/ld27

-- Class: TextInput

-- This is like a <Text> object, only it listens to user input and

-- adjusts its text property accordingly.

--

-- Extends:

--		<Text>

--

-- Events:

--		onChange - Occurs when the input's text has changed, either by a

--				   user's input or programmtically.

--		onType - Occurs when the input is about to accept input from a key.

--				 This event handler is passed the key about to be inserted.

--				 If the handler returns false, *not* nil or any other value,

--				 then the key is ignored.

TextInput = Text:extend{

	text = '',

	-- Property: listening

	-- Whether the input is currently listening to input.

	listening = true,

	-- Property: caret

	-- This shows the current insert position.

	caret = 0,

	-- Property: blinkRate

	-- How quickly the caret blinks, in seconds.

	blinkRate = 0.5,

	-- internal property: _blinkTimer

	-- Used to keep track of caret blinking.

	_blinkTimer = 0,

	-- internal property: _repeatKey

	-- Used to keep track of what movement key is being held down.

	-- internal property: _repeatTimer

	-- Used to keep track of how quickly movement keys repeat.

	-- internal property: _caretHeight

	-- How tall the caret is onscreen, based on the font.

	-- internal property: _caretX

	-- Where to draw the caret, relative to the sprite's x position.

	update = function (self, elapsed)

		if self.listening then

			-- listen to normal keys

			if the.keys.typed ~= '' then

				if (self.onType and self:onType(the.keys.typed)) or not self.onType then

					self.text = string.sub(self.text, 1, self.caret) .. the.keys.typed

								.. string.sub(self.text, self.caret + 1)

					self.caret = self.caret + string.len(the.keys.typed)

				end

			end

			if the.keys:justPressed('home') then

				self.caret = 0

			end

			if the.keys:justPressed('end') then

				self.caret = string.len(self.text)

			end

			-- handle movement keys that repeat

			local frameAction

			for _, key in pairs{'backspace', 'delete', 'left', 'right'} do

				if the.keys:pressed(key) then

					frameAction = key

					if the.keys:alreadyHandled(key) then

						frameAction = nil

					end

				end

			end

			if frameAction == 'backspace' and self.caret > 0 then

				self.text = string.sub(self.text, 1, self.caret - 1) .. string.sub(self.text, self.caret + 1)

				self.caret = self.caret - 1

			end

			if frameAction == 'delete' and self.caret < string.len(self.text) then

				self.text = string.sub(self.text, 1, self.caret) .. string.sub(self.text, self.caret + 2)

			end

			if frameAction == 'left' and self.caret > 0 then

				self.caret = self.caret - 1

			end

			if frameAction == 'right' and self.caret < string.len(self.text) then

				self.caret = self.caret + 1

			end

		end

		-- update caret position

		if self._set.caret ~= self.caret and self._fontObj then

			self._caretX = self._fontObj:getWidth(string.sub(self.text, 1, self.caret))

			self._caretHeight = self._fontObj:getHeight()

			self._set.caret = self.caret

		end

		-- update caret timer

		self._blinkTimer = self._blinkTimer + elapsed

		if self._blinkTimer > self.blinkRate * 2 then self._blinkTimer = 0 end

		-- call onChange handler as needed

		if self.text ~= self._set.text then

			if self.onChange then self:onChange() end

			self._set.text = self.text

		end

		Text.update(self, elapsed)

	end,

	draw = function (self, x, y)

		if self.visible then

			x = x or self.x

			y = y or self.y

			Text.draw(self, x, y)

			-- draw caret

			if (self._repeatKey or self._blinkTimer < self.blinkRate) and

			   (self._caretX and self._caretHeight) then

				love.graphics.setLineWidth(1)

				love.graphics.line(x + self._caretX, y, x + self._caretX, y + self._caretHeight)

			end

		end

	end

}