Use new IcedEditor trait that forwards GuiContext

nih_plug_iced/src/lib.rs

@@ -4,8 +4,8 @@
 
 use baseview::{Size, WindowOpenOptions, WindowScalePolicy};
 use crossbeam::atomic::AtomicCell;
-use nih_plug::prelude::{Editor, GuiContext, ParamSetter, ParentWindowHandle};
+use nih_plug::prelude::{Editor, GuiContext, ParentWindowHandle};
-use std::marker::PhantomData;
+use std::fmt::Debug;
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::Arc;
 
@@ -25,24 +25,73 @@ pub use iced_baseview::*;
 /// field on your parameters struct.
 ///
 /// See [`IcedState::from_size()`].
-pub fn create_iced_editor<A>(
+pub fn create_iced_editor<E: IcedEditor>(
     iced_state: Arc<IcedState>,
-    initialization_flags: A::Flags,
+    initialization_flags: E::InitializationFlags,
-) -> Option<Box<dyn Editor>>
+) -> Option<Box<dyn Editor>> {
-where
+    Some(Box::new(IcedEditorWrapper::<E> {
-    A: Application + 'static + Send + Sync,
-    A::Flags: Clone + Sync,
-{
-    Some(Box::new(IcedEditor::<A> {
         iced_state,
         initialization_flags,
 
         scaling_factor: AtomicCell::new(None),
-
-        _phantom: PhantomData,
     }))
 }
 
+/// A plugin editor using `iced`. This wraps around [`Application`] with the only change being that
+/// the usual `new()` function now additionally takes a `Arc<dyn GuiContext>` that the editor can
+/// store to interact with the parameters. The editor should have a `Pin<Arc<impl Params>>` as part
+/// of their [`Flags`][Self::Flags] so it can read the current parameter values. See [`Application`]
+/// for more information.
+pub trait IcedEditor: 'static + Send + Sync + Sized {
+    /// See [`Application::Executor`]. You'll likely want to use [`crate::executor::Default`].
+    type Executor: Executor;
+    /// See [`Application::Message`].
+    type Message: 'static + Clone + Debug + Send;
+    /// See [`Application::Flags`].
+    type InitializationFlags: 'static + Clone + Send + Sync;
+
+    /// See [`Application::new`]. This also receivs the GUI context in addition to the flags.
+    fn new(
+        initialization_fags: Self::InitializationFlags,
+        context: Arc<dyn GuiContext>,
+    ) -> (Self, Command<Self::Message>);
+
+    /// See [`Application::update`].
+    fn update(
+        &mut self,
+        window: &mut WindowQueue,
+        message: Self::Message,
+    ) -> Command<Self::Message>;
+
+    /// See [`Application::subscription`].
+    fn subscription(
+        &self,
+        _window_subs: &mut WindowSubs<Self::Message>,
+    ) -> Subscription<Self::Message> {
+        Subscription::none()
+    }
+
+    /// See [`Application::view`].
+    fn view(&mut self) -> Element<'_, Self::Message>;
+
+    /// See [`Application::background_color`].
+    fn background_color(&self) -> Color {
+        Color::WHITE
+    }
+
+    /// See [`Application::scale_policy`].
+    ///
+    /// TODO: Is this needed? Editors shouldn't change the scale policy.
+    fn scale_policy(&self) -> WindowScalePolicy {
+        WindowScalePolicy::SystemScaleFactor
+    }
+
+    /// See [`Application::renderer_settings`].
+    fn renderer_settings() -> iced_baseview::renderer::settings::Settings {
+        iced_baseview::renderer::settings::Settings::default()
+    }
+}
+
 // TODO: Once we add resizing, we may want to be able to remember the GUI size. In that case we need
 //       to make this serializable (only restoring the size of course) so it can be persisted.
 pub struct IcedState {
@@ -73,31 +122,16 @@ impl IcedState {
 }
 
 /// An [`Editor`] implementation that renders an iced [`Application`].
-struct IcedEditor<A>
+struct IcedEditorWrapper<E: IcedEditor> {
-where
-    A: Application + 'static + Send + Sync,
-    A::Flags: Clone + Sync,
-{
     iced_state: Arc<IcedState>,
-    initialization_flags: A::Flags,
+    initialization_flags: E::InitializationFlags,
 
-    // FIXME:
-    // /// The plugin's state. This is kept in between editor openenings.
-    // user_state: Arc<RwLock<T>>,
-    // 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.
     scaling_factor: AtomicCell<Option<f32>>,
-
-    _phantom: PhantomData<A>,
 }
 
-impl<A> Editor for IcedEditor<A>
+impl<E: IcedEditor> Editor for IcedEditorWrapper<E> {
-where
-    A: Application + 'static + Send + Sync,
-    A::Flags: Clone + Sync,
-{
     fn spawn(
         &self,
         parent: ParentWindowHandle,
@@ -108,9 +142,10 @@ where
 
         let (unscaled_width, unscaled_height) = self.iced_state.size();
         let scaling_factor = self.scaling_factor.load();
+
         // TODO: iced_baseview does not have gracefuly error handling for context creation failures.
         //       This will panic if the context could not be created.
-        let window = IcedWindow::<A>::open_parented(
+        let window = IcedWindow::<IcedEditorWrapperApplication<E>>::open_parented(
             &parent,
             Settings {
                 window: WindowOpenOptions {
@@ -147,7 +182,8 @@ where
                     #[cfg(not(feature = "opengl"))]
                     gl_config: None,
                 },
-                flags: self.initialization_flags.clone(),
+                // We use this wrapper to be able to pass the GUI context to the editor
+                flags: (context, self.initialization_flags.clone()),
             },
         );
 
@@ -168,7 +204,7 @@ where
     }
 }
 
-/// The window handle used for [`IcedEditor`].
+/// The window handle used for [`IcedEditorWrapper`].
 struct IcedEditorHandle<Message: 'static + Send> {
     iced_state: Arc<IcedState>,
     window: iced_baseview::WindowHandle<Message>,
@@ -185,3 +221,57 @@ impl<Message: Send> Drop for IcedEditorHandle<Message> {
         self.window.close_window();
     }
 }
+
+/// Wraps an `iced_baseview` [`Application`] around [`IcedEditor`]. Needed to allow editors to
+/// always receive a copy of the GUI context.
+struct IcedEditorWrapperApplication<E> {
+    editor: E,
+}
+
+impl<E: IcedEditor> Application for IcedEditorWrapperApplication<E> {
+    type Executor = E::Executor;
+    type Message = E::Message;
+    type Flags = (Arc<dyn GuiContext>, E::InitializationFlags);
+
+    fn new((context, flags): Self::Flags) -> (Self, Command<Self::Message>) {
+        let (editor, command) = E::new(flags, context);
+        (Self { editor }, command)
+    }
+
+    #[inline]
+    fn update(
+        &mut self,
+        window: &mut WindowQueue,
+        message: Self::Message,
+    ) -> Command<Self::Message> {
+        self.editor.update(window, message)
+    }
+
+    #[inline]
+    fn subscription(
+        &self,
+        window_subs: &mut WindowSubs<Self::Message>,
+    ) -> Subscription<Self::Message> {
+        self.editor.subscription(window_subs)
+    }
+
+    #[inline]
+    fn view(&mut self) -> Element<'_, Self::Message> {
+        self.editor.view()
+    }
+
+    #[inline]
+    fn background_color(&self) -> Color {
+        self.editor.background_color()
+    }
+
+    #[inline]
+    fn scale_policy(&self) -> WindowScalePolicy {
+        self.editor.scale_policy()
+    }
+
+    #[inline]
+    fn renderer_settings() -> iced_baseview::renderer::settings::Settings {
+        E::renderer_settings()
+    }
+}

plugins/diopser/src/editor.rs

@@ -14,8 +14,8 @@
 // You should have received a copy of the GNU General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-use nih_plug::prelude::Editor;
+use nih_plug::prelude::{Editor, GuiContext};
-use nih_plug_iced::{create_iced_editor, Application, Command, Element, IcedState};
+use nih_plug_iced::{create_iced_editor, Command, Element, IcedEditor, IcedState};
 use std::pin::Pin;
 use std::sync::Arc;
 
@@ -35,16 +35,20 @@ pub fn create(
 
 struct DiopserEditor {
     params: Pin<Arc<DiopserParams>>,
+    context: Arc<dyn GuiContext>,
 }
 
-impl Application for DiopserEditor {
+impl IcedEditor for DiopserEditor {
     type Executor = nih_plug_iced::executor::Default;
     // TODO:
     type Message = ();
-    type Flags = Pin<Arc<DiopserParams>>;
+    type InitializationFlags = Pin<Arc<DiopserParams>>;
 
-    fn new(flags: Self::Flags) -> (Self, Command<Self::Message>) {
+    fn new(
-        let editor = DiopserEditor { params: flags };
+        params: Self::InitializationFlags,
+        context: Arc<dyn GuiContext>,
+    ) -> (Self, Command<Self::Message>) {
+        let editor = DiopserEditor { params, context };
 
         (editor, Command::none())
     }