"""
PyColourChooser
Copyright (C) 2002 Michael Gilfix <mgilfix@eecs.tufts.edu>
This file is part of PyColourChooser.
This version of PyColourChooser is open source; you can redistribute it
and/or modify it under the licensed terms.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
"""
# 12/14/2003 - Jeff Grimmett (grimmtooth@softhome.net)
#
# o 2.5 compatability update.
#
# 12/21/2003 - Jeff Grimmett (grimmtooth@softhome.net)
#
# o wxPyColorChooser -> PyColorChooser
# o wxPyColourChooser -> PyColourChooser
#
import wx
class BitmapBuffer(wx.MemoryDC):
"""A screen buffer class.
This class implements a screen output buffer. Data is meant to
be drawn in the buffer class and then blitted directly to the
output device, or on-screen window.
"""
def __init__(self, width, height, colour):
"""Initialize the empty buffer object."""
wx.MemoryDC.__init__(self)
self.width = width
self.height = height
self.colour = colour
self.bitmap = wx.EmptyBitmap(self.width, self.height)
self.SelectObject(self.bitmap)
# Initialize the buffer to the background colour
self.SetBackground(wx.Brush(self.colour, wx.SOLID))
self.Clear()
# Make each logical unit of the buffer equal to 1 pixel
self.SetMapMode(wx.MM_TEXT)
def GetBitmap(self):
"""Returns the internal bitmap for direct drawing."""
return self.bitmap
# GetPixel seems to always return (-1, -1, -1, 255)
# on OS X so this is a workaround for that issue.
def GetPixelColour(self, x, y):
"""Gets the color value of the pixel at the given
cords.
"""
img = self.GetAsBitmap().ConvertToImage()
red = img.GetRed(x, y)
green = img.GetGreen(x, y)
blue = img.GetBlue(x, y)
return wx.Colour(red, green, blue)
class Canvas(wx.Window):
"""A canvas class for arbitrary drawing.
The Canvas class implements a window that allows for drawing
arbitrary graphics. It implements a double buffer scheme and
blits the off-screen buffer to the window during paint calls
by the windowing system for speed.
Some other methods for determining the canvas colour and size
are also provided.
"""
def __init__(self, parent, id,
pos=wx.DefaultPosition,
size=wx.DefaultSize,
style=wx.SIMPLE_BORDER):
"""Creates a canvas instance and initializes the off-screen
buffer. Also sets the handler for rendering the canvas
automatically via size and paint calls from the windowing
system."""
wx.Window.__init__(self, parent, id, pos, size, style)
# Perform an intial sizing
self.ReDraw()
# Register event handlers
self.Bind(wx.EVT_SIZE, self.onSize)
self.Bind(wx.EVT_PAINT, self.onPaint)
def MakeNewBuffer(self):
size = self.GetSize()
self.buffer = BitmapBuffer(size[0], size[1],
self.GetBackgroundColour())
def onSize(self, event):
"""Perform actual redraw to off-screen buffer only when the
size of the canvas has changed. This saves a lot of computation
since the same image can be re-used, provided the canvas size
hasn't changed."""
self.MakeNewBuffer()
self.DrawBuffer()
self.Refresh()
def ReDraw(self):
"""Explicitly tells the canvas to redraw it's contents."""
self.onSize(None)
def Refresh(self):
"""Re-draws the buffer contents on-screen."""
dc = wx.ClientDC(self)
self.Blit(dc)
def onPaint(self, event):
"""Renders the off-screen buffer on-screen."""
dc = wx.PaintDC(self)
self.Blit(dc)
def Blit(self, dc):
"""Performs the blit of the buffer contents on-screen."""
width, height = self.buffer.GetSize()
dc.BeginDrawing()
dc.Blit(0, 0, width, height, self.buffer, 0, 0)
dc.EndDrawing()
def GetBoundingRect(self):
"""Returns a tuple that contains the co-ordinates of the
top-left and bottom-right corners of the canvas."""
x, y = self.GetPosition()
w, h = self.GetSize()
return(x, y + h, x + w, y)
def DrawBuffer(self):
"""Actual drawing function for drawing into the off-screen
buffer. To be overrideen in the implementing class. Do nothing
by default."""
pass
|