neveko/neveko-gui/crates/egui/src/menu.rs

690 lines
22 KiB
Rust

//! Menu bar functionality (very basic so far).
//!
//! Usage:
//! ```
//! fn show_menu(ui: &mut egui::Ui) {
//! use egui::{menu, Button};
//!
//! menu::bar(ui, |ui| {
//! ui.menu_button("File", |ui| {
//! if ui.button("Open").clicked() {
//! // …
//! }
//! });
//! });
//! }
//! ```
use super::{
style::WidgetVisuals, Align, Context, Id, InnerResponse, PointerState, Pos2, Rect, Response,
Sense, TextStyle, Ui, Vec2,
};
use crate::{widgets::*, *};
use epaint::mutex::RwLock;
use std::sync::Arc;
/// What is saved between frames.
#[derive(Clone, Default)]
pub(crate) struct BarState {
open_menu: MenuRootManager,
}
impl BarState {
fn load(ctx: &Context, bar_id: Id) -> Self {
ctx.data_mut(|d| d.get_temp::<Self>(bar_id).unwrap_or_default())
}
fn store(self, ctx: &Context, bar_id: Id) {
ctx.data_mut(|d| d.insert_temp(bar_id, self));
}
/// Show a menu at pointer if primary-clicked response.
/// Should be called from [`Context`] on a [`Response`]
pub fn bar_menu<R>(
&mut self,
response: &Response,
add_contents: impl FnOnce(&mut Ui) -> R,
) -> Option<InnerResponse<R>> {
MenuRoot::stationary_click_interaction(response, &mut self.open_menu, response.id);
self.open_menu.show(response, add_contents)
}
}
impl std::ops::Deref for BarState {
type Target = MenuRootManager;
fn deref(&self) -> &Self::Target {
&self.open_menu
}
}
impl std::ops::DerefMut for BarState {
fn deref_mut(&mut self) -> &mut Self::Target {
&mut self.open_menu
}
}
fn set_menu_style(style: &mut Style) {
style.spacing.button_padding = vec2(2.0, 0.0);
style.visuals.widgets.active.bg_stroke = Stroke::NONE;
style.visuals.widgets.hovered.bg_stroke = Stroke::NONE;
style.visuals.widgets.inactive.weak_bg_fill = Color32::TRANSPARENT;
style.visuals.widgets.inactive.bg_stroke = Stroke::NONE;
}
/// The menu bar goes well in a [`TopBottomPanel::top`],
/// but can also be placed in a [`Window`].
/// In the latter case you may want to wrap it in [`Frame`].
pub fn bar<R>(ui: &mut Ui, add_contents: impl FnOnce(&mut Ui) -> R) -> InnerResponse<R> {
ui.horizontal(|ui| {
set_menu_style(ui.style_mut());
// Take full width and fixed height:
let height = ui.spacing().interact_size.y;
ui.set_min_size(vec2(ui.available_width(), height));
add_contents(ui)
})
}
/// Construct a top level menu in a menu bar. This would be e.g. "File", "Edit" etc.
///
/// Responds to primary clicks.
///
/// Returns `None` if the menu is not open.
pub fn menu_button<R>(
ui: &mut Ui,
title: impl Into<WidgetText>,
add_contents: impl FnOnce(&mut Ui) -> R,
) -> InnerResponse<Option<R>> {
stationary_menu_impl(ui, title, Box::new(add_contents))
}
/// Construct a top level menu with an image in a menu bar. This would be e.g. "File", "Edit" etc.
///
/// Responds to primary clicks.
///
/// Returns `None` if the menu is not open.
pub fn menu_image_button<R>(
ui: &mut Ui,
texture_id: TextureId,
image_size: impl Into<Vec2>,
add_contents: impl FnOnce(&mut Ui) -> R,
) -> InnerResponse<Option<R>> {
stationary_menu_image_impl(ui, texture_id, image_size, Box::new(add_contents))
}
/// Construct a nested sub menu in another menu.
///
/// Opens on hover.
///
/// Returns `None` if the menu is not open.
pub(crate) fn submenu_button<R>(
ui: &mut Ui,
parent_state: Arc<RwLock<MenuState>>,
title: impl Into<WidgetText>,
add_contents: impl FnOnce(&mut Ui) -> R,
) -> InnerResponse<Option<R>> {
SubMenu::new(parent_state, title).show(ui, add_contents)
}
/// wrapper for the contents of every menu.
pub(crate) fn menu_ui<'c, R>(
ctx: &Context,
menu_id: impl Into<Id>,
menu_state_arc: &Arc<RwLock<MenuState>>,
add_contents: impl FnOnce(&mut Ui) -> R + 'c,
) -> InnerResponse<R> {
let pos = {
let mut menu_state = menu_state_arc.write();
menu_state.entry_count = 0;
menu_state.rect.min
};
let area = Area::new(menu_id)
.order(Order::Foreground)
.constrain(true)
.fixed_pos(pos)
.interactable(true)
.drag_bounds(ctx.screen_rect());
let inner_response = area.show(ctx, |ui| {
set_menu_style(ui.style_mut());
Frame::menu(ui.style())
.show(ui, |ui| {
const DEFAULT_MENU_WIDTH: f32 = 150.0; // TODO(emilk): add to ui.spacing
ui.set_max_width(DEFAULT_MENU_WIDTH);
ui.set_menu_state(Some(menu_state_arc.clone()));
ui.with_layout(Layout::top_down_justified(Align::LEFT), add_contents)
.inner
})
.inner
});
menu_state_arc.write().rect = inner_response.response.rect;
inner_response
}
/// Build a top level menu with a button.
///
/// Responds to primary clicks.
fn stationary_menu_impl<'c, R>(
ui: &mut Ui,
title: impl Into<WidgetText>,
add_contents: Box<dyn FnOnce(&mut Ui) -> R + 'c>,
) -> InnerResponse<Option<R>> {
let title = title.into();
let bar_id = ui.id();
let menu_id = bar_id.with(title.text());
let mut bar_state = BarState::load(ui.ctx(), bar_id);
let mut button = Button::new(title);
if bar_state.open_menu.is_menu_open(menu_id) {
button = button.fill(ui.visuals().widgets.open.weak_bg_fill);
button = button.stroke(ui.visuals().widgets.open.bg_stroke);
}
let button_response = ui.add(button);
let inner = bar_state.bar_menu(&button_response, add_contents);
bar_state.store(ui.ctx(), bar_id);
InnerResponse::new(inner.map(|r| r.inner), button_response)
}
/// Build a top level menu with an image button.
///
/// Responds to primary clicks.
fn stationary_menu_image_impl<'c, R>(
ui: &mut Ui,
texture_id: TextureId,
image_size: impl Into<Vec2>,
add_contents: Box<dyn FnOnce(&mut Ui) -> R + 'c>,
) -> InnerResponse<Option<R>> {
let bar_id = ui.id();
let mut bar_state = BarState::load(ui.ctx(), bar_id);
let button_response = ui.add(ImageButton::new(texture_id, image_size));
let inner = bar_state.bar_menu(&button_response, add_contents);
bar_state.store(ui.ctx(), bar_id);
InnerResponse::new(inner.map(|r| r.inner), button_response)
}
/// Response to secondary clicks (right-clicks) by showing the given menu.
pub(crate) fn context_menu(
response: &Response,
add_contents: impl FnOnce(&mut Ui),
) -> Option<InnerResponse<()>> {
let menu_id = Id::new("__egui::context_menu");
let mut bar_state = BarState::load(&response.ctx, menu_id);
MenuRoot::context_click_interaction(response, &mut bar_state, response.id);
let inner_response = bar_state.show(response, add_contents);
bar_state.store(&response.ctx, menu_id);
inner_response
}
/// Stores the state for the context menu.
#[derive(Clone, Default)]
pub(crate) struct MenuRootManager {
inner: Option<MenuRoot>,
}
impl MenuRootManager {
/// Show a menu at pointer if right-clicked response.
/// Should be called from [`Context`] on a [`Response`]
pub fn show<R>(
&mut self,
response: &Response,
add_contents: impl FnOnce(&mut Ui) -> R,
) -> Option<InnerResponse<R>> {
if let Some(root) = self.inner.as_mut() {
let (menu_response, inner_response) = root.show(response, add_contents);
if MenuResponse::Close == menu_response {
self.inner = None;
}
inner_response
} else {
None
}
}
fn is_menu_open(&self, id: Id) -> bool {
self.inner.as_ref().map(|m| m.id) == Some(id)
}
}
impl std::ops::Deref for MenuRootManager {
type Target = Option<MenuRoot>;
fn deref(&self) -> &Self::Target {
&self.inner
}
}
impl std::ops::DerefMut for MenuRootManager {
fn deref_mut(&mut self) -> &mut Self::Target {
&mut self.inner
}
}
/// Menu root associated with an Id from a Response
#[derive(Clone)]
pub(crate) struct MenuRoot {
pub menu_state: Arc<RwLock<MenuState>>,
pub id: Id,
}
impl MenuRoot {
pub fn new(position: Pos2, id: Id) -> Self {
Self {
menu_state: Arc::new(RwLock::new(MenuState::new(position))),
id,
}
}
pub fn show<R>(
&mut self,
response: &Response,
add_contents: impl FnOnce(&mut Ui) -> R,
) -> (MenuResponse, Option<InnerResponse<R>>) {
if self.id == response.id {
let inner_response =
MenuState::show(&response.ctx, &self.menu_state, self.id, add_contents);
let mut menu_state = self.menu_state.write();
menu_state.rect = inner_response.response.rect;
if menu_state.response.is_close() {
return (MenuResponse::Close, Some(inner_response));
}
}
(MenuResponse::Stay, None)
}
/// Interaction with a stationary menu, i.e. fixed in another Ui.
///
/// Responds to primary clicks.
fn stationary_interaction(
response: &Response,
root: &mut MenuRootManager,
id: Id,
) -> MenuResponse {
if (response.clicked() && root.is_menu_open(id))
|| response.ctx.input(|i| i.key_pressed(Key::Escape))
{
// menu open and button clicked or esc pressed
return MenuResponse::Close;
} else if (response.clicked() && !root.is_menu_open(id))
|| (response.hovered() && root.is_some())
{
// menu not open and button clicked
// or button hovered while other menu is open
let mut pos = response.rect.left_bottom();
if let Some(root) = root.inner.as_mut() {
let menu_rect = root.menu_state.read().rect;
let screen_rect = response.ctx.input(|i| i.screen_rect);
if pos.y + menu_rect.height() > screen_rect.max.y {
pos.y = screen_rect.max.y - menu_rect.height() - response.rect.height();
}
if pos.x + menu_rect.width() > screen_rect.max.x {
pos.x = screen_rect.max.x - menu_rect.width();
}
}
return MenuResponse::Create(pos, id);
} else if response
.ctx
.input(|i| i.pointer.any_pressed() && i.pointer.primary_down())
{
if let Some(pos) = response.ctx.input(|i| i.pointer.interact_pos()) {
if let Some(root) = root.inner.as_mut() {
if root.id == id {
// pressed somewhere while this menu is open
let menu_state = root.menu_state.read();
let in_menu = menu_state.area_contains(pos);
if !in_menu {
return MenuResponse::Close;
}
}
}
}
}
MenuResponse::Stay
}
/// Interaction with a context menu (secondary clicks).
fn context_interaction(
response: &Response,
root: &mut Option<MenuRoot>,
id: Id,
) -> MenuResponse {
let response = response.interact(Sense::click());
response.ctx.input(|input| {
let pointer = &input.pointer;
if pointer.any_pressed() {
if let Some(pos) = pointer.interact_pos() {
let mut destroy = false;
let mut in_old_menu = false;
if let Some(root) = root {
let menu_state = root.menu_state.read();
in_old_menu = menu_state.area_contains(pos);
destroy = root.id == response.id;
}
if !in_old_menu {
if response.hovered() && pointer.secondary_down() {
return MenuResponse::Create(pos, id);
} else if (response.hovered() && pointer.primary_down()) || destroy {
return MenuResponse::Close;
}
}
}
}
MenuResponse::Stay
})
}
fn handle_menu_response(root: &mut MenuRootManager, menu_response: MenuResponse) {
match menu_response {
MenuResponse::Create(pos, id) => {
root.inner = Some(MenuRoot::new(pos, id));
}
MenuResponse::Close => root.inner = None,
MenuResponse::Stay => {}
}
}
/// Respond to secondary (right) clicks.
pub fn context_click_interaction(response: &Response, root: &mut MenuRootManager, id: Id) {
let menu_response = Self::context_interaction(response, root, id);
Self::handle_menu_response(root, menu_response);
}
// Responds to primary clicks.
pub fn stationary_click_interaction(response: &Response, root: &mut MenuRootManager, id: Id) {
let menu_response = Self::stationary_interaction(response, root, id);
Self::handle_menu_response(root, menu_response);
}
}
#[derive(Copy, Clone, PartialEq)]
pub(crate) enum MenuResponse {
Close,
Stay,
Create(Pos2, Id),
}
impl MenuResponse {
pub fn is_close(&self) -> bool {
*self == Self::Close
}
}
pub struct SubMenuButton {
text: WidgetText,
icon: WidgetText,
index: usize,
}
impl SubMenuButton {
/// The `icon` can be an emoji (e.g. `⏵` right arrow), shown right of the label
fn new(text: impl Into<WidgetText>, icon: impl Into<WidgetText>, index: usize) -> Self {
Self {
text: text.into(),
icon: icon.into(),
index,
}
}
fn visuals<'a>(
ui: &'a Ui,
response: &'_ Response,
menu_state: &'_ MenuState,
sub_id: Id,
) -> &'a WidgetVisuals {
if menu_state.is_open(sub_id) {
&ui.style().visuals.widgets.open
} else {
ui.style().interact(response)
}
}
pub fn icon(mut self, icon: impl Into<WidgetText>) -> Self {
self.icon = icon.into();
self
}
pub(crate) fn show(self, ui: &mut Ui, menu_state: &MenuState, sub_id: Id) -> Response {
let SubMenuButton { text, icon, .. } = self;
let text_style = TextStyle::Button;
let sense = Sense::click();
let button_padding = ui.spacing().button_padding;
let total_extra = button_padding + button_padding;
let text_available_width = ui.available_width() - total_extra.x;
let text_galley =
text.into_galley(ui, Some(true), text_available_width, text_style.clone());
let icon_available_width = text_available_width - text_galley.size().x;
let icon_galley = icon.into_galley(ui, Some(true), icon_available_width, text_style);
let text_and_icon_size = Vec2::new(
text_galley.size().x + icon_galley.size().x,
text_galley.size().y.max(icon_galley.size().y),
);
let mut desired_size = text_and_icon_size + 2.0 * button_padding;
desired_size.y = desired_size.y.at_least(ui.spacing().interact_size.y);
let (rect, response) = ui.allocate_at_least(desired_size, sense);
response.widget_info(|| {
crate::WidgetInfo::labeled(crate::WidgetType::Button, text_galley.text())
});
if ui.is_rect_visible(rect) {
let visuals = Self::visuals(ui, &response, menu_state, sub_id);
let text_pos = Align2::LEFT_CENTER
.align_size_within_rect(text_galley.size(), rect.shrink2(button_padding))
.min;
let icon_pos = Align2::RIGHT_CENTER
.align_size_within_rect(icon_galley.size(), rect.shrink2(button_padding))
.min;
if ui.visuals().button_frame {
ui.painter().rect_filled(
rect.expand(visuals.expansion),
visuals.rounding,
visuals.weak_bg_fill,
);
}
let text_color = visuals.text_color();
text_galley.paint_with_fallback_color(ui.painter(), text_pos, text_color);
icon_galley.paint_with_fallback_color(ui.painter(), icon_pos, text_color);
}
response
}
}
pub struct SubMenu {
button: SubMenuButton,
parent_state: Arc<RwLock<MenuState>>,
}
impl SubMenu {
fn new(parent_state: Arc<RwLock<MenuState>>, text: impl Into<WidgetText>) -> Self {
let index = parent_state.write().next_entry_index();
Self {
button: SubMenuButton::new(text, "", index),
parent_state,
}
}
pub fn show<R>(
self,
ui: &mut Ui,
add_contents: impl FnOnce(&mut Ui) -> R,
) -> InnerResponse<Option<R>> {
let sub_id = ui.id().with(self.button.index);
let button = self.button.show(ui, &self.parent_state.read(), sub_id);
self.parent_state
.write()
.submenu_button_interaction(ui, sub_id, &button);
let inner = self
.parent_state
.write()
.show_submenu(ui.ctx(), sub_id, add_contents);
InnerResponse::new(inner, button)
}
}
pub(crate) struct MenuState {
/// The opened sub-menu and its [`Id`]
sub_menu: Option<(Id, Arc<RwLock<MenuState>>)>,
/// Bounding box of this menu (without the sub-menu)
pub rect: Rect,
/// Used to check if any menu in the tree wants to close
pub response: MenuResponse,
/// Used to hash different [`Id`]s for sub-menus
entry_count: usize,
}
impl MenuState {
pub fn new(position: Pos2) -> Self {
Self {
rect: Rect::from_min_size(position, Vec2::ZERO),
sub_menu: None,
response: MenuResponse::Stay,
entry_count: 0,
}
}
/// Close menu hierarchy.
pub fn close(&mut self) {
self.response = MenuResponse::Close;
}
pub fn show<R>(
ctx: &Context,
menu_state: &Arc<RwLock<Self>>,
id: Id,
add_contents: impl FnOnce(&mut Ui) -> R,
) -> InnerResponse<R> {
crate::menu::menu_ui(ctx, id, menu_state, add_contents)
}
fn show_submenu<R>(
&mut self,
ctx: &Context,
id: Id,
add_contents: impl FnOnce(&mut Ui) -> R,
) -> Option<R> {
let (sub_response, response) = self.submenu(id).map(|sub| {
let inner_response = Self::show(ctx, sub, id, add_contents);
(sub.read().response, inner_response.inner)
})?;
self.cascade_close_response(sub_response);
Some(response)
}
/// Check if position is in the menu hierarchy's area.
pub fn area_contains(&self, pos: Pos2) -> bool {
self.rect.contains(pos)
|| self
.sub_menu
.as_ref()
.map_or(false, |(_, sub)| sub.read().area_contains(pos))
}
fn next_entry_index(&mut self) -> usize {
self.entry_count += 1;
self.entry_count - 1
}
/// Sense button interaction opening and closing submenu.
fn submenu_button_interaction(&mut self, ui: &mut Ui, sub_id: Id, button: &Response) {
let pointer = ui.input(|i| i.pointer.clone());
let open = self.is_open(sub_id);
if self.moving_towards_current_submenu(&pointer) {
// ensure to repaint once even when pointer is not moving
ui.ctx().request_repaint();
} else if !open && button.hovered() {
let pos = button.rect.right_top();
self.open_submenu(sub_id, pos);
} else if open && !button.hovered() && !self.hovering_current_submenu(&pointer) {
self.close_submenu();
}
}
/// Check if `dir` points from `pos` towards left side of `rect`.
fn points_at_left_of_rect(pos: Pos2, dir: Vec2, rect: Rect) -> bool {
let vel_a = dir.angle();
let top_a = (rect.left_top() - pos).angle();
let bottom_a = (rect.left_bottom() - pos).angle();
bottom_a - vel_a >= 0.0 && top_a - vel_a <= 0.0
}
/// Check if pointer is moving towards current submenu.
fn moving_towards_current_submenu(&self, pointer: &PointerState) -> bool {
if pointer.is_still() {
return false;
}
if let Some(sub_menu) = self.current_submenu() {
if let Some(pos) = pointer.hover_pos() {
return Self::points_at_left_of_rect(pos, pointer.velocity(), sub_menu.read().rect);
}
}
false
}
/// Check if pointer is hovering current submenu.
fn hovering_current_submenu(&self, pointer: &PointerState) -> bool {
if let Some(sub_menu) = self.current_submenu() {
if let Some(pos) = pointer.hover_pos() {
return sub_menu.read().area_contains(pos);
}
}
false
}
/// Cascade close response to menu root.
fn cascade_close_response(&mut self, response: MenuResponse) {
if response.is_close() {
self.response = response;
}
}
fn is_open(&self, id: Id) -> bool {
self.sub_id() == Some(id)
}
fn sub_id(&self) -> Option<Id> {
self.sub_menu.as_ref().map(|(id, _)| *id)
}
fn current_submenu(&self) -> Option<&Arc<RwLock<MenuState>>> {
self.sub_menu.as_ref().map(|(_, sub)| sub)
}
fn submenu(&mut self, id: Id) -> Option<&Arc<RwLock<MenuState>>> {
self.sub_menu
.as_ref()
.and_then(|(k, sub)| if id == *k { Some(sub) } else { None })
}
/// Open submenu at position, if not already open.
fn open_submenu(&mut self, id: Id, pos: Pos2) {
if !self.is_open(id) {
self.sub_menu = Some((id, Arc::new(RwLock::new(MenuState::new(pos)))));
}
}
fn close_submenu(&mut self) {
self.sub_menu = None;
}
}