File size: 4,831 Bytes
5b76e0f | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 | from decimal import Decimal
from textual.app import App, ComposeResult
from textual import events
from textual.containers import Container
from textual.reactive import var
from textual.widgets import Button, Static
class CalculatorApp(App):
"""A working 'desktop' calculator."""
CSS_PATH = "calculator.css"
numbers = var("0")
show_ac = var(True)
left = var(Decimal("0"))
right = var(Decimal("0"))
value = var("")
operator = var("plus")
KEY_MAP = {
"+": "plus",
"-": "minus",
".": "point",
"*": "multiply",
"/": "divide",
"_": "plus-minus",
"%": "percent",
"=": "equals",
}
def watch_numbers(self, value: str) -> None:
"""Called when numbers is updated."""
# Update the Numbers widget
self.query_one("#numbers", Static).update(value)
def compute_show_ac(self) -> bool:
"""Compute switch to show AC or C button"""
return self.value in ("", "0") and self.numbers == "0"
def watch_show_ac(self, show_ac: bool) -> None:
"""Called when show_ac changes."""
self.query_one("#c").display = not show_ac
self.query_one("#ac").display = show_ac
def compose(self) -> ComposeResult:
"""Add our buttons."""
yield Container(
Static(id="numbers"),
Button("AC", id="ac", variant="primary"),
Button("C", id="c", variant="primary"),
Button("+/-", id="plus-minus", variant="primary"),
Button("%", id="percent", variant="primary"),
Button("÷", id="divide", variant="warning"),
Button("7", id="number-7"),
Button("8", id="number-8"),
Button("9", id="number-9"),
Button("×", id="multiply", variant="warning"),
Button("4", id="number-4"),
Button("5", id="number-5"),
Button("6", id="number-6"),
Button("-", id="minus", variant="warning"),
Button("1", id="number-1"),
Button("2", id="number-2"),
Button("3", id="number-3"),
Button("+", id="plus", variant="warning"),
Button("0", id="number-0"),
Button(".", id="point"),
Button("=", id="equals", variant="warning"),
id="calculator",
)
def on_key(self, event: events.Key) -> None:
"""Called when the user presses a key."""
def press(button_id: str) -> None:
self.query_one(f"#{button_id}", Button).press()
self.set_focus(None)
key = event.key
if key.isdecimal():
press(f"number-{key}")
elif key == "c":
press("c")
press("ac")
elif key in self.KEY_MAP:
press(self.KEY_MAP[key])
def on_button_pressed(self, event: Button.Pressed) -> None:
"""Called when a button is pressed."""
button_id = event.button.id
assert button_id is not None
self.bell() # Terminal bell
def do_math() -> None:
"""Does the math: LEFT OPERATOR RIGHT"""
try:
if self.operator == "plus":
self.left += self.right
elif self.operator == "minus":
self.left -= self.right
elif self.operator == "divide":
self.left /= self.right
elif self.operator == "multiply":
self.left *= self.right
self.numbers = str(self.left)
self.value = ""
except Exception:
self.numbers = "Error"
if button_id.startswith("number-"):
number = button_id.partition("-")[-1]
self.numbers = self.value = self.value.lstrip("0") + number
elif button_id == "plus-minus":
self.numbers = self.value = str(Decimal(self.value or "0") * -1)
elif button_id == "percent":
self.numbers = self.value = str(Decimal(self.value or "0") / Decimal(100))
elif button_id == "point":
if "." not in self.value:
self.numbers = self.value = (self.value or "0") + "."
elif button_id == "ac":
self.value = ""
self.left = self.right = Decimal(0)
self.operator = "plus"
self.numbers = "0"
elif button_id == "c":
self.value = ""
self.numbers = "0"
elif button_id in ("plus", "minus", "divide", "multiply"):
self.right = Decimal(self.value or "0")
do_math()
self.operator = button_id
elif button_id == "equals":
if self.value:
self.right = Decimal(self.value)
do_math()
if __name__ == "__main__":
CalculatorApp().run()
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