Color picker

In plain words

A palette to choose a color, its transparency, or a blend of colors.

ui.ColorPicker is a component that picks a color with alpha, a linear gradient (stops you add, drag and remove, plus an angle) or a fill with an opacity mask. on_change receives an event whose value is a "#rrggbb[aa]" string, a pz.Gradient or a pz.Paint, all valid backgrounds. ui.color_swatch shows any of them over a checkerboard.

ui.ColorPicker · Category: Forms · Full reference →

Preview

Code

pz.row([
    ui.ColorPicker(value="#3b82f6cc", on_change=on_change),
    pz.column([
        ui.color_swatch("#3b82f6", size=28),
        ui.color_swatch("#a1c181aa", size=28),
        ui.color_swatch(pz.Gradient(["#f97316", "#7c3aed"], angle=90), size=28),
    ], spacing=8),
], spacing=16)

New

This component was added recently. Tell us how it works for you in the issue tracker.

When to use

• For theme editors, drawing apps and style properties.
• Show a color_swatch and open the picker in a Popover when it is pressed.

Usage

import pyzed as pz
from pyzed import ui

class Styles(pz.App):
    def __init__(self):
        self.fill = "#3b82f6"

    def view(self):
        return pz.row([
            ui.ColorPicker(value=self.fill, on_change=lambda e: setattr(self, "fill", e.value)),
            pz.container(width=120, height=120, bg=self.fill, radius=8),
        ], spacing=16)

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.

Options

Everything

Code

ui.ColorPicker(value="#3b82f6cc", on_change=on_change)

alpha=False, gradients=False, masks=False

Code

ui.ColorPicker(value="#a1c181", alpha=False, gradients=False, masks=False,
               on_change=on_change)

swatches=[...]

Code

ui.ColorPicker(value="#e5c07b", gradients=False, masks=False,
               swatches=["#e06c75", "#e5c07b", "#98c379", "#61afef", "#c678dd"], on_change=on_change)

Swatches

A swatch draws any color, gradient or paint over a checkerboard, so transparency shows.

Color

Code

ui.color_swatch("#3b82f6", size=32)

With alpha

Code

ui.color_swatch("#a1c181aa", size=32)

pz.Gradient

Code

ui.color_swatch(pz.Gradient(["#f97316", "#7c3aed"], angle=90), size=32)

ui.checkerboard

Code

ui.checkerboard(96, 48, size=8)

Events

Color picker has 2 events 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.

It is a pz.Component, so it also raises on_mount and on_unmount, and its handlers get a pz.Event whose value holds the data.

Event	Of	Handler gets	When
on_change	ui.ColorPicker	(event)	Receives event.value.
on_press	ui.color_swatch	()	Makes it clickable.

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 Styles(pz.App):
    def __init__(self):
        self.fill = "#3b82f6"

    def picked(self, event):             # a pz.Component: the color is event.value
        self.fill = event.value

    def view(self):
        return pz.row([
            ui.ColorPicker(value=self.fill, on_change=self.picked),
            pz.container(width=80, height=80, bg=self.fill, radius=8),
            ui.color_swatch("#ef4444", on_press=lambda: setattr(self, "fill", "#ef4444")),
        ], spacing=16)

Declarative

from dataclasses import dataclass


@dataclass
class Fill:
    color: str


class Styles(pz.App):
    fill = "#3b82f6"

    def update(self, message):
        match message:
            case Fill(color):
                self.fill = color

    def view(self):
        return pz.row([ui.ColorPicker(value=self.fill, on_change=lambda e: Fill(e.value)),
                       ui.color_swatch("#ef4444", on_press=Fill("#ef4444"))], spacing=16)

Functional

from dataclasses import dataclass


@dataclass(frozen=True)
class State:
    fill: str = "#3b82f6"


def view(state, set_state):
    return pz.row([ui.ColorPicker(value=state.fill, on_change=lambda e: set_state(fill=e.value)),
                   pz.container(width=80, height=80, bg=state.fill, radius=8)], spacing=16)

Properties and API

ui.ColorPicker

class ColorPicker

A component that picks a color with alpha, a linear gradient (stops you add, drag and remove, plus an angle) or a fill with an opacity mask. on_change gets a "#rrggbb[aa]" string, a pz.Gradient or a pz.Paint, all valid as a background. Pass the picked value back as value. See Styles.

Property	Default	Description
value	"#3b82f6"	A color, theme token, pz.Gradient or pz.Paint.
alpha	True	Shows the alpha bar and field.
gradients	True	Shows the Solid/Gradient switch.
masks	True	Shows the mask editor.
swatches	None	Quick colors (default: the theme’s accent and status colors).

Events: on_change (events).

Full reference →

ui.color_swatch

color_swatch(value, *, size=20, on_press=None)

A small square showing a color, gradient or paint over a checkerboard.

Property	Default	Description
value	required	What to show.
size	20	Side in pixels.

Events: on_press (events).

Full reference →

ui.checkerboard

checkerboard(width, height, size=6)

A light/dark checkerboard to draw under translucent colors.

Property	Default	Description
width	required	Width.
height	required	Height.
size	6	Cell size.

Full reference →

Related

PopoverFloating content at a point: context menus, color pickers.

CardA bordered surface with an optional title and actions.