def draw_on(self, canvas, offset=(0, 0)):
ox, oy = offset
w, h = self.width, self.height
self._resistor_zig_zags = draw_resistor_zig_zags(canvas, ox, oy, w, h)
self.parts |= self._resistor_zig_zags
# create button that lets user select a signal file for this pot when
# right-clicked
pot_alpha_window = canvas.create_rectangle(ox + (w - POT_ALPHA_WIDTH) / 2,
oy + (h - POT_ALPHA_HEIGHT) / 2, ox + (w + POT_ALPHA_WIDTH) / 2,
oy + (h + POT_ALPHA_HEIGHT) / 2, fill=POT_ALPHA_FILL if
self.signal_file else POT_ALPHA_EMPTY_FILL, outline=POT_ALPHA_OUTLINE)
pot_alpha_text = canvas.create_text(ox + w / 2, oy + h / 2 - 1,
text=POT_ALPHA_TEXT, justify=CENTER, fill='white' if self.signal_file
else 'black', font=FONT)
def set_signal_file():
"""
Opens a window to let the user choose a signal file.
"""
new_signal_file = askopenfilename(title=OPEN_POT_SIGNAL_FILE_TITLE,
filetypes=[('%s files' % POT_SIGNAL_FILE_TYPE,
POT_SIGNAL_FILE_EXTENSION)], initialfile=self.signal_file)
if new_signal_file and new_signal_file != self.signal_file:
self.signal_file = relpath(new_signal_file)
canvas.itemconfig(pot_alpha_window, fill=POT_ALPHA_FILL)
canvas.itemconfig(pot_alpha_text, fill='white')
self.on_signal_file_changed()
self.set_signal_file = set_signal_file
self.parts.add(pot_alpha_window)
self.parts.add(pot_alpha_text)
def draw_on(self, canvas, offset=(0, 0)):
ox, oy = offset
w, h = self.width, self.height
self._resistor_zig_zags = draw_resistor_zig_zags(canvas, ox, oy, w, h)
self.parts |= self._resistor_zig_zags
text = resistance_to_string(resistance_from_string(self.init_resistance))
if w > h: # horizontal
self.resistor_text = canvas.create_text(ox + w / 2,
oy - RESISTOR_TEXT_PADDING, text=text, font=FONT)
else: # vertical
self.resistor_text = canvas.create_text(ox + w + RESISTOR_TEXT_PADDING +
8, oy + h / 2, text=text, font=FONT)
self.parts.add(self.resistor_text)
def get_resistance():
"""
Returns the string representing this resistor's resistance.
"""
return canvas.itemcget(self.resistor_text, 'text')
self.get_resistance = get_resistance
def _set_resistance(r):
canvas.itemconfig(self.resistor_text, text=r)
self.init_resistance = r
def set_resistance(r):
"""
Sets the resistance of this resistor to be the string |r|, after
appropriately modifying it.
"""
if not r:
self.board.display_message('No resistance entered', ERROR)
return
try:
old_r = self.get_resistance()
new_r = resistance_to_string(resistance_from_string(r))
do = lambda: _set_resistance(new_r)
undo = lambda: _set_resistance(old_r)
do()
self.board.set_changed(True, Action(do, undo, 'set_resistance'))
except Exception as e:
self.board.display_message(e.message, ERROR)
self.set_resistance = set_resistance
