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egui/egui/src/widgets/mod.rs
2020-11-02 17:35:16 +01:00

571 lines
17 KiB
Rust

//! Widgets are pieces of GUI such as labels, buttons, sliders etc.
//!
//! Example widget uses:
//! * `ui.add(Label::new("Text").text_color(color::red));`//!
//! * `if ui.add(Button::new("Click me")).clicked { ... }`
#![allow(clippy::new_without_default)]
use crate::{layout::Direction, *};
pub mod color_picker;
mod drag_value;
mod image;
mod slider;
pub(crate) mod text_edit;
pub use {drag_value::DragValue, image::Image, slider::*, text_edit::*};
use paint::*;
// ----------------------------------------------------------------------------
/// Anything implementing Widget can be added to a Ui with `Ui::add`
pub trait Widget {
fn ui(self, ui: &mut Ui) -> Response;
}
// ----------------------------------------------------------------------------
/// Static text.
pub struct Label {
// TODO: not pub
pub(crate) text: String,
pub(crate) multiline: bool,
pub(crate) text_style: Option<TextStyle>,
pub(crate) text_color: Option<Srgba>,
}
impl Label {
pub fn new(text: impl Into<String>) -> Self {
Self {
text: text.into(),
multiline: true,
text_style: None,
text_color: None,
}
}
pub fn text(&self) -> &str {
&self.text
}
pub fn multiline(mut self, multiline: bool) -> Self {
self.multiline = multiline;
self
}
/// If you do not set a `TextStyle`, the default `style.text_style`.
pub fn text_style(mut self, text_style: TextStyle) -> Self {
self.text_style = Some(text_style);
self
}
pub fn heading(self) -> Self {
self.text_style(TextStyle::Heading)
}
pub fn monospace(self) -> Self {
self.text_style(TextStyle::Monospace)
}
pub fn small(self) -> Self {
self.text_style(TextStyle::Small)
}
pub fn text_color(mut self, text_color: Srgba) -> Self {
self.text_color = Some(text_color);
self
}
pub fn layout(&self, ui: &Ui) -> font::Galley {
let max_width = ui.available().width();
// Prevent word-wrapping after a single letter, and other silly shit:
// TODO: general "don't force labels and similar to wrap so early"
// TODO: max_width = max_width.at_least(ui.spacing.first_wrap_width);
self.layout_width(ui, max_width)
}
pub fn layout_width(&self, ui: &Ui, max_width: f32) -> font::Galley {
let text_style = self.text_style_or_default(ui.style());
let font = &ui.fonts()[text_style];
if self.multiline {
font.layout_multiline(self.text.clone(), max_width) // TODO: avoid clone
} else {
font.layout_single_line(self.text.clone()) // TODO: avoid clone
}
}
pub fn font_height(&self, fonts: &Fonts, style: &Style) -> f32 {
let text_style = self.text_style_or_default(style);
fonts[text_style].height()
}
// TODO: this should return a LabelLayout which has a paint method.
// We can then split Widget::Ui in two: layout + allocating space, and painting.
// this allows us to assemble labels, THEN detect interaction, THEN chose color style based on that.
// pub fn layout(self, ui: &mut ui) -> LabelLayout { }
// TODO: a paint method for painting anywhere in a ui.
// This should be the easiest method of putting text anywhere.
pub fn paint_galley(&self, ui: &mut Ui, pos: Pos2, galley: font::Galley) {
let text_style = self.text_style_or_default(ui.style());
let text_color = self
.text_color
.unwrap_or_else(|| ui.style().visuals.text_color());
ui.painter().galley(pos, galley, text_style, text_color);
}
/// Read the text style, or get the default for the current style
pub fn text_style_or_default(&self, style: &Style) -> TextStyle {
self.text_style.unwrap_or_else(|| style.body_text_style)
}
}
/// Shortcut for creating a `Label` widget.
///
/// Usage: `label!("Foo: {}", bar)` equivalent to `Label::new(format!("Foo: {}", bar))`.
#[macro_export]
macro_rules! label {
($fmt:expr) => ($crate::widgets::Label::new($fmt));
($fmt:expr, $($arg:tt)*) => ($crate::widgets::Label::new(format!($fmt, $($arg)*)));
}
impl Widget for Label {
fn ui(self, ui: &mut Ui) -> Response {
let galley = self.layout(ui);
let rect = ui.allocate_space(galley.size);
self.paint_galley(ui, rect.min, galley);
ui.interact_hover(rect)
}
}
impl Into<Label> for &str {
fn into(self) -> Label {
Label::new(self)
}
}
impl Into<Label> for &String {
fn into(self) -> Label {
Label::new(self)
}
}
impl Into<Label> for String {
fn into(self) -> Label {
Label::new(self)
}
}
// ----------------------------------------------------------------------------
/// A clickable hyperlink, e.g. to `"https://github.com/emilk/egui"`.
pub struct Hyperlink {
// TODO: wrap Label
url: String,
text: String,
pub(crate) text_style: Option<TextStyle>,
}
impl Hyperlink {
pub fn new(url: impl Into<String>) -> Self {
let url = url.into();
Self {
text: url.clone(),
url,
text_style: None,
}
}
/// Show some other text than the url
pub fn text(mut self, text: impl Into<String>) -> Self {
self.text = text.into();
self
}
/// If you do not set a `TextStyle`, the default `style.text_style`.
pub fn text_style(mut self, text_style: TextStyle) -> Self {
self.text_style = Some(text_style);
self
}
pub fn small(self) -> Self {
self.text_style(TextStyle::Small)
}
}
impl Widget for Hyperlink {
fn ui(self, ui: &mut Ui) -> Response {
let Hyperlink {
url,
text,
text_style,
} = self;
let color = color::LIGHT_BLUE;
let text_style = text_style.unwrap_or_else(|| ui.style().body_text_style);
let id = ui.make_child_id(&url);
let font = &ui.fonts()[text_style];
let galley = font.layout_multiline(text, ui.available().width());
let rect = ui.allocate_space(galley.size);
let response = ui.interact(rect, id, Sense::click());
if response.hovered {
ui.ctx().output().cursor_icon = CursorIcon::PointingHand;
}
if response.clicked {
ui.ctx().output().open_url = Some(url.clone());
}
let visuals = ui.style().interact(&response);
if response.hovered {
// Underline:
for line in &galley.lines {
let pos = response.rect.min;
let y = pos.y + line.y_max;
let y = ui.painter().round_to_pixel(y);
let min_x = pos.x + line.min_x();
let max_x = pos.x + line.max_x();
ui.painter().line_segment(
[pos2(min_x, y), pos2(max_x, y)],
(visuals.fg_stroke.width, color),
);
}
}
ui.painter()
.galley(response.rect.min, galley, text_style, color);
response.on_hover_text(url)
}
}
// ----------------------------------------------------------------------------
/// Clickable button with text
pub struct Button {
text: String,
text_color: Option<Srgba>,
text_style: TextStyle,
/// None means default for interact
fill: Option<Srgba>,
sense: Sense,
}
impl Button {
pub fn new(text: impl Into<String>) -> Self {
Self {
text: text.into(),
text_color: None,
text_style: TextStyle::Button,
fill: Default::default(),
sense: Sense::click(),
}
}
pub fn text_color(mut self, text_color: Srgba) -> Self {
self.text_color = Some(text_color);
self
}
pub fn text_color_opt(mut self, text_color: Option<Srgba>) -> Self {
self.text_color = text_color;
self
}
pub fn text_style(mut self, text_style: TextStyle) -> Self {
self.text_style = text_style;
self
}
pub fn fill(mut self, fill: Option<Srgba>) -> Self {
self.fill = fill;
self
}
/// By default, buttons senses clicks.
/// Change this to a drag-button with `Sense::drag()`.
pub fn sense(mut self, sense: Sense) -> Self {
self.sense = sense;
self
}
/// If you set this to `false`, the button will be grayed out and un-clickable.
/// `enabled(false)` has the same effect as calling `sense(Sense::nothing())`.
pub fn enabled(mut self, enabled: bool) -> Self {
if !enabled {
self.sense = Sense::nothing();
}
self
}
}
impl Widget for Button {
fn ui(self, ui: &mut Ui) -> Response {
let Button {
text,
text_color,
text_style,
fill,
sense,
} = self;
let button_padding = ui.style().spacing.button_padding;
let id = ui.make_position_id();
let font = &ui.fonts()[text_style];
let galley = font.layout_multiline(text, ui.available().width());
let mut desired_size = galley.size + 2.0 * button_padding;
desired_size = desired_size.at_least(ui.style().spacing.interact_size);
let rect = ui.allocate_space(desired_size);
let response = ui.interact(rect, id, sense);
let visuals = ui.style().interact(&response);
// let text_cursor = response.rect.center() - 0.5 * galley.size; // centered-centered (looks bad for justified drop-down menus
let text_cursor = pos2(
response.rect.left() + button_padding.x,
response.rect.center().y - 0.5 * galley.size.y,
); // left-centered
let fill = fill.unwrap_or(visuals.bg_fill);
ui.painter().rect(
response.rect,
visuals.corner_radius,
fill,
visuals.bg_stroke,
);
let text_color = text_color
.or(ui.style().visuals.override_text_color)
.unwrap_or_else(|| visuals.text_color());
ui.painter()
.galley(text_cursor, galley, text_style, text_color);
response
}
}
// ----------------------------------------------------------------------------
// TODO: allow checkbox without a text label
/// Boolean on/off control with text label
#[derive(Debug)]
pub struct Checkbox<'a> {
checked: &'a mut bool,
text: String,
text_color: Option<Srgba>,
}
impl<'a> Checkbox<'a> {
pub fn new(checked: &'a mut bool, text: impl Into<String>) -> Self {
Checkbox {
checked,
text: text.into(),
text_color: None,
}
}
pub fn text_color(mut self, text_color: Srgba) -> Self {
self.text_color = Some(text_color);
self
}
}
impl<'a> Widget for Checkbox<'a> {
fn ui(self, ui: &mut Ui) -> Response {
let Checkbox {
checked,
text,
text_color,
} = self;
let id = ui.make_position_id();
let text_style = TextStyle::Button;
let font = &ui.fonts()[text_style];
let galley = font.layout_single_line(text);
let spacing = &ui.style().spacing;
let icon_width = spacing.icon_width;
let icon_spacing = ui.style().spacing.icon_spacing;
let button_padding = spacing.button_padding;
let mut desired_size =
button_padding + vec2(icon_width + icon_spacing, 0.0) + galley.size + button_padding;
desired_size = desired_size.at_least(spacing.interact_size);
desired_size.y = desired_size.y.max(icon_width);
let rect = ui.allocate_space(desired_size);
let response = ui.interact(rect, id, Sense::click());
if response.clicked {
*checked = !*checked;
}
let visuals = ui.style().interact(&response);
let text_cursor = pos2(
response.rect.min.x + button_padding.x + icon_width + icon_spacing,
response.rect.center().y - 0.5 * galley.size.y,
);
let (small_icon_rect, big_icon_rect) = ui.style().spacing.icon_rectangles(response.rect);
ui.painter().add(PaintCmd::Rect {
rect: big_icon_rect,
corner_radius: visuals.corner_radius,
fill: visuals.bg_fill,
stroke: visuals.bg_stroke,
});
if *checked {
// Check mark:
ui.painter().add(PaintCmd::line(
vec![
pos2(small_icon_rect.left(), small_icon_rect.center().y),
pos2(small_icon_rect.center().x, small_icon_rect.bottom()),
pos2(small_icon_rect.right(), small_icon_rect.top()),
],
visuals.fg_stroke,
));
}
let text_color = text_color
.or(ui.style().visuals.override_text_color)
.unwrap_or_else(|| visuals.text_color());
ui.painter()
.galley(text_cursor, galley, text_style, text_color);
response
}
}
// ----------------------------------------------------------------------------
/// One out of several alternatives, either checked or not.
#[derive(Debug)]
pub struct RadioButton {
checked: bool,
text: String,
text_color: Option<Srgba>,
}
impl RadioButton {
pub fn new(checked: bool, text: impl Into<String>) -> Self {
Self {
checked,
text: text.into(),
text_color: None,
}
}
pub fn text_color(mut self, text_color: Srgba) -> Self {
self.text_color = Some(text_color);
self
}
}
impl Widget for RadioButton {
fn ui(self, ui: &mut Ui) -> Response {
let RadioButton {
checked,
text,
text_color,
} = self;
let id = ui.make_position_id();
let text_style = TextStyle::Button;
let font = &ui.fonts()[text_style];
let galley = font.layout_multiline(text, ui.available().width());
let icon_width = ui.style().spacing.icon_width;
let icon_spacing = ui.style().spacing.icon_spacing;
let button_padding = ui.style().spacing.button_padding;
let mut desired_size =
button_padding + vec2(icon_width + icon_spacing, 0.0) + galley.size + button_padding;
desired_size = desired_size.at_least(ui.style().spacing.interact_size);
desired_size.y = desired_size.y.max(icon_width);
let rect = ui.allocate_space(desired_size);
let response = ui.interact(rect, id, Sense::click());
let text_cursor = pos2(
response.rect.min.x + button_padding.x + icon_width + icon_spacing,
response.rect.center().y - 0.5 * galley.size.y,
);
let visuals = ui.style().interact(&response);
let (small_icon_rect, big_icon_rect) = ui.style().spacing.icon_rectangles(response.rect);
let painter = ui.painter();
painter.add(PaintCmd::Circle {
center: big_icon_rect.center(),
radius: big_icon_rect.width() / 2.0,
fill: visuals.bg_fill,
stroke: visuals.bg_stroke,
});
if checked {
painter.add(PaintCmd::Circle {
center: small_icon_rect.center(),
radius: small_icon_rect.width() / 3.0,
fill: visuals.fg_stroke.color, // Intentional to use stroke and not fill
stroke: Default::default(),
// fill: visuals.fg_fill,
// stroke: visuals.fg_stroke,
});
}
let text_color = text_color
.or(ui.style().visuals.override_text_color)
.unwrap_or_else(|| visuals.text_color());
painter.galley(text_cursor, galley, text_style, text_color);
response
}
}
// ----------------------------------------------------------------------------
/// A visual separator. A horizontal or vertical line (depending on `Layout`).
pub struct Separator {
spacing: f32,
}
impl Separator {
pub fn new() -> Self {
Self { spacing: 6.0 }
}
/// How much space we take up. The line is painted in the middle of this.
pub fn spacing(mut self, spacing: f32) -> Self {
self.spacing = spacing;
self
}
}
impl Widget for Separator {
fn ui(self, ui: &mut Ui) -> Response {
let Separator { spacing } = self;
let available_space = ui.available_finite().size();
let (points, rect) = match ui.layout().dir() {
Direction::Horizontal => {
let rect = ui.allocate_space(vec2(spacing, available_space.y));
(
[
pos2(rect.center().x, rect.top()),
pos2(rect.center().x, rect.bottom()),
],
rect,
)
}
Direction::Vertical => {
let rect = ui.allocate_space(vec2(available_space.x, spacing));
(
[
pos2(rect.left(), rect.center().y),
pos2(rect.right(), rect.center().y),
],
rect,
)
}
};
let stroke = ui.style().visuals.widgets.noninteractive.bg_stroke;
ui.painter().line_segment(points, stroke);
ui.interact_hover(rect)
}
}