* Mouse wheel handler. * @param {Object} event
(event)
| 407 | * @param {Object} event |
| 408 | */ |
| 409 | function wheel(event) { |
| 410 | if (!initDone) { |
| 411 | init(); |
| 412 | } |
| 413 | let target = event.target; |
| 414 | // leave early if default action is prevented |
| 415 | // or it's a zooming event with CTRL |
| 416 | if (event.defaultPrevented || event.ctrlKey) { |
| 417 | return true; |
| 418 | } |
| 419 | // leave embedded content alone (flash & pdf) |
| 420 | if ( |
| 421 | isNodeName(activeElement, "embed") || |
| 422 | (isNodeName(target, "embed") && /\.pdf/i.test(target.src)) || |
| 423 | isNodeName(activeElement, "object") || |
| 424 | target.shadowRoot |
| 425 | ) { |
| 426 | return true; |
| 427 | } |
| 428 | let deltaX = -event.wheelDeltaX || event.deltaX || 0; |
| 429 | let deltaY = -event.wheelDeltaY || event.deltaY || 0; |
| 430 | if (isMac) { |
| 431 | if (event.wheelDeltaX && isDivisible(event.wheelDeltaX, 120)) { |
| 432 | deltaX = -120 * (event.wheelDeltaX / Math.abs(event.wheelDeltaX)); |
| 433 | } |
| 434 | if (event.wheelDeltaY && isDivisible(event.wheelDeltaY, 120)) { |
| 435 | deltaY = -120 * (event.wheelDeltaY / Math.abs(event.wheelDeltaY)); |
| 436 | } |
| 437 | } |
| 438 | if (isLinux) { |
| 439 | // issues #148 #176 |
| 440 | let otherModifier = event.ctrlKey || event.altKey || event.metaKey; |
| 441 | if (event.shiftKey && !otherModifier) { |
| 442 | deltaX = deltaX || deltaY; |
| 443 | deltaY = 0; |
| 444 | } |
| 445 | } |
| 446 | // use wheelDelta if deltaX/Y is not available |
| 447 | if (!deltaX && !deltaY) { |
| 448 | deltaY = -event.wheelDelta || 0; |
| 449 | } |
| 450 | // line based scrolling |
| 451 | if (event.deltaMode === 1) { |
| 452 | deltaX *= 40; |
| 453 | deltaY *= 40; |
| 454 | } |
| 455 | // check if it's a touchpad scroll that should be ignored |
| 456 | if (!options.touchpadSupport && isTouchpad(deltaY)) { |
| 457 | return true; |
| 458 | } |
| 459 | let xOnly = deltaX && !deltaY; |
| 460 | let overflowing = overflowingAncestor(target, xOnly); |
| 461 | // nothing to do if there's no element that's scrollable |
| 462 | if (!overflowing) { |
| 463 | // Chrome iframes seem to eat wheel events, which we need to |
| 464 | // propagate up if the iframe has nothing overflowing to scroll |
| 465 | if (isFrame) { |
| 466 | event.preventDefault(); |
no test coverage detected