export declare function convertCopyString(selectionString: string, patterns: Array<string> | null): string;
/**
 * Helper function that builds a pattern array from the selected text nodes.
 * Extracts patterns from data-pattern attributes and skips data-expression nodes.
 *
 * Returns the pattern and the raw selected text.
 *
 * Both getRangeAt(0)+intersectsNode and selection.containsNode are unreliable for detecting which nodes are visually
 * selected when the selection spans multiple contenteditable elements. Instead, we use the treeWalker to go over all
 * nodes in the inputgroup, accumulating text and patterns while filtering out nodes that don't align with the
 * value type (e.g. skipping spin button nodes when in expression mode).
 * `contenteditable` needs to stay on the elements to avoid losing the focused element.
 * @internal
 */
export declare function getPatternAndSelectedText(selection: Selection): {
    pattern: string[] | null;
    text: string;
};
/**
 * Builds the clipboard text for the current selection by converting the selected
 * spin-button / expression values into a valid timeframe string.
 * Returns null if there is no selection or it does not belong to an inputgroup.
 * @internal
 */
export declare function buildTimeframeClipboardText(): string | null;
/**
 * Helper function that tries to parse parts of the current selection as valid time frames
 * and if successful, copies the correctly parsed ISO timestamp or timeframe to the clipboard.
 * Must be called from a native `copy` ClipboardEvent handler so that `clipboardEvent.clipboardData`
 * is available for synchronous writing.
 * @internal
 */
export declare function onTimeframeCopyCapture(clipboardEvent: Pick<ClipboardEvent, 'preventDefault' | 'clipboardData'>): void;