I have an issue with zooming. I want to block pinch to zoom in Mobile Safari on HTML elements. I use script to prevent default behavior of browser and it is working fine for normal pinching, but when I start scroll with one finger and later add second and pinch Safari still zooming the page...
Has anyone any idea how can I block this zooming?
I'am creating mobile game using canvas and use HTML for message windows so please don't write that it is a bad idea to block zooming for accessibility reasons.
Code to prevent zooming:
document.addEventListener("touchmove", function(event) {
event = event.originalEvent || event;
if(event.touches.length > 1 || event.scale > 1) {
event.preventDefault();
}
}, false);
UPDATE:
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no" />
This meta tag doesn't work because Apple disable it in Mobile Safari since iOS 10 up to accessibility reasons
can you test it?
document.documentElement.addEventListener('touchmove', function (event) {
event.preventDefault();
}, false);
Related
This question has been asked in a couple different flavors, but none satisfy.
The native browser (Google Chrome for Mac, for instance) supports the "pinch to zoom" gesture by default which will zoom the whole viewport. How do I disable (react to) this default behavior so I can write my own pinching/zooming logic? Google Maps https://maps.google.com/ seems to have achieved this since pinching on the map will only scale the map area, leaving the rest of the UI intact, while pinching on the left sidebar shows the default behavior.
I have tried a few approaches such as HTML "viewport" meta tag, CSS touch-action: none; and JavaScript document.addEventListener('touchmove', e => { e.preventDefault() }), but they all seem to only work on mobile.
I accidentally found a solution which works on Chrome. You basically have to preventDefault the "wheel" event. ctrlKey will be true if it is a pinch event instead of a scroll.
element.addEventListener('wheel', event => {
const { ctrlKey } = event
if (ctrlKey) {
event.preventDefault();
return
}
}, { passive: false })
I'd guess this is how Google Maps does it.
The (most) cross-browser solution is probably a combination of the techniques mentioned: user-scalable=no in the "viewport" meta tag for the browsers that do support it and this one for native Chrome.
Use this meta tag:
<meta name='viewport' content='width=device-width, height=device-height, initial-scale:1, user-scalable=no' />
I'm no expert in javascript/jquery and have searched and searched to find an answer to my situation. Some answers have been close but I'm not sure how to translate it to my own situation.
I have a form on my website which conveniently zooms in on mobile devices for the user to input their data. After they hit 'submit' the screen zoom remains the same and the post-submit message is not seen since it's out of the viewport.
Is there a way to reset the screen zoom after form submission?
I've found the metatag 'viewport' and can change that so that the zoom function doesn't trigger at all
<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1" />
but I'd still like the zoom function to be there...
You can update viewport on form submit, like:-
element.on('submit', function(event) {
var viewportmeta = document.querySelector('meta[name="viewport"]');
if (viewportmeta) {
viewportmeta.setAttribute('content', 'width=device-width, maximum-scale=1.0, initial-scale=1.0');
}
}
Try this.
I’ve tried the following approach:
<meta name="viewport" content="width=device-width, minimal-ui">
and
window.addEventListener('load', function() {
setTimeout(scrollTo, 0, 0, 1);
}, false);
But it hasn’t worked. Could you advise something on this?
The best solution I found is this one. Basically make your content higher than viewport and it would become fullscreen (Hiding toolbars) when switching to landscape. Not perfect but usable.
Is there anyway to disable the pinch zooming available on mac's touchpad on the desktop?
I tried adding:
<meta content='True' name='HandheldFriendly' />
<meta content='width=device-width; initial-scale=1.0; maximum-scale=1.0; user-scalable=0;' name='viewport' />
but this did nothing. Thanks!
I faced similar problem where I wanted to disable pinch-zoom gesture on windows machine, here's javascript code snippet that worked for me
window.addEventListener('wheel', (e) => {
if (e.ctrlKey) {
e.preventDefault();
}
}, {
"passive": false
});
FYI - Along with disabling the pinch-zoom functionality it also disables ctrl+mouse wheel up/down event functionality.
jsbin POC
I've encountered similar problems before and could never really understand the workarounds, and so I ended up relying on plugins like iScroll. This is such simple task that I refuse to include a plugin for it - what I want is to prevent horizontal scroll in iOS. This includes the rubber band effect for any content that might be on the page but that isn't visible.
From what I understand I need to disable the rubber band altogether first and then apply the touch scroll to a container element (which I've given the id "touch"). Not sure if this is the right approach?
$(document).bind('touchmove', function(e) {
if (!e.target == '#touch') {
e.preventDefault();
}
});
Style for #touch
-webkit-overflow-scrolling: touch;
overflow: hidden;
height: 100%;
#media only screen and (max-width: 768px) {
width: 768px;
}
This doesn't prevent the horizontal width from staying at 728px however, the user is still able to scroll and see the hidden content. Ideas?
Well, the above metas are useful as such:
<meta content="yes" name="apple-mobile-web-app-capable" />
<meta content="minimum-scale=1.0, width=device-width, maximum-scale=1, user-scalable=no" name="viewport" />
They prevent that bug in Safari that happens when the user rotates the screen. However, the most proper way to accomplish the desired functionality is:
Use a parent div with overflow hidden and make sure the height of this div is limited according to the viewport and a child div with overflow:auto or the css 3 overflow-y:scroll. So basically if the size of the content inside the child div exceeds the default size of the child, you can vertically/horizontally scroll through it. Because the parent has overflow:hidden, the content outside of the child will not be displayed, so you get a proper scroll effect. ** Also, if you use overflow: hidden and prevent default for all touchEvents, there will be no scrolling or weird browser behavior**
With the help of JavaScript, make sure that every element in the DOM is scaled according to the viewport, so avoid using static sizes for as many elements as possible.
Bind the touchStart, touchMove and touchEnd events. Safari doesn't always fire a touchEnd event unless a touchMove event is listened for as well. Even if it's just a placeholder, put it there to avoid the inconsistent behavior in Safari.
Horizontal sliding is possible in two ways: load new content in the same div after you detect the slide direction or populate that child div with all the elements and you are good to go and actually shifting the margins/position of the child inside it's parent to 'scroll'. Animation can be used for a slicker interface.
Bind your touch event listeners. I don't know what library or event management system you are using, but it doesn't matter. Just call the respective function for the respective task.
Get the slide direction(left/right):
var slideBeginX;
function touchStart(event){event.preventDefault();//always prevent default Safari actions
slideBeginX = event.targetTouches[0].pageX;
};
function touchMove(event) {
event.preventDefault();
// whatever you want to add here
};
function touchEnd(event) {
event.preventDefault();
var slideEndX = event.changedTouches[0].pageX;
// Now add a minimum slide distance so that the links on the page are still clickable
if (Math.abs(slideEndX - slideBeginX) > 200) {
if (slideEndX - slideBeginX > 0) {
// It means the user has scrolled from left to right
} else {
// It means the user has scrolled from right to left.
};
};
};
This work for me on Android, iPhone and iPad.
<!doctype html>
<html>
<head>
<meta content="yes" name="apple-mobile-web-app-capable" />
<meta content="minimum-scale=1.0, width=device-width, maximum-scale=1, user-scalable=no" name="viewport" />
<title>Main</title>
</head>
<body>
...
</body>
</html>
Following link might be useful to you, here vertical is disabled and horizontal enabled, you just need to tweak the code a little for your purpose.
jquery-tools-touch-horizontal-only-disable-vertical-touch
In case you aren't concerned about vertical sliding, you can try the following code also -
document.ontouchmove = function(e){
e.preventDefault();
}
Hope it helps.
If you dont use the meta you will always get a rubber band effect.
<meta name="viewport" content="width=device-width" />
Even if the page fitted exactly the user would still be able to stretch the page wider than it should be able to go, you must use the view port to prevent this, there is no other way...