workspace: Improve error handling when dropping a file that cannot be opened into the workspace pane

[ssut]

This PR can improve the UX when dropping a file that cannot be opened into the workspace pane. Previously, nothing happened without any messages when such error occurred, which could be awkward for users. Additionally the pane was being split even though the file failed to open.

Here's a screen recording demonstrating the previous/updated behavior:

zed-1.mp4

Changes:

• It now displays an error message if a file cannot be opened.
• Updated the logic to first try to open the file. The pane splits only if the file opening process is successful.

Release Notes:

• Improved error handling when opening files in the workspace pane. An error message will now be displayed if the file cannot be opened.
• Fixed an issue where unnecessary pane splitting occurred when a file fails to open.

[mrnugget]

Hey! I'm pretty sure you can simplify your code by using this method:

zed/crates/workspace/src/notifications.rs

Lines 585 to 595 in 3f3ed89

	fn notify_err(self, workspace: &mut Workspace, cx: &mut ViewContext<Workspace>) -> Option<T> {
	match self {
	Ok(value) => Some(value),
	Err(err) => {
	log::error!("TODO {err:?}");
	workspace.show_error(&err, cx);
	None
	}
	}
	}

You can see how it's used here:

zed/crates/terminal_view/src/terminal_view.rs

Lines 134 to 139 in 3f3ed89

	let terminal = workspace
	.project()
	.update(cx, |project, cx| {
	project.create_terminal(TerminalKind::Shell(working_directory), window, cx)
	})
	.notify_err(workspace, cx);

[ssut]

Hey! I'm pretty sure you can simplify your code by using this method:

zed/crates/workspace/src/notifications.rs

Lines 585 to 595 in 3f3ed89

	fn notify_err(self, workspace: &mut Workspace, cx: &mut ViewContext<Workspace>) -> Option<T> {
	match self {
	Ok(value) => Some(value),
	Err(err) => {
	log::error!("TODO {err:?}");
	workspace.show_error(&err, cx);
	None
	}
	}
	}

You can see how it's used here:

zed/crates/terminal_view/src/terminal_view.rs

Lines 134 to 139 in 3f3ed89

	let terminal = workspace
	.project()
	.update(cx, |project, cx| {
	project.create_terminal(TerminalKind::Shell(working_directory), window, cx)
	})
	.notify_err(workspace, cx);

Thanks for letting me know, I refactored the code accordingly calling notify_async_err.

[mrnugget]

Works for me! Thanks!
https://github.com/user-attachments/assets/dcd959df-c49b-48f7-a149-5e0f9db97c4a