defmodule Scenic.Component.Input.RadioButton do
@moduledoc """
Add a single radio button to a graph.
## Data
`{text, id}`
`{text, id, selected?}`
* `text` - a bitstring of the text to display
* `id` - any term. Identifies the radio button.
* `selected?` - boolean. `true` if selected. `false if not`. Default is `false` if
this term is not provided.
## Usage
The RadioButton component is used by the RadioGroup component and usually isn't accessed
directly, although you are free to do so if it fits your needs. There is no short-cut
helper function so you will need to add it to the graph manually.
The following example adds a caret to a graph.
graph
|> RadioButton.add_to_graph({"A button", :an_id, true})
"""
use Scenic.Component, has_children: false
alias Scenic.Scene
alias Scenic.Graph
alias Scenic.Primitive
alias Scenic.Primitive.Style.Theme
alias Scenic.Assets.Static
require Logger
import Scenic.Primitives
# import IEx
@default_font :roboto
@default_font_size 20
@border_width 2
# --------------------------------------------------------
@impl Scenic.Component
def validate({text, id, checked?}) when is_bitstring(text) and is_boolean(checked?) do
{:ok, {text, id, checked?}}
end
def validate(data) do
{
:error,
"""
#{IO.ANSI.red()}Invalid RadioButton specification
Received: #{inspect(data)}
#{IO.ANSI.yellow()}
The data for a RadioButton is {text, id, checked?}#{IO.ANSI.default_color()}
"""
}
end
# --------------------------------------------------------
@doc false
@impl Scenic.Scene
def init(scene, {text, id}, opts) when is_bitstring(text),
do: init(scene, {text, id, false}, opts)
def init(scene, {text, id, checked?}, opts) do
# theme is passed in as an inherited style
theme =
(opts[:theme] || Theme.preset(:dark))
|> Theme.normalize()
# font related info
{:ok, {Static.Font, fm}} = Static.meta(@default_font)
ascent = FontMetrics.ascent(@default_font_size, fm)
fm_width = FontMetrics.width(text, @default_font_size, fm)
space_width = FontMetrics.width(' ', @default_font_size, fm)
outer_radius = ascent * 0.5
inner_radius = ascent * 0.3125
box_height = ascent
box_width = fm_width + box_height + space_width + @border_width
# tune final position
# original behavior had the toggle higher up, use :compat for that mode
{dx, dv} =
case opts[:compat] do
true -> {-@border_width, -ascent + @border_width + 1}
_ -> {@border_width / 2, @border_width / 2}
end
graph =
Graph.build(font: @default_font, font_size: @default_font_size, t: {dx, dv})
|> Primitive.Group.add_to_graph(fn graph ->
graph
|> rect({box_width, box_height}, id: :btn, input: :cursor_button)
|> circle(
outer_radius,
fill: theme.background,
stroke: {2, theme.border},
id: :box,
t: {outer_radius, outer_radius}
)
|> circle(
inner_radius,
fill: theme.thumb,
id: :chx,
hidden: !checked?,
t: {outer_radius, outer_radius}
)
end)
|> text(
text,
fill: theme.text,
t: {box_height + space_width + @border_width, ascent - @border_width}
)
|> update_highlight(theme, Scene.get(scene, :pressed, false))
scene =
scene
|> assign(
graph: graph,
theme: theme,
checked?: checked?,
text: text,
id: id
)
|> assign_new(pressed: false)
|> push_graph(graph)
{:ok, scene}
end
@impl Scenic.Component
def bounds({text, _id, _chk}, _styles) when is_bitstring(text) do
{:ok, {Static.Font, fm}} = Static.meta(@default_font)
ascent = FontMetrics.ascent(@default_font_size, fm)
descent = FontMetrics.descent(@default_font_size, fm)
fm_width = FontMetrics.width(text, @default_font_size, fm)
space_width = FontMetrics.width(' ', @default_font_size, fm)
box_width = fm_width + ascent + space_width + @border_width
{0, 0, box_width, ascent - descent}
end
# --------------------------------------------------------
@doc false
@impl GenServer
def handle_cast({:set_to_msg, set_id}, %{assigns: %{id: id, graph: graph}} = scene) do
graph = update_check(graph, set_id == id)
scene =
scene
|> assign(graph: graph)
|> push_graph(graph)
{:noreply, scene}
end
# --------------------------------------------------------
@doc false
# --------------------------------------------------------
# pressed in the button
@impl Scenic.Scene
def handle_input(
{:cursor_button, {:btn_left, 1, _, _}},
:btn,
%{assigns: %{graph: graph, theme: theme}} = scene
) do
:ok = capture_input(scene, [:cursor_button])
graph = update_highlight(graph, theme, true)
scene =
scene
|> assign(graph: graph, pressed: true)
|> push_graph(graph)
{:noreply, scene}
end
# --------------------------------------------------------
# pressed outside the button
# only happens when input is captured
# could happen when reconnecting to a driver...
def handle_input(
{:cursor_button, {:btn_left, 1, _, _}},
_id,
%{assigns: %{graph: graph, theme: theme}} = scene
) do
:ok = release_input(scene)
graph = update_highlight(graph, theme, false)
scene =
scene
|> assign(graph: graph, pressed: false)
|> push_graph(graph)
{:noreply, scene}
end
# --------------------------------------------------------
# released inside the button
def handle_input(
{:cursor_button, {:btn_left, 0, _, _}},
:btn,
%{assigns: %{pressed: pressed, id: id, graph: graph, theme: theme}} = scene
) do
:ok = release_input(scene)
if pressed do
:ok = send_parent_event(scene, {:click, id})
end
graph = update_highlight(graph, theme, false)
scene =
scene
|> assign(graph: graph, pressed: false)
|> push_graph(graph)
{:noreply, scene}
end
# --------------------------------------------------------
# released outside the button
# only happens when input is captured
def handle_input(
{:cursor_button, {:btn_left, 0, _, _}},
_id,
%{assigns: %{graph: graph, theme: theme}} = scene
) do
:ok = release_input(scene)
graph = update_highlight(graph, theme, false)
scene =
scene
|> assign(graph: graph, pressed: false)
|> push_graph(graph)
{:noreply, scene}
end
# ignore other button press events
def handle_input({:cursor_button, {_, _, _, _}}, _id, scene) do
{:noreply, scene}
end
# ============================================================================
# internal utilities
# --------------------------------------------------------
defp update_highlight(graph, theme, pressed)
defp update_highlight(graph, theme, true) do
Graph.modify(graph, :box, &update_opts(&1, fill: theme.active))
end
defp update_highlight(graph, theme, _) do
Graph.modify(graph, :box, &update_opts(&1, fill: theme.background))
end
# --------------------------------------------------------
defp update_check(graph, true) do
Graph.modify(graph, :chx, &Primitive.put_style(&1, :hidden, false))
end
defp update_check(graph, false) do
Graph.modify(graph, :chx, &Primitive.put_style(&1, :hidden, true))
end
# --------------------------------------------------------
@doc false
@impl Scenic.Scene
def handle_get(_, %{assigns: %{checked?: checked?}} = scene) do
{:reply, checked?, scene}
end
@doc false
@impl Scenic.Scene
def handle_put(chk?, %{assigns: %{checked: checked}} = scene) when chk? == checked do
# no change
{:noreply, scene}
end
def handle_put(chk?, %{assigns: %{graph: graph, id: id}} = scene) when is_boolean(chk?) do
send_parent_event(scene, {:value_changed, id, chk?})
graph = update_check(graph, chk?)
scene =
scene
|> assign(graph: graph, checked?: chk?)
|> push_graph(graph)
{:noreply, scene}
end
def handle_put(v, %{assigns: %{id: id}} = scene) do
Logger.warning(
"Attempted to put an invalid value on Radio Button id: #{inspect(id)}, value: #{inspect(v)}"
)
{:noreply, scene}
end
@doc false
@impl Scenic.Scene
def handle_fetch(_, %{assigns: %{text: text, id: id, checked?: checked?}} = scene) do
{:reply, {:ok, {text, id, checked?}}, scene}
end
end
