egui/egui/src/containers/panel.rs
2020-12-19 14:48:04 +01:00

141 lines
4.4 KiB
Rust

//! Panels are fixed `Ui` regions.
//! Together with `Window` and `Area`:s they are
//! the only places where you can put you widgets.
use crate::*;
// ----------------------------------------------------------------------------
/// A panel that covers the entire left side of the screen.
///
/// Panels should be added before adding any `Window`s.
pub struct SidePanel {
id: Id,
max_width: f32,
}
impl SidePanel {
/// `id_source`: Something unique, e.g. `"my_side_panel"`.
/// The given `max_width` is a soft maximum (as always), and the actual panel may be smaller or larger.
pub fn left(id_source: impl std::hash::Hash, max_width: f32) -> Self {
Self {
id: Id::new(id_source),
max_width,
}
}
}
impl SidePanel {
pub fn show<R>(self, ctx: &CtxRef, add_contents: impl FnOnce(&mut Ui) -> R) -> (R, Response) {
let Self { id, max_width } = self;
let mut panel_rect = ctx.available_rect();
panel_rect.max.x = panel_rect.max.x.at_most(panel_rect.min.x + max_width);
let layer_id = LayerId::background();
let clip_rect = ctx.input().screen_rect();
let mut panel_ui = Ui::new(ctx.clone(), layer_id, id, panel_rect, clip_rect);
let frame = Frame::panel(&ctx.style());
let r = frame.show(&mut panel_ui, |ui| {
ui.set_min_height(ui.max_rect_finite().height()); // fill full height
add_contents(ui)
});
let panel_rect = panel_ui.min_rect();
let response = panel_ui.interact_hover(panel_rect);
ctx.frame_state().allocate_left_panel(panel_rect);
(r, response)
}
}
// ----------------------------------------------------------------------------
/// A panel that covers the entire top side of the screen.
///
/// Panels should be added before adding any `Window`s.
pub struct TopPanel {
id: Id,
max_height: Option<f32>,
}
impl TopPanel {
/// `id_source`: Something unique, e.g. `"my_top_panel"`.
/// Default height is that of `interact_size.y` (i.e. a button),
/// but the panel will expand as needed.
pub fn top(id_source: impl std::hash::Hash) -> Self {
Self {
id: Id::new(id_source),
max_height: None,
}
}
}
impl TopPanel {
pub fn show<R>(self, ctx: &CtxRef, add_contents: impl FnOnce(&mut Ui) -> R) -> (R, Response) {
let Self { id, max_height } = self;
let max_height = max_height.unwrap_or_else(|| ctx.style().spacing.interact_size.y);
let mut panel_rect = ctx.available_rect();
panel_rect.max.y = panel_rect.max.y.at_most(panel_rect.min.y + max_height);
let layer_id = LayerId::background();
let clip_rect = ctx.input().screen_rect();
let mut panel_ui = Ui::new(ctx.clone(), layer_id, id, panel_rect, clip_rect);
let frame = Frame::panel(&ctx.style());
let r = frame.show(&mut panel_ui, |ui| {
ui.set_min_width(ui.max_rect_finite().width()); // fill full width
add_contents(ui)
});
let panel_rect = panel_ui.min_rect();
let response = panel_ui.interact_hover(panel_rect);
ctx.frame_state().allocate_top_panel(panel_rect);
(r, response)
}
}
// ----------------------------------------------------------------------------
/// A panel that covers the remainder of the screen,
/// i.e. whatever area is left after adding other panels.
///
/// `CentralPanel` should be added after all other panels.
/// Any `Window`s and `Area`s will cover the `CentralPanel`.
#[derive(Default)]
pub struct CentralPanel {}
impl CentralPanel {
pub fn show<R>(self, ctx: &CtxRef, add_contents: impl FnOnce(&mut Ui) -> R) -> (R, Response) {
let Self {} = self;
let panel_rect = ctx.available_rect();
let layer_id = LayerId::background();
let id = Id::new("central_panel");
let clip_rect = ctx.input().screen_rect();
let mut panel_ui = Ui::new(ctx.clone(), layer_id, id, panel_rect, clip_rect);
let frame = Frame::background(&ctx.style());
let r = frame.show(&mut panel_ui, |ui| {
let r = add_contents(ui);
ui.expand_to_include_rect(ui.max_rect()); // Use it all
r
});
let panel_rect = panel_ui.min_rect();
let response = panel_ui.interact_hover(panel_rect);
ctx.frame_state().allocate_central_panel(panel_rect);
(r, response)
}
}