cpython/Tools/pynche/StripViewer.py

"""Strip viewer and related widgets.

The classes in this file implement the StripViewer shown in the top two thirds 
of the main Pynche window.  It consists of three StripWidgets which display
the variations in red, green, and blue respectively of the currently selected
r/g/b color value.

Each StripWidget shows the color variations that are reachable by varying an
axis of the currently selected color.  So for example, if the color is

  (R,G,B)=(127,163,196)

then the Red variations show colors from (0,163,196) to (255,163,196), the
Green variations show colors from (127,0,196) to (127,255,196), and the Blue
variations show colors from (127,163,0) to (127,163,255).

The selected color is always visible in all three StripWidgets, and in fact
each StripWidget highlights the selected color, and has an arrow pointing to
the selected chip, which includes the value along that particular axis.

Clicking on any chip in any StripWidget selects that color, and updates all
arrows and other windows.  By toggling on Update while dragging, Pynche will
select the color under the cursor while you drag it, but be forewarned that
this can be slow.
"""

import string
from Tkinter import *
import ColorDB

# Load this script into the Tcl interpreter and call it in
# StripWidget.set_color().  This is about as fast as it can be with the
# current _tkinter.c interface, which doesn't support Tcl Objects.
TCLPROC = '''\
proc setcolor {canv colors} {
    set i 1
    foreach c $colors {
        $canv itemconfigure $i -fill $c -outline $c
	incr i
    }
}
'''

# Tcl event types
BTNDOWN = 4
BTNUP = 5
BTNDRAG = 6


def constant(numchips):
    step = 255.0 / (numchips - 1)
    start = 0.0
    seq = []
    while numchips > 0:
	seq.append(int(start))
	start = start + step
	numchips = numchips - 1
    return seq

# red variations, green+blue = cyan constant
def constant_cyan_generator(numchips, red, green, blue):
    seq = constant(numchips)
    return map(None, seq, [green] * numchips, [blue] * numchips)

# green variations, red+blue = magenta constant
def constant_magenta_generator(numchips, red, green, blue):
    seq = constant(numchips)
    return map(None, [red] * numchips, seq, [blue] * numchips)

# blue variations, red+green = yellow constant
def constant_yellow_generator(numchips, red, green, blue):
    seq = constant(numchips)
    return map(None, [red] * numchips, [green] * numchips, seq)




class LeftArrow:
    _ARROWWIDTH = 30
    _ARROWHEIGHT = 15
    _YOFFSET = 13
    _TEXTYOFFSET = 1
    _TAG = ('leftarrow',)

    def __init__(self, canvas, x):
	self._canvas = canvas
	self.__arrow, self.__text = self._create(x)
	self.move_to(x)

    def _create(self, x):
	arrow = self._canvas.create_line(
	    x, self._ARROWHEIGHT + self._YOFFSET,
	    x, self._YOFFSET,
	    x + self._ARROWWIDTH, self._YOFFSET,
	    arrow='first',
	    width=3.0,
	    tags=self._TAG)
	text = self._canvas.create_text(
	    x + self._ARROWWIDTH + 13,
	    self._ARROWHEIGHT - self._TEXTYOFFSET,
	    tags=self._TAG,
	    text='128')
	return arrow, text

    def _x(self):
	coords = self._canvas.coords(self._TAG)
	assert coords
	return coords[0]

    def move_to(self, x):
	deltax = x - self._x()
	self._canvas.move(self._TAG, deltax, 0)

    def set_text(self, text):
	self._canvas.itemconfigure(self.__text, text=text)


class RightArrow(LeftArrow):
    _TAG = ('rightarrow',)

    def _create(self, x):
	arrow = self._canvas.create_line(
	    x, self._YOFFSET,
	    x + self._ARROWWIDTH, self._YOFFSET,
	    x + self._ARROWWIDTH, self._ARROWHEIGHT + self._YOFFSET,
	    arrow='last',
	    width=3.0,
	    tags=self._TAG)
	text = self._canvas.create_text(
	    x - self._ARROWWIDTH + 15,		  # TBD: kludge
	    self._ARROWHEIGHT - self._TEXTYOFFSET,
	    text='128',
	    tags=self._TAG)
	return arrow, text

    def _x(self):
	coords = self._canvas.bbox(self._TAG)
	assert coords
	return coords[2] - 6			  # TBD: kludge



class StripWidget:
    _CHIPHEIGHT = 50
    _CHIPWIDTH = 10
    _NUMCHIPS = 40

    def __init__(self, switchboard,
                 parent     = None,
                 chipwidth  = _CHIPWIDTH,
                 chipheight = _CHIPHEIGHT,
                 numchips   = _NUMCHIPS,
                 generator  = None,
                 axis       = None,
                 label      = '',
                 uwdvar     = None):
        # instance variables
	self.__generator = generator
	self.__axis = axis
        self.__numchips = numchips
	assert self.__axis in (0, 1, 2)
	self.__uwd = uwdvar
        # the last chip selected
        self.__lastchip = None
        self.__sb = switchboard
        
	canvaswidth = numchips * (chipwidth + 1)
	canvasheight = chipheight + 43		  # TBD: Kludge

	# create the canvas and pack it
	canvas = self.__canvas = Canvas(
	    parent,
	    width=canvaswidth,
	    height=canvasheight,
## 	    borderwidth=2,
## 	    relief=GROOVE
	    )

	canvas.pack()
	canvas.bind('<ButtonPress-1>', self.__select_chip)
	canvas.bind('<ButtonRelease-1>', self.__select_chip)
	canvas.bind('<B1-Motion>', self.__select_chip)

	# Load a proc into the Tcl interpreter.  This is used in the
	# set_color() method to speed up setting the chip colors.
	canvas.tk.eval(TCLPROC)

	# create the color strip
	chips = self.__chips = []
	x = 1
	y = 30
	tags = ('chip',)
	for c in range(self.__numchips):
	    color = 'grey'
	    rect = canvas.create_rectangle(
		x, y, x+chipwidth, y+chipheight,
		fill=color, outline=color,
		tags=tags)
	    x = x + chipwidth + 1		  # for outline
	    chips.append(color)

	# create the strip label
	self.__label = canvas.create_text(
	    3, y + chipheight + 8,
	    text=label,
	    anchor=W)

	# create the arrow and text item
	chipx = self.__arrow_x(0)
	self.__leftarrow = LeftArrow(canvas, chipx)

	chipx = self.__arrow_x(len(chips) - 1)
	self.__rightarrow = RightArrow(canvas, chipx)

    def __arrow_x(self, chipnum):
	coords = self.__canvas.coords(chipnum+1)
	assert coords
	x0, y0, x1, y1 = coords
	return (x1 + x0) / 2.0

    # Invoked when one of the chips is clicked.  This should just tell the
    # switchboard to set the color on all the output components
    def __select_chip(self, event=None):
        x = event.x
        y = event.y
        canvas = self.__canvas
        chip = canvas.find_overlapping(x, y, x, y)
        if chip and (1 <= chip[0] <= self.__numchips):
            color = self.__chips[chip[0]-1]
            red, green, blue = ColorDB.rrggbb_to_triplet(color)
            etype = int(event.type)
            if (etype == BTNUP or self.__uwd.get()):
                # update everyone
                self.__sb.update_views(red, green, blue)
            else:
                # just track the arrows
                self.__trackarrow(chip[0], (red, green, blue))

    def __trackarrow(self, chip, rgbtuple):
        # invert the last chip
        if self.__lastchip is not None:
            color = self.__canvas.itemcget(self.__lastchip, 'fill')
            self.__canvas.itemconfigure(self.__lastchip, outline=color)
        self.__lastchip = chip
	# get the arrow's text
	coloraxis = rgbtuple[self.__axis]
	text = repr(coloraxis)
	# move the arrow, and set it's text
	if coloraxis <= 128:
	    # use the left arrow
	    self.__leftarrow.set_text(text)
	    self.__leftarrow.move_to(self.__arrow_x(chip-1))
	    self.__rightarrow.move_to(-100)
	else:
	    # use the right arrow
	    self.__rightarrow.set_text(text)
	    self.__rightarrow.move_to(self.__arrow_x(chip-1))
	    self.__leftarrow.move_to(-100)
	# and set the chip's outline
        brightness = ColorDB.triplet_to_brightness(rgbtuple)
	if brightness <= 128:
	    outline = 'white'
	else:
	    outline = 'black'
	self.__canvas.itemconfigure(chip, outline=outline)


    def update_yourself(self, red, green, blue):
	assert self.__generator
	i = 1
	chip = 0
	chips = self.__chips = []
	tclcmd = []
	tk = self.__canvas.tk
        # get the red, green, and blue components for all chips
        for t in self.__generator(self.__numchips, red, green, blue):
            rrggbb = ColorDB.triplet_to_rrggbb(t)
            chips.append(rrggbb)
            tred, tgreen, tblue = t
            if tred <= red and tgreen <= green and tblue <= blue:
                chip = i
            i = i + 1
        # call the raw tcl script
        colors = string.join(chips)
        tk.eval('setcolor %s {%s}' % (self.__canvas._w, colors))
        # move the arrows around
        self.__trackarrow(chip, (red, green, blue))


class StripViewer:
    def __init__(self, switchboard, parent=None):
        self.__sb = switchboard
        # create a frame inside the parent
        self.__frame = Frame(parent) #, relief=GROOVE, borderwidth=2)
        self.__frame.grid(row=1, column=0, columnspan=2, sticky='EW')
        uwd = BooleanVar()
        self.__reds = StripWidget(switchboard, self.__frame,
                                  generator=constant_cyan_generator,
                                  axis=0,
                                  label='Red Variations',
                                  uwdvar=uwd)

        self.__greens = StripWidget(switchboard, self.__frame,
                                    generator=constant_magenta_generator,
                                    axis=1,
                                    label='Green Variations',
                                    uwdvar=uwd)

        self.__blues = StripWidget(switchboard, self.__frame,
                                   generator=constant_yellow_generator,
                                   axis=2,
                                   label='Blue Variations',
                                   uwdvar=uwd)
        self.__uwd = Checkbutton(self.__frame,
                                 text='Update while dragging',
                                 variable=uwd)
        self.__uwd.pack()
        self.__div = Frame(self.__frame,
                           height=2,
                           borderwidth=2,
                           relief=RAISED)
        self.__div.pack(expand=1, fill=X)

    def update_yourself(self, red, green, blue):
        self.__reds.update_yourself(red, green, blue)
        self.__greens.update_yourself(red, green, blue)
        self.__blues.update_yourself(red, green, blue)