Module textual.scroll_view

Expand source code 
from __future__ import annotations

from rich.console import RenderableType

from .geometry import Size
from .widget import Widget


class ScrollView(Widget):
    """
    A base class for a Widget that handles it's own scrolling (i.e. doesn't rely
    on the compositor to render children).

    """

    DEFAULT_CSS = """
    ScrollView {     
        overflow-y: auto;
        overflow-x: auto;   
    }    
    """

    @property
    def is_scrollable(self) -> bool:
        """Always scrollable."""
        return True

    @property
    def is_transparent(self) -> bool:
        """Not transparent, i.e. renders something."""
        return False

    def on_mount(self):
        self._refresh_scrollbars()

    def get_content_width(self, container: Size, viewport: Size) -> int:
        """Gets the width of the content area.

        Args:
            container (Size): Size of the container (immediate parent) widget.
            viewport (Size): Size of the viewport.

        Returns:
            int: The optimal width of the content.
        """
        return self.virtual_size.width

    def get_content_height(self, container: Size, viewport: Size, width: int) -> int:
        """Gets the height (number of lines) in the content area.

        Args:
            container (Size): Size of the container (immediate parent) widget.
            viewport (Size): Size of the viewport.
            width (int): Width of renderable.

        Returns:
            int: The height of the content.
        """
        return self.virtual_size.height

    def _size_updated(
        self, size: Size, virtual_size: Size, container_size: Size
    ) -> None:
        """Called when size is updated.

        Args:
            size (Size): New size.
            virtual_size (Size): New virtual size.
            container_size (Size): New container size.
        """
        if (
            self._size != size
            or virtual_size != self.virtual_size
            or container_size != self.container_size
        ):
            self._size = size
            virtual_size = self.virtual_size
            self._scroll_update(virtual_size)
            self._container_size = size - self.styles.gutter.totals
            self.scroll_to(self.scroll_x, self.scroll_y, animate=False)
            self.refresh()

    def render(self) -> RenderableType:
        """Render the scrollable region (if `render_lines` is not implemented).

        Returns:
            RenderableType: Renderable object.
        """
        from rich.panel import Panel

        return Panel(f"{self.scroll_offset} {self.show_vertical_scrollbar}")

Classes

class ScrollView (*children: Widget, name: str | None = None, id: str | None = None, classes: str | None = None)

A base class for a Widget that handles it's own scrolling (i.e. doesn't rely on the compositor to render children).

Expand source code 
class ScrollView(Widget):
    """
    A base class for a Widget that handles it's own scrolling (i.e. doesn't rely
    on the compositor to render children).

    """

    DEFAULT_CSS = """
    ScrollView {     
        overflow-y: auto;
        overflow-x: auto;   
    }    
    """

    @property
    def is_scrollable(self) -> bool:
        """Always scrollable."""
        return True

    @property
    def is_transparent(self) -> bool:
        """Not transparent, i.e. renders something."""
        return False

    def on_mount(self):
        self._refresh_scrollbars()

    def get_content_width(self, container: Size, viewport: Size) -> int:
        """Gets the width of the content area.

        Args:
            container (Size): Size of the container (immediate parent) widget.
            viewport (Size): Size of the viewport.

        Returns:
            int: The optimal width of the content.
        """
        return self.virtual_size.width

    def get_content_height(self, container: Size, viewport: Size, width: int) -> int:
        """Gets the height (number of lines) in the content area.

        Args:
            container (Size): Size of the container (immediate parent) widget.
            viewport (Size): Size of the viewport.
            width (int): Width of renderable.

        Returns:
            int: The height of the content.
        """
        return self.virtual_size.height

    def _size_updated(
        self, size: Size, virtual_size: Size, container_size: Size
    ) -> None:
        """Called when size is updated.

        Args:
            size (Size): New size.
            virtual_size (Size): New virtual size.
            container_size (Size): New container size.
        """
        if (
            self._size != size
            or virtual_size != self.virtual_size
            or container_size != self.container_size
        ):
            self._size = size
            virtual_size = self.virtual_size
            self._scroll_update(virtual_size)
            self._container_size = size - self.styles.gutter.totals
            self.scroll_to(self.scroll_x, self.scroll_y, animate=False)
            self.refresh()

    def render(self) -> RenderableType:
        """Render the scrollable region (if `render_lines` is not implemented).

        Returns:
            RenderableType: Renderable object.
        """
        from rich.panel import Panel

        return Panel(f"{self.scroll_offset} {self.show_vertical_scrollbar}")

Ancestors

Subclasses

  • textual.widgets._data_table.DataTable
  • textual.widgets._text_log.TextLog

Class variables

var COMPONENT_CLASSES : ClassVar[set[str]]
var DEFAULT_CSS

Instance variables

var is_scrollable : bool

Always scrollable.

Expand source code 
@property
def is_scrollable(self) -> bool:
    """Always scrollable."""
    return True
var is_transparent : bool

Not transparent, i.e. renders something.

Expand source code 
@property
def is_transparent(self) -> bool:
    """Not transparent, i.e. renders something."""
    return False

Methods

def get_content_height(self, container: Size, viewport: Size, width: int) ‑> int

Gets the height (number of lines) in the content area.

Args

container : Size
Size of the container (immediate parent) widget.
viewport : Size
Size of the viewport.
width : int
Width of renderable.

Returns

int
The height of the content.
Expand source code 
def get_content_height(self, container: Size, viewport: Size, width: int) -> int:
    """Gets the height (number of lines) in the content area.

    Args:
        container (Size): Size of the container (immediate parent) widget.
        viewport (Size): Size of the viewport.
        width (int): Width of renderable.

    Returns:
        int: The height of the content.
    """
    return self.virtual_size.height
def get_content_width(self, container: Size, viewport: Size) ‑> int

Gets the width of the content area.

Args

container : Size
Size of the container (immediate parent) widget.
viewport : Size
Size of the viewport.

Returns

int
The optimal width of the content.
Expand source code 
def get_content_width(self, container: Size, viewport: Size) -> int:
    """Gets the width of the content area.

    Args:
        container (Size): Size of the container (immediate parent) widget.
        viewport (Size): Size of the viewport.

    Returns:
        int: The optimal width of the content.
    """
    return self.virtual_size.width
def on_mount(self)
Expand source code 
def on_mount(self):
    self._refresh_scrollbars()
def render(self) ‑> Union[rich.console.ConsoleRenderable, rich.console.RichCast, str]

Render the scrollable region (if render_lines is not implemented).

Returns

RenderableType
Renderable object.
Expand source code 
def render(self) -> RenderableType:
    """Render the scrollable region (if `render_lines` is not implemented).

    Returns:
        RenderableType: Renderable object.
    """
    from rich.panel import Panel

    return Panel(f"{self.scroll_offset} {self.show_vertical_scrollbar}")

Inherited members