I'm using jQuery.kinetic to allow a div to be scrolled within its parent div by dragging the mouse, much like the demo on the author's site. By default, when the page loads, the upper left corner of the inner div is aligned with the upper left corner of the parent div (meaning it's scrolled as far up and left as possible). Like this:
I would like to "pre-scroll" when the page loads a specific number of pixels over so that the inner div is roughly centered. Something like this:
I'm not seeing anything in the documentation about being able to specify a starting position for the inner div but it looks like the author of jQuery.kinetic built in a way to extend the plugin beyond the default functionality like this:
$.Kinetic.prototype.newFeature = function(options){
// define the task
};
Then I can call that functionality:
// use the method
$('#elem').kinetic('newFeature', { options });
Is there a way to set a position on page load that I'm missing? If not, how can I extend the plugin to do what I want?
Thanks!
It took me forever to figure out that the Kinetic plugin has built-in abilities to manually scroll the container. It's not anywhere in the documentation, but through inspecting the plugin code I noticed that it has methods to control the x and y-axis scroll position.
In the file jquery.kinetic.js from line 458 to 475 (at the time of writing) the scrollLeft and scrollTop methods are defined. https://github.com/davetayls/jquery.kinetic/blob/master/jquery.kinetic.js#L458
You can use them on a container with an already active instance of Kinetic by calling the following methods:
$("container-selector").kinetic("scrollLeft", 50);
$("container-selector").kinetic("scrollTop", 480);
It's worthwhile to go through the Kinetic code and figure out how it works and what functionalities are available to use en lieu of a more fully fleshed-out documentation.
Related
I wonder how to achieve this effect on http://www.squarespace.com. What I mean is:
you scroll down and at one point the image of computer monitor stays at fixed position
after that, the images keep changing while you scroll.
How can you control content and change CSS using Javascript? It should be on window scroll event:
window.onscroll = function () {
// but I don't know what to use here
}
At smaller browser width, the above elements become a carousel, but I am not interested in that.
Because of the tags on this post I'm going to assume that this question is regarding the skrollr library
Skrollr is controlled via HTML data attributes. What you're seeing when the monitor scrolls, and then becomes fixed at a given position, is referred to as "pinning". How you define data attributes in Skrollr can be pretty confusing at first, but once that is understood, the library is kind of a dream to work with.
I printed and pinned Petr Tichy's cheat sheet next to my monitor the first few weeks of my first skrollr project.
An example of pinning in Skroller would be accomplished as such:
<div id="example"
data-100-top="position:fixed;"
data-anchor-target="#example">
These words are pinned 100px from the top of the screen
</div>
The purpose of Skrollr is that knowledge of jQuery/JavaScript isn't really required. The css is manipulated by the library, and defied in the data elements. The above example shows changing the position to fixed, but if you wanted the div to expand 100px from the top you could input width/height css parameters in there, or just about any other css you'd like.
If you're looking for a more robust skrolling library, in which jQuery knowledge is more of a requirement, I recommend you take a look at ScrollMagic (my lack of reputation prevents me from linking to scrollmagic).
Here is the setup, I have multiple divs on a page which are full widths and have blocks of color. The number of divs can vary from page to page. Each div with have a class associated to it (light or dark) and I have a logo pinned to the top of the browser window.
What I am trying to accomplish is this. I want to detect when each on of these div (with a common class) reach the top of the browser window. I then want to see if it has a light or dark class (only this div that just reached the top.) and then change the logo on the page depending on that value.
The closest thing I have come across is some onscreen jquery plugins that will add an :onscreen value to the current div that is on the screen. This would be great if I could only add this onscreen attribute when it reaches the top rather than just into view.
Does anyone have any suggestions as to how one might accomplish this?
// jsfiddle example
http://jsfiddle.net/UhrrR/
Funny, I was just looking at a library that does this very thing:
http://imakewebthings.com/jquery-waypoints/
You can add listeners to your elements that will fire off when your element hits the top of the viewport:
$('#myDiv').waypoint(function() {
var color = $(this).css('background-color');
$('img.logo').attr('src', 'logo.png');
});
For an amazing demo of it in use:
http://tympanus.net/codrops/2013/07/16/on-scroll-header-effects/
I completely agree with Chris Hardie that Waypoints is the way to go. I built a simple example based on your description.
https://github.com/imakewebthings/jquery-waypoints
http://codepen.io/cgspicer/pen/FrCgI
Here is the fiddle, I've used my own, because I've started before you posted your fiddle, but the idea is pretty the same.
I have a position of a logo element, and when scroll happens I check whether one of the desired blocks intersects logo block. On success a class from a custom data-trigger-class attribute is assigned to a logo element.
I'm trying to programmatically zoom in on what I'm seeing on the page, without changing which part of the content I'm seeing, regardless of where the scroll level is. I want this to be animated and pretty.
So I'm using $('body').animate({zoom:2.0}, 1000) to animate the zoom, but this has the irritating side effect of keeping the top of the visible window at the same point in the document (the browser's attempt to keep me where I was, actually, complete failure), so I need to basically continuously scroll to the same relative vertical center of the page as it's animating in order to get around that. How can that be done? I don't know how to do two things at once with animation--- I mean I could change multiple CSS properties at once, but how can I scroll?
Essentially, it needs to do something like this:
Call begin zoom animation:
1.Mark height level of any element that appears at center of window
2.Do one step of zoom animate
3.Scroll so that that element's height level relative to center of window is unchanged
4.Repeat until animation is complete
You can using Panzoom component for your goal.
I am developing a mobile web application using jQuery and i have been requested to have each page transition into the next with an animation where the page is "split in half", then have the upper part slides up and the bottom part slides down, thus revealing the next page.
I have a small idea, but i dont seem to have the knowledge to get trough:
2 Canvas with display: none, each width width: 100%, height: 50%. - Check
Have the actual display be rendered into said canvas's - I have not the slightest of ideas.
Ajax the next page in a div below both canvas's - Check
Slide the canvas's in the respective directions - Check
Set the canvas's to display: none and restore them to their original positions - Check
Any thoughts? I'm open to use any other framework appart from jQuery, if that's the need. I am also open to change my canvas idea into something else.
EDIT:
As for clarification imagine the page to be a closet, but a vertical one so its doors (the actual page) will slide into the roof and the floor respectively (Its not the greatest of comparisons, but please bear with me) and thus let you see and interact with the content of the closet (The next page). This will go on and on until the application's workflow ends at the last screen, as there will be no back button.
I'm pretty sure I know what you want. You have multiple pages in your registration/form process and instead of having the old fadein/fadeout or sliding effects, you want the top half to slide up and the bottom half to slide down. In order to do this, I'd dump the canvas idea. I don't think that there's an easy way to do it using canvas as of right now. You could try using the html2canvas script, but it's not 100% accurate when it comes to rendering things like this.
As an alternative, I'd recommend using the following process. As a preface, make sure that every step in your form has its own container div (called something obvious like "step-wrap" or "step-container"). Then, when you begin the animation, the first thing to do is to duplicate the current step-wrap, calling it something like step-wrap-animation. Give the original wrap, step-wrap, a height of 50% and position the duplicate below the first with the same height of 50%. Both of the divs should have styling that has an overflow of hidden. Make sure, also, that you set the scrollTop of the duplicate div to scroll to the bottom so that it looks like a continuation of the first div. Everything from here should be smooth sailing.
Second, once you have everything in the first step working, start the animation process. You can do this however you want now that we have the splitting functionality figured out. Make sure that before you start splitting the two divs apart you put the next step behind the previous so that it unravels.
Essentially, what you need to do is:
Duplicate the div
Position both divs (the original and the duplicate) so that both the heights equal 50% and they look like continuations of each other
Animate the top div up, bottom div down
Here's a basic fiddle illustrating how something like this should work. Click on the rendered screen to get the animation going.
Take a look at backbone.js and marionette.js based on backbone.js.
backbone.js is MVC framework where you can define separate views. Marionette is an extension which supports regions and switching views based on whatever you want. Inside switching logic you can easily implement your transitions. Very generic answer but perhaps it will help you to get started.
I want to guide an image through a path. The scroll down of browser should bring the image down the path, and the scroll up of browser should make the image to trace back its path.
Here is an example of what I would like to acheive:
I want to guide that bug down the path as the user scrolls down through the article on the page and make it retrace its path when the user scrolls up (The bug's head will always be in the direction of motion).
How can I achieve this using jQuery and javascript?
You'll need to calculate the path you intend to use, and then bind a function to the scroll event that moves the image based on the distance scrolled, something like :
$(window).on('scroll', function(e) {
var S = $(this).scrollTop(), // scrolled distance
T = 10 + (S/24), // value for Top
L = 10 + Math.abs(Math.sin(S/400)*50); // value for Left
$("img").css({top: T+'%', left: L+'%'}); //set CSS
});
FIDDLE
I don't believe you can directly capture the mouses scroll with javascript or jquery alone. As that works with whats part of the browser, and inside the "window". You can however capture a scroll event. Based on the windows height/width. It takes a little calculation via javascript to build a reliable/stable equation that will work on all browsers in all resolutions. I'm not going to go into details here more so due to the fact that your question is rather vague and doesn't supply a problem to be solved more than it sounds like a demand for an answer.
But the essence of what you may want to do is, get the width/height of the window/body. And through some trickery of smoke and mirrors or in this case HTML and CSS and properly laying out a bunch of layers on top of one another create a page thats a mile long, with a hidden scroll bar, that you have 2 layers on top of one acting as your "path" and the other your image.. Of which when scrolled from point a to point b is tracked via the scrolling event of the page being a mile long under it all. And then use that couples with the width/height found to make adjustments so it doesnt run off screen at any given point (less thats what you want).