checking if touchend comes after a drag
Use two listeners:
First set a variable to false:
var dragging = false;
Then ontouchmove set dragging to true
$("body").on("touchmove", function(){
dragging = true;
});
Then on drag complete, check to see if dragging is true, and if so count it as a dragged touch:
$("body").on("touchend", function(){
if (dragging)
return;
// wasn't a drag, just a tap
// more code here
});
The touch end will still fire, but will terminate itself before your tap script is run.
To ensure the next time you touch it isn't already set as dragged, reset it back to false on touch down.
$("body").on("touchstart", function(){
dragging = false;
});
Looks like one solution to my problem is found here:
http://alxgbsn.co.uk/2011/08/16/event-delegation-for-touch-events-in-javascript/
This bit of code detects any move after touchstart in order to abort tap behavior after tapend.
var tapArea, moved, startX, startY;
tapArea = document.querySelector('#list'); //element to delegate
moved = false; //flags if the finger has moved
startX = 0; //starting x coordinate
startY = 0; //starting y coordinate
//touchstart
tapArea.ontouchstart = function(e) {
moved = false;
startX = e.touches[0].clientX;
startY = e.touches[0].clientY;
};
//touchmove
tapArea.ontouchmove = function(e) {
//if finger moves more than 10px flag to cancel
//code.google.com/mobile/articles/fast_buttons.html
if (Math.abs(e.touches[0].clientX - startX) > 10 ||
Math.abs(e.touches[0].clientY - startY) > 10) {
moved = true;
}
};
//touchend
tapArea.ontouchend = function(e) {
e.preventDefault();
//get element from touch point
var element = e.changedTouches[0].target;
//if the element is a text node, get its parent.
if (element.nodeType === 3) {
element = element.parentNode;
}
if (!moved) {
//check for the element type you want to capture
if (element.tagName.toLowerCase() === 'label') {
alert('tap');
}
}
};
//don't forget about touchcancel!
tapArea.ontouchcancel = function(e) {
//reset variables
moved = false;
startX = 0;
startY = 0;
};
More here: https://developers.google.com/mobile/articles/fast_buttons