I am developing a website where diagrams can be dragged around the screen, using raphael js.
An well-known limitation of Raphael js is that it there is no built in method for grouping and dragging elements around.
In order to deal with this, I was thinking of creating an individual div element for each diagram. Each div would then have its own raphael canvas and I would use jquery ui to drag these mini raphael canvases around.
I tried this with a a few elements and it works perfectly, but before I implement this into a fully functional prototype I was wondering if anyone has used similar solutions and if there are any known issues with this approach.
Thanks.
If it works for you it is great, still there is one limitation I am aware of. When you want to handle mouse click events of the elements on different svg canvases, there might be a problem when these canvases overlap. When clicking on the element which is overlapped by the other canvas, even if the canvas does not contain any elements, you will not be able to intercept the click. This issue is broadly explained here.
Related
I'm getting into web animations, WebGL, Canvas, ThreeJS, GSAP and all those fun tools. I'm investigating different websites and how they're able to achieve certain effects.
I am mind blown by these two sites: https://14islands.com/ & https://www.hellomonday.com/.
Their animations look simple(ish). Liquid effect on images. I know with ThreeJS filters or WebGL or other Canvas libraries you can achieve the effects. What I don't understand is that both of these sites have a full-sized <canvas> element fixed to the background. And render almost all the images on the site through the <canvas> rather than pure HTML elements.
This allows to have all images to have really dope effects. But what I don't understand is how can they sync the positions and sizes of the images with HTML DOM elements so perfectly?
This seems like a nightmare to code. Also wouldn't it be a huge performance burden to update every image on the canvas when the user scrolls or resizes the page?
I believe I'm missing something. Perhaps there's a library that handles most of this?
If there are any simple examples, I'd love to see them.
Thank you for your time :)
Welp turns out this can be done quite simply with ThreeJS. Perhaps there are ways as well but this seems easiest to me.
TL;DR: You can create a scene for a div, and you can do this multiple times with ThreeJS so that it renders a scene within the specified div.
Demo: https://threejs.org/examples/?q=multiple#webgl_multiple_elements
Code: https://github.com/mrdoob/three.js/blob/master/examples/webgl_multiple_elements.html
How does one implement functionality similar to the one shown in this gif in a website?
Specifically, the part where the user clicks on a (non-rectangular) area of the image and that area then changes colour.
A long, long time ago when the internet was still young, there was something called image maps. Is that still the preferred approach? I heard about svg, does that provide this type of functionality? What about canvas?
I don't know about image maps to get them in this shape of hit areas.
But I recommend using canvas for these type of applications.
You have multiple options for doing that, being image maps one of them. However, I wouldn't do it with it, nowadays, there are better solutions.
You can either use canvas, as suggested before, for example using a canvas library like http://fabricjs.com/ or, maybe a bit easier, using SVG elements.
The benefit of SVG is that they render as normal DOM elements in a website, so you can debug then in the inspector, attach normal click events to them, style them using CSS, etc.
multiple options for this.
SVGs + CSS
CANVAS animations
FLASH( wouldn't recommend this option.,Pretty outdated)
Plain html css (But this wont be customisable in future for different shapes, a lot of time consuming when compared to other ways and confusing unless written with good documentation.)
html+css way: you can always make most of the geometrical shapes with css and html. But, curves we have svgs to go for and use css/svg transitions for visuals
Okay, so I'm finding a lot of answers that don't quite fit my need. Here is my scenario: I have an app in javascript/html/css. I have two independently rotatable overlayed elements (in this case both svg's) that both have elements that need to be clickable which move around their perimers with the rotation of the two elements. One layer has 7 clickable points, the other has 12 clickable points, and the two rotate to a given point based on onclick events that set a target degree for the rotation. Only the points (i.e. small transparent circles at the edge of a circular radius on each of the two svg's) need to be clickable. My problem is that whichever layer I put on top works, but the buttons on the other layer then stop working, apparently blocked by the other's background. I've tried messing with all sorts of pointer events and some other ideas on StackOverflow, but all end with the same result: one set of buttons doesn't work. They need to be on separate layers so the rotation will put them at the correct position as they rotate in real-time. Any ideas would be welcome. I am looking for an answer that requires no libraries (including jquery), however if it can be done with jquery, then it can be done without jquery-- if I can find out how. Ideas anyone?
#dandavis is pretty much right here, except I think he meant to say pointer-events: auto . Was just noting there's not an official 'answer' posted. For now, marking this one, but if you want to re-post as an 'answer', Dan, I will gladly mark it as the accepted one.
I am trying to make a webpage, where I want to plot points with which I can associate Mouse events (Jquery).
So, I guess I want them to be dom objects and not want to just paint them. (Please suggest if we can paint using html5 and still treat them as dom elements)
So essentially I have a text files with x,y co-ordinates and I want to plot those but want to associate Jquery events with them. for example: on left clicking them a graph appears or right clicking them a menu appears depending on which node I clicked.
Imho, it would be a very silly approach, to write DOM elements with lines and dots.. For instance, how would you make a round line - you could create diagonal lines with border CSS styling but.. Well - there are many options available! Another approach could be Highslide.
jqueryui-visualize
jQuery top5 graphing tools
http://www.filamentgroup.com/lab/update_to_jquery_visualize_accessible_charts_with_html5_from_designing_with/
Demo
Dojo Toolkit
Since you for some reason have tagged this with dojo, check out this blog entry;
http://www.sitepen.com/blog/2008/05/27/dojo-charting-event-support-has-landed/
2dChart Demo
Read about Scrolling / Zooming here
Zoom Demo
Here's a nice little introduction slideshow from an apache user
Well, several approaches.
You can take your coords and create absolute positioned elements on the DOM using those points. Using jQuery you can set 'top' and 'left' points to position them. This method may be easiest for you because jQuery can easily apply click events.
You can use the HTML5 canvas and draw shapes onto it using the coords from your file. With this method you would either need to write your own event library or use libraries already written such as kinetic.js. Also styling these is going to be a bit less dynamic and extensive than using DOM objects and CSS as with the first method.
I'm making an TV Guide. See http://i.tv/guide for an example implementation using Canvas.
I need to make lots of little boxes representing each show. I need to be able to scroll them around, both vertically (channels) and horizontally (time). To make it with Canvas, my understanding is that the only way to implement scrolling is to intercept the correct events, and redraw the canvas smoothly with new offsets many times a second.
If I were to use divs, I could slap scrollbars on it and let it scroll normally. I could position them once, and let the scrolling move them around, rather than re-calculating their new offsets.
Which should I pick for this kind of project? If I use divs will it be too slow? Some lineups have 500 channels. I want to display up to 4 hours at once.
Thanks!
I would strongly recommend using plain HTML in preference to canvas, for interactive elements. Apart from the speed issue (divs are usually going to be faster than drawing it all manually yourself), HTML is designed to offer accessibility and usability features for free, which you'd have to do a lot of work to get even partially from canvas.
The canvas-based guide as linked has the following drawbacks:
very slow to render/scroll, for me;
impervious to keyboard navigation;
no HTML link actions (like middle-click-link-to-open-in-new-tab or right-click-bookmark);
text not copy/pastable;
a dead loss for accessibility tools like screen-readers;
reduced browser compatibility;
invisible to search engines.
Use canvas for pretty graphical and interactive effects you can't achieve with plain HTML. To be honest I don't even see any of that on i.tv's site; I have no idea why they have implemented it in this seemingly-crazy way.
Doing it with DIV's wont have issues with speed. Browsers rendering engines are built to render elements. DOM rendering is faster than canvas rendering in a lot of cases, take isogenicengine they use DOM based rendering to render thousands of elements to make games You should implement it based on your technical ability. Both technologies will be able to do what you want. Personally I would choose canvas but I see no issue with DOM rendering.
Good Luck.