rivers_vertical.elevation - 1
    local ch
    local fg
    local bg
    local tile_color

    for k = 0, last do
      for i = 0, last do
        tile_color = (i == x and k == y)

        if region.rivers_vertical.active [i] [k] ~= 0 then
          ch = tostring (region.rivers_vertical.elevation [i] [k] % 10)

          if i == x and k == y then
            fg = COLOR_BLACK
            bg = Range_Color (region.rivers_vertical.elevation [i] [k])

          else
            fg = Range_Color (region.rivers_vertical.elevation [i] [k])
            bg = COLOR_BLACK
          end

        elseif region.rivers_horizontal.active [i] [k] ~= 0 then
          ch = tostring (region.rivers_horizontal.elevation [i] [k] % 10)

          if i == x and k == y then
            fg = COLOR_BLACK
            bg = Range_Color (region.rivers_horizontal.elevation [i] [k])

          else
            fg = Range_Color (region.rivers_horizontal.elevation [i] [k])
            bg = COLOR_BLACK
          end

        else
          if i == x and k == y then
            ch = 'X'
            fg = COLOR_DARKGREY
            bg = COLOR_BLACK

          else
            ch = '.'
            fg = COLOR_BLACK
            bg = COLOR_DARKGREY
          end
        end

        Main_Page.riversGrid:set (i, k, {ch = ch,
                                         fg = fg,
                                         bg = bg,
                                         bold = false,
                                         tile = nil,
                                         tile_color = tile_color,
                                         tile_fg = nil,
                                         tile_bg = nil})
      end
    end
  end

  --============================================================

   function Set_Edit_Focus (index, active)
      Main_Page.Edit_List [index] [1].active = active
      for i = 2, #Main_Page.Edit_List [index] do
        Main_Page.Edit_List [index] [i].visible = active
      end
   end

  --============================================================

  function Set_Visibility (item, visible)
    for i, object in ipairs (Main_Page.Visibility_List [item]) do
      object.visible = visible
    end
  end

  --============================================================

  function Bool_Image (b)
    if b then
      return 'Y'
    else
      return 'N'
    end
  end

  --==============================================================

  function Update (x, y, pages)
    Make_Elevation (x, y)
    Make_Biome (x, y)
    Make_Rivers (x, y)

    Main_Page.Heading_Label_X:setText (Fit_Right (tostring (x), 2))
    Main_Page.Heading_Label_Y:setText (Fit_Right (tostring (y), 2))

    Main_Page.Region_Elevation_Edit:setText (Fit_Right (region.elevation [x] [y], 4))

    Main_Page.Region_Biome_Edit:setText (Fit_Right (region.biome [x] [y], 1))

    Main_Page.River_Elevation_Edit:setText (Fit_Right (River_Elevation_Image (x, y), 4))
    Set_Visibility ("River_Elevation", River_Elevation_Image (x, y) ~= "")
    if Main_Page.Edit_Focus == 3 and not Main_Page.Edit_List [3] [1].visible then
      Set_Edit_Focus (3, false)
      Set_Edit_Focus (1, true)
      Main_Page.Edit_Focus = 1
    end

    Main_Page.Vertical_Edit:setText (Vertical_River_Image [region.rivers_vertical.active [x] [y]])

    Main_Page.X_Min_Edit:setText (Fit_Right (region.rivers_vertical.x_min [x] [y], 2))
    Main_Page.X_Max_Edit:setText (Fit_Right (region.rivers_vertical.x_max [x] [y], 2))

    Set_Visibility ("Vertical", region.rivers_vertical.active [x] [y] ~= 0)
    if region.rivers_vertical.active [x] [y] == 0 then
      if Main_Page.Edit_Focus == 5 then
        Set_Edit_Focus (5, false)
        Set_Edit_Focus (1, true)
        Main_Page.Edit_Focus = 1
      end

      if Main_Page.Edit_Focus == 6 then
        Set_Edit_Focus (6, false)
        Set_Edit_Focus (1, true)
        Main_Page.Edit_Focus = 1
      end
    end

    Main_Page.Horizontal_Edit:setText (Horizontal_River_Image [region.rivers_horizontal.active [x] [y]])

    Main_Page.Y_Min_Edit:setText (Fit_Right (region.rivers_horizontal.y_min [x] [y], 2))
    Main_Page.Y_Max_Edit:setText (Fit_Right (region.rivers_horizontal.y_max [x] [y], 2))

    Set_Visibility ("Horizontal", region.rivers_horizontal.active [x] [y] ~= 0)
    if region.rivers_horizontal.active [x] [y] == 0 then
      if Main_Page.Edit_Focus == 8 then
        Set_Edit_Focus (8, false)
        Set_Edit_Focus (1, true)
        Main_Page.Edit_Focus = 1
      end

      if Main_Page.Edit_Focus == 9 then
        Set_Edit_Focus (9, false)
        Set_Edit_Focus (1, true)
        Main_Page.Edit_Focus = 1
      end
    end

    Main_Page.Is_Brook_Edit:setText (Bool_Image (df.global.world.world_data.region_map[region.pos.x]:_displace(region.pos.y).flags.is_brook))
  end

  --============================================================

  RegionManipulatorUi = defclass (RegionManipulatorUi, gui.FramedScreen)
  RegionManipulatorUi.ATTRS = {
    frame_style = gui.GREY_LINE_FRAME,
    frame_title = "Region Manipulator",
  }

  --============================================================

  function RegionManipulatorUi:onHelp ()
    self.subviews.pages:setSelected (2)
    Focus = "Help"
  end

  --============================================================

  function Disclaimer ()
    local helptext = {{text = "Help/Info"}, NEWLINE, NEWLINE}

    for i, v in pairs (keybindings) do
      table.insert (helptext, {text = v.desc, key = v.key, key_sep = ': '})
      table.insert (helptext, NEWLINE)
    end

    table.insert (helptext, NEWLINE)
    local dsc =
      {"The Region Manipulator is used pre embark to manipulate the region where the embark", NEWLINE,
       "is intended to be performed. Due to the way DF works, any manipulation performed on", NEWLINE,
       "the region is lost/discarded once DF's focus is changed to another region and", NEWLINE,
       "is lost when returned. Similarly, Embarking anew in the same region as a previous", NEWLINE,
       "fortress will have the region manipulations performed prior to the previous embark", NEWLINE,
       "reversed on the region level, but their effects are 'frozen' in the fortress itself.", NEWLINE,
       "However, manipulation and manipulation reversal can probably cause interesting effects", NEWLINE,
       "if an adventurer was to visit such a fortress.", NEWLINE,
       "Manipulations are effected immediately in DF, but the 'erase' function inherent in DF", NEWLINE,
       "can be used to remove them (just swich the focus to a different region and back)", NEWLINE,
       "The Region Manipulator allows you to change region level elevations, biomes, and rivers.", NEWLINE,
       "The UI provides edit fields that can be traversed between using <TAB> and shift-<TAB>,", NEWLINE,
       "where you change the value end press enter to commit a value. Changing to a different", NEWLINE,
       "field will cause uncommited changes to be discarded. Some River fields are dependent", NEWLINE,
       "upon the higher level Vertical/Horizontal field being set to a river course and will", NEWLINE,
       "not be displayed until the higher level field makes them relevant. Apart from the", NEWLINE,
       "fields, the UI also contains 'graphic' grid over the region which starts showing the", NEWLINE,
       "Elevation. ALT-b changes that to a reference to the Biome of the region tile, while", NEWLINE,
       "ALT-r changes it to display river elevation information, and ALT-e changes back to the", NEWLINE,
       "region Elevation information. Movement on this grid is performed using the numpad keys.", NEWLINE,
       "In addition to this, there is the ALT-f Flatten Embark command that changes the elevation", NEWLINE,
       "of all tiles to take on the elevation of the current tile. Note that this does NOT change", NEWLINE,
       "river elevations...", NEWLINE,
       "The 'Is Brook' field changes whether you'll embark at a brook or a stream. Note that this", NEWLINE,
       "field is persistent, as it is part of the world tile info, not the generated region data.", NEWLINE,
       "Manipulating rivers is ... messy, but can give rather spectacular results. The River", NEWLINE,
       "Elevation specifies the level at which the water flows, and DF will cut a sheer gorge", NEWLINE,
       "down to that level if below the Region Elevation, or make an 'aqueduct' if above it.", NEWLINE,
       "Waterfalls can be created by making the down river River Elevation lower than the upriver", NEWLINE,
       "one, while the reverse is ignored by DF (water won't jump up).", NEWLINE,
       "The messy part is making and changing river courses, and the author hasn't quite figured", NEWLINE,
       "out what the rules are: you need to experiment. However, it was possible to create a 3*3", NEWLINE,
       "embark where the center tile was surrounded by a bifurcating river that rejoined at the", NEWLINE,
       "other side, creating a natural moat with a waterfall one each side. The embark team was", NEWLINE,
       "spawned at the bottom of the gorge, however, so it was fortunate it was a brook...", NEWLINE,
       "Elevations are color coded. The color ranges are:", NEWLINE,
       {text = "WHITE        < 100, with the actual decile lost.", pen = dfhack.pen.parse {fg = COLOR_WHITE, bg = 0}}, NEWLINE,
       {text = "LIGHT CYAN     100 - 109", pen = dfhack.pen.parse {fg = COLOR_LIGHTCYAN, bg = 0}}, NEWLINE,
       {text = "CYAN           110 - 119", pen = dfhack.pen.parse {fg = COLOR_CYAN, bg = 0}}, NEWLINE,
       {text = "LIGHT BLUE     120 - 129", pen = dfhack.pen.parse {fg = COLOR_LIGHTBLUE, bg = 0}}, NEWLINE,
       {text = "BLUE           130 - 139", pen = dfhack.pen.parse {fg = COLOR_BLUE, bg = 0}}, NEWLINE,
       {text = "LIGHT GREEN    140 - 149", pen = dfhack.pen.parse {fg = COLOR_LIGHTGREEN, bg = 0}}, NEWLINE,
       {text = "GREEN          150 - 159", pen = dfhack.pen.parse {fg = COLOR_GREEN, bg = 0}}, NEWLINE,
       {text = "YELLOW         160 - 169", pen = dfhack.pen.parse {fg = COLOR_YELLOW, bg = 0}}, NEWLINE,
       {text = "LIGHT MAGENTA  170 - 179", pen = dfhack.pen.parse {fg = COLOR_LIGHTMAGENTA, bg = 0}}, NEWLINE,
       {text = "LIGHT RED      180 - 189", pen = dfhack.pen.parse {fg = COLOR_LIGHTRED, bg = 0}}, NEWLINE,
       {text = "RED            190 - 199", pen = dfhack.pen.parse {fg = COLOR_RED, bg = 0}}, NEWLINE,
       {text = "GREY           200 - 219", pen = dfhack.pen.parse {fg = COLOR_GREY, bg = 0}}, NEWLINE,
       {text = "DARK GREY    > 219, with the actual decile lost.", pen = dfhack.pen.parse {fg = COLOR_DARKGREY, bg = 0}}, NEWLINE, NEWLINE,
       "Version 0.5, 2017-06-23", NEWLINE,
       "Caveats: As indicated above, region manipulation has the potential to mess up adventure", NEWLINE,
       "mode seriously. Similarly, changing things in silly ways can result in any kind of", NEWLINE,
       "reaction from DF, so don't be surprised if DF crashes (no crashes have been noted so far)", NEWLINE,
       "or parts of the caverns caves in on embark because you've cut away the walls that should", NEWLINE,
       "have supported them.", NEWLINE
       }

    for i, v in pairs (dsc) do
      table.insert (helptext, v)
    end

    return helptext
  end

  --============================================================

  function RegionManipulatorUi:init ()
    self.stack = {}
    self.item_count = 0
    self.keys = {}

    Main_Page.Edit_List = {}
    Main_Page.Visibility_List =  {}
    Main_Page.Edit_Focus = 1

    Main_Page.Heading_Label =
      widgets.Label {text = {{text = "Help/Info",
                                      key = keybindings.help.key,
                                      key_sep = '()'},
                             " X =   , Y =   ", NEWLINE,
                             "Region Elevation:", NEWLINE,
                             "Region Biome:", NEWLINE,
                             NEWLINE,
                             "Vertical:       Horizontal:", NEWLINE,
                             NEWLINE,
                             NEWLINE,
                             "Is_Brook:"},
                     frame = {l = 1, t = 1, y_align = 0}}

    Main_Page.Heading_Label_X =
      widgets.Label {text = Fit_Right (tostring (x), 2),
                     frame = {l = 19, r = 20, t = 1, yalign = 0}}

    Main_Page.Heading_Label_Y =
      widgets.Label {text = Fit_Right (tostring (y), 2),
                     frame = {l = 27,
                              r = 28,
                              t = 1,
                              yalign = 0}}

    Main_Page.Heading_Label_Variable =
      widgets.Label {text = " Region Elevation",
                     frame = {l = 30, t = 1, yalign = 0}}

    Main_Page.Region_Elevation_Edit =
      MarkEditField {text = Fit_Right (region.elevation [x] [y], 4),
                     frame = {l = 19,
                              r = 22,
                              t = 2,
                              yalign = 0},
                     active = true,
                     on_submit = self:callback ("updateElevation")}

    Main_Page.Elevation_Edit_Help_Header =
      widgets.Label {text = "Elevation value key",
                     frame = {l = 19, t = 10, yalign = 0},
                     text_pen = COLOR_YELLOW,
                     visible = true}

    Main_Page.Elevation_Edit_Help =
      widgets.Label {text = "-999 -   0 is deep underground,\n" ..
                            "           capped to the SMR.\n" ..
                            "   1 -   0 is ocean level.\n" ..
                            " 100 - 149 is normal terrain.\n" ..
                            " 150 - 250 is mountain.",
                     frame = {l = 19, t = 11, yalign = 0},
                     visible = true}

    table.insert (Main_Page.Edit_List, {Main_Page.Region_Elevation_Edit,
                                        Main_Page.Elevation_Edit_Help_Header,
                                        Main_Page.Elevation_Edit_Help})

    Main_Page.Region_Biome_Edit =
      MarkEditField {text = Fit_Right (region.biome [x] [y], 1),
                     frame = {l = 22,
                              r = 22,
                              t = 3,
                              yalign = 0},
                     active = false,
                     on_submit = self:callback ("updateBiome")}

    Main_Page.Biome_Edit_Help =
      widgets.Label {text = {{text = "Take biome from neighbor world tile",
                              pen = COLOR_YELLOW}, NEWLINE,
                             "7: NW 8: N   9: NE", NEWLINE,
                             "4: E  5: Own 6: E", NEWLINE,
                             "1: SW 2: S   3: SE"},
                     frame = {l = 19, t = 10, yalign = 0},
                     visible = false}

    table.insert (Main_Page.Edit_List, {Main_Page.Region_Biome_Edit,
                                        Main_Page.Biome_Edit_Help})

    local River_Elevation_Label_Text = "River Elevation: "

    Main_Page.River_Elevation_Label =
      widgets.Label {text = River_Elevation_Label_Text,
                     frame = {l = 1, t = 4, yalign = 0},
                     visible = River_Elevation_Image (x, y) ~= ""}

    Main_Page.River_Elevation_Edit =
      MarkEditField {text = Fit_Right (River_Elevation_Image (x, y), 4),
                     frame = {l = River_Elevation_Label_Text:len () + 1,
                              r = River_Elevation_Label_Text:len () + 4,
                              t = 4,
                              yalign = 0},
                     active = false,
                     visible = River_Elevation_Image (x, y) ~= "",
                     on_submit = self:callback ("updateRiversElevation")}

    Main_Page.River_Elevation_Edit_Help_Header =
      widgets.Label {text = "River Elevation value key",
                     frame = {l = 19, t = 10, yalign = 0},
                     text_pen = COLOR_YELLOW,
                     visible = false}

    table.insert (Main_Page.Edit_List, {Main_Page.River_Elevation_Edit,
                                        Main_Page.River_Elevation_Edit_Help_Header,
                                        Main_Page.Elevation_Edit_Help})

    Main_Page.Visibility_List ["River_Elevation"] = {Main_Page.River_Elevation_Label,
                                                     Main_Page.River_Elevation_Edit}

    Main_Page.Vertical_Edit =
      MarkEditField {text = Vertical_River_Image [region.rivers_vertical.active [x] [y]],
                     frame = {l = 11, r = 15, t = 5, yalign = 0},
                     active = false,
                     on_submit = self:callback ("updateRiversVerticalActive")}

    Main_Page.Vertical_Edit_Help =
      widgets.Label {text = {{text = "Vertical River Course",
                              pen = COLOR_YELLOW}, NEWLINE,
                             "None", NEWLINE,
                             "South", NEWLINE,
                             "North"},
                     frame = {l = 19, t = 10, yalign = 0},
                     visible = false}

    table.insert (Main_Page.Edit_List, {Main_Page.Vertical_Edit,
                                        Main_Page.Vertical_Edit_Help})

    Main_Page.X_Label =
      widgets.Label {text = "x min:\nX Max:",
                     frame = {l = 1, t = 6, yalign = 0},
                     visible = region.rivers_vertical.active [x] [y] ~= 0}

    Main_Page.X_Min_Edit =
      MarkEditField {text = Fit_Right (region.rivers_vertical.x_min [x] [y], 2),
                     frame = {l = 8, r = 9, t = 6, yalign = 0},
                     active = false,
                     visible = region.rivers_vertical.active [x] [y] ~= 0,
                     on_submit = self:callback ("updateRiversVerticalXMin")}

    Main_Page.X_Min_Help_Header =
      widgets.Label {text = "Vertical River x min",
                     frame = {l = 19, t = 10, yalign = 0},
                     text_pen = COLOR_YELLOW,
                     visible = false}

    Main_Page.X_Y_Help =
      widgets.Label {text = "0 - 47 in 2 m tiles",
                     frame = {l = 19, t = 11, yalign = 0},
                     visible = false}

    table.insert (Main_Page.Edit_List, {Main_Page.X_Min_Edit,
                                        Main_Page.X_Min_Help_Header,
                                        Main_Page.X_Y_Help})

    Main_Page.X_Max_Edit =
      MarkEditField {text = Fit_Right (region.rivers_vertical.x_max [x] [y], 2),
                     frame = {l = 8, r = 9, t = 7, yalign = 0},
                     active = false,
                     visible = region.rivers_vertical.active [x] [y] ~= 0,
                     on_submit = self:callback ("updateRiversVerticalXMax")}

    Main_Page.X_Max_Help_Header =
      widgets.Label {text = "Vertical River X Max",
                     frame = {l = 19, t = 10, yalign = 0},
                     text_pen = COLOR_YELLOW,
                     visible = false}

    table.insert (Main_Page.Edit_List, {Main_Page.X_Max_Edit,
                                        Main_Page.X_Max_Help_Header,
                                        Main_Page.X_Y_Help})

    Main_Page.Visibility_List ["Vertical"] = {Main_Page.X_Label,
                                              Main_Page.X_Min_Edit,
                                              Main_Page.X_Max_Edit}
    Main_Page.Horizontal_Edit =
      MarkEditField {text = Horizontal_River_Image [region.rivers_horizontal.active [x] [y]],
                     frame = {l = 29, r = 33, t = 5, yalign = 0},
                     active = false,
                     on_submit = self:callback ("updateRiversHorizontalActive")}

    Main_Page.Horizontal_Edit_Help =
      widgets.Label {text = {{text = "Horizontal River Course",
                              pen = COLOR_YELLOW}, NEWLINE,
                             "None", NEWLINE,
                             "East", NEWLINE,
                             "West"},
                     frame = {l = 19, t = 10, yalign = 0},
                     visible = false}

    table.insert (Main_Page.Edit_List, {Main_Page.Horizontal_Edit,
                                        Main_Page.Horizontal_Edit_Help})

    Main_Page.Y_Label =
      widgets.Label {text = "y min:\nY Max:",
                     frame = {l = 17, t = 6, yalign = 0},
                     visible = region.rivers_horizontal.active [x] [y] ~= 0}

    Main_Page.Y_Min_Edit =
      MarkEditField {text = Fit_Right (region.rivers_horizontal.y_min [x] [y], 2),
                     frame = {l = 24, t = 6, yalign = 0},
                     active = false,
                     visible = region.rivers_horizontal.active [x] [y] ~= 0,
                     on_submit = self:callback ("updateRiversHorizontalYMin")}

    Main_Page.Y_Min_Help_Header =
      widgets.Label {text = "Horizontal River y min",
                     frame = {l = 19, t = 10, yalign = 0},
                     text_pen = COLOR_YELLOW,
                     visible = false}

    table.insert (Main_Page.Edit_List, {Main_Page.Y_Min_Edit,
                                        Main_Page.Y_Min_Help_Header,
                                        Main_Page.X_Y_Help})

    Main_Page.Y_Max_Edit =
      MarkEditField {text = Fit_Right (region.rivers_horizontal.y_max [x] [y], 2),
                     frame = {l = 24, t = 7, yalign = 0},
                     active = false,
                     visible = region.rivers_horizontal.active [x] [y] ~= 0,
                     on_submit = self:callback ("updateRiversHorizontalYMax")}

    Main_Page.Y_Max_Help_Header =
      widgets.Label {text = "Horizontal River Y Max",
                     frame = {l = 19, t = 10, yalign = 0},
                     text_pen = COLOR_YELLOW,
                     visible = false}

    table.insert (Main_Page.Edit_List, {Main_Page.Y_Max_Edit,
                                        Main_Page.Y_Max_Help_Header,
                                        Main_Page.X_Y_Help})

    Main_Page.Visibility_List ["Horizontal"] = {Main_Page.Y_Label,
                                                Main_Page.Y_Min_Edit,
                                                Main_Page.Y_Max_Edit}

    Main_Page.Is_Brook_Edit =
      MarkEditField {text = Bool_Image (df.global.world.world_data.region_map[region.pos.x]:_displace(region.pos.y).flags.is_brook),
                     frame = {l = 22, r = 22, t = 8, yalign = 0},
                     active = false,
                     visible = true,
                     on_submit = self:callback ("updateBrook")}

    Main_Page.Is_Brook_Edit_Help =
      widgets.Label {text = {{text = "Is it a brook or a stream?",
                              pen = COLOR_YELLOW}, NEWLINE,
                             "Y", NEWLINE,
                             "N", NEWLINE},
                     frame = {l = 19, t = 10, yalign = 0},
                     visible = false}

    table.insert (Main_Page.Edit_List, {Main_Page.Is_Brook_Edit,
                                        Main_Page.Is_Brook_Edit_Help})

    Main_Page.elevationGrid = Grid {frame = {l = 1, t = 11, r = 17, b = 27},
                                    width = 17,
                                    height = 17,
                                    visible = true}

    Main_Page.biomeGrid = Grid {frame = {l = 1, t = 11, r = 17, b = 27},
                                width = 17,
                                height = 17,
                                visible = false}

    Main_Page.riversGrid = Grid {frame = {l = 1, t = 11, r = 16, b = 26},
                                 width = 16,
                                 height = 16,
                                 visible = false}

    Make_Elevation (x, y)
    Make_Biome (x, y)
    Make_Rivers (x, y)

    helpPage = widgets.Panel {
        subviews = {widgets.Label {text = Disclaimer (),
                    frame = {l = 1, t = 1, yalign = 0}}}}

    local mainPage = widgets.Panel {
      subviews = {Main_Page.Heading_Label,
                  Main_Page.Heading_Label_X,
                  Main_Page.Heading_Label_Y,
                  Main_Page.Heading_Label_Variable,
                  Main_Page.Region_Elevation_Edit,
                  Main_Page.Elevation_Edit_Help_Header,
                  Main_Page.Elevation_Edit_Help,
                  Main_Page.Region_Biome_Edit,
                  Main_Page.Biome_Edit_Help,
                  Main_Page.River_Elevation_Label,
                  Main_Page.River_Elevation_Edit,
                  Main_Page.River_Elevation_Edit_Help_Header,
                  Main_Page.Vertical_Edit,
                  Main_Page.Vertical_Edit_Help,
                  Main_Page.X_Label,
                  Main_Page.X_Min_Edit,
                  Main_Page.X_Min_Help_Header,
                  Main_Page.X_Y_Help,
                  Main_Page.X_Max_Edit,
                  Main_Page.X_Max_Help_Header,
                  Main_Page.Horizontal_Edit,
                  Main_Page.Horizontal_Edit_Help,
                  Main_Page.Y_Label,
                  Main_Page.Y_Min_Edit,
                  Main_Page.Y_Min_Help_Header,
                  Main_Page.Y_Max_Edit,
                  Main_Page.Y_Max_Help_Header,
                  Main_Page.Is_Brook_Edit,
                  Main_Page.Is_Brook_Edit_Help,
                  Main_Page.elevationGrid,
                  Main_Page.biomeGrid,
                  Main_Page.riversGrid}}

    local pages = widgets.Pages
      {subviews = {mainPage,
                   helpPage},view_id = "pages",
                   }

    pages:setSelected (1)
    Focus = "Main"

    self:addviews {pages}
  end

  --============================================================

  function RegionManipulatorUi:updateElevation (value)
    if not tonumber (value) or
       tonumber (value) < -999 or
       tonumber (value) > 250 then
      dialog.showMessage ("Error!", "The Elevation legal range is -999 - 250", COLOR_RED)
    else
      region.elevation [x] [y] = tonumber (value)
    end

    Update (x, y, self.subviews.pages)
  end

  --==============================================================

  function RegionManipulatorUi:updateBiome (value)
    if not tonumber (value) or
       tonumber (value) < 1 or
       tonumber (value) > 9 then
      dialog.showMessage ("Error!", "The Biome legal range is 1 - 9", COLOR_RED)
    else
      region.biome [x] [y] = tonumber (value)
    end

    Update (x, y, self.subviews.pages)
  end

  --==============================================================

  function RegionManipulatorUi:flattenRegion ()
    for i = 0, #region.elevation - 1 do
      for k = 0, #region.elevation [0] -1 do
        region.elevation [i] [k] = region.elevation [x] [y]
      end
    end

    Make_Elevation (x, y)
    Update (x, y, self.subviews.pages)
  end

  --==============================================================

  function RegionManipulatorUi:updateRiversElevation (value)
    if not tonumber (value) or
       tonumber (value) < -999 or
       tonumber (value) > 250 then
      dialog.showMessage ("Error!", "The Elevation legal range is -999 - 250", COLOR_RED)

    else
      if region.rivers_horizontal.active [x] [y] ~= 0 then
        region.rivers_horizontal.elevation [x] [y] = tonumber (value)
      end

      if region.rivers_vertical.active [x] [y] ~= 0 then
        region.rivers_vertical.elevation [x] [y] = tonumber (value)
      end
    end

    Update (x, y, self.subviews.pages)
  end

  --==============================================================

  function RegionManipulatorUi:updateRiversVerticalActive (value)
    if string.upper (value) == "SOUTH" or
       string.upper (value) == "NORTH" then
      if region.rivers_vertical.active [x] [y] == 0 then
        region.rivers_vertical.x_min [x] [y] = 23
        region.rivers_vertical.x_max [x] [y] = 25

        if region.rivers_horizontal.active [x] [y] ~= 0 then
          region.rivers_vertical.elevation [x] [y] = region.rivers_horizontal.elevation [x] [y]

        else
          region.rivers_vertical.elevation [x] [y] = region.elevation [x] [y]
        end
      end

      if string.upper (value) == "SOUTH" then
        region.rivers_vertical.active [x] [y] = 1
      else
        region.rivers_vertical.active [x] [y] = -1
      end

    elseif string.upper (value) == "NONE" then
      region.rivers_vertical.active [x] [y] = 0
      region.rivers_vertical.elevation [x] [y] = 100
      region.rivers_vertical.x_min [x] [y] = -30000
      region.rivers_vertical.x_max [x] [y] = -30000

    else
      dialog.showMessage ("Error!", "The legal values are 'None', 'North', and 'South'", COLOR_RED)
    end

    Update (x, y, self.subviews.pages)
  end

  --==============================================================

  function RegionManipulatorUi:updateRiversVerticalXMin (value)
    if not tonumber (value) or
       tonumber (value) < 0 or
       tonumber (value) > 47 then
      dialog.showMessage ("Error!", "The X Min legal range is 0 - 47", COLOR_RED)

    elseif tonumber (value) > region.rivers_vertical.x_max [x] [y] then
      dialog.showMessage ("Error!", "The X Min value cannot be larger than X Max", COLOR_RED)

    else
      region.rivers_vertical.x_min [x] [y] = tonumber (value)
    end

    Update (x, y, self.subviews.pages)
  end

  --==============================================================

  function RegionManipulatorUi:updateRiversVerticalXMax (value)
    if not tonumber (value) or
       tonumber (value) < 0 or
       tonumber (value) > 47 then
      dialog.showMessage ("Error!", "The X Max legal range is 0 - 47", COLOR_RED)

    elseif tonumber (value) < region.rivers_vertical.x_min [x] [y] then
      dialog.showMessage ("Error!", "The X Max value cannot be smaller than X Min", COLOR_RED)

    else
      region.rivers_vertical.x_max [x] [y] = tonumber (value)
    end

    Update (x, y, self.subviews.pages)
  end

  --==============================================================

  function RegionManipulatorUi:updateRiversHorizontalActive (value)
    if string.upper (value) == "EAST" or
       string.upper (value) == "WEST" then
      if region.rivers_horizontal.active [x] [y] == 0 then
        region.rivers_horizontal.y_min [x] [y] = 23
        region.rivers_horizontal.y_max [x] [y] = 25

        if region.rivers_vertical.active [x] [y] ~= 0 then
          region.rivers_horizontal.elevation [x] [y] = region.rivers_vertical.elevation [x] [y]

        else
          region.rivers_horizontal.elevation [x] [y] = region.elevation [x] [y]
        end
      end

      if string.upper (value) == "WEST" then
        region.rivers_horizontal.active [x] [y] = 1
      else
        region.rivers_horizontal.active [x] [y] = -1
      end

    elseif string.upper (value) == "NONE" then
      region.rivers_horizontal.active [x] [y] = 0
      region.rivers_horizontal.elevation [x] [y] = 100
      region.rivers_horizontal.y_min [x] [y] = -30000
      region.rivers_horizontal.y_max [x] [y] = -30000
    else
      dialog.showMessage ("Error!", "The legal values are 'None', 'East', and 'West'", COLOR_RED)
    end

    Update (x, y, self.subviews.pages)
  end

  --==============================================================

  function RegionManipulatorUi:updateRiversHorizontalYMin (value)
    if not tonumber (value) or
       tonumber (value) < 0 or
       tonumber (value) > 47 then
      dialog.showMessage ("Error!", "The Y Min legal range is 0 - 47", COLOR_RED)

    elseif tonumber (value) > region.rivers_horizontal.y_max [x] [y] then
      dialog.showMessage ("Error!", "The Y Min value cannot be larger than Y Max", COLOR_RED)

    else
      region.rivers_horizontal.y_min [x] [y] = tonumber (value)
    end

    Update (x, y, self.subviews.pages)
  end

  --==============================================================

  function RegionManipulatorUi:updateRiversHorizontalYMax (value)
    if not tonumber (value) or
       tonumber (value) < 0 or
       tonumber (value) > 47 then
      dialog.showMessage ("Error!", "The Y Max legal range is 0 - 47", COLOR_RED)

    elseif tonumber (value) < region.rivers_horizontal.y_min [x] [y] then
      dialog.showMessage ("Error!", "The Y Max value cannot be smaller than Y Min", COLOR_RED)

    else
      region.rivers_horizontal.y_max [x] [y] = tonumber (value)
    end

    Update (x, y, self.subviews.pages)
  end

  --==============================================================

  function RegionManipulatorUi:updateBrook (value)
    if string.upper (value) ~= "Y" and
       string.upper (value) ~= "N" then
      dialog.showMessage ("Error!", "The legal values are Y and N", COLOR_RED)

    else
      df.global.world.world_data.region_map[region.pos.x]:_displace(region.pos.y).flags.is_brook = string.upper (value) == 'Y'
    end

    Update (x, y, self.subviews.pages)
  end

  --==============================================================

  function RegionManipulatorUi:onInput (keys)
    if keys.LEAVESCREEN_ALL  then
        self:dismiss ()
    end

    if keys.LEAVESCREEN then
      if Focus == "Help" then
        Focus = "Main"
        self.subviews.pages:setSelected (1)

      else
        self:dismiss ()
      end
    end

    if keys [keybindings.next_edit.key] then
      local Done = false

      Set_Edit_Focus (Main_Page.Edit_Focus, false)

      for i = Main_Page.Edit_Focus + 1, #Main_Page.Edit_List do
        if Main_Page.Edit_List [i] [1].visible then
          Set_Edit_Focus (i, true)

          Main_Page.Edit_Focus = i
          Done = true
          break
        end
      end

      if not Done then
        for i = 1, Main_Page.Edit_Focus - 1 do
          if Main_Page.Edit_List [i] [1].visible then
            Set_Edit_Focus (i, true)

            Main_Page.Edit_Focus = i
            break
          end
        end
      end

      Update (x, y, self.subviews.pages)  --  To reset modified but not committed values

    elseif keys [keybindings.prev_edit.key] then
      local Done = false

      Set_Edit_Focus (Main_Page.Edit_Focus, false)

      for i = Main_Page.Edit_Focus - 1, 1, -1 do
        if Main_Page.Edit_List [i] [1].visible then
          Set_Edit_Focus (i, true)

          Main_Page.Edit_Focus = i
          Done = true
          break
        end
      end

      if not Done then
        for i = #Main_Page.Edit_List, Main_Page.Edit_Focus + 1, -1 do
          if Main_Page.Edit_List [i] [1].visible then
            Set_Edit_Focus (i, true)

            Main_Page.Edit_Focus = i
            break
          end
        end
      end

      Update (x, y, self.subviews.pages)  --  To reset modified but not committed values

    elseif keys [keybindings.elevation.key] then
      Main_Page.elevationGrid.visible = true
      Main_Page.biomeGrid.visible = false
      Main_Page.riversGrid.visible = false

    elseif keys [keybindings.biome.key] then
      Main_Page.elevationGrid.visible = false
      Main_Page.biomeGrid.visible = true
      Main_Page.riversGrid.visible = false

    elseif keys [keybindings.rivers.key] then
      Main_Page.elevationGrid.visible = false
      Main_Page.biomeGrid.visible = false
      Main_Page.riversGrid.visible = true

    elseif keys [keybindings.flatten.key] then
      dialog.showYesNoPrompt ("Flatten Terrain?",
                              "The whole region will be set to an elevation of " .. tostring (region.elevation [x] [y]) .. " on Enter.",
                              COLOR_WHITE,
                              NIL,
                              self:callback ("flattenRegion"))

    elseif keys [keybindings.up.key] and not keys._STRING then
      if focus ~= "Help" then
        if y > 0 then
          y = y - 1
        end

        Update (x, y, self.subviews.pages)
      end

    elseif keys [keybindings.down.key] and not keys._STRING then
      if focus ~= "Help" then
        if y < max_y - 1 then
          y = y + 1
        end

        Update (x, y, self.subviews.pages)
      end

    elseif keys [keybindings.left.key] and not keys._STRING then
      if focus ~= "Help"  then
        if x > 0 then
          x = x - 1
        end

        Update (x, y, self.subviews.pages)
      end

    elseif keys [keybindings.right.key] and not keys._STRING then
      if focus ~= "Help" then
        if x < max_x - 1 then
          x = x + 1
        end

        Update (x, y, self.subviews.pages)
      end

    elseif keys [keybindings.upleft.key] and not keys._STRING then
      if focus ~= "Help" then
        if x > 0 then
          x = x - 1
        end

        if y > 0 then
          y = y - 1
        end

        Update (x, y, self.subviews.pages)
      end

    elseif keys [keybindings.upright.key] and not keys._STRING then
      if focus ~= "Help" then
        if x < max_x - 1 then
          x = x + 1
        end

        if y > 0 then
          y = y - 1
        end

        Update (x, y, self.subviews.pages)
      end

    elseif keys [keybindings.downleft.key] and not keys._STRING then
      if focus ~= "Help" then
        if x > 0 then
          x = x - 1
        end

        if y < max_y - 1 then
          y = y + 1
        end

        Update (x, y, self.subviews.pages)
      end

    elseif keys [keybindings.downright.key] and not keys._STRING then
      if focus ~= "Help" then
        if x < max_x - 1 then
          x = x + 1
        end

        if y < max_y - 1 then
          y = y + 1
        end

        Update (x, y, self.subviews.pages)
      end
    end

    self.super.onInput (self, keys)
  end

  --============================================================

  function Show_Viewer ()
    local screen = RegionManipulatorUi {}
    persist_screen = screen
    screen:show ()
  end

  --============================================================

  Show_Viewer ()
end

regionmanipulator ()