Enum DevToolsPolicy 

#[non_exhaustive]
pub enum DevToolsPolicy {
    Auto,
    Allowed,
    Disallowed,
}

Whether this application may open a DevTools window at all.

Application-wide, and combined with the per-webview WebviewAttributes::devtools: either one saying no is a no. Both are enforced on the paths this runtime owns — the context menu entries, the F12 and Ctrl+Shift+I chords, the IDC_DEV_TOOLS commands and Webview::open_devtools.

Why it is not Chromium’s own preference

Chromium has a profile preference for exactly this, devtools.availability, and DevToolsWindow::AllowDevToolsFor consults it on every path that opens a DevTools window — including the ones this runtime does not own, such as a Chrome-owned popup. This policy deliberately does not reach for it, and the runtime pins it to its default instead.

CEF gates more than the window on that preference: SendDevToolsMessage is refused on a profile carrying kDisallowed, and refused silently — the send still reports success, and no result or event ever reaches a registered observer. This runtime drives its own startup over the DevTools protocol (the document-start scripts, the per-webview user agent) and holds each webview’s first navigation until that round trip answers, so setting the preference leaves every window stuck on a blank placeholder. A webview’s on_dev_tools_protocol would go silent with it.

So the DevTools protocol stays available whatever this policy says. An application that has to close that path too wants RemoteDebugging, which is what exposes the protocol to anything outside the process.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Auto

Allow DevTools in a build that could open them anyway — a debug build, or one with the devtools feature — and refuse them otherwise.

Allowed

Allow DevTools, whatever the build profile.

Per-webview WebviewAttributes::devtools still applies; this only stops the runtime from refusing DevTools application-wide.

Disallowed

Refuse DevTools, whatever the build profile.

Trait Implementations

impl Clone for DevToolsPolicy

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for DevToolsPolicy

impl Debug for DevToolsPolicy

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for DevToolsPolicy

fn default() -> Self

Returns the “default value” for a type.

impl Eq for DevToolsPolicy

impl PartialEq for DevToolsPolicy

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for DevToolsPolicy