I am testing a page on an IPad (IOS 14.3) in portrait mode . (see code below)
I am outputting the touched Y-value of the screen.
When I tap the screen near the top the output is near 0 (depending on the thickness of finger).
When I tap the screen near the bottom the output is near 1000.
However when I swipe vertically from the top to bottom the values start from 0 but when I reach the bottom with my finger it stops near 600.
The same issue in the other directory, when I start at the bottom is shows a value around 1000 and when it reaches the top is stops around 300.
It almost seems there are missing 300px in each (vertical) direction.
Note: the X-value (horizontal swipes) is accurate, hence I've excluded it in this example. Also on Android the output from the console.log seems fine.
<!doctype html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1,minimum-scale=1.0, user-scalable=yes">
<style>
body,
html {
position: fixed;
width: 100%;
height: 100%;
margin: 0;
padding 0;
background-color: #AAAAAA;
}
</style>
</head>
<body>
<div style='text-align:center;font-size:25px;width:100px;border:1px solid blue;margin:auto' id='feedback'>Hello</div>
</body>
</html>
<script>
var func = function (e) {
var evt = (typeof e.originalEvent === 'undefined') ? e : e.originalEvent;
var touch = evt.touches[0] || evt.changedTouches[0];
document.getElementById('feedback').textContent = 'top:'+touch.pageY;
};
document.body.addEventListener('touchstart', func);
document.body.addEventListener('touchmove', func);
document.body.addEventListener('touchend', func);
</script>
What is the reason the with swipping vertically I am getting different results than when I touch the screen?
question from:
https://stackoverflow.com/questions/65903149/conflicting-value-for-pagey-on-ipad 与恶龙缠斗过久,自身亦成为恶龙；凝视深渊过久,深渊将回以凝视…
