| 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.""" |
| |
| 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() |
|
|
| 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() |
|
|
