kopia lustrzana https://github.com/peterhinch/micropython-micro-gui
61 wiersze
2.6 KiB
Python
61 wiersze
2.6 KiB
Python
# knob.py Extension to microgui providing a control knob (rotary potentiometer) widget
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# Released under the MIT License (MIT). See LICENSE.
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# Copyright (c) 2021 Peter Hinch
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from gui.core.ugui import LinearIO, display
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import math
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TWOPI = 2 * math.pi
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# Null function
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dolittle = lambda *_ : None
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# *********** CONTROL KNOB CLASS ***********
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class Knob(LinearIO):
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def __init__(self, writer, row, col, *, height=70, arc=TWOPI, ticks=9, value=0.0,
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fgcolor=None, bgcolor=None, color=None, bdcolor=None, prcolor=None,
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callback=dolittle, args=[], active=True):
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super().__init__(writer, row, col, height, height, fgcolor, bgcolor, bdcolor, value, active, prcolor)
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super()._set_callbacks(callback, args)
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radius = height / 2
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self.arc = min(max(arc, 0), TWOPI) # Usable angle of control
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self.radius = radius
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self.xorigin = col + radius
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self.yorigin = row + radius
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self.ticklen = 0.1 * radius
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self.pointerlen = radius - self.ticklen - 5
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self.ticks = max(ticks, 2) # start and end of travel
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self.color = color
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self.draw = True # Ensure a redraw on next refresh
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# Run callback (e.g. to set dynamic colors)
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self.callback(self, *self.args)
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def show(self):
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if super().show(False): # Honour bgcolor
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arc = self.arc
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ticks = self.ticks
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radius = self.radius
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ticklen = self.ticklen
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for tick in range(ticks):
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theta = (tick / (ticks - 1)) * arc - arc / 2
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x_start = int(self.xorigin + radius * math.sin(theta))
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y_start = int(self.yorigin - radius * math.cos(theta))
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x_end = int(self.xorigin + (radius - ticklen) * math.sin(theta))
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y_end = int(self.yorigin - (radius - ticklen) * math.cos(theta))
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display.line(x_start, y_start, x_end, y_end, self.fgcolor)
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if self.color is not None:
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display.fillcircle(self.xorigin, self.yorigin, radius - ticklen, self.color)
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display.circle(self.xorigin, self.yorigin, radius - ticklen, self.fgcolor)
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display.circle(self.xorigin, self.yorigin, radius - ticklen - 3, self.fgcolor)
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self._drawpointer(self._value, self.fgcolor) # draw new
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def _drawpointer(self, value, color):
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arc = self.arc
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length = self.pointerlen
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angle = value * arc - arc / 2
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x_end = int(self.xorigin + length * math.sin(angle))
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y_end = int(self.yorigin - length * math.cos(angle))
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display.line(int(self.xorigin), int(self.yorigin), x_end, y_end, color)
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