flxzt/rnote · warning

Tried to open unsupported file type

Error message

Tried to open unsupported file type

What it means

FileType::lookup_file_type classifies the input file by extension/content. If it yields FileType::Unsupported, try_open_file explicitly returns this error because the file dispatcher has no branch to handle it.

Solutions

1. Check the extension against the supported list (rnote/xopp/svg/pdf/images/text) before invoking open; only register supported types as handlers in the desktop file.
2. Convert unsupported formats externally first (e.g. xopp-to-rnote converters, export PDF/images to supported types).
3. In the app, replace the raw error with a user dialog listing supported formats so the failure is actionable.
4. If the file actually is supported but misdetected, verify the extension or fix FileType::lookup_file_type detection.

Example fix

// before
FileType::Unsupported => {
    return Err(anyhow::anyhow!("Tried to open unsupported file type"));
}
// after
FileType::Unsupported => {
    dialogs::app::dialog_message(
        self,
        &gettext("Unsupported file"),
        &gettext("Supported: .rnote, .xopp, .svg, images, PDF, text."),
    );
    return Ok(false);
}

// rust
let ft = FileType::lookup_file_type(&file);
if matches!(ft, FileType::Unsupported) {
    eprintln!("{:?} is not a supported type (rnote/xopp/svg/images/pdf/text/folder)", file.uri());
}
// shell
case "${file##*.}" in rnote|xopp|svg|png|jpg|jpeg|pdf|txt|md) ;; *) echo unsupported ;; esac

fn is_supported(f: &gio::File) -> bool { !matches!(FileType::lookup_file_type(f), FileType::Unsupported) }

match appwindow.try_open_file(&file, pos, new_tab).await {
    Ok(v) => v,
    Err(e) if e.to_string().contains("unsupported file type") => {
        dialogs::app::dialog_message(&appwindow, &gettext("Unsupported"), &e.to_string());
        false
    }
    Err(e) => return Err(e),
}

When it happens

Trigger: open_file_w_dialogs -> try_open_file with a file whose type detection resolves to FileType::Unsupported — any path not matching .rnote, xopp, vector image, bitmap image, PDF, plaintext, or folder extensions.

Common situations: Associating arbitrary file types with rnote in the OS and double-clicking them; passing a binary or unknown extension via CLI; opening files with wrong/missing extensions (e.g. .zip) expecting import.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

• Failed to get filename from rnote_file
• Creating Pdf instance failed, Err
• no page at index
• Stroke has empty widths vector.
• Could not generate pen path from coordinates vector

AI-assisted analysis of flxzt/rnote@bbc5354502 (2026-09-08). Data as JSON: /api/errors/b709f374fbe54574. Report an issue: GitHub.

Appendix: source

Thrown at crates/rnote-ui/src/appwindow/mod.rs:702

                let canvas = self
                    .active_tab_wrapper()
                    .ok_or_else(|| anyhow::anyhow!("No active tab to import into"))?
                    .canvas();
                let (bytes, _) = input_file.load_bytes_future().await?;
                canvas.load_in_text(String::from_utf8(bytes.to_vec())?, target_pos)?;
                true
            }
            FileType::Folder => {
                if let Some(dir) = input_file.path() {
                    self.sidebar()
                        .workspacebrowser()
                        .workspacesbar()
                        .set_selected_workspace_dir(dir);
                }
                false
            }
            FileType::Unsupported => {
                return Err(anyhow::anyhow!("Tried to open unsupported file type"));
            }
        };

        Ok(file_imported)
    }

    /// Refresh the UI from the global state and from the current active tab page.
    pub(crate) fn refresh_ui(&self) {
        let canvas = self.active_tab_canvas();

        self.overlays().penssidebar().brush_page().refresh_ui(self);
        self.overlays().penssidebar().shaper_page().refresh_ui(self);
        self.overlays()
            .penssidebar()
            .typewriter_page()
            .refresh_ui(self);
        self.overlays().penssidebar().eraser_page().refresh_ui(self);
        self.overlays()

View on GitHub (pinned to bbc5354502)