Struct AgentMuxHandler 

pub struct AgentMuxHandler {
    browser_list: Vec<Browser>,
    is_closing: bool,
    state: Arc<AppState>,
    ipc_port: u16,
    is_browser_pane: bool,
}

Core handler state shared across all CEF callback interfaces.

Fields

browser_list: Vec<Browser>

is_closing: bool

state: Arc<AppState>

ipc_port: u16

is_browser_pane: bool

Implementations

impl AgentMuxHandler

pub fn new(state: Arc<AppState>, ipc_port: u16) -> Arc<Mutex<Self>>

pub fn new_with_browser_pane( state: Arc<AppState>, ipc_port: u16, is_browser_pane: bool, ) -> Arc<Mutex<Self>>

fn on_title_change( &mut self, browser: Option<&mut Browser>, title: Option<&CefString>, )

fn on_favicon_urlchange( &mut self, browser: Option<&mut Browser>, icon_urls: Option<&mut CefStringList>, )

fn on_after_created(&mut self, browser: Option<&mut Browser>)

fn do_close(&mut self, _browser: Option<&mut Browser>) -> bool

fn on_before_popup( &mut self, browser: Option<&mut Browser>, _frame: Option<&mut Frame>, target_url: Option<&CefString>, _target_disposition: WindowOpenDisposition, ) -> bool

Intercept target="_blank" / window.open() from embedded pages so they don’t spawn rogue top-level CEF windows. Instead navigate the current frame to the target URL — matches the UX expectation that AgentMux owns window management, not the page.

Returning non-zero cancels popup creation. Applies to both main and pane clients: main’s frontend never relies on window.open (link clicks go through openExternal IPC), and panes explicitly don’t want popups. See specs/SPEC_BROWSER_PANE_DEFAULT_URL_AND_POPUP_2026_04_21.md.

The load_url call is deferred via post_task, not run inline. Inline load_url caused a UI-thread deadlock on link click: on_before_popup runs while AgentMuxLifeSpanHandler holds self.inner.lock() (via the wrap macro). Inline load_url starts a new navigation on the same UI thread, which triggers on_loading_state_change on AgentMuxLoadHandler, which also tries to take self.inner.lock() → deadlock. The host hung with backend heartbeats still running but the whole UI frozen. Posting the load_url as a separate UI task lets the popup handler return, release the lock, then pick up the load on the next loop iteration.

fn on_before_close(&mut self, browser: Option<&mut Browser>)

fn on_loading_state_change( &mut self, browser: Option<&mut Browser>, _is_loading: i32, can_go_back: i32, can_go_forward: i32, )

CEF fires this whenever the browser’s loading/history state changes (navigation started, navigation committed, back/forward enabled). can_go_back / can_go_forward come directly from the navigation controller — no need to query browser.can_go_back() (which races with history commit when called from on_load_end).

For panes: emit browser-pane-nav-state so the frontend address bar + back/forward buttons reflect CEF’s real history state.

fn on_load_end( &mut self, browser: Option<&mut Browser>, frame: Option<&mut Frame>, _http_status_code: i32, )

fn on_load_error( &mut self, _browser: Option<&mut Browser>, frame: Option<&mut Frame>, error_code: Errorcode, error_text: Option<&CefString>, failed_url: Option<&CefString>, )

fn on_render_process_terminated( &mut self, browser: Option<&mut Browser>, status: TerminationStatus, error_code: i32, error_string: Option<&CefString>, )

Render-process terminated — typically OOM, a renderer-side panic, or some native bug inside CEF/Chromium. Without this hook the window just turns white. We log the cause and replace the white page with a recovery HTML page that offers Reload / Quit buttons.

See specs/SPEC_GRACEFUL_CRASH_HANDLING_2026_04_13.md (PR 1).

fn on_auth_credentials( &mut self, browser: Option<&mut Browser>, origin_url: Option<&CefString>, is_proxy: c_int, host: Option<&CefString>, port: c_int, realm: Option<&CefString>, _scheme: Option<&CefString>, callback: Option<&mut AuthCallback>, ) -> c_int

CEF asks the embedder for HTTP Basic / Digest credentials on a 401/407. Browser-pane requests get surfaced to the renderer via browser-pane-auth-required so the user can type credentials; non-browser-pane requests (the main host window’s frontend load) are declined — those shouldn’t hit auth-challenged resources, and silently failing matches the prior behavior.

Returns 1 (async — we’ll resolve the callback via browser_pane_auth_submit / browser_pane_auth_cancel) or 0 (sync no — CEF aborts the request).

Phase α of SPEC_BROWSER_PANE_HTTP_BASIC_AUTH_2026_05_18.md.