Enum DebugLayer 

pub enum DebugLayer {
    All,
    TopMost,
    BaseOnly,
}

Which layers the F12 debug overlay should outline (issue #201).

All (the default) outlines both the base layer and any active overlays/modals — matching the user’s expectation for “show everything the renderer is producing this frame.” TopMost only outlines the topmost overlay (or the base if no overlay is active), and BaseOnly keeps the legacy pre-fix behavior of skipping overlays entirely.

At runtime, Shift+F12 cycles All → TopMost → BaseOnly → All so a developer debugging a stacked modal can shrink the visible outlines to just the layer they care about without leaving the keyboard. Plain F12 independently toggles the overlay on/off.

Example

use slt::{Context, DebugLayer};

slt::run(|ui: &mut Context| {
    // Match on the current layer to drive bespoke debug UI.
    let label = match ui.debug_layer() {
        DebugLayer::All => "showing base + overlays",
        DebugLayer::TopMost => "showing topmost overlay only",
        DebugLayer::BaseOnly => "showing base layer only",
    };
    ui.text(label);
})
.unwrap();

Variants

All

Outline both the base tree and every active overlay/modal.

Default. Matches the reporter expectation that F12 reflects everything the renderer is producing this frame. Each layer family gets its own hue so a glance distinguishes base, overlay, and modal containers.

TopMost

Outline only the topmost overlay (or the base if no overlay is active).

Useful when modals or popovers stack and you only care about the active dialog — base-tree outlines become noise underneath an open modal.

BaseOnly

Outline only the base layer (legacy v0.19.x behavior).

Skips overlays and modals entirely. Use when an overlay is confirmed correct and you want to inspect the base layout underneath it.

Trait Implementations

impl Clone for DebugLayer

fn clone(&self) -> DebugLayer

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for DebugLayer

impl Debug for DebugLayer

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

Formats the value using the given formatter.

impl Default for DebugLayer

fn default() -> DebugLayer

Returns the “default value” for a type.

impl Eq for DebugLayer

impl PartialEq for DebugLayer

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for DebugLayer