Merge pull request 'Filter file dialog error log' (#145) from issue/133 into master

Reviewed-on: #145

crates/dtmm/src/ui/window/dialog.rs

@@ -7,11 +7,14 @@ use crate::ui::widget::button::Button;
 
 const WINDOW_SIZE: (f64, f64) = (600., 250.);
 
+/// Show an error dialog.
+/// The title and message are extracted from the error chain in the given `Report`.
 pub fn error<T: Data>(err: Report, _parent: WindowHandle) -> WindowDesc<T> {
     let (title, msg) = {
         let count = err.chain().count();
 
         if count == 1 {
+            // If there is only one error, that's all we can show.
             (
                 String::from("An error occurred!"),
                 err.root_cause().to_string(),
@@ -20,13 +23,20 @@ pub fn error<T: Data>(err: Report, _parent: WindowHandle) -> WindowDesc<T> {
             let first = err.chain().next().unwrap();
             let root = err.root_cause();
 
+            // If there is more than one error in the chain we want to show
+            // - The first one: This will describe the overall operation that failed
+            // - The root cause: The actual thing that failed (e.g. 'No such file or directory')
+            // - The one before the root cause: With diligent `wrap_err` usage, this will provide
+            // context to the root cause (e.g. the file name we failed to access)
+            //
+            // If there are only two errors, the first one is also the context to the root cause.
             if count > 2 {
                 // The second to last one, the context to the root cause
                 let context = err.chain().nth(count - 2).unwrap();
 
                 (format!("{first}!"), format!("{}: {}", context, root))
             } else {
-                (format!("{first}!"), root.to_string())
+                ("An error occurred!".to_string(), format!("{}: {}", first, root))
             }
         }
     };

crates/dtmm/src/util/log.rs

@@ -56,7 +56,7 @@ impl std::io::Write for ChannelWriter {
 }
 
 pub fn create_tracing_subscriber(tx: UnboundedSender<Vec<u8>>, level: Option<LogLevel>) {
-    let env_layer = if let Some(level) = level {
+    let mut env_layer = if let Some(level) = level {
         EnvFilter::from(level)
     } else if cfg!(debug_assertions) {
         EnvFilter::try_from_default_env().unwrap_or_else(|_| EnvFilter::new("info"))
@@ -64,6 +64,18 @@ pub fn create_tracing_subscriber(tx: UnboundedSender<Vec<u8>>, level: Option<Log
         EnvFilter::new("error,dtmm=info")
     };
 
+    // The internal implementation of Druid's GTK file dialog turns
+    // cancelling the dialog into an error. The, also internal, wrapper
+    // then logs and swallows the error.
+    // Therefore, as a consumer of the library, we don't have any way
+    // to customize this behavior, and instead have to filter out the
+    // tracing event.
+    env_layer = env_layer.add_directive(
+        "druid_shell::backend::gtk::window=off"
+            .parse()
+            .expect("Invalid env filter directive"),
+    );
+
     let stdout_layer = fmt::layer().pretty();
 
     let channel_layer = fmt::layer()