If you've used a Mac desktop machine, one of the first things you'll notice is that scrolling is different on a Mac than on a Windows desktop.
Windows desktops scrolls in big chunks - multiple lines at a time.
Mac desktops have smooth scrolling - a few pixels at a time.
The difference is pretty obvious when you look at scroll-oriented websites such as http://benthebodyguard.com or http://nikebetterworld.com
Is there a means by which we can control that scroll distance in the browser using javascript?
How the scroll wheel works is dependent on the users configuration of the scroll wheel, and isn't up to you. Users can choose how far the scroll goes.
Even if you were to hack something in place to get this working, I certainly wouldn't recommend it. Not everyone has fast machines that make such smooth scrolling a reasonable task.
You could implement your own scrolling method. Override the default behavior in JS and you'll get the same scrolling in all browsers. $(document).scroll(); should do the trick and do your own calculations and scrolling inside of it.
Related
Mouse Cursor styling, like Col-Resize and Not-Allowed
See Examples Here
do not seem to apply to the mouse that appears on a phone or tablet through USB OTG. Any way to apply CSS, Javascript or other styles to the OTG mouse?
It is actually Android's kernel that doesn't support different mouse cursors. Even in the app IDE's it is impossible to change the cursor without drawing on top of it. People don't typically use mice on mobile devices for Internet browsing therefore that's why it is not implemented.
If you're absolutely looking for a solution, you will have to host your webpage inside an app container with a WebView and use Android's Javascript Communication Interface to detect the mouse hovers, and a System Overlay to draw on top the mouse cursor. It is a difficult implementation but it is the only solution for the specific situation. I can maybe help you out with the implementation if you request.
Happy developing,
According to Mozilla on this page (scroll down to Browser Compatibility and click the Mobile tab) the question, even of which features might be available for a Mouse cursor that doesn't generally appear on Mobile, remains an unknown, or maybe up in the air. As more OTG applications take hold (one thinks of the usefulness of a tailored mouse in certain game environments - crosshairs, anyone?) perhaps the spec will rise to the occasion...
I've been researching how to prevent Safari's feature of swiping at the edge of the screen to navigate to previous/next pages in browser history. I have an application that uses Hammer.js to pan an image, and on mobile the image takes up the whole screen. So if the user happens to start panning at the left edge of the image, for example, it forgoes that by ignoring my little javascript app and instead going to the previous page. I haven't found anything saying it is actually possible to prevent this edge swipe feature...though I did find this: https://gist.github.com/mountainstorm/9430618. However, all it seemed to accomplish for me was breaking mouse scroll functionality.
Any help would be greatly appreciated. Thanks!
I don't think it can be done since it is an OS level feature. As long as the swipes initiate inside the web page, there should not be any issue. If you have sufficient margin from the edge, then it should not be a problem.
This isn't a specific JS code issue, but more the way iOS deals with JS that is causing more problems on my site than most others.
On iOS only (it doesn't happen on Android) if I'm natively scrolling (up/down) and then try to activate some JS just before the scroll has finished (very quickly) then it completely ignores the JS.
I believe that Apple do this so that the UX always remains priority (don't let any crappy JS slow down the user), but in this case it's just a very simple piece of JS that I want to allow to run.
As an example, if a user is scrolling and then quickly presses a tab at the top of the screen that opens a fixed navigation panel then it won't register if the native scroll is still happening. If they press it again (the scroll has finished) then it works.
I'm also using a JS slider to scroll horizontally through images and if I try to scroll left/right just before the native up/down scroll has finished it sort of jumps and isn't good UX. I think it's prioritising the native scroll but still activating the horizontal scroll with some sort of delay.
It's not a massive problem, but not perfect. If everybody slowly navigated the site and waited for the native scroll to come to a complete stop, it would be great. But of course people won't do this.
I don't think preventing the default behaviour will do anything. I have tried to take over the native scroll before on iOS and I just don't think you can.
I think this may actually happen on many sites. I've just tried to find a good example by visiting stackoverflow.com on an iPhone and if you scroll quickly and then quickly hit a link before the scroll has finished it won't register. I don't think text links are as big a UX issue though, but a horizontal slider and big 'open menu' button at the top are much more likely to be hit quickly before the native scroll has ended (as you don't need to read something before you press it, like with text links).
I have various JS scripts on a site that would benefit from this being improved in iOS, so if I can understand a way around it, why it happens, what is going on, then I can apply individual fixes to each of those scripts.
Thanks.
The problem is not that iOS ignores javascript while scrolling (more precisely, while the scroll momentum is active). The problem is that, while that happens, iOS does not really register the position change of elements on the screen. In fact, if you have a handler attached to the scroll event, it will stop firing the moment you stop touching the screen, and then will fire just once when the scrolling stops.
Consequence? You think you're touching a link, but you aren't. The image on the screen has moved up or down, but, to the broswer, everything is on the same position, so, actually, you aren't touching anything (or are touching something different). I got very annoyed when I found this behaviour because, in my case, my page is full of images that are links to a gallery ... and if you touch them while scrolling, the gallery opens showing you not the image you touched, but another (The one that really was on that position when your fingers stopped touching the screen).
Is there a workaround? The only one that I know of is disabling the scroll momentum, but you lose scrolling performance.
Before you say this isn't possible, I know it is. Here's an example: http://victoriabeckham.landrover.com/INT
The main problem is that iOS freezes DOM manipulation on scroll, so you have to use some sort of technique to overcome the problem. The parallax plugin I was hoping to use is stellar.js, but the issue I am running into is that the "iOS demo" for that plugin isn't really usable on a desktop. I fiddled with it for 3 hours this morning, and couldn't get a setup that works correctly on both iOS and desktop.
I need some ideas, either a technique to configure stellar.js to work the same way on both (I'm not sure if that's possible), or another library that works on both, or maybe some insight on how I could program a workaround myself.
Any help is appreciated.
Step 1: Create and object like this
{
startFrameNumber: {
//first obj
id: idOfElement
duration: howeverManyFrames
startLeft: whatever
endLeft: whatever
startTop: stillWhatever
endTop: whateverAgain
},
nextStartFrameNumber: {
}
}
Step 2: Make the page unscrollable via CSS, ie 100% height and width with and overflow: hidden
Step 3: When the user scrolls (via custom scrollbar, keyboard action, or touch events) advance the animation x frames based on how far they scrolled or whatever. If your animation object you created has a key [frame] then add that to the queue of things that are visible and moving, and move all those things in the queue to their appropriate places and/or remove them from the queue of active objects
That's it. The function for moving things around should be pretty straight forward, except getting the animations smooth will take a little playing around with.
Simply scroll each layer of parallax effect manually and control them yourself without relying on browser's page scrolling.
I've successfully implemented cross device/browser parallax scrolling with the help of the Zynga Scroller js library.
It takes care of one of your main concerns which is the interoperability of click and touch events and scrolling on mobile webkit devices – this allows you to manipulate the DOM as you scroll.
Then, to create the parallax effect you have three options:
Simulating a real-world 3d parallax by using 3d transforms (with a parent/wrapper element that controls perspective and transform origin).
Using a 2d parallax library such as stellar.js or skrollr
Building your own parallax scrolling algorithm.
Here's a quick demo (using existing sample code) of option 1 showing how smooth parallax scrolling would work across desktop and mobile devices. Of course, you're limited to devices that have support for 3d transforms. Note that the Zynga Scroller works via click/touch and drag – it should probably not be used as a dekstop solution as the only thing that would be required is overflow: scroll in CSS.
Have a look at the jQuery-Plugin "Scroll Path" http://joelb.me/scrollpath and combine this with different layers and speeds. You will have recognized that the scrolling of the example page is not just a vertical parallax stage but also moves layers horizontally while you scroll up and down. This is possible with Scroll Path.
Try using http://cubiq.org/iscroll-4 and stellar.js together.
Do your parallax stuff for desktop normally and then add a 'touchmove' Event Listener to fire the scroll event:
document.body.addEventListener('touchmove', function(){$window.scroll()}, true);
Tested and working on iPad 2 with iOs 5.1.1
I have a need to create a part of a mobile web page that can scroll on its own (even though I tend to disagree with that being a good thing on mobile). The standard method is to set it to overflow: scroll and there you go.
Alas, on iOS one needs to use two fingers to scroll that area which many still feel is unintuitive. This will be fixed in iOS5, but until then, I need to support it with one touch.
So I found a few JS options. One is Scrollability. The catch is that it only supports iOS. In addition to iOS I need to support android, BlackBerry OS6 and Nokia. So that one is out.
I then tried iScroll. This works pretty well. The catch, for me, is that it does this through pure JS in that you never see a native scrollbar. As such, the scrollbar it generates is more of a dummy in that there's no way to make it work with a mouse or keyboard.
So, the question: Is anyone aware of a JS solution for creating a scrolling div on a mobile web page that a) allows for one-touch scrolling on touch devices and b) uses a native scroll bar to enable keyboard devices?
If there isn't one, we can revert to device detection, giving touch devices the JS and keyboard devices the scrollbar...though that still leaves us the issue of some touch devices also having keyboards.