We Keep Coding

Javascript : is there a way to detect user scrolling, but not scrolling done by code (i.e. scrollLeft etc)?

So. I'm making a page with buttons; clicking the buttons smoothly scrolls the page (actually a container) to anchors located further right. This is done with container.scrollLeft.
Now I'm trying to make it so that when the user scrolls manually (scrollbar, mousewheel, arrow keys etc), the automated smooth scrolling instantly stops.
I've tried doing this with container.addEventListener('scroll',StopScroll,false); but this fires up for any scroll, even done through code, not just done by the user.
Is there a way to detect only user scrolling ? Or maybe a work-around ?
Also, I'd rather not use Jquery, but I'll switch to it if it's the only way.

I've got a feeling that DOM scrolling and event scrolling are managed the same way, and therefore indistinguishable.
However, you might hook into mousedown/keydown and update a variable when a key or mouse button is held, and only perform scrollStop if that variable is set?

Javascript: don't stop scrolling window if the cursor passes over a scrollable div

I'm building a web app that has a grid of many small scrollable divs (actually, Ace editors), and this grid has enough elements that it is larger than the window. When a user begins scrolling over empty space, I want them to be scrolling the window itself; when a user begins scrolling inside a grid element, I want them to scroll the div contents there. The thing is, if a user begins scrolling over empty space, and then scrolls such that their mouse goes over a grid element, that scrollable div captures all the scrolling events, interrupting the user's flow over the grid and "trapping" them inside the grid element.
I can't manually capture onmousewheel events, since AFAIK there's no way to capture horizontal mouse wheel movement separately from vertical, and I want users on Mac OS X to be able to scroll in all directions. I've thought about using JS to add an invisible div with a very high z-index on the first onscroll event, and removing it as soon as onscroll events aren't triggered for a certain period of time. Haven't yet coded this up, but I'm wondering if there's a better solution, or if there are any potential pitfalls that I haven't thought of. Any help or advice would be great! Thanks!

I think a solution for this would be incredibly difficult due to browser support, and the actual solution, which would probably be something like calculating the scroll, backtracking the div, and applying the scroll to the page.
You could do something like this:
$('div').scroll(function(e){
// figure out how much it has scrolled
window.scrollBy(0,howmuch);
});
I don't recommend this solution in the slightest though, I think the better option would be to set the divs to overflow:hidden; and pick up a solid scroll plugin, and use that to customize the scroll behavior on the divs.

Horizontal scroller with Mootools

I'm working on a site for myself, and I'm using a custom horizontal scroller done with Mootools that I got from another site (and got their permission to use). While I've managed to get the scroller to function the way I want to, there are two issues I'm looking to fixed and don't have the know-how myself to figure out.
I've set up a simple demo page here.
You can scroll with your mousewheel/trackpad up and down or left and right, you can grab the scroller and drag it, and you can click anywhere along the line to jump directly. So all the functionality is okay. My issues are:
If you scroll to the middle (or anywhere except the start position), then resize your browser window, the scroller handle will jump back to the start/left even though the contents stays put. If you then start scrolling again the contents will jump back to align with the scroller handle's position. Ideally the handle would stay put when the window is resized, but I can't figure out how to do this on my own.
At the end/right of the page I'd like to have a back button that smoothly scrolls you back to the start/"top". The best I've managed is what you see there now, where the contents scrolls back smoothly, while the scroller simply jumps back to it's first position. While I could work around that by simply have it jump straight back to the start, it would certainly look much nicer if the scroller would smoothly scroll its way back like the contents does.
Any help with this would be greatly appreciated!

Your first issue is occurring because positionIt() is being called every time the window resizes. Looking into that function, you can see that the bottomSlider is being initialized every time. I would break positionIt() into a initializing function and positioning function, and ensure that only the positioning function is called when the window resizes.
The second issue could probably be fixed by creating a separate step() function for the bottomSlider and calling that within onChange, rather than using an inline anonymous function. You could then create a timer or tween that calls step() to move the scrollbar back to its original position (and subsequently move the viewport in accordance with it.)
Hopefully that makes some sense!

Morphing content based on window part focus

What I'm trying to achieve is basically have a code that will morph (move around the page) based on the part of the window which is currently viewed.
Scenario:
actual page height : 2000px
actual screen height( pc, laptop whatever ) : 800px
1 image of 600px
3 div's or virtual boxes ( just to prove what I want to do )
Workflow
When you open the page, you'd see the first part of the page with the image loaded in the first div.
What I want and need to achieve is when scrolling the page, and the focus would be on the second div (or the image simply gets out of focus - you can't see it no more),
the image would move (disappear from the first box) and appear in the second one, which is currently visible.
The idea might seem pretty easy but I'm not JavaScript savvy.
Ideally, the answer should include a way to load a JavaScript instead of that image.

The way you use the word focus can be misleading, as focus is a JS event that happens after an element is clicked. You need to get familiar with the jQuery scroll event and scrollTop. Here is similar Thread here in StackOverflow that you may want to read Jquery / Javascript find first visible element after scroll

How can I temporarily prevent a scrollable div from scrolling?

Here is my current situation:
I have a web page containing a couple scrollable divs. Each of those divs contains a number of objects. I am using YUI to display popup menus of actions that can be performed on each object. Each object has its own menu associated with it that is constructed and displayed dynamically. The popup menus can be large and can overlap the bounds of the scrollable div.
From what I believe are issues with focus (the menus must be accessible), when I hover the mouse over an action that lies on top of an edge of the scrollable div, the div automatically scrolls, moving the content but leaving the menu stationary. Trying to move the menu dynamically when this happens is not something I want to do as I believe it would provide a poor user experience.
So I need to prevent this focused menu from scrolling the div. My idea for providing the best user interface is to prevent these inner divs from scrolling when a menu is open. This leaves the menu positioned in the optimal location to show the user which item is being acted upon. If the user wants to scroll the box, they can click to close the menu and then scroll normally.
How can I do this? I need a solution that works across the major browsers.
My first thought was to listen to the onscroll event for that particular element. Unfortunately, there does not seem to be an easy way from there to just prevent the scrolling from happening. For one, my JavaScript event code appears to execute after the actual scrolling has occurred.
Then, I thought that since my code is being run after the object has scrolled, I could just reset obj.scrollTop and obj.scrollLeft. Sure enough, this appears to work, though I am worried that on slow browsers the user will see the content inside the div "jump around". Also, it would be really nice if the amount the element scrolls is part of the event object. Is it stuck in there somewhere? I'm looking for an alternative to having to store the scrollTop and scrollLeft variables for this element and then using them while the scrolling is temporarily disabled.
What is the best way to solve this entire problem?

I agree with Anthony regarding the presentation of the functionality you're trying to disallow. If you're going to disable scrolling, then you should make that part of the page visually disabled or removed.
To that end, you can position a semi-transparent div on top of the scrollable div in question, which would capture the mouse events and visually show that the scrollable div is inactive for now. It would be hard to make cross-browser compatible and wouldn't be perfect, but then again very few client-side tricks like this are.

The simple answer is no you can't do this. Its doubly no if you want a cross-browser solution.
Providing the user with the clear affordance that something can be scrolled then denying them that is just plain poor UI design.
Ok so after your edit it turns out you are not actually trying to prevent the user from scrolling.
The main answer remains true though. It sounds as though the focus is going to rectangle (probably an anchor?) that is not fully in view and causes a scroll. Is there a reason this rectangle must get the focus? For accessibility?

What if you didn't have overflow: scroll and instead you used overflow: hidden and provided scroll up/down buttons that allowed the user to scroll when necessary? These buttons could of course be disabled easily.

Though it may not be the answer you are looking for, if you are to set the display value of the div to 'none' while the page loads (from the server) and then have an event wired to the page load (either pageLoad in ajax.net or attach it to the onload event via javascript) that will make the div display set to 'block' .. that would ensure that slower browsers wouldn't see the div 'jumping around' (could even put a 'loading' image in the div to show users it's doing something and not just invisible)
sorry i couldn't provide a more complex/fluent solution.

I found a way to work around this issue. By removing the menu element from the scrollable div and then appending it directly to document.body, the browsers all stop trying to scroll the div to reveal the focused element (even though the element is already completely visible).
Thanks to all for your time and your answers!