make some receivers &mut and remove unnecessary receivers from traits

v2/src/dialog.rs

@@ -1,33 +1,57 @@
 use crate::config::FileExtensions;
+use anyhow::Error;
 use rfd::{FileDialog, MessageDialog, MessageLevel};
+use std::fmt::Write as _;
 use std::path::{Path, PathBuf};
 
-pub trait Dialog: Default {
-    fn pick_file(&self, dir: &Path, extensions: &FileExtensions) -> Option<PathBuf>;
-    fn pick_dir(&self, dir: &Path) -> Option<PathBuf>;
-    fn alert(&self, title: impl Into<String>, message: impl Into<String>);
+#[non_exhaustive]
+pub enum DialogMessageLevel {
+    Error,
 }
 
-#[derive(Default)]
+pub trait Dialog {
+    fn pick_file(dir: &Path, extensions: &FileExtensions) -> Option<PathBuf>;
+
+    fn pick_dir(dir: &Path) -> Option<PathBuf>;
+
+    fn message(level: DialogMessageLevel, title: impl Into<String>, body: impl Into<String>);
+
+    fn alert(error: &Error) {
+        let mut errs = error.chain();
+        let title = format!("Error: {}", errs.next().unwrap());
+        let mut message = title.clone();
+        for err in errs {
+            write!(message, "\n  Caused by: {}", err).unwrap();
+        }
+        log::error!("{}", message);
+        Self::message(DialogMessageLevel::Error, title, message);
+    }
+}
+
+// TODO: Consider to set parent window of dialog. rfd provides `set_parent` methods to dialogs.
+
 pub struct SystemDialog;
 
 impl Dialog for SystemDialog {
-    fn pick_file(&self, dir: &Path, extensions: &FileExtensions) -> Option<PathBuf> {
+    fn pick_file(dir: &Path, extensions: &FileExtensions) -> Option<PathBuf> {
         FileDialog::new()
             .add_filter("Markdown", extensions.as_slice())
             .set_directory(dir)
             .pick_file()
     }
 
-    fn pick_dir(&self, dir: &Path) -> Option<PathBuf> {
+    fn pick_dir(dir: &Path) -> Option<PathBuf> {
         FileDialog::new().set_directory(dir).pick_folder()
     }
 
-    fn alert(&self, title: impl Into<String>, message: impl Into<String>) {
+    fn message(level: DialogMessageLevel, title: impl Into<String>, body: impl Into<String>) {
+        let level = match level {
+            DialogMessageLevel::Error => MessageLevel::Error,
+        };
         MessageDialog::new()
-            .set_level(MessageLevel::Error)
+            .set_level(level)
             .set_title(title.into())
-            .set_description(message.into())
+            .set_description(body.into())
             .show();
     }
 }

v2/src/renderer.rs

@@ -209,6 +209,6 @@ pub trait Rendering: Sized {
 pub trait EventHandler {
     fn handle_user_event(&mut self, event: UserEvent) -> Result<RenderingFlow>;
     fn handle_menu_event(&mut self, item: MenuItem) -> Result<RenderingFlow>;
-    fn handle_exit(&self) -> Result<()>;
-    fn handle_error(&self, err: Error) -> RenderingFlow;
+    fn handle_exit(&mut self) -> Result<()>;
+    fn handle_error(&mut self, err: Error) -> RenderingFlow;
 }

v2/src/shiba.rs

@@ -10,8 +10,8 @@ use crate::renderer::{
 use crate::watcher::{PathFilter, Watcher};
 use anyhow::{Context as _, Error, Result};
 use std::collections::VecDeque;
-use std::fmt::Write as _;
 use std::fs;
+use std::marker::PhantomData;
 use std::mem;
 use std::path::{Path, PathBuf, MAIN_SEPARATOR};
 
@@ -189,17 +189,6 @@ impl PreviewContent {
     }
 }
 
-fn alert_error<D: Dialog>(dialog: &D, error: &Error) {
-    let mut errs = error.chain();
-    let title = format!("Error: {}", errs.next().unwrap());
-    let mut message = title.clone();
-    for err in errs {
-        write!(message, "\n  Caused by: {}", err).unwrap();
-    }
-    log::error!("{}", message);
-    dialog.alert(title, message);
-}
-
 pub struct Shiba<R: Rendering, O, W, D> {
     renderer: R::Renderer,
     opener: O,
@@ -208,7 +197,7 @@ pub struct Shiba<R: Rendering, O, W, D> {
     config: Config,
     preview: PreviewContent,
     init_file: Option<PathBuf>,
-    dialog: D,
+    _dialog: PhantomData<D>,
 }
 
 impl<R, O, W, D> Shiba<R, O, W, D>
@@ -224,7 +213,7 @@ where
     {
         fn on_err<D: Dialog>(err: Error) -> Error {
             let err = err.context("Could not launch application");
-            alert_error(&D::default(), &err);
+            D::alert(&err);
             err
         }
         let mut rendering = R::new().map_err(on_err::<D>)?;
@@ -262,7 +251,7 @@ where
             config,
             preview: PreviewContent::default(),
             init_file,
-            dialog: D::default(),
+            _dialog: PhantomData,
         })
     }
 
@@ -310,7 +299,7 @@ where
     fn open_file(&mut self) -> Result<()> {
         let extensions = self.config.watch().file_extensions();
         let dir = self.config.dialog().default_dir()?;
-        let file = self.dialog.pick_file(&dir, extensions);
+        let file = D::pick_file(&dir, extensions);
         #[cfg(windows)]
         let file = file.and_then(|p| p.canonicalize().ok()); // Ensure \\? at the head of the path
 
@@ -324,7 +313,7 @@ where
 
     fn open_dir(&mut self) -> Result<()> {
         let dir = self.config.dialog().default_dir()?;
-        let dir = self.dialog.pick_dir(&dir);
+        let dir = D::pick_dir(&dir);
         #[cfg(windows)]
         let dir = dir.and_then(|p| p.canonicalize().ok()); // Ensure \\? at the head of the path
 
@@ -511,7 +500,7 @@ where
         Ok(RenderingFlow::Continue)
     }
 
-    fn handle_exit(&self) -> Result<()> {
+    fn handle_exit(&mut self) -> Result<()> {
         log::debug!("Handling application exit");
         let data_dir = self.config.data_dir();
         if self.config.window().restore {
@@ -524,8 +513,8 @@ where
         Ok(())
     }
 
-    fn handle_error(&self, err: Error) -> RenderingFlow {
-        alert_error(&self.dialog, &err);
+    fn handle_error(&mut self, err: Error) -> RenderingFlow {
+        D::alert(&err);
         RenderingFlow::Continue
     }
 }