Javascript elements buggy overtop of iFrame - javascript

I'm using the jQuery UI framework to create a draggable panel. It works fine, but when I drag it over top of an embedded iframe on the page it becomes buggy and stops moving. I thought it could just be the plugin, but it happens with all of my dynamically created elements that move overtop of the iframe.
Does anyone know what is going wrong or how to fix this?

You've to kind of hide the iframe when you drag/resize the panel. This can be done by placing a hidden transparent div right over the iframe (of the same size), and showing it up only when the drag/resize event is triggered. So keep on toggling as soon as the drag/resize start and stop events are triggered.

Related

JavaScript/Vue.js: How to execute multiple methods at once before the DOM updates

Here is what I am trying to do: When the user is clicking a button, a transparent overlay is opening. The background shouldn't be scrollable but stay at the scroll position. So what I am doing at the moment is that once the button is clicked, I safe the current scroll position via window.scrollY, then add overflow: hidden to both the html and body tag (which unfortunately scrolls the page to the very top), then proceed to scroll to the saved position inside the main div of the website. In most browsers these steps aren't noticeable so it seems like everything just stays at the same position. In Safari however, you can see that for a few ms the background scrolls to the very top and then back again.
So what I would like to know is how to execute multiple methods at once before the DOM updates. Or maybe you can think of another way of doing this?
Thank you!

jQuery - smart hovering plugin

Hover events are playing an important role in the navigation of my web page, and I don't want the user to get distracted by triggering them accidentally.
I'm aware of hoverIntent, which doesn't fire a hover event until the mouse has slowed down sufficiently. However, it always fires a hover event when the user scrolls down and lands atop the element.
Google Images manages to solve this quite beautifully: it doesn't fire hovers when scrolling down, and additionally even jerking the mouse a tiny bit after scrolling into an element doesn't trigger a hover.
Is there any plugin out there that implements hovering behavior similar to Google Images?
Maybe with this will help: http://james.padolsey.com/javascript/special-scroll-events-for-jquery/
So you will know when the user is scrolling, so you will also know not to fire the hover-event.

Scrolling a div vertically using buttons

I'm building a mobile app using HTML, CSS, Javascript and jQuery.
Is there a way to scroll a div that is longer (700px) than the mobile screen (480px) using only two buttons, one for down and one for up?
So when a user presses and holds the down button it appears to scroll down the div by about 10px at a time.
Edit:
The mobile app is actually being compiled with Phonegap, so it won't be a mobile website but an actual application.
The application features dragging and dropping quite heavily and in order to do this using JQuery and HTML, I've had to bind the mousedown, mouseup and mousehover events to touch events.
Because of this the user cannot simply drag the screen to scroll as they would a typical application. Therefore, I have decided to go with physical buttons instead of scrolling the navigation div.
The navigation div is set to have a greater height than the canvas (screen height and width) div. This will be the div the user is scrolling.
Is the div you're talking about scrolling the full page itself? Or is it a specific div that you want to "scroll" within the page (kind of like an iframe)?
Both can be done. If you're scrolling the full page, I'm not sure why you'd want to use buttons rather than let Safari simply handle the standard swipe gestures. But, it could be done this way:
Use fixed positioning on the buttons so that they don't move as the rest of the screen scrolls.
Use use jQuery's .scrollTop method to do the scrolling.
If, on the other hand, you want to make a scroll effect on a single div, without the rest of the page scrolling, then just do the following:
Wrap that div in another div that has overflow:hidden; position:relative
Make the inner div position:absolute
Animate the inner div's top property to create the scrolling effect.
You may find this plugin useful: http://logicbox.net/jquery/simplyscroll/vertical.html
Anyway, why would you need that? The user may be able to scroll normally with a finger swipe if the content is bigger than the screen.

Hiding and showing div during page scroll on iphone

Need to display an element (div) ontop of webpage. During scroll the element should disappear and reappear after scroll ends.
To add to the complexity:
our code is a guest code (thus we cannot manipulate DOM structure etc).
our code is intended to work on iPhone/iPad (mobile Safari browser)
We've tried to listen to touchstart event on document / body and hide the element (div) in our dedicated handler. However, in some sites, (when DOM structure becomes reasonably complex) the scroll response time increases significantly, even if handler implementation is entirely empty.
We are looking for the proper way to manage the element (re)appearance with a minimal affect of the user experience while scrolling.
I would think Javascript is your best solution. You can dynamically insert your DIV to any content using document.createElement, then also add some javascript to listen for onScroll...
You could even populate the DIV using custom HTML built from the native code if you want.
Any help?
I don't know if you are a jQuery user, but this .scroll() function may help you do exactly what you want to do. Check out the demo to see how it works.
http://api.jquery.com/scroll/
In recent iOS version (5.x) fixed positioning (position:fixed in CSS) is fluently supported, so that your element will be positioned on screen coordinates. That might be a good starting point for solving your troubles.

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!

Categories