/zoeplat : revision 12

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-- Class: Keys

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-- This tracks the state of the keyboard, i.e. if a key

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-- was just pressed or released this frame. You can look

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-- up a key either by its name or its Unicode number.

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-- Not all keys sensed have Unicode equivalents (e.g. modifiers

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-- like Control or Alt).

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--

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-- Only one Keys object can be active at one time. The one currently

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-- listening to the keyboard can be accessed globally via <the>.keys.

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--

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-- See http://love2d.org/wiki/KeyConstant for a list of key names.

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-- This class aliases modifiers for you, so that if you want to check

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-- whether either the left or right Control key is pressed, you can check

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-- on 'ctrl' instead of both 'lctrl' and 'rctrl'.

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--

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-- Extends:

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-- <Sprite>

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Keys = Sprite:extend

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{

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visible = false,

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-- Property: typed

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-- This is literally what is being typed during the current frame.

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-- e.g. if the user holds the shift key and presses the 'a' key,

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-- this will be set to 'A'. Consult <allPressed()> if you

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-- want to know what specific keys are being pressed.

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typed = '',

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-- private property: _thisFrame

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-- what keys are pressed this frame

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-- if you are interested in this, use allPressed() instead

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_thisFrame = {},

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-- private property: _lastFrame

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-- what keys were pressed last frame

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_lastFrame = {},

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new = function (self, obj)

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obj = self:extend(obj)

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the.keys = obj

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love.keypressed = function (key, unicode) obj:keyPressed(key, unicode) end

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love.keyreleased = function (key, unicode) obj:keyReleased(key, unicode) end

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if obj.onNew then obj:onNew() end

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return obj

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end,

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-- Method: pressed

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-- Are *any* of the keys passed held down this frame?

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--

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-- Arguments:

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-- string key descriptions passed as individual arguments

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--

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-- Returns:

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-- boolean

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pressed = function (self, ...)

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local keys = {...}

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for _, value in pairs(keys) do

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if STRICT then

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assert(type(value) == 'string', 'all keys are strings; asked to check a ' .. type(value))

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end

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if self._thisFrame[value] then

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return true

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end

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end

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return false

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end,

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-- Method: justPressed

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-- Are *any* of the keys passed pressed for the first time this frame?

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--

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-- Arguments:

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-- string key descriptions passed as individual arguments

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--

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-- Returns:

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-- boolean

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justPressed = function (self, ...)

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local keys = {...}

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for _, value in pairs(keys) do

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if STRICT then

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assert(type(value) == 'string', 'all keys are strings; asked to check a ' .. type(value))

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end

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if self._thisFrame[value] and not self._lastFrame[value] then

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return true

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end

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end

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return false

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end,

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-- Method: released

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-- Are *all* of the keys passed not held down this frame?

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--

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-- Arguments:

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-- string key descriptions passed as individual arguments

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--

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-- Returns:

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-- boolean

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released = function (self, ...)

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local keys = {...}

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for _, value in pairs(keys) do

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if STRICT then

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assert(type(value) == 'string', 'all keys are strings; asked to check a ' .. type(value))

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end

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if self._thisFrame[value] then

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return false

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end

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end

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return true

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end,

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-- Method: justReleased

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-- Are *any* of the keys passed released after being held last frame?

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--

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-- Arguments:

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-- string key descriptions passed as individual arguments

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--

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-- Returns:

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-- boolean

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justReleased = function (self, ...)

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local keys = {...}

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for _, value in pairs(keys) do

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if STRICT then

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assert(type(value) == 'string', 'all keys are strings; asked to check a ' .. type(value))

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end

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if self._lastFrame[value] and not self._thisFrame[value] then

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return true

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end

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end

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return false

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end,

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-- Method: allPressed

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-- Returns all buttons currently pressed this frame.

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--

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-- Arguments:

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-- none

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--

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-- Returns:

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-- string key descriptions; if nothing is pressed, nil

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allPressed = function (self)

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local result = {}

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for key, value in pairs(self._thisFrame) do

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if value then table.insert(result, key) end

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end

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return unpack(result)

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end,

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-- Method: allJustPressed

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-- Returns all keys just pressed this frame.

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--

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-- Arguments:

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-- none

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--

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-- Returns:

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-- string key descriptions; if nothing is just pressed, nil

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allJustPressed = function (self)

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local result = {}

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for key, value in pairs(self._thisFrame) do

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if value and not self._lastFrame[key] then table.insert(result, key) end

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end

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return unpack(result)

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end,

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-- Method: allJustReleased

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-- Returns all keys just released this frame.

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--

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-- Arguments:

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-- none

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--

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-- Returns:

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-- string key descriptions; if nothing is just pressed, nil

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allJustReleased = function (self)

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local result = {}

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for key, value in pairs(self._thisFrame) do

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if not value and self._lastFrame[key] then table.insert(result, key) end

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end

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return unpack(result)

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end,

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-- Converts a character code to a Unicode string

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-- see http://stackoverflow.com/questions/7780179/what-is-the-way-to-represent-a-unichar-in-lua/7799843

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unicodeChar = function (self, code)

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if code == nil then return nil end

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if code < 32 then return string.format('\\x%02x', code) end

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if code < 126 then return string.char(code) end

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if code < 65539 then return string.format("\\u%04x", code) end

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if code < 1114111 then return string.format("\\u%08x", code) end

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end,

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-- Connects to the love.keypressed callback

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keyPressed = function (self, key, unicode)

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self._thisFrame[key] = true

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if unicode and unicode >= 0x20 and unicode ~= 127 and unicode < 0x3000 then

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self.typed = self.typed .. self:unicodeChar(unicode)

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end

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-- aliases for modifiers

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if key == 'rshift' or key == 'lshift' or

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key == 'rctrl' or key == 'lctrl' or

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key == 'ralt' or key == 'lalt' or

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key == 'rmeta' or key == 'lmeta' or

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key == 'rsuper' or key == 'lsuper' then

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self._thisFrame[string.sub(key, 2)] = true

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end

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end,

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-- Connects to the love.keyreleased callback

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keyReleased = function (self, key, unicode)

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self._thisFrame[key] = false

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-- aliases for modifiers

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if key == 'rshift' or key == 'lshift' or

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key == 'rctrl' or key == 'lctrl' or

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key == 'ralt' or key == 'lalt' or

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key == 'rmeta' or key == 'lmeta' or

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key == 'rsuper' or key == 'lsuper' then

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self._thisFrame[string.sub(key, 2)] = false

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end

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end,

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endFrame = function (self, elapsed)

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for key, value in pairs(self._thisFrame) do

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self._lastFrame[key] = value

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end

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self.typed = ''

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Sprite.endFrame(self, elapsed)

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end,

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update = function() end

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}