/ld26-basecode

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1 by Josh C
zoetrope 1.4
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-- Class: TextInput
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-- This is like a <Text> object, only it listens to user input and
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-- adjusts its text property accordingly.
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--
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-- Extends:
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--		<Text>
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--
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-- Events:
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--		onChange - Occurs when the input's text has changed, either by a
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--				   user's input or programmtically.
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--		onType - Occurs when the input is about to accept input from a key.
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--				 This event handler is passed the key about to be inserted.
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--				 If the handler returns false, *not* nil or any other value,
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--				 then the key is ignored.
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TextInput = Text:extend{
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	text = '',
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	-- Property: listening
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	-- Whether the input is currently listening to input.
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	listening = true,
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	-- Property: caret
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	-- This shows the current insert position.
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	caret = 0,
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	-- Property: blinkRate
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	-- How quickly the caret blinks, in seconds.
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	blinkRate = 0.5,
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	-- internal property: _blinkTimer
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	-- Used to keep track of caret blinking.
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	_blinkTimer = 0,
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	-- internal property: _repeatKey
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	-- Used to keep track of what movement key is being held down.
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	-- internal property: _repeatTimer
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	-- Used to keep track of how quickly movement keys repeat.
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	-- internal property: _caretHeight
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	-- How tall the caret is onscreen, based on the font.
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	-- internal property: _caretX
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	-- Where to draw the caret, relative to the sprite's x position.
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	update = function (self, elapsed)
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		if self.listening then
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			-- listen to normal keys
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			if the.keys.typed ~= '' then
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				if (self.onType and self:onType(the.keys.typed)) or not self.onType then
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					self.text = string.sub(self.text, 1, self.caret) .. the.keys.typed
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								.. string.sub(self.text, self.caret + 1)
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					self.caret = self.caret + string.len(the.keys.typed)
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				end
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			end
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			if the.keys:justPressed('home') then
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				self.caret = 0
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			end
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			if the.keys:justPressed('end') then
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				self.caret = string.len(self.text)
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			end
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			-- handle movement keys that repeat
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			-- we have to simulate repeat rates manually :(
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			local delay, rate = love.keyboard.getKeyRepeat()
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			local frameAction
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			for _, key in pairs{'backspace', 'delete', 'left', 'right'} do
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				if the.keys:pressed(key) then
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					if self._repeatKey == key then
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						self._repeatTimer = self._repeatTimer + elapsed
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						-- if we've made it past the maximum delay, then
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						-- we reset the timer and take action
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						if self._repeatTimer > delay + rate then
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							self._repeatTimer = delay
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							frameAction = key
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						end
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					else
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						-- we've just started holding down the key
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						self._repeatKey = key
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						self._repeatTimer = 0
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						frameAction = key
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					end
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				else
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					if self._repeatKey == key then
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						self._repeatKey = nil
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					end
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				end
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			end
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			if frameAction == 'backspace' and self.caret > 0 then
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				self.text = string.sub(self.text, 1, self.caret - 1) .. string.sub(self.text, self.caret + 1)
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				self.caret = self.caret - 1
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			end
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			if frameAction == 'delete' and self.caret < string.len(self.text) then
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				self.text = string.sub(self.text, 1, self.caret) .. string.sub(self.text, self.caret + 2)
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			end
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			if frameAction == 'left' and self.caret > 0 then
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				self.caret = self.caret - 1
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			end
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			if frameAction == 'right' and self.caret < string.len(self.text) then
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				self.caret = self.caret + 1
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			end
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		end
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		-- update caret position
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		if self._set.caret ~= self.caret and self._fontObj then
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			self._caretX = self._fontObj:getWidth(string.sub(self.text, 1, self.caret))
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			self._caretHeight = self._fontObj:getHeight()
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			self._set.caret = self.caret
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		end
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		-- update caret timer
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		self._blinkTimer = self._blinkTimer + elapsed
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		if self._blinkTimer > self.blinkRate * 2 then self._blinkTimer = 0 end
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		-- call onChange handler as needed
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		if self.text ~= self._set.text then
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			if self.onChange then self:onChange() end
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			self._set.text = self.text
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		end
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		Text.update(self, elapsed)
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	end,
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	draw = function (self, x, y)
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		if self.visible then
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			x = x or self.x
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			y = y or self.y
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			Text.draw(self, x, y)
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			-- draw caret
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			if (self._repeatKey or self._blinkTimer < self.blinkRate) and
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			   (self._caretX and self._caretHeight) then
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				love.graphics.setLineWidth(1)
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				love.graphics.line(x + self._caretX, y, x + self._caretX, y + self._caretHeight)
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			end
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		end
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	end
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}