ios-utils.ts

export function isIOS() {
  // deprecated api but still exists in mobile safari for now
  if (navigator.platform) {
    return (
      [
        "iPad Simulator",
        "iPhone Simulator",
        "iPod Simulator",
        "iPad",
        "iPhone",
        "iPod",
      ].includes(navigator.platform) ||
      // iPad on iOS 13 detection
      (navigator.userAgent.includes("Mac") && "ontouchend" in document)
    );
  }

  // weak test
  return (
    /iPad|iPhone|iPod/.test(navigator.userAgent) &&
    window.navigator.vendor === "Apple Computer, Inc."
  );
}

export function disableIOSPinchZoom() {
  if (isIOS()) {
    // disable pinch zoom
    document.addEventListener(
      "touchmove",
      function (event: any) {
        if (event.scale !== 1) {
          event.preventDefault();
        }
      },
      { passive: false }
    );
  }
}

export function disableIOSDoubleTapZoom() {
  if (isIOS()) {
    // disable double tap to zoom
    let lastTouchEnd = 0;
    document.addEventListener(
      "touchend",
      function (event: any) {
        const now = new Date().getTime();
        if (now - lastTouchEnd <= 300) {
          event.preventDefault();
        }
        lastTouchEnd = now;
      },
      false
    );
  }
}

export function disableIOSZoom() {
  disableIOSPinchZoom();
  disableIOSDoubleTapZoom();
}