egui/emigui/src/floating.rs

104 lines
2.9 KiB
Rust

//! A Floating is a region that has no parent, it floats on the background.
//! It is potentioally movable.
//! It has no frame or own size.
//! It is the foundation for a window
//!
use std::{fmt::Debug, hash::Hash, sync::Arc};
use crate::*;
// struct State {
// pos: Pos2,
// /// used for catching clickes
// size: Vec2,
// }
type State = crate::window::State;
#[derive(Clone, Copy, Debug)]
pub struct Floating {
movable: bool,
default_pos: Option<Pos2>,
}
impl Floating {
pub fn new() -> Self {
Self {
movable: true,
default_pos: None,
}
}
pub fn movable(mut self, movable: bool) -> Self {
self.movable = movable;
self
}
}
impl Floating {
pub fn show(
self,
ctx: &Arc<Context>,
id_source: impl Copy + Debug + Hash,
add_contents: impl FnOnce(&mut Region),
) {
let default_pos = self.default_pos.unwrap_or_else(|| pos2(100.0, 100.0)); // TODO
let id = ctx.make_unique_id(id_source, default_pos);
let layer = Layer::Window(id);
let (mut state, _is_new) = match ctx.memory.lock().get_window(id) {
Some(state) => (state, false),
None => {
let state = State {
outer_pos: default_pos,
inner_size: Vec2::zero(),
outer_rect: Rect::from_min_size(default_pos, Vec2::zero()),
};
(state, true)
}
};
state.outer_pos = state.outer_pos.round();
let mut region = Region::new(
ctx.clone(),
layer,
id,
Rect::from_min_size(state.outer_pos, Vec2::infinity()),
);
add_contents(&mut region);
let size = region.bounding_size.ceil();
state.outer_rect = Rect::from_min_size(state.outer_pos, size);
let move_interact = ctx.interact(layer, &state.outer_rect, Some(id.with("move")));
if move_interact.active {
state.outer_pos += ctx.input().mouse_move;
}
// Constrain to screen:
let margin = 32.0;
state.outer_pos = state.outer_pos.max(pos2(margin - size.x, 0.0));
state.outer_pos = state.outer_pos.min(pos2(
ctx.input.screen_size.x - margin,
ctx.input.screen_size.y - margin,
));
state.outer_pos = state.outer_pos.round();
state.inner_size = size;
state.outer_rect = Rect::from_min_size(state.outer_pos, size);
if move_interact.active || mouse_pressed_on_window(ctx, id) {
ctx.memory.lock().move_window_to_top(id);
}
ctx.memory.lock().set_window_state(id, state);
}
}
fn mouse_pressed_on_window(ctx: &Context, id: Id) -> bool {
if let Some(mouse_pos) = ctx.input.mouse_pos {
ctx.input.mouse_pressed && ctx.memory.lock().layer_at(mouse_pos) == Layer::Window(id)
} else {
false
}
}