textfield.lua

local TextField = {
  text = "",
  placeholder = "",
  position = lovr.math.newVec3(0, 0, 0),
  width = 6,
  fontScale = 0.6,
  font = lovr.graphics.getFont(),
  isKey = false,
  caps = false,
  isHighlighted = false,
  onReturn = function(field, text) return true end, -- whether to insert the return or not 
  onChange = function(field, oldText, newText) return true end, -- whether to accept change
}
setmetatable(TextField, {__index=letters.Node})
local TextField_mt = {
  __index = TextField
}

function TextField:new(o)
  o = letters.Node.new(self, o)
  setmetatable(o, TextField_mt)
  -- TODO: Update collider to match size when text changes
  o.collider = letters.world:newBoxCollider(o.position.x + (o.width/2), o.position.y - (o.font:getHeight()*o.fontScale/2), o.position.z, o.width, o.font:getHeight()*o.fontScale, 0.1)
  o.collider:setUserData(o)
  return o
end
function TextField:remove()
  self.collider:destroy()
end
function TextField:draw()
  local totalWidth, lines = self.font:getWidth(self.text, self.width*self.fontScale)
  totalWidth = totalWidth*self.fontScale

  local lastLine = string.match(self.text, "[^%c]*$")
  local lastLineWidth = self.font:getWidth(lastLine)*self.fontScale
  local height = self.font:getHeight()*self.fontScale

  lovr.graphics.setShader()
  lovr.graphics.setColor(1, 1, 1, self.isKey and 1.0 or (self.isHighlighted and 0.9 or 0.7))
  lovr.graphics.plane(
    'fill',
    self.position.x + self.width/2 - 0.01, self.position.y - (height*lines)/2 - 0.01, self.position.z - 0.01,
    self.width + 0.02, height * lines + 0.02
  )

  if self.text == "" then
    -- grayed out placeholder text
    lovr.graphics.setColor(0.7, 0.7, 0.7)
  else
    lovr.graphics.setColor(0, 0, 0)
  end
  lovr.graphics.setFont(self.font)
  lovr.graphics.print(
    self.text ~= "" and self.text or self.placeholder, 
    self.position.x, self.position.y, self.position.z, 
    self.fontScale, -- scale
    0, 0, 1, 0, -- rotation
    self.width,
    'left',
    'top'
  )

  lovr.graphics.setColor(0, 0, 0, math.sin(lovr.timer.getTime()*5)*0.5 + 0.6)
  if self.isKey then
    lovr.graphics.line(
      self.position.x + lastLineWidth + 0.03, self.position.y - height*(lines-1), self.position.z,
      self.position.x + lastLineWidth + 0.03, self.position.y - height*lines, self.position.z
    )
  end
end
function TextField:update()
end

function TextField:onKeyPressed(code, scancode, repeated)
  --print("keypress", code, scancode, repeated)
  local newText = self.text
  -- lol this is hard-coding a US keyboard layout and shift key behavior... think we're gonna have to delegate to OS somehow
  if code == "backspace" then
    newText = self.text:sub(1, -2)
  elseif code == "return" or code == "enter" then
    if self.onReturn(self, self.text) then
      newText = self.text .. "\n"
    end
  elseif code == "escape" then
    self:resignKey()
  end

  if newText ~= self.text and self.onChange(self, self.text, newText) then
    self.text = newText
  end
end

function TextField:onKeyReleased(code, scancode)
end

function TextField:onTextInput(code, scancode)
  --print("input", code, scancode)
  local newText = self.text .. code

  if newText ~= self.text and self.onChange(self, self.text, newText) then
    self.text = newText
  end
end

function TextField:select()
end
function TextField:deselect()

end
function TextField:actuate()
  self:makeKey()
end
function TextField:highlight()
  self.isHighlighted = true
end
function TextField:dehighlight()
  self.isHighlighted = false
end

function TextField:makeKey()
  if letters.currentEditor then
    letters.currentEditor:resignKey()
  end
  letters.currentEditor = self

  self.isKey = true
  self.oldPressedHandler = lovr.handlers["keypressed"]
  self.oldReleasedHandler = lovr.handlers["keyreleased"]
  lovr.handlers["keypressed"] = function(a, b, c) self:onKeyPressed(a,b,c) end
  lovr.handlers["keyreleased"] = function(a, b) self:onKeyReleased(a,b) end
  lovr.handlers["textinput"] = function(text, code) self:onTextInput(text, code) end
  
  letters.displayKeyboard()
end
function TextField:resignKey()
  letters.currentEditor = nil
  self.isKey = false
  lovr.handlers["keypressed"] = self.oldPressedHandler
  lovr.handlers["keyreleased"] = self.oldReleasedHandler
  self.oldPressedHandler = nil
  self.oldReleasedHandler = nil
  letters.hideKeyboard()
end

return TextField