Lib/lib-stdwin/Sliders.py

   1 # Module 'Sliders'
   2
   3
   4 import stdwin
   5 from stdwinevents import *
   6 import rect
   7 from Buttons import *
   8 from HVSplit import HSplit
   9
  10
  11 # Field indices in event detail
  12 #
  13 _HV = 0
  14 _CLICKS = 1
  15 _BUTTON = 2
  16 _MASK = 3
  17
  18
  19 # DragSlider is the simplest possible slider.
  20 # It looks like a button but dragging the mouse left or right
  21 # changes the controlled value.
  22 # It does not support any of the triggers or hooks defined by Buttons,
  23 # but defines its own setval_trigger and setval_hook.
  24 #
  25 class DragSliderReactivity(BaseReactivity):
  26         #
  27         def mouse_down(self, detail):
  28                 h, v = hv = detail[_HV]
  29                 if self.enabled and self.mousetest(hv):
  30                         self.anchor = h
  31                         self.oldval = self.val
  32                         self.active = 1
  33         #
  34         def mouse_move(self, detail):
  35                 if self.active:
  36                         h, v = detail[_HV]
  37                         self.setval(self.oldval + (h - self.anchor))
  38         #
  39         def mouse_up(self, detail):
  40                 if self.active:
  41                         h, v = detail[_HV]
  42                         self.setval(self.oldval + (h - self.anchor))
  43                         self.active = 0
  44         #
  45
  46 class DragSliderAppearance(ButtonAppearance):
  47         #
  48         # INVARIANTS maintained by the setval method:
  49         #
  50         #       self.min <= self.val <= self.max
  51         #       self.text = self.pretext + `self.val` + self.postext
  52         #
  53         # (Notice that unlike Python ranges, the end point belongs
  54         # to the range.)
  55         #
  56         def init_appearance(self):
  57                 ButtonAppearance.init_appearance(self)
  58                 self.min = 0
  59                 self.val = 0
  60                 self.max = 100
  61                 self.hook = 0
  62                 self.pretext = self.postext = ''
  63                 self.recalctext()
  64         #
  65         # The 'get*' and 'set*' methods belong to the generic slider interface
  66         #
  67         def getval(self): return self.val
  68         #
  69         def sethook(self, hook):
  70                 self.hook = hook
  71         #
  72         def setminvalmax(self, min, val, max):
  73                 self.min = min
  74                 self.max = max
  75                 self.setval(val)
  76         #
  77         def settexts(self, pretext, postext):
  78                 self.pretext = pretext
  79                 self.postext = postext
  80                 self.recalctext()
  81         #
  82         def setval(self, val):
  83                 val = min(self.max, max(self.min, val))
  84                 if val <> self.val:
  85                         self.val = val
  86                         self.recalctext()
  87                         self.trigger()
  88         #
  89         def trigger(self):
  90                 if self.hook:
  91                         self.hook(self)
  92         #
  93         def recalctext(self):
  94                 self.settext(self.pretext + `self.val` + self.postext)
  95         #
  96
  97 class DragSlider(DragSliderReactivity, DragSliderAppearance, Define):
  98         def definetext(self, parent, text):
  99                 raise RuntimeError, 'DragSlider.definetext() not supported'
 100
 101
 102 # Auxiliary class for PushButton incorporated in ComplexSlider
 103 #
 104 class _StepButton(PushButton):
 105         def define(self, parent):
 106                 self = PushButton.define(self, parent)
 107                 self.step = 0
 108                 return self
 109         def setstep(self, step):
 110                 self.step = step
 111         def definetextstep(self, parent, text, step):
 112                 self = self.definetext(parent, text)
 113                 self.setstep(step)
 114                 return self
 115         def init_reactivity(self):
 116                 PushButton.init_reactivity(self)
 117                 self.parent.need_timer(self)
 118         def step_trigger(self):
 119                 self.parent.setval(self.parent.getval() + self.step)
 120         def down_trigger(self):
 121                 self.step_trigger()
 122                 self.parent.settimer(5)
 123         def timer(self):
 124                 if self.hilited:
 125                         self.step_trigger()
 126                 if self.active:
 127                         self.parent.settimer(1)
 128
 129
 130 # A complex slider is an HSplit initialized to three buttons:
 131 # one to step down, a dragslider, and one to step up.
 132 #
 133 class ComplexSlider(HSplit):
 134         #
 135         # Override Slider define() method
 136         #
 137         def define(self, parent):
 138                 self = self.create(parent) # HSplit
 139                 #
 140                 self.downbutton = _StepButton().definetextstep(self, '-', -1)
 141                 self.dragbutton = DragSlider().define(self)
 142                 self.upbutton = _StepButton().definetextstep(self, '+', 1)
 143                 #
 144                 return self
 145         #
 146         # Override HSplit methods
 147         #
 148         def getminsize(self, m, (width, height)):
 149                 w1, h1 = self.downbutton.getminsize(m, (0, height))
 150                 w3, h3 = self.upbutton.getminsize(m, (0, height))
 151                 w1 = max(w1, h1)
 152                 w3 = max(w3, h3)
 153                 w2, h2 = self.dragbutton.getminsize(m, (width-w1-w3, height))
 154                 return w1+w2+w3, max(h1, h2, h3)
 155         #
 156         def setbounds(self, bounds):
 157                 (left, top), (right, bottom) = self.bounds = bounds
 158                 size = bottom - top
 159                 self.downbutton.setbounds(((left, top), (left+size, bottom)))
 160                 self.dragbutton.setbounds(((left+size, top), \
 161                                                 (right-size, bottom)))
 162                 self.upbutton.setbounds(((right-size, top), (right, bottom)))
 163         #
 164         # Pass other Slider methods on to dragbutton
 165         #
 166         def getval(self): return self.dragbutton.getval()
 167         def sethook(self, hook): self.dragbutton.sethook(hook)
 168         def setminvalmax(self, args): self.dragbutton.setminvalmax(args)
 169         def settexts(self, args): self.dragbutton.settexts(args)
 170         def setval(self, val): self.dragbutton.setval(val)
 171         def enable(self, flag):
 172                 self.downbutton.enable(flag)
 173                 self.dragbutton.enable(flag)
 174                 self.upbutton.enable(flag)