wxPython/wx/lib/colourchooser/pycolourslider.py

   1 """
   2 wxPyColourChooser
   3 Copyright (C) 2002 Michael Gilfix
   4
   5 This file is part of wxPyColourChooser.
   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 wxPyColourChooser 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
  24 import  wx
  25
  26 import  canvas
  27 import  colorsys
  28
  29 class PyColourSlider(canvas.Canvas):
  30     """A Pure-Python Colour Slider
  31
  32     The colour slider displays transitions from value 0 to value 1 in
  33     HSV, allowing the user to select a colour within the transition
  34     spectrum.
  35
  36     This class is best accompanying by a wxSlider that allows the user
  37     to select a particular colour shade.
  38     """
  39
  40     HEIGHT = 172
  41     WIDTH = 12
  42
  43     def __init__(self, parent, id, colour=None):
  44         """Creates a blank slider instance. A colour must be set before the
  45         slider will be filled in."""
  46         # Set the base colour first since our base class calls the buffer
  47         # drawing function
  48         self.SetBaseColour(colour)
  49
  50         canvas.Canvas.__init__(self, parent, id, size=(self.WIDTH, self.HEIGHT))
  51
  52     def SetBaseColour(self, colour):
  53         """Sets the base, or target colour, to use as the central colour
  54         when calculating colour transitions."""
  55         self.base_colour = colour
  56
  57     def GetBaseColour(self):
  58         """Return the current colour used as a colour base for filling out
  59         the slider."""
  60         return self.base_colour
  61
  62     def GetValue(self, pos):
  63         """Returns the colour value for a position on the slider. The position
  64         must be within the valid height of the slider, or results can be
  65         unpredictable."""
  66         return self.buffer.GetPixel((0, pos))
  67
  68     def DrawBuffer(self):
  69         """Actual implementation of the widget's drawing. We simply draw
  70         from value 0.0 to value 1.0 in HSV."""
  71         if self.base_colour is None:
  72             return
  73
  74         target_red = self.base_colour.Red()
  75         target_green = self.base_colour.Green()
  76         target_blue = self.base_colour.Blue()
  77
  78         h,s,v = colorsys.rgb_to_hsv(target_red / 255.0, target_green / 255.0,
  79                                     target_blue / 255.0)
  80         v = 1.0
  81         vstep = 1.0 / self.HEIGHT
  82         for y_pos in range(0, self.HEIGHT):
  83             r,g,b = [c * 255.0 for c in colorsys.hsv_to_rgb(h,s,v)]
  84             colour = wx.Colour(int(r), int(g), int(b))
  85             self.buffer.SetPen(wx.Pen(colour, 1, wx.SOLID))
  86             self.buffer.DrawRectangle((0, y_pos), (15, 1))
  87             v = v - vstep