Easy Button
Easy Button + marker creation flow with emoji picker, form popup, and view mode.
Overview
Click the smile button on the map (top-left) to enter create mode → a dmc.Popover opens directly to the right of the button with a DashEmojiMart picker. Click the map to place the marker; a form popup opens above it with name/type fields. Pick an emoji at any time to update the marker's icon live. Create finalizes the marker (pushes to a markers store, exits create mode, closes everything); Cancel discards.
(We use dmc.Popover, not dmc.HoverCard. HoverCard is hover-triggered only — it would close the moment the user moves their mouse off the button toward the map to place a marker. Popover supports click-triggered + controlled opened, same visual styling.)
Live demo
The shape
dl2.EasyButton + marker-creation pattern
# File: docs/easy-button/example.py (region: map)
dl2.Map(
id="eb-map",
center=DENVER.center,
zoom=12,
style={
"height": "100%"
}, # fills the dmc.Paper, which fills the flex row
children=[
dl2.TileLayer(
id="eb-tile", url=TILE_URL, attribution=ATTR
),
dl2.EasyButton(
id="eb-add",
position="topleft",
icon="mdi:emoticon-happy-outline",
iconSize=20,
title="Add an emoji marker",
),
html.Div(id="eb-pending-container"),
html.Div(id="eb-markers-container"),
],
),Source
# File: docs/easy-button/example.py
"""
Easy Button + marker creation flow with emoji picker, form popup, and view mode.
Click the smile button on the map (top-left) to enter create mode → a dmc.Popover opens
directly to the right of the button with a DashEmojiMart picker. Click the map to place
the marker; a form popup opens above it with name/type fields. Pick an emoji at any time
to update the marker's icon live. Create finalizes the marker (pushes to a markers store,
exits create mode, closes everything); Cancel discards.
(We use dmc.Popover, not dmc.HoverCard. HoverCard is hover-triggered only — it would close
the moment the user moves their mouse off the button toward the map to place a marker.
Popover supports click-triggered + controlled `opened`, same visual styling.)
"""
import dash
import dash_leaflet2 as dl2
import dash_mantine_components as dmc
from dash import Input, Output, State, callback, clientside_callback, ctx, dcc, html
from dash_emoji_mart import DashEmojiMart
from dash_iconify import DashIconify
from dl2_tiles import ESRI_CANVAS, register_theme_swap
from dl2_locations import DENVER
from dl2_shared import info_panel
# CARTO Positron (light) + Dark Matter — the standard light/dark pair the rest of the
# showcase already uses (see assets/leaflet2_maps.js). The tile URL is swapped at
# runtime via a clientside callback driven by the app's color-scheme toggle.
# Basemap pair for this page. dl2_tiles owns the light/dark wiring so
# every example themes the same way — see register_theme_swap below.
TILES = ESRI_CANVAS
TILE_URL = TILES.url("light")
ATTR = TILES.attribution()
MARKER_TYPES = ["Market", "Event", "Bounty", "Other"]
TYPE_COLORS = {"Market": "green", "Event": "blue", "Bounty": "grape", "Other": "gray"}
# ---- helpers ---------------------------------------------------------------
def form_layout(pending):
"""The form rendered INSIDE the leaflet popup above the pending marker."""
return html.Div(
style={"minWidth": "260px", "padding": "2px"},
children=dmc.Stack(
[
dmc.TextInput(
id="eb-name",
placeholder="Marker name",
value=(pending or {}).get("name", ""),
size="xs",
),
dmc.SegmentedControl(
id="eb-type",
data=MARKER_TYPES,
value=(pending or {}).get("type", "Market"),
size="xs",
fullWidth=True,
),
dmc.Group(
[
dmc.Button(
"Cancel",
id="eb-cancel",
size="xs",
variant="light",
color="gray",
),
dmc.Button(
"Create",
id="eb-create",
size="xs",
color="green",
leftSection=DashIconify(icon="mdi:check", width=14),
),
],
gap="xs",
grow=True,
),
],
gap="xs",
),
)
# ---- layout ----------------------------------------------------------------
component = dmc.Stack(
[
# Toggle button for the side panel. Mirrors /resize-observer's UX so this page
# gets the same "expand for full-screen map / collapse to see context" affordance.
dmc.Button(
"Toggle side panel",
id="eb-panel-toggle",
color="green",
variant="light",
leftSection=DashIconify(icon="mdi:panel-right-open", width=16),
),
# Flex row: relative-positioned map wrapper on the left, collapsible info panel on
# the right. Starts OPEN (the Mode badge + marker list are useful context while
# creating markers); the user can collapse it for a full-width map. We bump the
# panel width via --dl2-resize-panel-w because the code snippet inside is wider
# than what /resize-observer's default 320px shows comfortably.
html.Div(
id="eb-row",
className="dl2-resize-row open",
style={"height": "62vh", "--dl2-resize-panel-w": "380px"},
children=[
html.Div(
# Relative container so the Popover anchor div positions absolutely over
# the EasyButton location inside the Paper. `dl2-resize-main` makes this
# the flex-grow main area (height: 100%, flex: 1 — see assets/style.css).
className="dl2-resize-main",
style={"position": "relative"},
children=[
dmc.Paper(
# region map
dl2.Map(
id="eb-map",
center=DENVER.center,
zoom=12,
style={
"height": "100%"
}, # fills the dmc.Paper, which fills the flex row
children=[
dl2.TileLayer(
id="eb-tile", url=TILE_URL, attribution=ATTR
),
dl2.EasyButton(
id="eb-add",
position="topleft",
icon="mdi:emoticon-happy-outline",
iconSize=20,
title="Add an emoji marker",
),
html.Div(id="eb-pending-container"),
html.Div(id="eb-markers-container"),
],
),
# endregion
shadow="sm",
radius="md",
withBorder=True,
style={"overflow": "hidden", "height": "100%"},
),
# Popover anchor: invisible Dash element positioned over the EasyButton.
# Leaflet anchors top-left controls 10px from the map edges, button is
# 30px wide → anchor at left:46px puts the popover dropdown right of it.
dmc.Popover(
id="eb-popover",
opened=False,
position="right-start",
offset=6,
withArrow=True,
arrowSize=10,
shadow="lg",
radius="md",
# Fully suppress the "outside click closes me" behavior — we control
# `opened` from the picker-open store. Listening to no events means
# the popover never tries to auto-close.
closeOnClickOutside=False,
closeOnEscape=False,
clickOutsideEvents=[],
keepMounted=True,
children=[
# PopoverTarget wraps its child in a dmc.Box that drops inline
# absolute styles on the inner element — so position the Box
# itself via boxWrapperProps instead.
dmc.PopoverTarget(
html.Div(id="eb-popover-anchor"),
boxWrapperProps={
"style": {
"position": "absolute",
"top": "10px",
"left": "46px",
"width": "1px",
"height": "30px",
"pointerEvents": "none",
"zIndex": 600,
}
},
),
dmc.PopoverDropdown(
DashEmojiMart(
id="eb-emoji",
theme="auto",
perLine=8,
emojiSize=22,
emojiButtonSize=30,
previewPosition="none",
),
p=4,
),
],
),
],
),
# Side panel — holds everything that used to live in the right grid column
# and the bottom code panel: Mode readout, Created markers list, and the
# snippet showing the dl2.EasyButton + marker-creation pattern.
html.Div(
className="dl2-resize-panel",
children=dmc.Stack(
[
info_panel(
"Mode",
dmc.Group(
[
dmc.Badge(
id="eb-mode-badge",
color="gray",
variant="light",
children="view",
),
DashIconify(
id="eb-mode-icon",
icon="mdi:eye-outline",
width=20,
color="var(--mantine-color-dimmed)",
),
],
gap="xs",
),
),
info_panel(
"Created markers",
html.Div(
id="eb-list",
children=dmc.Text(
"Click the smile button on the map to create your first marker.",
size="sm",
c="dimmed",
),
),
),
],
gap="md",
),
),
],
),
# State stores
dcc.Store(id="eb-mode", data="view"),
dcc.Store(id="eb-pending", data=None),
dcc.Store(id="eb-markers", data=[]),
dcc.Store(id="eb-picker-open", data=False),
],
gap="md",
)
# ---- callbacks --------------------------------------------------------------
# 1) EasyButton click → toggle create mode + picker.
@callback(
Output("eb-mode", "data"),
Output("eb-picker-open", "data"),
Output("eb-pending", "data"),
Input("eb-add", "n_clicks"),
State("eb-mode", "data"),
prevent_initial_call=True,
)
def toggle_create(_, mode):
if mode == "create":
# Toggling off while in create mode: bail out without finalizing.
return "view", False, None
return "create", True, None
# 2) Picker open state → DMC Popover.opened
@callback(Output("eb-popover", "opened"), Input("eb-picker-open", "data"))
def reflect_picker(opened):
return bool(opened)
# 3) Mode badge readout.
@callback(
Output("eb-mode-badge", "children"),
Output("eb-mode-badge", "color"),
Output("eb-mode-icon", "icon"),
Output("eb-mode-icon", "color"),
Input("eb-mode", "data"),
)
def mode_readout(mode):
if mode == "create":
return "create", "green", "mdi:pencil-outline", "var(--mantine-color-green-6)"
return "view", "gray", "mdi:eye-outline", "var(--mantine-color-dimmed)"
# 4) Picking an emoji updates pending (creating a stub if none yet) + resets the picker.
@callback(
Output("eb-pending", "data", allow_duplicate=True),
Output("eb-emoji", "value"),
Input("eb-emoji", "value"),
State("eb-mode", "data"),
State("eb-pending", "data"),
prevent_initial_call=True,
)
def pick_emoji(emoji, mode, pending):
if not emoji or mode != "create":
return dash.no_update, dash.no_update
base = pending or {}
return {**base, "emoji": emoji}, ""
# 5) Map click while in create mode → place the pending marker (only first click).
@callback(
Output("eb-pending", "data", allow_duplicate=True),
Input("eb-map", "clickData"),
State("eb-mode", "data"),
State("eb-pending", "data"),
prevent_initial_call=True,
)
def place_pending(click, mode, pending):
if mode != "create" or not click:
return dash.no_update
if pending and "lat" in pending:
return dash.no_update # already placed; further clicks ignored (drag to move)
lat, lng = click["latlng"]
base = pending or {}
return {
**base,
"lat": lat,
"lng": lng,
"name": base.get("name", ""),
"type": base.get("type", "Market"),
}
# 6) Cancel → discard pending + exit create mode.
@callback(
Output("eb-mode", "data", allow_duplicate=True),
Output("eb-pending", "data", allow_duplicate=True),
Output("eb-picker-open", "data", allow_duplicate=True),
Output("eb-emoji", "value", allow_duplicate=True),
Input("eb-cancel", "n_clicks"),
prevent_initial_call=True,
)
def cancel(n):
# Cancel/Create are dynamically mounted via render_pending; Dash fires their
# callbacks on first mount with n_clicks=None despite prevent_initial_call=True.
# Guard against the mount-fire so it doesn't immediately close the popover.
if not n:
return dash.no_update, dash.no_update, dash.no_update, dash.no_update
return "view", None, False, ""
# 7) Create → finalize pending (push to markers) + exit.
@callback(
Output("eb-markers", "data"),
Output("eb-mode", "data", allow_duplicate=True),
Output("eb-pending", "data", allow_duplicate=True),
Output("eb-picker-open", "data", allow_duplicate=True),
Output("eb-emoji", "value", allow_duplicate=True),
Input("eb-create", "n_clicks"),
State("eb-pending", "data"),
State("eb-name", "value"),
State("eb-type", "value"),
State("eb-markers", "data"),
prevent_initial_call=True,
)
def create(n, pending, name, type_, markers):
# Same mount-fire guard as cancel — without it, the Create button mounting fires
# this callback with n=None and closes everything before the user can interact.
if not n:
return (
dash.no_update,
dash.no_update,
dash.no_update,
dash.no_update,
dash.no_update,
)
if not pending or "lat" not in pending:
return dash.no_update, "view", None, False, ""
final = {**pending, "name": name or "", "type": type_ or "Market"}
return list(markers or []) + [final], "view", None, False, ""
# 8) Render the pending marker (+ form popup) into the map.
@callback(Output("eb-pending-container", "children"), Input("eb-pending", "data"))
def render_pending(pending):
if not pending or "lat" not in pending:
return []
emoji = pending.get("emoji")
return dl2.Marker(
id="eb-pending-marker",
position=[pending["lat"], pending["lng"]],
emoji=emoji,
iconSize=34 if emoji else None,
draggable=True,
children=dl2.Popup(
id="eb-pending-popup",
opened=True,
closeOnClick=False,
autoClose=False,
closeButton=False,
maxWidth=320,
minWidth=260,
children=form_layout(pending),
),
)
# 9) Drag the pending marker → update its position in pending.
@callback(
Output("eb-pending", "data", allow_duplicate=True),
Input("eb-pending-marker", "position"),
State("eb-pending", "data"),
prevent_initial_call=True,
)
def drag_pending(pos, pending):
if not pending or not pos:
return dash.no_update
if pos[0] == pending.get("lat") and pos[1] == pending.get("lng"):
return dash.no_update
return {**pending, "lat": pos[0], "lng": pos[1]}
# 10) Render finalized markers (view mode).
@callback(
Output("eb-markers-container", "children"),
Output("eb-list", "children"),
Input("eb-markers", "data"),
)
def render_markers(markers):
markers = markers or []
if not markers:
empty = dmc.Text(
"Click the smile button on the map to create your first marker.",
size="sm",
c="dimmed",
)
return [], empty
children = []
for i, m in enumerate(markers):
emoji = m.get("emoji")
type_ = m.get("type", "Other")
name = m.get("name") or "(unnamed)"
children.append(
dl2.Marker(
position=[m["lat"], m["lng"]],
emoji=emoji,
iconSize=34 if emoji else None,
children=[
dl2.Tooltip(children=name),
dl2.Popup(
children=html.Div(
style={"minWidth": "180px"},
children=dmc.Stack(
[
dmc.Text(name, fw=600, size="sm"),
dmc.Badge(
type_,
color=TYPE_COLORS.get(type_, "gray"),
variant="light",
size="sm",
),
],
gap=4,
),
)
),
],
)
)
listing = dmc.Stack(
[
dmc.Group(
[
dmc.Text(m.get("emoji") or "📍", size="lg"),
dmc.Stack(
[
dmc.Text(m.get("name") or "(unnamed)", size="sm", fw=600),
dmc.Badge(
m.get("type", "Other"),
color=TYPE_COLORS.get(m.get("type", "Other"), "gray"),
variant="light",
size="xs",
),
],
gap=0,
),
],
gap="sm",
)
for m in markers
],
gap="sm",
)
return children, listing
# ---- side-panel toggle (mirrors /resize-observer) --------------------------
# Toggle the .open class on the flex row; the panel slides in/out via CSS
# transition (assets/style.css → .dl2-resize-row + .dl2-resize-panel). Because
# the map's container is a flex item, Leaflet 2's ResizeObserver picks up the
# width change and reflows the tiles automatically — no invalidateSize() needed.
clientside_callback(
"""
(n) => {
const r = document.getElementById('eb-row');
if (r) r.classList.toggle('open');
return window.dash_clientside.no_update;
}
""",
Output("eb-panel-toggle", "id"),
Input("eb-panel-toggle", "n_clicks"),
prevent_initial_call=True,
)
# ---- theme sync (light/dark) ------------------------------------------------
# The header toggle (`color-scheme-toggle.checked`) drives the app's color scheme —
# checked=True means light. Mirror it to the dl2.TileLayer URL (CARTO Positron vs
# Dark Matter) and to DashEmojiMart's `theme` prop so the picker UI follows along
# too. Same pattern the /emoji-iconify page uses.
register_theme_swap("eb-tile", TILES)
clientside_callback(
# Same fix as the tile swap: read the STORE, not the header ActionIcon.
"(scheme) => (scheme === 'dark' ? 'dark' : 'light')",
Output("eb-emoji", "theme"),
Input("color-scheme-storage", "data"),
)Source: /easy-button
Note for AI agents: This is the static, prerendered view of an interactive Dash application served because we detected a non-JS user agent. Full prose docs:
- /easy-button/llms.txt — LLM-friendly documentation
- /sitemap.xml
- /robots.txt