<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8">
<title>Swipe </title>
<style type="text/css">
body
{
font-family: Helvetica, san-serif;
text-align: center;
font-size:24px;
}
div { padding: 128px 0 0 0; }
</style>
<script type="text/javascript">
// TOUCH-EVENTS SINGLE-FINGER SWIPE-SENSING JAVASCRIPT
// Courtesy of PADILICIOUS.COM and MACOSXAUTOMATION.COM
// this script can be used with one or more page elements to perform actions based on them being swiped with a single finger
var triggerElementID = null; // this variable is used to identity the triggering element
var fingerCount = 0;
var startX = 0;
var startY = 0;
var curX = 0;
var curY = 0;
var deltaX = 0;
var deltaY = 0;
var horzDiff = 0;
var vertDiff = 0;
var minLength = 72; // the shortest distance the user may swipe
var swipeLength = 0;
var swipeAngle = null;
var swipeDirection = null;
// The 4 Touch Event Handlers
// NOTE: the touchStart handler should also receive the ID of the triggering element
// make sure its ID is passed in the event call placed in the element declaration, like:
// <div id="picture-frame" ontouchstart="touchStart(event,'picture-frame');" ontouchend="touchEnd(event);" ontouchmove="touchMove(event);" ontouchcancel="touchCancel(event);">
function touchStart(event,passedName) {
// disable the standard ability to select the touched object
event.preventDefault();
// get the total number of fingers touching the screen
fingerCount = event.touches.length;
// since we're looking for a swipe (single finger) and not a gesture (multiple fingers),
// check that only one finger was used
if ( fingerCount == 1 ) {
// get the coordinates of the touch
startX = event.touches[0].pageX;
startY = event.touches[0].pageY;
// store the triggering element ID
triggerElementID = passedName;
} else {
// more than one finger touched so cancel
touchCancel(event);
}
}
function touchMove(event) {
event.preventDefault();
if ( event.touches.length == 1 ) {
curX = event.touches[0].pageX;
curY = event.touches[0].pageY;
} else {
touchCancel(event);
}
}
function touchEnd(event) {
event.preventDefault();
// check to see if more than one finger was used and that there is an ending coordinate
if ( fingerCount == 1 && curX != 0 ) {
// use the Distance Formula to determine the length of the swipe
swipeLength = Math.round(Math.sqrt(Math.pow(curX - startX,2) + Math.pow(curY - startY,2)));
// if the user swiped more than the minimum length, perform the appropriate action
if ( swipeLength >= minLength ) {
caluculateAngle();
determineSwipeDirection();
processingRoutine();
touchCancel(event); // reset the variables
} else {
touchCancel(event);
}
} else {
touchCancel(event);
}
}
function touchCancel(event) {
// reset the variables back to default values
fingerCount = 0;
startX = 0;
startY = 0;
curX = 0;
curY = 0;
deltaX = 0;
deltaY = 0;
horzDiff = 0;
vertDiff = 0;
swipeLength = 0;
swipeAngle = null;
swipeDirection = null;
triggerElementID = null;
}
function caluculateAngle() {
var X = startX-curX;
var Y = curY-startY;
var Z = Math.round(Math.sqrt(Math.pow(X,2)+Math.pow(Y,2))); //the distance - rounded - in pixels
var r = Math.atan2(Y,X); //angle in radians (Cartesian system)
swipeAngle = Math.round(r*180/Math.PI); //angle in degrees
if ( swipeAngle < 0 ) { swipeAngle = 360 - Math.abs(swipeAngle); }
}
function determineSwipeDirection() {
if ( (swipeAngle <= 45) && (swipeAngle >= 0) ) {
swipeDirection = 'left';
} else if ( (swipeAngle <= 360) && (swipeAngle >= 315) ) {
swipeDirection = 'left';
} else if ( (swipeAngle >= 135) && (swipeAngle <= 225) ) {
swipeDirection = 'right';
} else if ( (swipeAngle > 45) && (swipeAngle < 135) ) {
swipeDirection = 'down';
} else {
swipeDirection = 'up';
}
}
function processingRoutine() {
var swipedElement = document.getElementById(triggerElementID);
if ( swipeDirection == 'left' ) {
window.location.href = 'seite2.html';
} else if ( swipeDirection == 'right' ) {
window.location.href = 'seite1.html';
}
</script>
</head>
<body>
<div id="swipeBox" ontouchstart="touchStart(event,'swipeBox');" ontouchend="touchEnd(event);" ontouchmove="touchMove(event);" ontouchcancel="touchCancel(event);" style="position:relative;width:100%;height:100%;">
<p>Startseite</p>
</div>
</body>
</html>
Schleifen erkennt man am Schlüsselwort "for", "while" oder "do while").
