/zoeplat : revision 16

1

-- Class: Keys

2

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

3

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

4

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

5

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

6

-- like Control or Alt).

7

--

8

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

9

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

10

--

11

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

12

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

13

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

14

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

15

--

16

-- Extends:

17

-- <Sprite>

18

19

Keys = Sprite:extend

20

{

21

visible = false,

22

23

-- Property: typed

24

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

25

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

26

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

27

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

28

29

typed = '',

30

31

-- private property: _thisFrame

32

-- what keys are pressed this frame

33

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

34

35

_thisFrame = {},

36

37

-- private property: _lastFrame

38

-- what keys were pressed last frame

39

40

_lastFrame = {},

41

42

new = function (self, obj)

43

obj = self:extend(obj)

44

the.keys = obj

45

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

46

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

47

if obj.onNew then obj:onNew() end

48

return obj

49

end,

50

51

-- Method: pressed

52

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

53

--

54

-- Arguments:

55

-- string key descriptions passed as individual arguments

56

--

57

-- Returns:

58

-- boolean

59

60

pressed = function (self, ...)

61

local keys = {...}

62

for _, value in pairs(keys) do

63

if STRICT then

64

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

65

end

66

67

if self._thisFrame[value] then

68

return true

69

end

70

end

71

72

return false

73

end,

74

75

-- Method: justPressed

76

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

77

--

78

-- Arguments:

79

-- string key descriptions passed as individual arguments

80

--

81

-- Returns:

82

-- boolean

83

84

justPressed = function (self, ...)

85

local keys = {...}

86

87

for _, value in pairs(keys) do

88

if STRICT then

89

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

90

end

91

92

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

93

return true

94

end

95

end

96

97

return false

98

end,

99

100

-- Method: released

101

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

102

--

103

-- Arguments:

104

-- string key descriptions passed as individual arguments

105

--

106

-- Returns:

107

-- boolean

108

109

released = function (self, ...)

110

local keys = {...}

111

112

for _, value in pairs(keys) do

113

if STRICT then

114

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

115

end

116

117

if self._thisFrame[value] then

118

return false

119

end

120

end

121

122

return true

123

end,

124

125

-- Method: justReleased

126

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

127

--

128

-- Arguments:

129

-- string key descriptions passed as individual arguments

130

--

131

-- Returns:

132

-- boolean

133

134

justReleased = function (self, ...)

135

local keys = {...}

136

137

for _, value in pairs(keys) do

138

if STRICT then

139

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

140

end

141

142

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

143

return true

144

end

145

end

146

147

return false

148

end,

149

150

-- Method: allPressed

151

-- Returns all buttons currently pressed this frame.

152

--

153

-- Arguments:

154

-- none

155

--

156

-- Returns:

157

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

158

159

allPressed = function (self)

160

local result = {}

161

162

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

163

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

164

end

165

166

return unpack(result)

167

end,

168

169

-- Method: allJustPressed

170

-- Returns all keys just pressed this frame.

171

--

172

-- Arguments:

173

-- none

174

--

175

-- Returns:

176

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

177

178

allJustPressed = function (self)

179

local result = {}

180

181

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

182

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

183

end

184

185

return unpack(result)

186

end,

187

188

-- Method: allJustReleased

189

-- Returns all keys just released this frame.

190

--

191

-- Arguments:

192

-- none

193

--

194

-- Returns:

195

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

196

197

allJustReleased = function (self)

198

local result = {}

199

200

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

201

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

202

end

203

204

return unpack(result)

205

end,

206

207

-- Converts a character code to a Unicode string

208

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

209

210

unicodeChar = function (self, code)

211

if code == nil then return nil end

212

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

213

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

214

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

215

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

216

end,

217

218

-- Connects to the love.keypressed callback

219

220

keyPressed = function (self, key, unicode)

221

self._thisFrame[key] = true

222

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

223

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

224

end

225

226

-- aliases for modifiers

227

228

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

229

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

230

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

231

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

232

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

233

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

234

end

235

end,

236

237

-- Connects to the love.keyreleased callback

238

239

keyReleased = function (self, key, unicode)

240

self._thisFrame[key] = false

241

242

-- aliases for modifiers

243

244

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

245

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

246

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

247

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

248

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

249

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

250

end

251

end,

252

253

endFrame = function (self, elapsed)

254

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

255

self._lastFrame[key] = value

256

end

257

258

self.typed = ''

259

Sprite.endFrame(self, elapsed)

260

end,

261

262

update = function() end

263

}