maplibre-gl/src/ui/anchor.ts

BSD licensed community fork of mapbox-gl, a WebGL interactive maps library

export type PositionAnchor = 'center' | 'top' | 'bottom' | 'left' | 'right' | 'top-left' | 'top-right' | 'bottom-left' | 'bottom-right';

export const anchorTranslate: {
    [_ in PositionAnchor]: string;
} = {
    'center': 'translate(-50%,-50%)',
    'top': 'translate(-50%,0)',
    'top-left': 'translate(0,0)',
    'top-right': 'translate(-100%,0)',
    'bottom': 'translate(-50%,-100%)',
    'bottom-left': 'translate(0,-100%)',
    'bottom-right': 'translate(-100%,-100%)',
    'left': 'translate(0,-50%)',
    'right': 'translate(-100%,-50%)'
};

export function applyAnchorClass(element: HTMLElement, anchor: PositionAnchor, prefix: string) {
    const classList = element.classList;
    for (const key in anchorTranslate) {
        classList.remove(`maplibregl-${prefix}-anchor-${key}`, `mapboxgl-${prefix}-anchor-${key}`);
    }
    classList.add(`maplibregl-${prefix}-anchor-${anchor}`, `mapboxgl-${prefix}-anchor-${anchor}`);
}