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@webcss
Last active May 26, 2020 15:34
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mithril-touch, consume touch and mouse events evenly with mithril
/*****************************************
/* DOM touch support module
/*****************************************/
if (!window.CustomEvent) {
window.CustomEvent = function (event, params) {
params = params || { bubbles: false, cancelable: false, detail: undefined };
var evt = document.createEvent('CustomEvent');
evt.initCustomEvent(event, params.bubbles, params.cancelable, params.detail);
return evt;
};
window.CustomEvent.prototype = window.Event.prototype;
}
(function(document) {
var TAPTRESHOLD = 200, // time within a double tap should have happend
TAPPRECISION = 60 / 2, // distance to identify a swipe gesture
touch = { },
tapCount = 0, // counts the number of touchstart events
tapTimer = 0, // timer to detect double tap
isTouchSwipe = false, // set to true whenever
absolute = Math.abs,
touchSupported = 'ontouchstart' in window;
function parentIfText (node) {
return 'tagName' in node ? node : node.parentNode;
}
function dispatchEvent(type, touch) {
if(touchSupported) {
touch.originalEvent.preventDefault();
touch.originalEvent.stopImmediatePropagation();
}
var event = new CustomEvent(type, {
detail: touch,
bubbles: true,
cancelable: true
});
touch.target.dispatchEvent(event);
console.log(type);
touch = { };
tapCount = 0;
return event;
}
function touchStart(e) {
if( !touchSupported || e.touches.length === 1) {
var coords = e.targetTouches ? e.targetTouches[0] : e;
touch = {
originalEvent: e,
target: parentIfText(e.target),
x1: coords.pageX,
y1: coords.pageY,
x2: coords.pageX,
y2: coords.pageY
};
isTouchSwipe = false;
tapCount++;
if (!e.button || e.button === 1) {
clearTimeout(tapTimer);
tapTimer = setTimeout(function() {
if(absolute(touch.x2 - touch.x1) < TAPPRECISION &&
absolute(touch.y2 - touch.y2) < TAPPRECISION &&
!isTouchSwipe) {
dispatchEvent((tapCount===2)? 'dbltap' : 'tap', touch);
clearTimeout(tapTimer);
}
tapCount = 0;
}, TAPTRESHOLD);
}
}
}
function touchMove(e) {
var coords = e.changedTouches ? e.changedTouches[0] : e;
isTouchSwipe = true;
touch.x2 = coords.pageX;
touch.y2 = coords.pageY;
/* the following is obsolete since at least chrome handles this
// if movement is detected within 200ms from start, preventDefault to preserve browser scroll etc.
// if (touch.target &&
// (absolute(touch.y2 - touch.y1) <= TAPPRECISION ||
// absolute(touch.x2 - touch.x1) <= TAPPRECISION)
// ) {
// e.preventDefault();
// touchCancel(e);
// }
*/
}
function touchCancel(e) {
touch = {};
tapCount = 0;
isTouchSwipe = false;
}
function touchEnd(e) {
var distX = touch.x2 - touch.x1,
distY = touch.y2 - touch.y1,
absX = absolute(distX),
absY = absolute(distY);
// use setTimeout here to register swipe over tap correctly,
// otherwise a tap would be fired immediatly after a swipe
setTimeout(function() {
isTouchSwipe = false;
},0);
// if there was swipe movement, resolve the direction of swipe
if(absX || absY) {
if(absX > absY) {
dispatchEvent((distX<0)? 'swipeleft': 'swiperight', touch);
} else {
dispatchEvent((distY<0)? 'swipeup': 'swipedown', touch);
}
}
}
document.addEventListener(touchSupported ? 'touchstart' : 'mousedown', touchStart, false);
document.addEventListener(touchSupported ? 'touchmove' : 'mousemove', touchMove, false);
document.addEventListener(touchSupported ? 'touchend' : 'mouseup', touchEnd, false);
// on touch devices, the taphold complies with contextmenu
document.addEventListener('contextmenu', function(e) {
e.preventDefault();
e.stopImmediatePropagation();
dispatchEvent('taphold', {
originalEvent: e,
target: parentIfText(e.target)
});
}, false);
if (touchSupported) {
document.addEventListener('touchcancel', touchCancel, false);
}
}(window.document));
m.touchHelper = function(options) {
return function(element, initialized, context) {
if (!initialized) {
Object.keys(options).forEach(function(touchType) {
element.addEventListener(touchType, options[touchType], false);
});
context.onunload = function() {
Object.keys(options).forEach(function(touchType) {
element.removeEventListener(touchType, options[touchType], false);
});
};
}
};
};
@hnakamur
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@webcss Thanks for sharing a nice library! Could you tell us what is the license for this library and https://gist.github.com/webcss/98fba43578c2954dd5cb#file-eventsmixin-js ? MIT would be great. Thanks!

@hieunc229
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@webcss thanks for great library
Is there anyway that trigger redraw after event tap is fired?

Thank you!

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