// Get from offsetParent export function offsetXYFromParentOf(evt: MouseEvent): { x: number; y: number } { const offsetParent = (evt.target as HTMLElement).offsetParent || document.body; const offsetParentRect = offsetParent === document.body ? { left: 0, top: 0 } : offsetParent.getBoundingClientRect(); const x = evt.clientX + offsetParent.scrollLeft - offsetParentRect.left; const y = evt.clientY + offsetParent.scrollTop - offsetParentRect.top; /* const x = Math.round(evt.clientX + offsetParent.scrollLeft - offsetParentRect.left); const y = Math.round(evt.clientY + offsetParent.scrollTop - offsetParentRect.top);*/ return { x, y }; } // Get {x, y} positions from event. export function getControlPosition(e: MouseEvent): { x: number; y: number } { return offsetXYFromParentOf(e); } function isNum(num: any): boolean { return typeof num === 'number' && !isNaN(num); } // Create an data object exposed by 's events export function createCoreData( lastX: number, lastY: number, x: number, y: number, ): { deltaX: number; deltaY: number; lastX: number; lastY: number; x: number; y: number } { // State changes are often (but not always!) async. We want the latest value. const isStart = !isNum(lastX); if (isStart) { // If this is our first move, use the x and y as last coords. return { deltaX: 0, deltaY: 0, lastX: x, lastY: y, x, y, }; } // Otherwise calculate proper values. return { deltaX: x - lastX, deltaY: y - lastY, lastX, lastY, x, y, }; }