I'm very new to JavaScript so forgive me if this question is naive/obvious. I'm using jQuery UI drag and drop (and the jQuery Collision Detection library from this site: http://eruciform.com/static//jquerycollision/jquery-collision-drag-collision-example.html). Although I have no problems detecting which divs are colliding with each other (and doing things to said divs with ($(this).collisions(".collisionclass")).each(function() ...)), I haven't been able to find this list of divs that have NOT collided with each other or the target collider, at least not an elegant solution (and the reason is I wanted to do other actions on those remaining, uncollided divs).
Does anyone know of an elegant way to find which divs have not collided without resorting to brute force (e.g., add all such divs to a collection and every time there is a collision event check which ones from original collection are not in the resulting collision collection)? The example source code via the link above seems to simply add and remove dynamic div overlays on portions of original divs that are collided, but that doesn't tell me how to detect not-collided divs...
You can use the jquery not method.
var not_collided = $(".item").not(".collisionclass")
Technically this will check all the items if they have the "collisionclass" class, however it is still efficient until you get to huge numbers of items.
Related
I have this tool tip that is created every so often. What is the appropriate actionscript etiquite?
A. To Create and remove the tooltip moveclip when needed?
or
B. To hide and show the tooltip movieclip when needed?
With these A and B, the answer is B, because creating and then removing an object a lot of times creates a lot of garbage in the memory, which eventually leads to garbage collector calls, that slow your SWF's performance. You can easily go with a single tooltip MC, just fill it with information that corresponds to the new mouse coordinates before you show it.
There is another question, not so straightforward as yours, about how to hide and show a movie clip, either via visible property or via addChild() and removeChild() (AS3 only). If you are using AS2 or AS1, use visible property to hide and show your tooltip.
There are three ways to hide something in Actionscript : Alpha, visible and remove child.
Apha: If you turn the alpha zero the renderer always comes to this displayObject and renders it at alpha zero. So the object is always rendered you just cannot see it.
Visible == false In this case the object still exists in your displaylist. So the renderer comes to the object. Sees it's property is false and leaves it but it still exists in the display list.
removeChild This means that you're removing the object from the display list. This means that the renderer never had to even check for it. Which makes it the fastest option.
addChild doesn't take that much computing power as visible check. I'm sure you can find benchmarks on this.
If you don't have a lot of objects on yours screen and the tooltip is there every second I'd go with visible is false. In all other cases go with the third option.
On a side note, I've found it always easier to manage them with a toolTipManager. A class that makes sure that you have one tooltip on the screen because usually users only use one tooltip. So that makes things easier for me. I just always create the necessary tooltips and add them to the displaylist when required and remove them. (Not recreate them) At the same time have only one tooltip on stage.
Is it possible to make Sprites position themselves one after another automatically.
Similar to display:display-block in CSS.
For example i'm adding Sprites to some parent in a row, the way they are in xml skin file and they are automatically position themselves next to each other.
Is there an event, which tells that a child were added to the parent?
I could implement some extended Sprite, to position pushed elements automatically, by calculating where the last element is located?
Why the hell Actionscipt doesn't have something like CSS in it? It's a pain in the ass to build UI inside it, compared to HTML...
Madness...
In case of "raw" ActionScript you should either search for an appropriate library or do it your self. ActionScript doesn't define any CSS like logic.
On the other hand Flex does, but you will not find any CSS that let you define layout. CSS is used to modify visual appearance of containers and components in Flex. Layout is usually done with the layout property of the container classes provided by Flex. For example yo can use a Group and set its layout property to an instance of HorizontalLayout or VerticalLayout. This will automatically position all child components of the group either in x or in y direction. In case of using Flex you cannot use sprites directly, but there are many components you can use. Maybe there is one for your purposes.
See the Flex API documentation. The spark.components package will be a good starting point.
I am trying to swap two TD elements in table on Drag&Drop. I found this plugin Swappable and it works in some way. But when I drag some element the cursor change position to some specific value. I do not want changing cursor position. But when I rework this plugin it stops work.
Does anyone have experience with it or know about any other plugin?
Thanks,
Zbynek
Usually I use the jQuery sortable. It does pretty much want you want. You can use it in a table too.
Then I do my stuff (including ajax updates) in a function setted in the receive event
Did you try the JQuery Sortable() option?
See http://jqueryui.com/sortable/#display-grid
I'm having an odd problem with jQuery draggable this morning, I wonder if anyone else has come across this.
I have many small divs inside a large div. They are absolutely positioned: "position:absolute" in CSS for their class, with the actual position itself calculated and set in JS on demand.
Now I'm adding functionality to allow these divs to be draggable.
But, as soon as I make one draggable, it is given "position:relative" directly on the element, which as you might imagine, seriously messes up the on screen position.
Does anyone know why it changes the "position" like this or how to tell it not to?
EDIT:
Just realised there is a rather obvious answer staring me in the face - !important on my position:absolute! This seems to fix it. BUT I'm still interested if anyone knows why it sets "position: relative" like this (and doesn't either make it configurable or check first if it needs position)...I'm wondering what problems I've just stored up for myself ;-)
"I came across the same problem today. The reason was I was applying draggable() on a dynamically created element. I was 'later' appending it to dom. The element should be in dom when you apply draggable() (if style is being applied by a class). In short, when it finds no position attached with the element , it adds relative." - Jashwant
Firs do: .append(jElement) Then: jElement.draggable()
For some reason Jashwant put his answer in the comment to the question. So I thought it will be convenient to other to repost it here.
It also happened to me, but only on Chrome. Reason?
It was like this:
$("#div-popup").draggable({ handle: ".top", containment: 'document'});
Then I removed the containment parameter, like this:
$("#div-popup").draggable({ handle: ".top"});
So it's about the Browser (Chrome in this case), which sets position to Relative when you specify which containment the element will be draggable.
in my case it seems to be a race condition between the stylesheets and javascript loading...
i realized i'd made the mistake of including the stylesheets AFTER the javascript in the document head. they should be included BEFORE the javascript because $(document).ready() does not account for the CSS being loaded by the browser: https://stackoverflow.com/a/1324720/3633109
I contribute to develop a wrapper for a bioinformatics program.
The program's output is quite long (dozens of pages if printed), but structured into sections.
I would like to add "next" and "previous" section buttons to facilitate jumping up and down in the output.
One way of doing this would involve parsing the complete output, adding "id" or "name" anchors and linking to neighboring sections using <a href="#section2"> type links. However, thats a pain in the butt to do, adds the potential of new bugs, and would slow down the display.
All sections start "in the same manner" (ie. if you control-F search for a specific text, you will jump to the next section). Is there an easy way of using the fact that all sections start with the same text to add links that will let you jump to the next one?
Cheers
Perhaps the jQuery ScrollTo plugin can help you. You could add the links you need for navigating by Javascript/jQuery after the page has loaded.