I'm trying to implement Google's Fast button for the mobile touch events, and I seem to be stuck. I'm trying to set it up so that I can make links into fastbuttons, but I can't seem to get my library structure right. What ends up happening is the fastbutton re-inits itself when I try to run a for loop on the links.
I'm sure it's just the way I'm setting up the library. Can someone please check it out?
http://code.google.com/mobile/articles/fast_buttons.html
;(function() {
/*Construct the FastButton with a reference to the element and click handler.*/
this.FastButton = function(element, handler) {
console.log('fastbutton init');
this.element = element;
this.handler = handler;
console.log(this);
element.addEventListener('touchstart', this, false);
element.addEventListener('click', this, false);
};
/*acts as an event dispatcher*/
this.FastButton.prototype.handleEvent = function(event) {
console.log(event);
switch (event.type) {
case 'touchstart': this.onTouchStart(event); break;
case 'touchmove': this.onTouchMove(event); break;
case 'touchend': this.onClick(event); break;
case 'click': this.onClick(event); break;
}
};
/*Save a reference to the touchstart coordinate and start listening to touchmove and
touchend events. Calling stopPropagation guarantees that other behaviors don’t get a
chance to handle the same click event. This is executed at the beginning of touch.*/
this.FastButton.prototype.onTouchStart = function(event) {
event.stopPropagation();
this.element.addEventListener('touchend', this, false);
document.body.addEventListener('touchmove', this, false);
this.startX = event.touches[0].clientX;
this.startY = event.touches[0].clientY;
};
/*When /if touchmove event is invoked, check if the user has dragged past the threshold of 10px.*/
this.FastButton.prototype.onTouchMove = function(event) {
if (Math.abs(event.touches[0].clientX - this.startX) > 10 ||
Math.abs(event.touches[0].clientY - this.startY) > 10) {
this.reset(); //if he did, then cancel the touch event
}
};
/*Invoke the actual click handler and prevent ghost clicks if this was a touchend event.*/
this.FastButton.prototype.onClick = function(event) {
event.stopPropagation();
this.reset();
this.handler(event);
if (event.type == 'touchend') {
console.log('touchend');
//clickbuster.preventGhostClick(this.startX, this.startY);
}
};
this.FastButton.prototype.reset = function() {
this.element.removeEventListener('touchend', this, false);
document.body.removeEventListener('touchmove', this, false);
};
this.clickbuster = function() {
console.log('init clickbuster');
}
/*Call preventGhostClick to bust all click events that happen within 25px of
the provided x, y coordinates in the next 2.5s.*/
this.clickbuster.preventGhostClick = function(x, y) {
clickbuster.coordinates.push(x, y);
window.setTimeout(this.clickbuster.pop, 2500);
};
this.clickbuster.pop = function() {
this.clickbuster.coordinates.splice(0, 2);
};
/*If we catch a click event inside the given radius and time threshold then we call
stopPropagation and preventDefault. Calling preventDefault will stop links
from being activated.*/
this.clickbuster.onClick = function(event) {
for (var i = 0; i < clickbuster.coordinates.length; i += 2) {
console.log(this);
var x = clickbuster.coordinates[i];
var y = clickbuster.coordinates[i + 1];
if (Math.abs(event.clientX - x) < 25 && Math.abs(event.clientY - y) < 25) {
event.stopPropagation();
event.preventDefault();
}
}
};
})(this);
document.addEventListener('click', clickbuster.onClick, true);
clickbuster.coordinates = [];
