getting touchy - an introduction to touch and pointer events / future of web apps / london...
TRANSCRIPT
mouseover > mousemove* > mousedown >
(focus) > mouseup > click
mouseover > mousemove > mousedown >
(focus) > mouseup > click
mousemove > mousedown > (focus) >
mouseup > click
mouseout > (blur)
focus/blur
mouseout
touchstart
touchmove
touchend
touchcancel
touchenter
touchleave
touchstart > [touchmove]+ > touchend >
mouseover > mousemove > mousedown >
(focus) > mouseup > click
touchstart > [touchmove]+ > touchend > mouseover >
mousemove > mousedown > (focus) > mouseup > click
touchstart > [touchmove]+ > touchend > mousemove >
mousedown > (focus) > mouseup > click
mouseout > (blur)
touchmove touchend
touchmove
mouseover > mousemove > touchstart > touchend > mousedown >
mouseup > click
touchstart > mouseover > mousemove > mousedown > touchend >
mouseup > click
if ('ontouchstart' in window) {
/* some clever stuff here */
}
/* common performance “trick” */
var clickEvent = ('ontouchstart' in window ?
'touchend' : 'click');
blah.addEventListener(clickEvent,
function() { ... }, false);
if ('ontouchstart' in window) {
/* browser supports touch events
but user is not necessarily
using touch (exclusively) */
}
touchstart > touchend > mouseover > mousemove > mousedown > mouseup > click
mouseover > mousedown > mousemove > mouseup > click
focus > click
focus > touchstart > touchend > mouseover > mousemove > mousedown
blur > mouseup > click
focus > touchstart > touchend > mouseover > mousemove > mousedown
blur > mouseup > click
focus > blur > mousedown > mouseup > click > focus(?)
/* doubled-up event listeners */
foo.addEventListener('touchstart',
someFunction, false);
foo.addEventListener('click',
someFunction, false);
/* doubled-up event listeners */
foo.addEventListener('touchstart',
function(e) {
/* prevent delay+mouse events */
e.preventDefault();
someFunction();
/* or even e.target.click(); */
}, false);
foo.addEventListener('click',
someFunction, false);
preventDefault
touchstart > [touchmove]+ > touchend >
mouseover > mousemove* > mousedown >
(focus) > mouseup > click
mousemove touchmove
var posX, posY;
...
function positionHandler(e) {
posX = e.clientX;
posY = e.clientY;
}
...
canvas.addEventListener('mousemove',
positionHandler, false);
var posX, posY;
...
function positionHandler(e) {
/* handle both mouse and touch? */
}
...
canvas.addEventListener('mousemove',
positionHandler, false);
canvas.addEventListener('touchmove',
positionHandler, false);
interface MouseEvent : UIEvent {
readonly attribute long screenX;
readonly attribute long screenY;
readonly attribute long clientX;
readonly attribute long clientY;
readonly attribute boolean ctrlKey;
readonly attribute boolean shiftKey;
readonly attribute boolean altKey;
readonly attribute boolean metaKey;
readonly attribute unsigned short button;
readonly attribute EventTarget
relatedTarget;
void initMouseEvent(...);
};
interface TouchEvent : UIEvent {
readonly attribute TouchList touches;
readonly attribute TouchList targetTouches;
readonly attribute TouchList changedTouches;
readonly attribute boolean altKey;
readonly attribute boolean metaKey;
readonly attribute boolean ctrlKey;
readonly attribute boolean shiftKey;
};
interface Touch {
readonly attribute long identifier;
readonly attribute EventTarget target;
readonly attribute long screenX;
readonly attribute long screenY;
readonly attribute long clientX;
readonly attribute long clientY;
readonly attribute long pageX;
readonly attribute long pageY;
};
var posX, posY;
...
function positionHandler(e) {
if ((e.clientX)&&(e.clientY)) {
posX = e.clientX;
posY = e.clientY;
} else if (e.targetTouches) {
posX = e.targetTouches[0].clientX;
posY = e.targetTouches[0].clientY;
e.preventDefault();
}
}
...
canvas.addEventListener('mousemove',
positionHandler, false );
canvas.addEventListener('touchmove',
positionHandler, false );
touchmove
touchmove
requestAnimationFrame
setInterval
interface TouchEvent : UIEvent {
readonly attribute TouchList touches;
readonly attribute TouchList targetTouches;
readonly attribute TouchList changedTouches;
readonly attribute boolean altKey;
readonly attribute boolean metaKey;
readonly attribute boolean ctrlKey;
readonly attribute boolean shiftKey;
};
for (i=0; i<e.targetTouches.length; i++) {
...
posX = e.targetTouches[i].clientX;
posY = e.targetTouches[i].clientY;
...
}
preventDefault()
preventDefault()
/* iOS/Safari has gesture events for size/rotation,
not supported in Chrome/Firefox/Opera,
not part of the W3C Touch Events spec. */
gesturestart, gesturechange, gestureend
e.scale, e.rotation
/* with some trigonometry we can replicate these
from basic principles. */
var distance = Math.sqrt(Math.pow(...)+Math.pow(...));
var angle = Math.atan2(...);
pointerover > mouseover >
pointerdown > mousedown >
pointermove > mousemove >
(focus) >
pointerup > mouseup >
pointerout > mouseout >
click
pointerenter
pointerleave
gotpointercapture
lostpointercapture
MSPointerDown
MSPointerMove
MSPointerUp
navigator.msPointerEnabled
navigator.msMaxTouchPoints
-ms-touch-action
interface MouseEvent : UIEvent {
readonly attribute long screenX;
readonly attribute long screenY;
readonly attribute long clientX;
readonly attribute long clientY;
readonly attribute boolean ctrlKey;
readonly attribute boolean shiftKey;
readonly attribute boolean altKey;
readonly attribute boolean metaKey;
readonly attribute unsigned short button;
readonly attribute EventTarget
relatedTarget;
void initMouseEvent(...);
};
/* Pointer Events extend Mouse Events
vs Touch Events and their completely new objects/arrays */
interface PointerEvent : MouseEvent {
readonly attribute long pointerId;
readonly attribute long width;
readonly attribute long height;
readonly attribute float pressure;
readonly attribute long tiltX;
readonly attribute long tiltY;
readonly attribute DOMString pointerType;
readonly attribute boolean isPrimary;
};
preventDefault()
pointerdown
touch-action: auto|none|[pan-x][pan-y]
touch-action:none
touch-action:none
touch-action:none
/* PointerEvents don't have the handy touch arrays,
so we have to replicate something similar... */
/* PointerEvents don't have the handy touch arrays,
so we have to replicate something similar... */
var points = [];
switch (e.type) {
case 'pointerdown':
/* add to the array */
break;
case 'pointermove':
/* update the relevant array entry's x and y */
break;
case 'pointerup':
/* remove the relevant array entry */
break;
}
/* like iOS/Safari, IE10/Win has higher-level gestures,
but these are not part of the W3C Pointer Events spec.
Replicate these from basic principles again? */
