Image clickable multiple areas approach - javascript

I've just started to learn web development and I have an idea to do the following:
Take simple image (jpeg/png) and make some areas of that image clickable (or other events on those areas). For example, when I click on specific area on the image, this area highlights, other part of the image shadows.
First what I googled was HTML map/area tags. But I want to know other approaches which I can use to do that. Just give me some keywords, nothing more.
Thanks in advance

I stumbled upon the same problem some time ago:
HTML maps tags are the quickest way but in the long run often give problems often because of the lack of support.
Going for an SVG image which is widely supported across all browsers is a good solution. There are many JPEG/PNG to SVG converters on the web (even if quality would not be the same)
Another brutal approach is to create some clickable overlay divs over the image, it is a good approach if the areas to click are rectangular.
Hope you find a good solution :)

Related

Completely Scalable Website similar to SVGs and PowerPoints

Good morning/evening, hope you're having a great day. I had a problem I've been postponing for the last couple of months.
Short Question: Is there a way I can make my website scale, everything in it scale, from text to images, to tables,... when the window size is changed?
Long Question: I've been working on a program that is similar to PowerPoint, I have been giving a lot of webinars/events in my local area and PowerPoint isn't that good for programmers, or if you want to use it for teaching, there is a lot of repetitive things I can automate with programming. Now I have one problem, I just can't figure out what can I do to make a presentation scalable just like how PowerPoint is doing so, I had an idea and that was just to create each slide as an SVG image, or at least use an SVG tag but with the ForeignObject tag and just stick my HTML code in it, but that is ugly coding and will lead to some trouble. On the other hand, if I ditch SVGs and use something like media queries for adjusting the font size, it wont work, since the font will not scale nicely and some text may go to the next line and you know what I mean.
Is there anything I can do about this? I know that this question is too lengthy and I'm sorry. I can code in HTML, CSS, JavaScript and (soon React) if that helps.

HTML Image map with selectable regions triggering popup content

It has been a long time since I have had to do Image Mapping! Probably like 4-5 years.
The last time I achieved this using the tag and creating tags for polygonal shapes. This of course works, and is still supported html, even in HTML5. Question is though, is this still a good way to go for image mapping? Or should i scrap this direction and aim to use Canvas or SVG techniques instead?
There are a couple of factors in regards to the decision:
The client uses IE7, so the solution has to work with IE7 and IE8, hence me thinking not to use SVG or Canvas, it would be easier I guess to use the old school map tag, at least it will easily work across all platforms.
The Map has quite custom styles (strokes around the areas with a margin gap too)
Each area has a rollover state, with a popup with content unique for each region. This will have to be achieved with JS. Are there any issues using JS to interact with the DOM structure of the map using map tag?
It's not essential, but I would to make the map somewhat responsive to the viewport.
Using the tag frankly feels really old school, dated and dirty. But, to be honest for my case, it seems like the most suited solution. What does everyone think?
Any feedback welcome,
Thanks,
Craig
For your requirements I think best suite is SVG. By some work around you can make use of all time favorite jQuery with SVG and build cool stuff so quickly. I was able to develope a ticket booking tool on theaters with SVG maps within two weeks.
Also now every one needs every thing on mobile and it works on mobile with just no efforts.
Try to convince client to upgrade IE, that will be best for you. All the best.

Hover over an image area to change the image src

Basically, I have an image (of text) that I want to change to one of four other images on rollover of different areas. The difference is, on roll-off, I want it to remain what it was changed to, unless my mouse enters a different area. I've tried image-maps and whatnot but I can't seem to get this right. As far as my overall coding knowledge goes... well, I started last week, but I'm getting there.
Here's a link to an image overview of what i (kind of) mean.
I know it has probably been answered somewhere at some point but I really haven't managed to find anything that works yet - all I've managed is stuff that either disappears completely or doesn't work with multiple images. Any help would be much, much appreciated.
YOu can use image maps
http://www.outsharked.com/imagemapster/
this is great tool, try it. it is not so hard :)

Approach comparison: EaselJS vs Multiple Canvases vs Hidden Canvas for interactiveness

1.) I found a canvas API called EaselJS, it does an amazing job of creating a display list for each elements you draw. They essentially become individually recognizable objects on the canvas (on one single canvas)
2.) Then I saw on http://simonsarris.com/ about this tutorial that can do drag and drop, it makes use of a hidden canvas concept for selection.
3.) And the third approach, a working approach, http://www.lucidchart.com/ , which is exactly what I'm trying to achieve, basically have every single shape on a different canvas, and use to position them. There's a huge amount of canvas.
The question is, what is the easiest way to achieve interactive network diagram as seen on http://www.lucidchart.com/
A side question is, is it better to get text input through positioning on canvas or using multiple canvas (one for rendering text) as in LucidChart
I'm the person who made the tutorials in 2. There's a lot going on here, so I'll try to explain a bit.
I use a hidden canvas for selection simply because it is easy to learn and will work for ANY kind of object (text, complex paths, rectangles, semi-transparent images). In the real diagramming library that I am writing, I don't do anything of the sort, instead I use a lot of math to determine selection. The hidden-canvas method is fine for less than 1000 objects, but eventually performance starts to suffer.
Lucidchart actually uses more than one canvas per object. And it doesn't just have them in memory, they are all there the DOM. This is an organizational choice on their part, a pretty weird one in my opinion. SVG might have made their work a lot easier if thats what they are going to do, as if seems they are doing a lot of footwork just to be able to emulate how SVG works a bit. There aren't too many good reasons to have so many canvases in the DOM if you can avoid it.
It seems to me that the advantage of them doing it that way is that if they have 10,000 objects, when you click, you only have to look at the one (small) canvas that is clicked for selection testing, instead of the entire canvas. So they did it to make their selection code a little shorter. I'd much rather only have one canvas in the DOM; their way seems needlessly messy. The point of canvas is to have a fast rendering surface instead of a thousand divs representing objects. But they just made a thousand canvases.
Anyway, to answer your question, the "easiest" way to achieve interactive network diagrams like lucidchart is to either use a library or use SVG (or an SVG library). Unfortunately there aren't too many yet. Getting all the functionality yourself in Canvas is hard but certainly doable, and will afford you better performance than SVG, especially if you plan on having more than 5,000 objects in your diagrams. Starting with EaselJS for now isn't too bad of an idea, though you'll probably find yourself modifying more and more of it as you get deeper into your project.
I am making one such interactive canvas diagramming library for Northwoods Software, but it won't be done for a few more months.
To answer the question that is sort-of in your title: The fastest method of doing interactiveness such as hit-testing is using math. Any high-performance canvas library with the features to support a lot of different types of objects will end up implementing functions like getNearestIntersectionPoint, getIntersectionsOnRect, pathContainsPoint, and so on.
As for your side question, it is my opinion that creating a text field on top of the canvas when a user wants to change text and then destroying it when the user is done entering text is the most intuitive-feeling way to get text input. Of course you need to make sure the field is positioned correctly over the text you are editing and that the font and font sizes are the same for a consistent feel.
Best of luck with your project. Let me know how it goes.
Using SVG (and maybe libraries as Raphael)!!
Then any element can receive mouse events.

Between SVG and canvas, which is better suited for manipulating/animating several images? Maybe neither and just use css3 transforms?

The 2nd part of the question is, which javascript library is better/easier to manipulate images with? I won't be actually drawing any shapes or anything. Other info: I'll be using jQuery and don't need to support all browsers, just webkit.
Edit:
More information: the current design is to layout/draw several rows/columns of images in a grid-like layout, with the image in the center being in "focus" (a little larger, with a border or something and some text next to it). The tricky thing is that we want the whole canvas of images to appear to slide/glide over to bring another random image into focus. So obviously the number of images in this grid needs to exceed what is visible in the viewport so that when the transition occurs there are always images occupying the canvas. Other than moving the images around, I won't be blurring them or otherwise modifying them. Eventually we will add user interactions like clicking/touching on a visible image to bring it to focus manually.
Let me know if this is not clear or still confusing.
I ran across scripty2 which seems like an alternative to using canvas/SVG for my purposes. I also started farting around with EaselJS last night, and it seems like this might work, but I'm wondering if it'll end up being more work/complex than just using standard HTML/CSS and a tool like Scripty2 to aid with animations and click/touch events. Just looking for any suggestions. Thanks!
The answer depends on your manipulation and animation.
If it's just translations, CSS wins for speed compared to canvas. I haven't tested, but I feel confident it easily beats SVG for the same sort of thing.
If you're going to be doing non-affine transformations or otherwise messing with the images (e.g. blurring them) you clearly want Canvas.
If you need event handlers per object, you clearly want a retained-mode drawing system like SVG or HTML+CSS. I haven't done enough CSS3 transforms to say how they compare in terms of speed to SVG, but they clearly do not have the robust transformation DOM of SVG.
This is a rather subjective question (or suite of questions) and you haven't yet given sufficient information for a clear answer to be possible.

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