import { MaybeRefOrGetter, Ref } from '../../node_modules/vue';
/**
 * Resolves the image source to display based on the active Bootstrap color mode.
 *
 * Internal building block for the `ImageMode` component. It observes the
 * `.image-mode-source` descendants rendered by `ImageModeSource`, tracks the
 * color mode of the closest themed ancestor, and picks the matching source URL
 * (falling back to the default-mode source, then to the provided `src`).
 *
 * Not exported from `@icij/murmur-next`: it relies on the `.image-mode-source`
 * DOM convention and is only useful inside `ImageMode`.
 *
 * @param element - Element whose color mode and source descendants are observed.
 * @param defaultColorMode - Color mode to resolve the fallback source from.
 * @param fallbackSrc - Source URL used when no matching color-mode source exists.
 * @returns Reactive `colorMode` and the resolved `src` to render.
 * @example
 * <script setup>
 * import { useImageMode } from '@/composables/useImageMode'
 *
 * const element = useTemplateRef('element')
 * const { colorMode, src } = useImageMode(element, 'light', () => props.src)
 * </script>
 */
export declare function useImageMode(element: Ref<HTMLElement | null>, defaultColorMode?: string, fallbackSrc?: MaybeRefOrGetter<string | undefined>): {
    colorMode: Ref<string, string>;
    src: import('../../node_modules/vue').ComputedRef<string | undefined>;
};