Panel

In plain words

A side area of the window, like the file list on the left, that you can make wider or narrower.

A dockable panel with an optional header. side decides which edge gets the border line; with a numeric width (height for the bottom) that edge can be dragged to resize it, and on_resize reports the new size.

ui.panel · Category: Workspace · Full reference →

Preview

Code

pz.row([
    ui.panel(
        pz.column([ui.list_item("Inbox", on_open, icon="inbox", selected=True, inset=True),
                   ui.list_item("Archive", on_open, icon="archive", inset=True)]),
        header=ui.panel_header("Mail", [ui.icon_button("plus", on_new, size="xs")], icon="mail"),
        width=220, side="left",
    ),
    pz.container(ui.muted("Content"), center=True, width="fill", height="fill"),
], height="fill")

When to use

• When you build your own layout instead of ui.workspace: sidebars, inspectors, outlines.

Usage

import pyzed as pz
from pyzed import ui

pz.row([
    ui.panel(
        pz.column([ui.list_item("Inbox", on_open, icon="inbox", selected=True, inset=True),
                   ui.list_item("Archive", on_open, icon="archive", inset=True)]),
        header=ui.panel_header("Mail", [ui.icon_button("plus", on_new, size="xs")], icon="mail"),
        width=220, side="left",
    ),
    pz.container(ui.muted("Content"), center=True, width="fill", height="fill"),
], height="fill")

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.

Side

side="left"

Code

pz.row([ui.panel(ui.list_item("Inbox", icon="inbox", inset=True), header=ui.panel_header("Mail"),
                 width=160, side="left"), pz.container(width="fill")], height="fill")

side="right"

Code

pz.row([pz.container(width="fill"), ui.panel(ui.muted("Properties"), header=ui.panel_header("Inspector"),
                                          width=160, side="right")], height="fill")

side="bottom"

Code

pz.column([pz.container(height="fill"), ui.panel(ui.terminal("$ ls"), header=ui.panel_header("Terminal"),
                                             height=100, side="bottom")], width="fill")

Events

Panel 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_resize	(size)	Called with the new size when a drag ends.

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 Mail(pz.App):
    def __init__(self):
        self.width = 220

    def view(self):
        return pz.row([
            ui.panel(ui.muted("Inbox"), header=ui.panel_header("Mail"), width=self.width,
                     on_resize=lambda size: setattr(self, "width", size)),   # when the drag ends
            main_view(),
        ], height="fill")

Declarative

from dataclasses import dataclass


@dataclass
class Width:
    size: float


class Mail(pz.App):
    width = 220

    def update(self, message):
        match message:
            case Width(size):
                self.width = size

    def view(self):
        return pz.row([ui.panel(ui.muted("Inbox"), width=self.width, on_resize=Width), main_view()],
                      height="fill")

Functional

from dataclasses import dataclass


@dataclass(frozen=True)
class State:
    width: float = 220


def view(state, set_state):
    return pz.row([ui.panel(ui.muted("Inbox"), width=state.width, on_resize=lambda s: set_state(width=s)),
                   main_view()], height="fill")

Properties and API

ui.panel

panel(
    content,
    *,
    header=None,
    width=None,
    height=None,
    side='left',
    resizable=True,
    on_resize=None,
    min_size=120,
    theme=None,
)

A dockable panel. side decides which edge gets the border line; with a numeric width (height for the bottom) that border can be dragged to resize it.

Property	Default	Description
content	required	Content: a Widget, a string or a number (converted to text).
header	None	Header (ui.panel_header).
width	None	Width: pixels, "fill", "shrink" or "fill:N" (proportion).
height	None	Height: pixels, "fill", "shrink" or "fill:N" (proportion).
side	"left"	"left", "right" or "bottom".
resizable	True	False keeps the size fixed.
min_size	120	Smallest size when resizing.
theme	None	Theme to use instead of the current one (pyzed.theme.current()).

Events: on_resize (events).

Full reference →

Related

Panel headerIcon, title and actions on top of a dock.

WorkspaceThe layout of an editor-style window: title bar, docks, center, status bar.

SplitTwo panes with a draggable divider.