1
0
Fork 0
nih-plug/nih_plug_egui/src/editor.rs
2022-11-15 16:28:53 +01:00

128 lines
4.6 KiB
Rust

//! An [`Editor`] implementation for egui.
use baseview::gl::GlConfig;
use baseview::{Size, WindowHandle, WindowOpenOptions, WindowScalePolicy};
use crossbeam::atomic::AtomicCell;
use egui::Context;
use egui_baseview::EguiWindow;
use nih_plug::prelude::{Editor, GuiContext, ParamSetter, ParentWindowHandle};
use parking_lot::RwLock;
use std::sync::atomic::Ordering;
use std::sync::Arc;
use crate::EguiState;
/// An [`Editor`] implementation that calls an egui draw loop.
pub(crate) struct EguiEditor<T> {
pub(crate) egui_state: Arc<EguiState>,
/// The plugin's state. This is kept in between editor openenings.
pub(crate) user_state: Arc<RwLock<T>>,
/// The user's build function. Applied once at the start of the application.
pub(crate) build: Arc<dyn Fn(&Context, &mut T) + 'static + Send + Sync>,
/// The user's update function.
pub(crate) update: Arc<dyn Fn(&Context, &ParamSetter, &mut T) + 'static + Send + Sync>,
/// The scaling factor reported by the host, if any. On macOS this will never be set and we
/// should use the system scaling factor instead.
pub(crate) scaling_factor: AtomicCell<Option<f32>>,
}
impl<T> Editor for EguiEditor<T>
where
T: 'static + Send + Sync,
{
fn spawn(
&self,
parent: ParentWindowHandle,
context: Arc<dyn GuiContext>,
) -> Box<dyn std::any::Any + Send> {
let build = self.build.clone();
let update = self.update.clone();
let state = self.user_state.clone();
let (unscaled_width, unscaled_height) = self.egui_state.size();
let scaling_factor = self.scaling_factor.load();
let window = EguiWindow::open_parented(
&parent,
WindowOpenOptions {
title: String::from("egui window"),
// Baseview should be doing the DPI scaling for us
size: Size::new(unscaled_width as f64, unscaled_height as f64),
// NOTE: For some reason passing 1.0 here causes the UI to be scaled on macOS but
// not the mouse events.
scale: scaling_factor
.map(|factor| WindowScalePolicy::ScaleFactor(factor as f64))
.unwrap_or(WindowScalePolicy::SystemScaleFactor),
#[cfg(feature = "opengl")]
gl_config: Some(GlConfig {
version: (3, 2),
red_bits: 8,
blue_bits: 8,
green_bits: 8,
alpha_bits: 8,
depth_bits: 24,
stencil_bits: 8,
samples: None,
srgb: true,
double_buffer: true,
vsync: true,
..Default::default()
}),
},
state,
move |egui_ctx, _queue, state| build(egui_ctx, &mut state.write()),
move |egui_ctx, _queue, state| {
let setter = ParamSetter::new(context.as_ref());
// For now, just always redraw. Most plugin GUIs have meters, and those almost always
// need a redraw. Later we can try to be a bit more sophisticated about this. Without
// this we would also have a blank GUI when it gets first opened because most DAWs open
// their GUI while the window is still unmapped.
egui_ctx.request_repaint();
(update)(egui_ctx, &setter, &mut state.write());
},
);
self.egui_state.open.store(true, Ordering::Release);
Box::new(EguiEditorHandle {
egui_state: self.egui_state.clone(),
window,
})
}
fn size(&self) -> (u32, u32) {
self.egui_state.size()
}
fn set_scale_factor(&self, factor: f32) -> bool {
self.scaling_factor.store(Some(factor));
true
}
fn param_values_changed(&self) {
// As mentioned above, for now we'll always force a redraw to allow meter widgets to work
// correctly. In the future we can use an `Arc<AtomicBool>` and only force a redraw when
// that boolean is set.
}
}
/// The window handle used for [`EguiEditor`].
struct EguiEditorHandle {
egui_state: Arc<EguiState>,
window: WindowHandle,
}
/// The window handle enum stored within 'WindowHandle' contains raw pointers. Is there a way around
/// having this requirement?
unsafe impl Send for EguiEditorHandle {}
impl Drop for EguiEditorHandle {
fn drop(&mut self) {
self.egui_state.open.store(false, Ordering::Release);
// XXX: This should automatically happen when the handle gets dropped, but apparently not
self.window.close();
}
}