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Welcome¶
Welcome to the Textual framework documentation.
Get started or go straight to the Tutorial
What is Textual?¶
Textual is a Rapid Application Development framework for Python, built by Textualize.io.
Build sophisticated user interfaces with a simple Python API. Run your apps in the terminal or a web browser!
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Rapid development
Uses your existing Python skills to build beautiful user interfaces.
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Low requirements
Run Textual on a single board computer if you want to.
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Cross platform
Textual runs just about everywhere.
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Remote
Textual apps can run over SSH.
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CLI Integration
Textual apps can be launched and run from the command prompt.
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Open Source
Textual is licensed under MIT.
from time import monotonic
from textual.app import App, ComposeResult
from textual.containers import ScrollableContainer
from textual.reactive import reactive
from textual.widgets import Button, Footer, Header, Static
class TimeDisplay(Static):
"""A widget to display elapsed time."""
start_time = reactive(monotonic)
time = reactive(0.0)
total = reactive(0.0)
def on_mount(self) -> None:
"""Event handler called when widget is added to the app."""
self.update_timer = self.set_interval(1 / 60, self.update_time, pause=True)
def update_time(self) -> None:
"""Method to update time to current."""
self.time = self.total + (monotonic() - self.start_time)
def watch_time(self, time: float) -> None:
"""Called when the time attribute changes."""
minutes, seconds = divmod(time, 60)
hours, minutes = divmod(minutes, 60)
self.update(f"{hours:02,.0f}:{minutes:02.0f}:{seconds:05.2f}")
def start(self) -> None:
"""Method to start (or resume) time updating."""
self.start_time = monotonic()
self.update_timer.resume()
def stop(self):
"""Method to stop the time display updating."""
self.update_timer.pause()
self.total += monotonic() - self.start_time
self.time = self.total
def reset(self):
"""Method to reset the time display to zero."""
self.total = 0
self.time = 0
class Stopwatch(Static):
"""A stopwatch widget."""
def on_button_pressed(self, event: Button.Pressed) -> None:
"""Event handler called when a button is pressed."""
button_id = event.button.id
time_display = self.query_one(TimeDisplay)
if button_id == "start":
time_display.start()
self.add_class("started")
elif button_id == "stop":
time_display.stop()
self.remove_class("started")
elif button_id == "reset":
time_display.reset()
def compose(self) -> ComposeResult:
"""Create child widgets of a stopwatch."""
yield Button("Start", id="start", variant="success")
yield Button("Stop", id="stop", variant="error")
yield Button("Reset", id="reset")
yield TimeDisplay()
class StopwatchApp(App):
"""A Textual app to manage stopwatches."""
CSS_PATH = "stopwatch.tcss"
BINDINGS = [
("d", "toggle_dark", "Toggle dark mode"),
("a", "add_stopwatch", "Add"),
("r", "remove_stopwatch", "Remove"),
]
def compose(self) -> ComposeResult:
"""Called to add widgets to the app."""
yield Header()
yield Footer()
yield ScrollableContainer(Stopwatch(), Stopwatch(), Stopwatch(), id="timers")
def action_add_stopwatch(self) -> None:
"""An action to add a timer."""
new_stopwatch = Stopwatch()
self.query_one("#timers").mount(new_stopwatch)
new_stopwatch.scroll_visible()
def action_remove_stopwatch(self) -> None:
"""Called to remove a timer."""
timers = self.query("Stopwatch")
if timers:
timers.last().remove()
def action_toggle_dark(self) -> None:
"""An action to toggle dark mode."""
self.dark = not self.dark
if __name__ == "__main__":
app = StopwatchApp()
app.run()
Stopwatch {
layout: horizontal;
background: $boost;
height: 5;
min-width: 50;
margin: 1;
padding: 1;
}
TimeDisplay {
content-align: center middle;
text-opacity: 60%;
height: 3;
}
Button {
width: 16;
}
#start {
dock: left;
}
#stop {
dock: left;
display: none;
}
#reset {
dock: right;
}
.started {
text-style: bold;
background: $success;
color: $text;
}
.started TimeDisplay {
text-opacity: 100%;
}
.started #start {
display: none
}
.started #stop {
display: block
}
.started #reset {
visibility: hidden
}
from textual.app import App, ComposeResult
from textual.widgets import Static
class PrideApp(App):
"""Displays a pride flag."""
COLORS = ["red", "orange", "yellow", "green", "blue", "purple"]
def compose(self) -> ComposeResult:
for color in self.COLORS:
stripe = Static()
stripe.styles.height = "1fr"
stripe.styles.background = color
yield stripe
if __name__ == "__main__":
PrideApp().run()
"""
An implementation of a classic calculator, with a layout inspired by macOS calculator.
Works like a real calculator. Click the buttons or press the equivalent keys.
"""
from decimal import Decimal
from textual import events, on
from textual.app import App, ComposeResult
from textual.containers import Container
from textual.css.query import NoMatches
from textual.reactive import var
from textual.widgets import Button, Digits
class CalculatorApp(App):
"""A working 'desktop' calculator."""
CSS_PATH = "calculator.tcss"
numbers = var("0")
show_ac = var(True)
left = var(Decimal("0"))
right = var(Decimal("0"))
value = var("")
operator = var("plus")
# Maps button IDs on to the corresponding key name
NAME_MAP = {
"asterisk": "multiply",
"slash": "divide",
"underscore": "plus-minus",
"full_stop": "point",
"plus_minus_sign": "plus-minus",
"percent_sign": "percent",
"equals_sign": "equals",
"minus": "minus",
"plus": "plus",
}
def watch_numbers(self, value: str) -> None:
"""Called when numbers is updated."""
self.query_one("#numbers", Digits).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."""
with Container(id="calculator"):
yield Digits(id="numbers")
yield Button("AC", id="ac", variant="primary")
yield Button("C", id="c", variant="primary")
yield Button("+/-", id="plus-minus", variant="primary")
yield Button("%", id="percent", variant="primary")
yield Button("รท", id="divide", variant="warning")
yield Button("7", id="number-7", classes="number")
yield Button("8", id="number-8", classes="number")
yield Button("9", id="number-9", classes="number")
yield Button("ร", id="multiply", variant="warning")
yield Button("4", id="number-4", classes="number")
yield Button("5", id="number-5", classes="number")
yield Button("6", id="number-6", classes="number")
yield Button("-", id="minus", variant="warning")
yield Button("1", id="number-1", classes="number")
yield Button("2", id="number-2", classes="number")
yield Button("3", id="number-3", classes="number")
yield Button("+", id="plus", variant="warning")
yield Button("0", id="number-0", classes="number")
yield Button(".", id="point")
yield Button("=", id="equals", variant="warning")
def on_key(self, event: events.Key) -> None:
"""Called when the user presses a key."""
def press(button_id: str) -> None:
"""Press a button, should it exist."""
try:
self.query_one(f"#{button_id}", Button).press()
except NoMatches:
pass
key = event.key
if key.isdecimal():
press(f"number-{key}")
elif key == "c":
press("c")
press("ac")
else:
button_id = self.NAME_MAP.get(key)
if button_id is not None:
press(self.NAME_MAP.get(key, key))
@on(Button.Pressed, ".number")
def number_pressed(self, event: Button.Pressed) -> None:
"""Pressed a number."""
assert event.button.id is not None
number = event.button.id.partition("-")[-1]
self.numbers = self.value = self.value.lstrip("0") + number
@on(Button.Pressed, "#plus-minus")
def plus_minus_pressed(self) -> None:
"""Pressed + / -"""
self.numbers = self.value = str(Decimal(self.value or "0") * -1)
@on(Button.Pressed, "#percent")
def percent_pressed(self) -> None:
"""Pressed %"""
self.numbers = self.value = str(Decimal(self.value or "0") / Decimal(100))
@on(Button.Pressed, "#point")
def pressed_point(self) -> None:
"""Pressed ."""
if "." not in self.value:
self.numbers = self.value = (self.value or "0") + "."
@on(Button.Pressed, "#ac")
def pressed_ac(self) -> None:
"""Pressed AC"""
self.value = ""
self.left = self.right = Decimal(0)
self.operator = "plus"
self.numbers = "0"
@on(Button.Pressed, "#c")
def pressed_c(self) -> None:
"""Pressed C"""
self.value = ""
self.numbers = "0"
def _do_math(self) -> 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"
@on(Button.Pressed, "#plus,#minus,#divide,#multiply")
def pressed_op(self, event: Button.Pressed) -> None:
"""Pressed one of the arithmetic operations."""
self.right = Decimal(self.value or "0")
self._do_math()
assert event.button.id is not None
self.operator = event.button.id
@on(Button.Pressed, "#equals")
def pressed_equals(self) -> None:
"""Pressed ="""
if self.value:
self.right = Decimal(self.value)
self._do_math()
if __name__ == "__main__":
CalculatorApp().run(inline=True)
Screen {
overflow: auto;
}
#calculator {
layout: grid;
grid-size: 4;
grid-gutter: 1 2;
grid-columns: 1fr;
grid-rows: 2fr 1fr 1fr 1fr 1fr 1fr;
margin: 1 2;
min-height: 25;
min-width: 26;
height: 100%;
&:inline {
margin: 0 2;
}
}
Button {
width: 100%;
height: 100%;
}
#numbers {
column-span: 4;
padding: 0 1;
height: 100%;
background: $primary-lighten-2;
color: $text;
content-align: center middle;
text-align: right;
}
#number-0 {
column-span: 2;
}