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wasp-os/wasp/apps/calc.py
Daniel Thompson 21210c5c07 apps: calc: Rewrite the display and calculation engine
Currently calculations such as 22/7 do not work correctly on the
simulator (which uses double precision floating point). Fix this
by explicitly truncating the strings when needed.

Additionally the current calculate() method has some problems when
the calculation cannot be evaluated since it will needlessly clear out
the calculation. Push calculate (and the exception handling) into the
caller and report errors using the vibration motor instead.

Finally we rename display_output() to the more idiomatic _update().

Signed-off-by: Daniel Thompson <daniel@redfelineninja.org.uk>
2020-12-29 08:59:53 +00:00

114 lines
3.8 KiB
Python

# SPDX-License-Identifier: LGPL-3.0-or-later
# Copyright (C) 2020 Johannes Wache
"""Calculator application
This is a simple calculator app that uses the build-in eval() function to
compute the solution.
"""
import wasp, fonts
# 2-bit RLE, generated from res/calc.png, 413 bytes
calc = (
b'\x02'
b'`@'
b'(@\x03P?\x0eV?\x08[?\x04_?\x01b'
b'<f9h7j5l3n1p/r-t'
b'+H\xd1D\xd1H*H\xd2B\xd2H)I\xd2B'
b"\xd2I'J\xd2B\xd2I'J\xc8\xc2\xc8B\xd2J"
b'%K\xc7\xc1\x02\xc1\xc7B\xd2J%K\xc7\xc1\x02\xc2'
b'\xc6B\xd2K$K\xc5\xc2\xc1\x02\xc1\xc2\xc5B\xd2K'
b'#L\xc4\xc1\x08\xc1\xc4B\xc5\x08\xc5L"L\xc4\xc1'
b'\x08\xc2\xc3B\xc5\x08\xc1\xc1\xc3L"L\xc5\xc2\xc1\x02'
b'\xc8B\xcf\xc1\xc2L!M\xc6\xc2\x02\xc8B\xd0\xc1\xc1'
b'M M\xc7\xc1\x02\xc8B\xd1\xc1M M\xc8\xc2\xc8'
b'B\xd2M M\xc9\xc1\xc8B\xd2M M\xd2B\xd2'
b'M M\xd2B\xd2M N\xd0D\xd0N \x7f\x01'
b' \x7f\x01 N\xd0D\xc1\xcfN M\xd2B\xc1\xd1'
b'M M\xd2B\xd2AL M\xd2B\xd2AL '
b'M\xd2B\xd2AL M\xc7\xc1\xcaB\xc5\xc8\xc5A'
b'L M\xc5\xc1\x02\xc2\x02\xc1\xc5B\xc4\xc1\x08\xc1\xc4'
b'AL!L\xc5\xc1\x06\xc1\xc5B\xc4\xc1\x08\xc1\xc1\xc3'
b'AK"L\xc6\xc1\x04\xc1\xc6B\xc6\xca\xc2AK"'
b'L\xc6\xc1\x04\xc1\xc6B\xc7\xca\xc1L#K\xc5\xc1\x06'
b'\xc1\xc5B\xc4\xc1\x08\xc1\xc4JA$K\xc5\xc1\x02\xc2'
b'\x02\xc1\xc5B\xc4\xc1\x08\xc1\xc4K%J\xc6\xc2\xc2\xc2'
b"\xc6B\xc5\xc8\xc5J&J\xd2B\xc6\xccJ'I\xd2"
b'B\xc7\xcbI(I\xd2B\xc8\xcaI)H\xd2B\xc9'
b'\xc9H*H\xd1D\xc9\xc8H+t-r/p1'
b'n3l5j7h9f<b?\x01^?\x05'
b'XAA?\tV?\x0eP(')
fields = ( '789+('
'456-)'
'123*^'
'C0./=' )
class CalculatorApp():
NAME = 'Calc'
ICON = calc
def __init__(self):
self.output = ""
def foreground(self):
self._draw()
self.output = ""
wasp.system.request_event(wasp.EventMask.TOUCH)
def touch(self, event):
if (event[2] < 48):
if (event[1] > 200): # undo button pressed
if (self.output != ""):
self.output = self.output[:-1]
else:
x = event[1] // 47
y = (event[2] // 48) - 1
# Error handling for touching at the border
if x > 4:
x = 4
if y > 3:
y = 3
button_pressed = fields[x + 5*y]
if (button_pressed == "C"):
self.output = ""
elif (button_pressed == "="):
try:
self.output = str(eval(self.output.replace('^', '**')))[:12]
except:
wasp.watch.vibrator.pulse()
else:
self.output += button_pressed
self._update()
def _draw(self):
draw = wasp.watch.drawable
draw.fill()
# Make grid:
draw.set_color(wasp.system.theme('accent-lo'))
for i in range(4):
# horizontal lines
draw.line(x0=0,y0=(i+1)*47,x1=239,y1=(i+1)*47)
# vertical lines
draw.line(x0=(i+1)*47,y0=47,x1=(i+1)*47,y1=239)
draw.line(x0=0, y0=47, x1=0, y1=239)
draw.line(x0=239, y0=47, x1=239, y1=239)
draw.line(x0=0, y0=239, x1=239, y1=239)
# Draw button label:
draw.set_color(wasp.system.theme('accent-hi'))
for x in range(5):
if x == 3:
draw.set_color(wasp.system.theme('accent-mid'))
for y in range(4):
label = fields[x + 5*y]
if (x == 0):
draw.string(label, x*47+14, y*47+60)
else:
draw.string(label, x*47+16, y*47+60)
draw.string("<", 215, 10)
draw.set_color(wasp.system.theme('accent-hi'))
def _update(self):
output = self.output if len(self.output) < 12 else self.output[len(self.output)-12:]
wasp.watch.drawable.string(output, 0, 14, width=200, right=True)