The reason for asking this question is because I want to be able to draw an arrow between two svg images. I want to use canvas to create the arrows, so firstly I generate the svgs then place a canvas on top of them to be able to draw the arrows.
I've tried using style=... but haven't had any luck as everytime I add the canvas element it just pushes my svg images to another pl
If there's no easy way to do this I'll just create arrows using SVG, I figured it would be more efficient to use canvas if I had to do lots of arrows in a short amount of time.
You need position:absolute on the CSS for the canvas to take it out of the flow, and then you can layer it as you like using z-index.
However, I instead suggest that you can use one or two tiny canvases to create the arrowheads and use toDataURL() on them to create a url you can use for <image> tags in the SVG. This way all your graphics are in SVG but you can use the canvas for complex raster effects if you need to.
have you tried z-index? it's a useful css trick
#svgcontent
{
z-index:1
}
#html5content
{
z-index:3
}
EDIT: accidentally screwed the #s up. 'scuse me.
Related
I have an image. I have a second graphical element ontop of this image, whose alpha I want to use to "hide" parts of the image below it, while the top element itself isn't shown.
Something along the lines of
CanvasRenderingContext2D.globalCompositeOperation = "destination-out"
This top element will change transparency and shape live, so prerendering everything onto a seperate canvas won't be an option.
I was thinking of "multiply" but it didn't do what I expected it to. I thought if I put the alpha of the top layer to "0", that would be multiplied with the layer below, also making it transparent. (I was sad it didn't work)
Is there someway to "hack" this using the existing CSS blending modes (or any other method)?
As an alternative, consider mask-image (however, note that currently there's no support for this on IE / Edge):
img {
-webkit-mask-image: url(http://www.lordtennyson.ca/uploads/1/2/4/2/12421219/paw_print_small.png);
mask-image: url(http://www.lordtennyson.ca/uploads/1/2/4/2/12421219/paw_print_small.png);
}
<img src="http://www.dizzydi.com/uploads/6/5/6/5/65656887/6168555.jpg" />
Is it possible to only trigger a div's mouseover when the cursor is over an opaque part of the div's background image? Perhaps via Javascript?
All I can find with Google are old IE PNG fixes.
This looks like a similar question to this one: Hit detection on non-transparent pixel
I suppose this could also be done for background image by getting the attribute with jQuery:
$('#myDiv').css('background-image');
I haven't personally done this, but it seems like a viable solution. This will only work for modern browsers, but you should be able to make it back-compatible with excanvas.
It is possible, just not very easily. You'll have to use a lot of Javascript.
You'd want to attach to your <div>'s onmousemove event, which returns the X,Y coordinates of the cursor. Your event handler function would then test to see if the cursor is in the correct place in order to trigger an alternative onmouseover event.
Implementing the "is the cursor over an opaque pixel or not?" test can be done two ways: the first is to create a simple mathematical expression (say if the opaque parts of the image make neat rectangles, circles or polygons). The more difficult (and less browser-supported) way is to load the background image into a Canvas object and then get the current pixel value's opacity figure and take it from there, like so:
var pixel = canvas.getImageData(x, y, 1, 1).data;
var alpha = pixel[3]; // assuming RGBA
if( alpha > threshold ) onMouseOver(); // raise the event
Another alternative is to create an entirely transparent div (or some other element) positioned and sized so that it only covers the opaque part of the div below, then just test the mouseover of that element's box.
It's a bit of tweaking but why don't you add a class to your opaque div, and use JavaScript to check for it?
In jQuery:
$('div').mouseover(function(){
if ($(this).is('.opaque')) {
//Some actions
}
});
I've been wrecking my brain trying to figure this out. is there any way to set one background image in css for multiple elements? I have a square-ish speech bubble, made with regular css, the triangle made with the border technique, but i want an background image to fill them both so it looks like a cut out all together.
I dont know any other way to design a solid shape using html/css other than squares and rectangles. If i could create a speech bubble as one solid shape, then giving it a bg would be simple lol.
I was wondering about html5's drawing capabilites, but im not sure...
Any ideas?
Edit: No, there's no option to do what you want. But if you wanna do spech bubbles, you can check any of these links:
http://nicolasgallagher.com/pure-css-speech-bubbles/demo/
http://konigi.com/tools/css-tooltips-and-speech-bubbles
http://desandro.com/resources/css-speech-bubble-icon/
Usless Background Info
Hello, all. This is my first post here, but I often come here for help.
I am an amateur web designer and have been in web designing for almost a year now.
The Problem
My question is about CSS3 transforms. I have a small, circular element in the center of my page that transforms successfully when I hover over it. I have a larger circular element that is, by z-index, underneath it. The larger circle also has CSS3 transforms coded in the CSS, but will not transform, or even triggerd when hovered over. Both circles are overlaid, with the smallest on top, to create concentric circles.
My Attempted Solution
One word: Z-index. I have tried putting the larger circle on top, which works fine. The problem with this is that the smaller circle no longer triggers...
The Result I Want
I would like for the circles to remain in their 'concentric' positions and for the larger circle on the outside to transform by :hover. Is it possible to have an 'alternate trigger'? e.g.: in JavaScript, I can trigger an animation by hovering over any element that I specify. Is this possible to do in CSS? Can I hover element (I), and change properties for element (II)? If I cannot do this, how would I go about triggering animations for both circles, by hovering over only one? I am trying to stay with pure CSS/HTML, but I will accept JavaScript answers.
Last Notes
I hope I have provided ample info for a decent answer... Here is a screenshot: http://i.stack.imgur.com/WPj62.png
The circle with the infinity sign is the smaller circle element. The larger circle with the faint border around the screen is the other element.
EDIT:
Something's still not right, please take a look at the full code posted here: http://cssdesk.com/eJ8BH
If I understand your question, it sounds like when you hover over the small circle, you want both the large and small circle to transform, correct?
The easiest way is likely to use javascript for this. If you are using jQuery, it's even easier:
$('.littleCircle')
.hover(function(){
$(this).addClass('myTransformationClass');
$('.biggerCircle').addClass('myTransformationClass');
})
UPDATE: Some further examples based on follow-up feedback.
Here's what I'd do. First, give all 4 related elements a class so you can grab them via jQuery. For the example I use .rolloverSet
// grab all 4 elements and cache them
$rolloverSet = $('.rolloverSet');
// grab the one element that needs to have two classes
$otherElement = $rolloverSet.find('.otherElement');
$rolloverSet
.hover(function(){ // we'll add a hover event to each element in the group
$(this).addClass('myTransformationClass');
$otherElement.addClass('myOtherTransformationClass');
})
.blur(function(){ // remove the classes on mousout
$(this).removeClass('myTransformationClass');
$otherElement.removeClass('myOtherTransformationClass');
})
You do not need jQuery for this. You need to apply :hover on the parent element of the concentric circles and then apply the animation to its immediate children like this: http://jsfiddle.net/nimbu/taqr4/
Things I changed:
Updated to use shorter transitions, animations property
Added moz, o, unprefixed properties
Removed -webkit- from border-radius
Gathered common properties of concentric circles to prevent repetition
Fixed incorrect background-color (#00000000)
http://www.deviantart.com/#order=9&q=sun
As you can see, each picture...underneath it...it has a little tiny shadow around the edges.
How can this be done with a variable size image? (css)
Beside the answers above, let me explain how devianart does it ..
they have an image generator, that creates the shadow image at anysize they want ..
You can see the background shadow of an image at http://sh.deviantart.net/shadow/x/113/150/logo3.png
now playing around with the url and altering the 113 and 150 creates new images of arbitrary size which they use ...
You can use box-shadow, but it wouldn't work cross browser: http://www.css3.info/preview/box-shadow/
You can do this by shifting a background image behind the original image. There are quite a few tutorials on the internet:
Tutorial 1
Tutorial 2