simvx.core.ui.virtual_scroll

VirtualScrollContainer – only renders visible items for large lists.

Items are provided via a data source callback. Only items within the visible viewport range are instantiated and laid out, enabling efficient handling of thousands of items.

Module Contents

Classes

VirtualScrollContainer

ScrollContainer that only renders visible items.

Data

log
__all__

API

simvx.core.ui.virtual_scroll.log

‘getLogger(…)’

simvx.core.ui.virtual_scroll.__all__

[‘VirtualScrollContainer’]

class simvx.core.ui.virtual_scroll.VirtualScrollContainer(item_height: float = 24.0, show_scrollbar: bool = False, **kwargs)

Bases: simvx.core.ui.containers.Container

ScrollContainer that only renders visible items.

Items are provided via a data source callback. Only items within the visible viewport range are instantiated and laid out. Off-screen items are recycled to minimize allocation.

Set show_scrollbar = True to display a vertical scrollbar thumb when content overflows (default False).

Example: vs = VirtualScrollContainer(item_height=24.0, show_scrollbar=True) vs.size = Vec2(300, 400)

def make_label(index, recycled):
    from simvx.core.ui.widgets import Label
    lbl = recycled or Label()
    lbl.text = f"Item {index}"
    return lbl

vs.set_data_source(10000, make_label)

Initialization

clip_contents

‘Property(…)’

size_x

‘Property(…)’

size_y

‘Property(…)’

scrollbar_colour

‘ThemeColour(…)’

scrollbar_track_colour

‘ThemeColour(…)’

set_data_source(count: int, factory: collections.abc.Callable[[int, simvx.core.ui.core.Control | None], simvx.core.ui.core.Control], data_fn: collections.abc.Callable[[int], Any] | None = None)

Configure the virtual list.

Args: count: Total number of items. factory: Creates/updates a Control for item at index. Signature: fn(index, existing_or_None) -> Control data_fn: Optional callback returning data for item at index.

update_item_count(count: int)

Update total item count and refresh visible items.

property total_height: float

Total content height based on item count and row height.

property visible_range: tuple[int, int]

Return (first_visible_index, last_visible_index_exclusive).

scroll_to(offset: float)

Scroll to absolute pixel offset.

scroll_to_index(index: int)

Scroll so the item at index is at the top of the viewport.

on_scroll(delta: float)

Handle scroll wheel input (positive delta = scroll down).

on_draw(renderer)

separation

‘Property(…)’

on_enter_tree()

on_ready()

on_exit_tree()

add_child(node: simvx.core.node.T) → simvx.core.node.T

remove_child(node: simvx.core.node.Node) → None

mark_layout_dirty()

min_size_x

‘Property(…)’

min_size_y

‘Property(…)’

anchor_left

‘Property(…)’

anchor_top

‘Property(…)’

anchor_right

‘Property(…)’

anchor_bottom

‘Property(…)’

margin_left

‘Property(…)’

margin_top

‘Property(…)’

margin_right

‘Property(…)’

margin_bottom

‘Property(…)’

dismiss_on_outside_click

‘Property(…)’

focus_mode

‘Property(…)’

tooltip

‘Property(…)’

mouse_filter

‘Property(…)’

size_flags_horizontal

‘Property(…)’

size_flags_vertical

‘Property(…)’

stretch_ratio

‘Property(…)’

max_size

‘Property(…)’

property size: simvx.core.math.types.Vec2

property min_size: simvx.core.math.types.Vec2

content_signature() → object

content_uses(chars: str) → bool

autosize_to_content() → None

touch_mode: str

‘mouse’

property theme: simvx.core.ui.types.Theme | None

property mouse_over: bool

property focused: bool

property disabled: bool

get_theme() → simvx.core.ui.types.Theme

queue_redraw()

get_minimum_size() → simvx.core.math.types.Vec2

get_rect() → tuple[float, float, float, float]

get_global_rect() → tuple[float, float, float, float]

is_point_inside(point) → bool

place_bottom_strip(height: float) → None

place_top_strip(height: float) → None

set_anchor_preset(preset: simvx.core.ui.enums.AnchorPreset)

activate() → bool

set_focus()

grab_focus()

release_focus()

has_focus() → bool

focus_next_control()

focus_previous_control()

grab_mouse()

release_mouse()

set_drag_preview(control: simvx.core.ui.core.Control)

property is_overlay_open: bool

show_overlay(modality: str = 'light', *, dim: bool | None = None, dismiss: bool | None = None, inert: bool | None = None, owner: simvx.core.ui.core.Control | None = None, initial_focus: simvx.core.ui.core.Control | None = None) → None

close_overlay() → None

position

‘_SpatialVecProperty(…)’

rotation

‘Property(…)’

scale

‘_SpatialVecProperty(…)’

z_index

‘Property(…)’

z_as_relative

‘Property(…)’

render_layer

‘Property(…)’

set_render_layer(index: int, enabled: bool = True) → None

is_on_render_layer(index: int) → bool

property absolute_z_index: int

property rotation_degrees: float

property world_position: simvx.core.math.types.Vec2

property world_rotation: float

property world_scale: simvx.core.math.types.Vec2

property world_transform: tuple[simvx.core.math.types.Vec2, simvx.core.math.types.Vec2, float]

property forward: simvx.core.math.types.Vec2

property right: simvx.core.math.types.Vec2

translate(offset: tuple[float, float] | numpy.ndarray)

rotate(radians: float)

rotate_deg(degrees: float)

look_at(target: tuple[float, float] | numpy.ndarray)

transform_points(points: list[simvx.core.math.types.Vec2]) → list[simvx.core.math.types.Vec2]

draw_polygon(renderer, points: list[simvx.core.math.types.Vec2], closed=True, colour=None)

wrap_screen(margin: float = 20)

hdr

‘Property(…)’

property transform_render_dirty: bool

strict_errors: ClassVar[bool]

True

dev_checks: ClassVar[bool]

None

script_error_raised

‘Signal(…)’

dynamic: bool

False

visible

‘Property(…)’

update_mode

‘Property(…)’

__properties__: ClassVar[dict[str, simvx.core.descriptors.Property]]

None

classmethod __init_subclass__(**kwargs)

property name: str

property visible_in_tree: bool

reset_error() → None

reparent(new_parent: simvx.core.node.Node)

node_at(path, default=_NO_DEFAULT)

find(target, *, direct: bool = False)

find_all(target, *, direct: bool = False)

expect(target, *, direct: bool = False)

ancestor(target)

walk(*, include_self: bool = True) → collections.abc.Iterator[simvx.core.node.Node]

property path: str

property is_scene_root: bool

add_to_group(group: str)

remove_from_group(group: str)

is_in_group(group: str) → bool

on_update(dt: float) → None

on_fixed_update(dt: float) → None

on_picked(event: simvx.core.events.InputEvent) → None

on_unhandled_input(event: simvx.core.events.TreeInputEvent) → None

start_coroutine(gen: simvx.core.descriptors.Coroutine) → simvx.core.descriptors.CoroutineHandle

stop_coroutine(gen_or_handle)

property render_dirty: bool

clear_children()

destroy()

property destroying: bool

call_deferred(method: collections.abc.Callable[..., Any], *args: Any) → None

property app

property tree: simvx.core.scene_tree.SceneTree

property physics

property physics_2d

__getitem__(key: str)

classmethod get_properties() → dict[str, simvx.core.descriptors.Property]

__repr__()