Documentation Index
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The Battery service provides access to device battery information, including battery level, charging state, and battery save mode status.
Usage
Add the Battery service to your page overlay and use its methods to retrieve battery information:
import flet as ft
async def main(page: ft.Page):
battery = ft.Battery()
page.overlay.append(battery)
# Get battery level
level = await battery.get_battery_level()
print(f"Battery level: {level}%")
# Get battery state
state = await battery.get_battery_state()
print(f"Battery state: {state.value}")
await page.update_async()
ft.app(main)
Methods
get_battery_level()
Gets the current battery level as a percentage.
await battery.get_battery_level() -> Optional[int]
None when it is unavailable on the current environment.
Example:
level = await battery.get_battery_level()
if level is not None:
if level < 20:
print(f"Low battery: {level}%")
else:
print(f"Battery level: {level}%")
else:
print("Battery level unavailable")
get_battery_state()
Returns the current battery state.
await battery.get_battery_state() -> BatteryState
BatteryState enum value indicating the current state.
Example:
state = await battery.get_battery_state()
if state == ft.BatteryState.CHARGING:
print("Battery is charging")
elif state == ft.BatteryState.FULL:
print("Battery is full")
elif state == ft.BatteryState.DISCHARGING:
print("Battery is discharging")
is_in_battery_save_mode()
Checks if the device is currently in battery save mode.
await battery.is_in_battery_save_mode() -> bool
True if the device is currently in battery save mode, otherwise False.
Example:
if await battery.is_in_battery_save_mode():
print("Device is in battery save mode")
# Reduce app functionality to save power
else:
print("Normal power mode")
Events
on_state_change
Called when the battery state changes (charging, discharging, full, etc.).
battery.on_state_change = handle_state_change
BatteryStateChangeEvent with:
state (BatteryState): Current battery state
Example:
def handle_state_change(e: ft.BatteryStateChangeEvent):
if e.state == ft.BatteryState.CHARGING:
print("Device started charging")
elif e.state == ft.BatteryState.DISCHARGING:
print("Device unplugged")
elif e.state == ft.BatteryState.FULL:
print("Battery fully charged")
battery.on_state_change = handle_state_change
Enums
BatteryState
Enum representing the battery state:
CHARGING: The battery is currently chargingCONNECTED_NOT_CHARGING: The battery is connected to a power source but not chargingDISCHARGING: The battery is dischargingFULL: The battery is fully chargedUNKNOWN: The battery state is unknown
Complete Example
import flet as ft
async def main(page: ft.Page):
page.title = "Battery Monitor"
battery_level = ft.Text(size=30)
battery_state = ft.Text(size=20)
battery_save_mode = ft.Text()
battery = ft.Battery()
page.overlay.append(battery)
async def update_battery_info():
# Get battery level
level = await battery.get_battery_level()
if level is not None:
battery_level.value = f"Battery: {level}%"
# Change color based on level
if level < 20:
battery_level.color = ft.colors.RED
elif level < 50:
battery_level.color = ft.colors.ORANGE
else:
battery_level.color = ft.colors.GREEN
else:
battery_level.value = "Battery level unavailable"
# Get battery state
state = await battery.get_battery_state()
battery_state.value = f"State: {state.value}"
# Check battery save mode
save_mode = await battery.is_in_battery_save_mode()
battery_save_mode.value = f"Battery save mode: {'ON' if save_mode else 'OFF'}"
await page.update_async()
def on_state_change(e: ft.BatteryStateChangeEvent):
battery_state.value = f"State: {e.state.value}"
page.update()
battery.on_state_change = on_state_change
async def refresh_clicked(e):
await update_battery_info()
page.add(
battery_level,
battery_state,
battery_save_mode,
ft.ElevatedButton("Refresh", on_click=refresh_clicked),
)
# Initial update
await update_battery_info()
ft.app(main)
| Platform | Support |
|---|
| Android | ✓ |
| iOS | ✓ |
| macOS | ✓ |
| Windows | ✓ |
| Linux | ✓ |
| Web | ✓ |