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App Theme

Source: ui/app_theme.py

Process-wide theme mode and content background colors, loaded from and saved to preferences. Ownership and preference keys are in State and persistence; startup restore order is in Startup.

Runtime theme mode and page background shade backed by preferences.

AppTheme

Process-wide theme mode and content background colors.

Settings updates these class attributes and persists keys through SharedPreferences. Startup loads them before the first route so the first frame matches saved preferences. Shell chrome colors in app.py are separate and are not stored here.

Attributes:

Name Type Description
theme_mode ThemeMode | None

Current ThemeMode, synced from page.theme_mode.
dark_theme_slider_value

Shade index (1–4) for dark mode.
light_theme_slider_value

Shade index (1–4) for light mode.
dark_theme_bgcolor

Resolved dark page/view background color.
light_theme_bgcolor

Resolved light page/view background color.
Source code in src/learning_app/ui/app_theme.py 
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class AppTheme:
    """Process-wide theme mode and content background colors.

    Settings updates these class attributes and persists keys through
    ``SharedPreferences``. Startup loads them before the first route so the
    first frame matches saved preferences. Shell chrome colors in ``app.py``
    are separate and are not stored here.

    Attributes:
        theme_mode: Current ``ThemeMode``, synced from ``page.theme_mode``.
        dark_theme_slider_value: Shade index (1–4) for dark mode.
        light_theme_slider_value: Shade index (1–4) for light mode.
        dark_theme_bgcolor: Resolved dark page/view background color.
        light_theme_bgcolor: Resolved light page/view background color.
    """

    DEFAULT_THEME_MODE = ThemeMode.DARK
    DEFAULT_SLIDER_VALUE = 2
    DEFAULT_BGCOLOR = ft.Colors.SURFACE

    theme_mode: ThemeMode | None = None
    dark_theme_slider_value = DEFAULT_SLIDER_VALUE
    light_theme_slider_value = DEFAULT_SLIDER_VALUE
    dark_theme_bgcolor = None
    light_theme_bgcolor = None

    @classmethod
    def is_dark_mode(cls) -> bool:
        """Return whether the active theme mode is dark."""
        return cls.theme_mode == ThemeMode.DARK

    @classmethod
    def sync_from_page(cls, page: ft.Page):
        """Copy ``page.theme_mode`` into ``theme_mode``.

        Args:
            page: Application page whose theme mode is authoritative.
        """
        cls.theme_mode = page.theme_mode

    @classmethod
    def set_slider_value(cls, theme_mode: ThemeMode, value):
        """Store the shade slider index for one theme mode.

        Args:
            theme_mode: Light or dark mode the value belongs to.
            value: Slider position (typically 1–4).
        """
        value = int(value)
        if theme_mode == ThemeMode.DARK:
            cls.dark_theme_slider_value = value
        else:
            cls.light_theme_slider_value = value

    @classmethod
    def get_slider_value(cls, theme_mode=""):
        """Return the shade slider index for a mode or the active mode.

        Args:
            theme_mode: ``ThemeMode.DARK``, ``ThemeMode.LIGHT``, or ``""``
                for the current ``theme_mode``.

        Returns:
            Integer slider value for that mode.
        """
        if theme_mode == ThemeMode.DARK:
            return cls.dark_theme_slider_value
        if theme_mode == "":
            return (
                cls.light_theme_slider_value
                if cls.theme_mode == ThemeMode.LIGHT
                else cls.dark_theme_slider_value
            )
        return cls.light_theme_slider_value

    @classmethod
    def _normalize_color(cls, color):
        return color.value if hasattr(color, "value") else color

    @classmethod
    def set_bgcolor(cls, theme_mode: ThemeMode, color):
        """Store the content background color for one theme mode.

        Args:
            theme_mode: Light or dark mode the color belongs to.
            color: Flet color enum or string value.
        """
        normalized = cls._normalize_color(color)
        if theme_mode == ThemeMode.DARK:
            cls.dark_theme_bgcolor = normalized
        else:
            cls.light_theme_bgcolor = normalized

    @classmethod
    def resolve_bgcolor(cls):
        """Return the active mode bgcolor, or ``SURFACE`` if unset.

        Returns:
            Normalized color string for page and view backgrounds.
        """
        bgcolor = cls.get_bgcolor()
        if bgcolor is not None:
            return bgcolor
        return cls._normalize_color(cls.DEFAULT_BGCOLOR)

    @classmethod
    def apply_bgcolor(cls, page: ft.Page, bgcolor):
        """Set ``page.bgcolor`` and every stacked view's bgcolor.

        Args:
            page: Application page.
            bgcolor: Color to apply (enum or string).
        """
        normalized = cls._normalize_color(bgcolor)
        page.bgcolor = normalized
        for view in page.views:
            view.bgcolor = normalized

    @classmethod
    def apply_to_page(cls, page: ft.Page):
        """Apply the resolved current bgcolor to the page and views.

        Args:
            page: Application page.
        """
        cls.apply_bgcolor(page, cls.resolve_bgcolor())

    @classmethod
    def current_bgcolor(cls):
        """Return the bgcolor currently used for new views and layouts."""
        return cls.resolve_bgcolor()

    @classmethod
    async def save_slider_settings(cls, theme_mode_value: str, value: int, color):
        """Persist slider index and bgcolor for one theme mode string.

        Writes ``{mode}_theme_slider_value`` and ``{mode}_theme_bgcolor``.

        Args:
            theme_mode_value: ``ThemeMode`` ``.value`` (``"dark"`` / ``"light"``).
            value: Slider index to store.
            color: Background color to store.
        """
        storage = get_shared_preferences()
        await storage.set(f"{theme_mode_value}_theme_slider_value", str(value))
        await storage.set(f"{theme_mode_value}_theme_bgcolor", cls._normalize_color(color))

    @classmethod
    def get_bgcolor(cls, theme_mode=""):
        """Return the stored bgcolor for a mode or the active mode.

        Args:
            theme_mode: ``ThemeMode.DARK``, ``ThemeMode.LIGHT``, or ``""``
                for the current ``theme_mode``.

        Returns:
            Stored color value, or ``None`` if not set.
        """
        if theme_mode == ThemeMode.DARK:
            return cls.dark_theme_bgcolor
        if theme_mode == "":
            return (
                cls.light_theme_bgcolor
                if cls.theme_mode == ThemeMode.LIGHT
                else cls.dark_theme_bgcolor
            )
        return cls.light_theme_bgcolor

    @classmethod
    async def load_from_preferences(cls):
        """Load light/dark slider values and bgcolors from preferences.

        Does not set ``theme_mode``; call ``sync_from_page`` after the page
        theme mode is restored at startup.
        """
        storage = get_shared_preferences()
        cls.dark_theme_slider_value = int(await storage.get("dark_theme_slider_value"))
        cls.light_theme_slider_value = int(await storage.get("light_theme_slider_value"))
        cls.dark_theme_bgcolor = await storage.get("dark_theme_bgcolor")
        cls.light_theme_bgcolor = await storage.get("light_theme_bgcolor")

is_dark_mode classmethod 

is_dark_mode() -> bool

Return whether the active theme mode is dark.

Source code in src/learning_app/ui/app_theme.py 
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@classmethod
def is_dark_mode(cls) -> bool:
    """Return whether the active theme mode is dark."""
    return cls.theme_mode == ThemeMode.DARK

sync_from_page classmethod 

sync_from_page(page: Page)

Copy page.theme_mode into theme_mode.

Parameters:

Name Type Description Default
page Page

Application page whose theme mode is authoritative.

 required
Source code in src/learning_app/ui/app_theme.py 
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@classmethod
def sync_from_page(cls, page: ft.Page):
    """Copy ``page.theme_mode`` into ``theme_mode``.

    Args:
        page: Application page whose theme mode is authoritative.
    """
    cls.theme_mode = page.theme_mode

set_slider_value classmethod 

set_slider_value(theme_mode: ThemeMode, value)

Store the shade slider index for one theme mode.

Parameters:

Name Type Description Default
theme_mode ThemeMode

Light or dark mode the value belongs to.

 required
value

Slider position (typically 1–4).

 required
Source code in src/learning_app/ui/app_theme.py 
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@classmethod
def set_slider_value(cls, theme_mode: ThemeMode, value):
    """Store the shade slider index for one theme mode.

    Args:
        theme_mode: Light or dark mode the value belongs to.
        value: Slider position (typically 1–4).
    """
    value = int(value)
    if theme_mode == ThemeMode.DARK:
        cls.dark_theme_slider_value = value
    else:
        cls.light_theme_slider_value = value

get_slider_value classmethod 

get_slider_value(theme_mode='')

Return the shade slider index for a mode or the active mode.

Parameters:

Name Type Description Default
theme_mode

ThemeMode.DARK, ThemeMode.LIGHT, or "" for the current theme_mode.

 ''

Returns:

Type Description

Integer slider value for that mode.
Source code in src/learning_app/ui/app_theme.py 
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@classmethod
def get_slider_value(cls, theme_mode=""):
    """Return the shade slider index for a mode or the active mode.

    Args:
        theme_mode: ``ThemeMode.DARK``, ``ThemeMode.LIGHT``, or ``""``
            for the current ``theme_mode``.

    Returns:
        Integer slider value for that mode.
    """
    if theme_mode == ThemeMode.DARK:
        return cls.dark_theme_slider_value
    if theme_mode == "":
        return (
            cls.light_theme_slider_value
            if cls.theme_mode == ThemeMode.LIGHT
            else cls.dark_theme_slider_value
        )
    return cls.light_theme_slider_value

set_bgcolor classmethod 

set_bgcolor(theme_mode: ThemeMode, color)

Store the content background color for one theme mode.

Parameters:

Name Type Description Default
theme_mode ThemeMode

Light or dark mode the color belongs to.

 required
color

Flet color enum or string value.

 required
Source code in src/learning_app/ui/app_theme.py 
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@classmethod
def set_bgcolor(cls, theme_mode: ThemeMode, color):
    """Store the content background color for one theme mode.

    Args:
        theme_mode: Light or dark mode the color belongs to.
        color: Flet color enum or string value.
    """
    normalized = cls._normalize_color(color)
    if theme_mode == ThemeMode.DARK:
        cls.dark_theme_bgcolor = normalized
    else:
        cls.light_theme_bgcolor = normalized

resolve_bgcolor classmethod 

resolve_bgcolor()

Return the active mode bgcolor, or SURFACE if unset.

Returns:

Type Description

Normalized color string for page and view backgrounds.
Source code in src/learning_app/ui/app_theme.py 
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@classmethod
def resolve_bgcolor(cls):
    """Return the active mode bgcolor, or ``SURFACE`` if unset.

    Returns:
        Normalized color string for page and view backgrounds.
    """
    bgcolor = cls.get_bgcolor()
    if bgcolor is not None:
        return bgcolor
    return cls._normalize_color(cls.DEFAULT_BGCOLOR)

apply_bgcolor classmethod 

apply_bgcolor(page: Page, bgcolor)

Set page.bgcolor and every stacked view's bgcolor.

Parameters:

Name Type Description Default
page Page

Application page.

 required
bgcolor

Color to apply (enum or string).

 required
Source code in src/learning_app/ui/app_theme.py 
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@classmethod
def apply_bgcolor(cls, page: ft.Page, bgcolor):
    """Set ``page.bgcolor`` and every stacked view's bgcolor.

    Args:
        page: Application page.
        bgcolor: Color to apply (enum or string).
    """
    normalized = cls._normalize_color(bgcolor)
    page.bgcolor = normalized
    for view in page.views:
        view.bgcolor = normalized

apply_to_page classmethod 

apply_to_page(page: Page)

Apply the resolved current bgcolor to the page and views.

Parameters:

Name Type Description Default
page Page

Application page.

 required
Source code in src/learning_app/ui/app_theme.py 
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@classmethod
def apply_to_page(cls, page: ft.Page):
    """Apply the resolved current bgcolor to the page and views.

    Args:
        page: Application page.
    """
    cls.apply_bgcolor(page, cls.resolve_bgcolor())

current_bgcolor classmethod 

current_bgcolor()

Return the bgcolor currently used for new views and layouts.

Source code in src/learning_app/ui/app_theme.py 
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@classmethod
def current_bgcolor(cls):
    """Return the bgcolor currently used for new views and layouts."""
    return cls.resolve_bgcolor()

save_slider_settings async classmethod 

save_slider_settings(
    theme_mode_value: str, value: int, color
)

Persist slider index and bgcolor for one theme mode string.

Writes {mode}_theme_slider_value and {mode}_theme_bgcolor.

Parameters:

Name Type Description Default
theme_mode_value str

ThemeMode .value ("dark" / "light").

 required
value int

Slider index to store.

 required
color

Background color to store.

 required
Source code in src/learning_app/ui/app_theme.py 
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@classmethod
async def save_slider_settings(cls, theme_mode_value: str, value: int, color):
    """Persist slider index and bgcolor for one theme mode string.

    Writes ``{mode}_theme_slider_value`` and ``{mode}_theme_bgcolor``.

    Args:
        theme_mode_value: ``ThemeMode`` ``.value`` (``"dark"`` / ``"light"``).
        value: Slider index to store.
        color: Background color to store.
    """
    storage = get_shared_preferences()
    await storage.set(f"{theme_mode_value}_theme_slider_value", str(value))
    await storage.set(f"{theme_mode_value}_theme_bgcolor", cls._normalize_color(color))

get_bgcolor classmethod 

get_bgcolor(theme_mode='')

Return the stored bgcolor for a mode or the active mode.

Parameters:

Name Type Description Default
theme_mode

ThemeMode.DARK, ThemeMode.LIGHT, or "" for the current theme_mode.

 ''

Returns:

Type Description

Stored color value, or None if not set.
Source code in src/learning_app/ui/app_theme.py 
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@classmethod
def get_bgcolor(cls, theme_mode=""):
    """Return the stored bgcolor for a mode or the active mode.

    Args:
        theme_mode: ``ThemeMode.DARK``, ``ThemeMode.LIGHT``, or ``""``
            for the current ``theme_mode``.

    Returns:
        Stored color value, or ``None`` if not set.
    """
    if theme_mode == ThemeMode.DARK:
        return cls.dark_theme_bgcolor
    if theme_mode == "":
        return (
            cls.light_theme_bgcolor
            if cls.theme_mode == ThemeMode.LIGHT
            else cls.dark_theme_bgcolor
        )
    return cls.light_theme_bgcolor

load_from_preferences async classmethod 

load_from_preferences()

Load light/dark slider values and bgcolors from preferences.

Does not set theme_mode; call sync_from_page after the page theme mode is restored at startup.

Source code in src/learning_app/ui/app_theme.py 
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@classmethod
async def load_from_preferences(cls):
    """Load light/dark slider values and bgcolors from preferences.

    Does not set ``theme_mode``; call ``sync_from_page`` after the page
    theme mode is restored at startup.
    """
    storage = get_shared_preferences()
    cls.dark_theme_slider_value = int(await storage.get("dark_theme_slider_value"))
    cls.light_theme_slider_value = int(await storage.get("light_theme_slider_value"))
    cls.dark_theme_bgcolor = await storage.get("dark_theme_bgcolor")
    cls.light_theme_bgcolor = await storage.get("light_theme_bgcolor")