Scrollable

In plain words

Lets you scroll content that doesn’t fit, with a scroll bar.

Makes its content scrollable vertically, horizontally or "both". Give it an id to scroll from code (pz.Command.scroll_to), anchor_bottom=True to stick to the end (chats, logs), and style the rail and scroller with the theme or your own colors.

pz.scrollable · Category: Layout · Full reference →

Preview

Code

pz.container(pz.scrollable(
    pz.column([ui.list_item(f"Item {i}", on_open, icon="file", inset=True) for i in range(1, 30)]),
    height=220,
), width=300)

When to use

• For long lists, documents and any content taller than its space.

Usage

import pyzed as pz
from pyzed import ui

pz.container(pz.scrollable(
    pz.column([ui.list_item(f"Item {i}", on_open, icon="file", inset=True) for i in range(1, 30)]),
    height=220,
), width=300)

Variants

About these captures

Each capture is recorded by pyzed itself, off-screen at 2x, in One Dark or One Light to match this site’s theme, and cropped to the component so it shows at its real size. The pointer hovers, presses or types into it; a component that does not react to the pointer cycles through a few themes. With reduced motion you see the first frame. Open Code under a capture to see the snippet that draws it; free names such as on_save stand for your own callbacks.

Direction

Vertical

Code

pz.container(pz.scrollable(pz.column([ui.list_item(f"Item {i}", icon="file", inset=True)
                                       for i in range(1, 30)]), height=130), width=240)

direction="horizontal"

Code

pz.container(pz.scrollable(pz.container(pz.row([ui.chip(f"tag {i}") for i in range(1, 25)], spacing=6),
                                        padding=(0, 0, 14, 0)),
                           direction="horizontal"), width=300)

Events

Scrollable has 1 event of its own, listed below. Like every widget it also has the 18 common events (click, double_click, right_click, mouse_enter, drag, key_down, resize…), attached with .on(...): see Events and Events of every component.

Event	Handler gets	When
on_scroll	(info)	Callable that receives a dict with x, y, relative_x, relative_y, width, height, content_width and content_height.

Handler gets is what Pyzed passes to your callable: () means nothing. Any handler can also be a message (a value that is not callable), which goes to update().

Handling the events

The same events written three ways. Imperative: methods of the app change self. Declarative: the handlers produce messages and one update() decides. Functional: a pure function draws an immutable state and asks for changes with set_state(...). See Imperative, declarative and functional.

Imperative

class Feed(pz.App):
    def __init__(self):
        self.items = [f"Post {i}" for i in range(1, 30)]
        self.at_end = False

    def scrolled(self, info):            # on_scroll: x, y, relative_x, relative_y, sizes
        self.at_end = info["relative_y"] > 0.95

    def view(self):
        return pz.column([
            pz.scrollable(pz.column([ui.list_item(p, icon="file") for p in self.items]),
                          height=200, on_scroll=self.scrolled),
            ui.muted("You reached the end" if self.at_end else "Scroll down"),
        ], spacing=6, width=300)

Declarative

from dataclasses import dataclass


@dataclass
class Scrolled:
    info: dict


class Feed(pz.App):
    items = [f"Post {i}" for i in range(1, 30)]

    def update(self, message):
        match message:
            case Scrolled(info) if info["relative_y"] > 0.95:
                self.items = self.items + [f"Post {len(self.items) + 1}"]   # load more

    def view(self):
        return pz.scrollable(pz.column([ui.list_item(p) for p in self.items]), height=200,
                             on_scroll=Scrolled)

Functional

from dataclasses import dataclass


@dataclass(frozen=True)
class State:
    progress: float = 0.0


def view(state, set_state):
    return pz.column([
        ui.progress(state.progress),
        pz.scrollable(pz.column([ui.list_item(f"Post {i}") for i in range(30)]), height=200,
                      on_scroll=lambda info: set_state(progress=info["relative_y"])),
    ], spacing=6, width=300)

Properties and API

pz.scrollable

scrollable(
    content,
    *,
    direction='vertical',
    width=None,
    height=None,
    padding=None,
    id=None,
    anchor_bottom=False,
    rail=None,
    scroller=None,
    scroller_hover=None,
    scrollbar_width=8.0,
    scroller_width=None,
    margin=0.0,
    on_scroll=None,
)

Makes its content scrollable.

Property	Default	Description
content	required	Content: a Widget, a string or a number (converted to text).
direction	"vertical"	"vertical", "horizontal" or "both".
width	None	Width: pixels, "fill", "shrink" or "fill:N" (proportion).
height	None	Height: pixels, "fill", "shrink" or "fill:N" (proportion).
padding	None	Inner padding: 8, (vertical, horizontal) or (top, right, bottom, left).
id	None	Stable identifier used to focus or scroll it with a Command.
anchor_bottom	False	Keeps the scroll pinned to the end (logs, terminals, chats).
rail	None	Scrollbar rail color.
scroller	None	Scroller color.
scroller_hover	None	Scroller color on hover.
scrollbar_width	8.0	Scrollbar width.
scroller_width	None	Scroller width (defaults to the scrollbar’s).
margin	0.0	Margin between the scrollbar and the content.

Events: on_scroll (events).

Full reference →

Related

ColumnStacks children vertically.

List itemA list row with icon, text and an end slot.