js 的 mouseDown mouseMove 在手機上不能使用的解法

因為手機上使用的 event 是 touchStart 和 touchMove

國外的神人有解，下面是註冊 touch 事件再轉發 mouse 事件的程式

var mouseEventTypes = {
touchstart : "mousedown",
touchmove : "mousemove",
touchend : "mouseup"
};

for (originalType in mouseEventTypes) {
document.addEventListener(originalType, function(originalEvent) {
event = document.createEvent("MouseEvents");
touch = originalEvent.changedTouches[0];
event.initMouseEvent(mouseEventTypes[originalEvent.type], true, true,
window, 0, touch.screenX, touch.screenY, touch.clientX,
touch.clientY, touch.ctrlKey, touch.altKey, touch.shiftKey,
touch.metaKey, 0, null);
originalEvent.target.dispatchEvent(event);
});
}