wxPython/wx/lib/colourchooser/pycolourslider.py

   1 """
   2 PyColourChooser
   3 Copyright (C) 2002 Michael Gilfix
   4
   5 This file is part of PyColourChooser.
   6
   7 You should have received a file COPYING containing license terms
   8 along with this program; if not, write to Michael Gilfix
   9 (mgilfix@eecs.tufts.edu) for a copy.
  10
  11 This version of PyColourChooser is open source; you can redistribute it and/or
  12 modify it under the terms listed in the file COPYING.
  13
  14 This program is distributed in the hope that it will be useful,
  15 but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  17 """
  18
  19 # 12/14/2003 - Jeff Grimmett (grimmtooth@softhome.net)
  20 #
  21 # o 2.5 compatability update.
  22 #
  23 # 12/21/2003 - Jeff Grimmett (grimmtooth@softhome.net)
  24 #
  25 # o wxPyColorChooser -> PyColorChooser
  26 # o wxPyColourChooser -> PyColourChooser
  27 #
  28
  29 import  wx
  30
  31 import  canvas
  32 import  colorsys
  33
  34 class PyColourSlider(canvas.Canvas):
  35     """A Pure-Python Colour Slider
  36
  37     The colour slider displays transitions from value 0 to value 1 in
  38     HSV, allowing the user to select a colour within the transition
  39     spectrum.
  40
  41     This class is best accompanying by a wxSlider that allows the user
  42     to select a particular colour shade.
  43     """
  44
  45     HEIGHT = 172
  46     WIDTH = 12
  47
  48     def __init__(self, parent, id, colour=None):
  49         """Creates a blank slider instance. A colour must be set before the
  50         slider will be filled in."""
  51         # Set the base colour first since our base class calls the buffer
  52         # drawing function
  53         self.SetBaseColour(colour)
  54
  55         canvas.Canvas.__init__(self, parent, id, size=(self.WIDTH, self.HEIGHT))
  56
  57     def SetBaseColour(self, colour):
  58         """Sets the base, or target colour, to use as the central colour
  59         when calculating colour transitions."""
  60         self.base_colour = colour
  61
  62     def GetBaseColour(self):
  63         """Return the current colour used as a colour base for filling out
  64         the slider."""
  65         return self.base_colour
  66
  67     def GetValue(self, pos):
  68         """Returns the colour value for a position on the slider. The position
  69         must be within the valid height of the slider, or results can be
  70         unpredictable."""
  71         return self.buffer.GetPixel((0, pos))
  72
  73     def DrawBuffer(self):
  74         """Actual implementation of the widget's drawing. We simply draw
  75         from value 0.0 to value 1.0 in HSV."""
  76         if self.base_colour is None:
  77             return
  78
  79         target_red = self.base_colour.Red()
  80         target_green = self.base_colour.Green()
  81         target_blue = self.base_colour.Blue()
  82
  83         h,s,v = colorsys.rgb_to_hsv(target_red / 255.0, target_green / 255.0,
  84                                     target_blue / 255.0)
  85         v = 1.0
  86         vstep = 1.0 / self.HEIGHT
  87         for y_pos in range(0, self.HEIGHT):
  88             r,g,b = [c * 255.0 for c in colorsys.hsv_to_rgb(h,s,v)]
  89             colour = wx.Colour(int(r), int(g), int(b))
  90             self.buffer.SetPen(wx.Pen(colour, 1, wx.SOLID))
  91             self.buffer.DrawRectangle((0, y_pos), (15, 1))
  92             v = v - vstep