Moving SVG group in z space with Snap.svg - javascript

I am using Snap.svg to make elements of my SVG interactive.
How can I move an Element.group group of shapes in 'front' of all my other shapes? This action will take place upon a hover.
A simple JSFiddle example here:
http://jsfiddle.net/offmilk/b0av7jx6/
I'm trying to get the back two circles to come to the front when they are hovered over.
I know Raphaƫl has similar functionality for individual elements in the form of Element.toFront(). The creator of both answers a similar question here, but I'm unable to add his solution to my hover set-up.
Thanks in advance for your help!

I think this depends on whether you mind the actual SVG being changed, or whether you need the SVG to remain as it is (in which case you will need CSS).
As you mention toFront(), I'm assuming its ok to change the SVG.
In this case, all you need to do is append the element to the paper/svg again, and it will go to the front.
So you can write
s.append( element )
or
this.paper.append( element )
if you want this to be a function which works for any paper.
In this example, I would write it like the following with a reusable hover function...
function hoverOverFront() {
this.paper.append( this );
this.attr({ fill: 'green' });
}
function hoverOut() {
this.attr({ fill: 'black' });
};
back.hover( hoverOverFront, hoverOut );
front.hover( hoverOverFront, hoverOut );
jsfiddle

Related

Drag and mouseover in snap.svg

I'm relatively new to javascript, and am learning about drag and drop using snap.svg. My problem is in the drop. I can't tell if the dragged element is over the drop target. In this code, I want to drag the circle over the square, and thought I could use mouseover. My (distilled) example may also be a simpler version of this post.
var paper = Snap(300, 300);
var square = paper.rect(100, 100, 40, 40).attr({fill:"blue"});
var circle = paper.circle(50, 50, 20).attr({fill:"red"});
circle.drag();
square.mouseover(
function() {
console.log("Over the square");
}
);
As written, the mouseover will fire when you move the pointer over the blue square, but not when you drag the red circle over the blue square. If you reverse the creation of the square and circle, the mouseover fires either way, but of course the circle is behind the square.
Evidently the event gets caught in the view hierarchy (or something) and doesn't propagate. There must be an easy way around this. Any help?
(And if the best answer is, "use jQuery," fine, but I'd love to learn how to make this work directly, since snap.svg makes dragging so easy.)
Addition: The direction I'm hoping for: the snap.svg documentation for Element.drag() says, in part, "When Element is dragged over another element, drag.over.<id> fires as well." A fine, event-based direction, which would let me (for example) highlight the drop target without a lot of fuss.
But I haven't figured out how to listen for that event! Any help or advice?
Only quick way without collision or element detection from points that I can think of, is to place an almost invisible clone in front of the object, later in the DOM that you can't really see, eg ...
paper.append( square.clone().attr({ opacity: 0.000001 }) )
jsfiddle
Depends how complex your svgs are going to be as to whether this would work I guess, you also have a slight issue if you drop the element over it, your redrag start won't get picked up, so you would need to code around that as well. I think some testing is probably going to be the most bug free solution (there are a few solutions on S.O for getElementFromPoint or hit detection type solutions).
jsfiddle workaround for point above

Circular canvas corners clickable in Chrome

I have two canvases. I have made them circular using border-radius. The 2nd is positioned inside the first one (using absolute position).
I have click events on both circles. If you click on inside canvas, the color at the point of the click is loaded in the outside canvas with opacity varying from white to the picked color and finally to black. If you click on outer canvas the exact color value at that point is loaded in the text-box at the bottom
I am unable to click in red zones (as shown in figure below) of the outer canvas when using chrome. I tried z-idex, arcs but nothing is helping me. But In Firefox everything is working fine.
Note: You can drag the picker object in the outer circle. But if you leave it in red zones, you would not be able to click it again in Chrome. Clicking in green zone will get you its control again
Code in this JSFiddle
Edit
I excluded all irrelevant code to make it easy. Now there is only a container having two canvas.
Filled simply with two distinct colors. Open following fiddle link in both chrome and firefox. Click on both cirles in different zones and see difference in chrome and firefox. I want them to behave in chrome as they do in firefox
Note I will ultimately draw an image in inner canvas.
Updated Fiddle Link
-
Your problem is because canvases currently are always rectangular, even if they don't look rectangular. Border radius makes the edges except the circle transparent, but it still doesn't stop events in Chrome on the corner areas. This is why you cannot click the bottom circle in those areas
I even tried putting it inside of a container that had a border-radius instead but the click event still goes through
With that being said, you have two options. You could either change your code to only use one canvas with the same type of layout, just drawing the background circle before the other each time. Essentially you'd draw a circle, draw your black to color to white gradient, use the xor operation to combine the two into one circle, then do the same with the rainbox gradient. You must draw the background circle first because canvas paints over the old layers every time
or
You could use javascript to only detect clicks in the circular area which takes just a little bit of math (: This solution is featured in edit below
In the future, CSS Shapes may allow canvases to be non-rectangular elements to be used, I'm actually not sure, but we don't have that capability yet at least
Edit
Alright, so after going through your code a bit it seems there are some things I should cover before I offer a solution
Setup all your finite variables outside of the functions that run every time. This means you don't put them (like radiuses, offsets, etc.) in the click function or something that runs often since they don't change
Your "radius"es are actually "diameter"s. The format of .rect goes .rect(x, y, width (diameter of circle), height (diameter of circle))
Almost always when overlaying canvases like you are you want to make them equal dimensions and starting position to prevent calculation error. In the end it makes it easier, doing all relative positioning with javascript instead of mixing it with CSS. In this case, however, since you're using border-radius instead of arc to make a circle, keep it like it is but position it using javascript ....
jQuery isn't needed for something this simple. If you're worried about any load speed I'd recommend doing it in vanilla javascript, essentially just changing the .click() functions into .onclick functions, but I left jQuery for now
You can declare multiple variables in a row without declaring var each time by using the following format:
var name1 = value1,
name2 = value2;
Variables with the same value you can declare like so:
var name1 = name2 = sameValue;
When children have position:absolute and you want it to be positioned relative to the parent, the parent can have position:relative, position:fixed, or position:absolute. I would think you'd want position:relative in this case
When you don't declare var for a variable it becomes global (unlessed chained with a comma like above). For more on that read this question
Now, onto the solution.
After talking with a friend I realized I could sort do the math calculation a lot easier than I originally thought. We can just calculate the center of the circles and use their radiuses and some if statements to make sure the clicks are in the bounds.
Here's the demo
After everything is set up correctly, you can use the following to detect whether or not it's in the bounds of each
function clickHandler(e, r) {
var ex = e.pageX,
ey = e.pageY,
// Distance from click to center
l = Math.sqrt(Math.pow(cx - ex, 2) + Math.pow(cy - ey, 2));
if(l > r) { // If the distance is greater than the radius
if(r === LARGE_RADIUS) { // Outside of the large
// Do nothing
} else { // The corner area you were having a problem with
clickHandler(e, LARGE_RADIUS);
}
} else {
if(r === LARGE_RADIUS) { // Inside the large cirle
alert('Outer canvas clicked x:' + ex + ',y:' + ey);
} else { // Inside the small circle
alert('Inner canvas clicked x:' + ex + ',y:' + ey);
}
}
}
// Just call the function with the appropriate radius on click
$(img_canvas).click(function(e) { clickHandler(e, SMALL_RADIUS); });
$(wheel_canvas).click(function(e) { clickHandler(e, LARGE_RADIUS); });
Hopefully the comments above and code make enough sense, I tried to clean it up as best as I could. If you have any questions don't hesitate to ask!

Changing opacity on Mouseover

The ultimate goal of my project is to make my image of circle chart interactive on mouseovers. I want the pieces of the circle to change opacity to .5 (from 1) when the user hovers them. I have an image of the chart but I'm not sure how to make areas of one single image change opacity on hover. I have tried several things:
I image mapped the chart with each piece in its own map, but I wasn't sure how to change opacity of an area of one single image (css)(if its even possible)
My second approach was that i sliced the chart up into individual pieces and made their opacity .5 and saved them all separately. Then, I image mapped the single image of the chart and tried to load the individual piece on hover (css)
My final approach was saving each piece of the chart as individual images and when the image is hovered, change the opacity to .5 with css. This works perfectly except i am not sure how to position the pieces to form a perfect circle in dreamweaver.
Any direction or advise is greatly appreciated. I am willing to learn javascript or jquery to help get this done.
Thank you
EDIT Image of the chart is now attached
http://i.stack.imgur.com/KwIfY.jpg
I'm not sure if I understood the question right regarding the current answers but if you want to make the parts of the chart interactive I have 2 approaches:
To achieve the effect with pure CSS I guess you need to divide the chart in individual images as you already mentioned. The positioning is quite simple. I've used in my demo below one image an let it rotate. In your case you can cut each part of the chart individually and get the right place for them with absolute positionig.
Again as you already mentioned you can use map area to define the parts of the chart. With a plugin like this: ImageMapster you can achieve what you want. I've used this once for the following map. It's again very simple, when hovering any part of the map it's background will be replaced by another background. In your case you could save the chart with full opacity and display on hover an image of the chart with 50% opacity.
Demo
The Demo is not very clean as I didn't spent much time in position the parts perfectly but you can see how it works.
transform: rotate(45deg);
I don't know if CSS3 transition will fit to you:
http://www.w3schools.com/css/css3_transitions.asp
.chart-item { opacity: 0.5; transition:opacity 2s; }
.chart-item:hover { opacity: 1; }
Check documentation for browser support.
Maybe create a div and put each image as the background or content of one div (in order), then create a listener for the div class to change opacity upon mouseenter or mouseleave using jQuery.
Here's a simple example (pardon any mistakes):
jQuery:
$( ".somedivclass" )
.mouseenter(function() {
$(this).fadeTo(200, 0.5);
})
.mouseleave(function() {
$(this).fadeTo(200, 1);
});
Here's more info on $.mouseenter(). Here's some for $.fadeTo().
Check this demo. Hover your cursor exactly on the eyes of the owl, and you will see the opacity changing. It will not change if you hover on the rest of the image.
http://jsfiddle.net/q6d57/14/
$('.eye1').on('mouseenter mouseleave', function(e) {
$('.box2').stop(true, false).fadeToggle(1500)
});
I suggest using svg. Here is an implementation of exactly what you are trying to do, because I felt like learning d3.js today:
http://jsfiddle.net/6m26k/1/
You don't need to make the chart through code though, because you can just load the svg onto the page with html5 and use css similar to mine:
.arc.filled:hover {
opacity: .8;
cursor: pointer;
}

KineticJS: Draw Arrow between two shapes

So, I want to create a finite state machine-visualizer/editor with the help of kineticjs and i'm stumbling with the following scenario:
I have two "nodes", let's say circle-objects (grouped with a label) which are draggable on my stage. Now I wan't to click on one circle, hold the mouse and move it and add a connection (an arrow, for simplicities sake) between the two shapes.
So it would be great to have any hints on how to accomplish this for I haven't found a solution yet.
To specify it: The nodes themselves should stay draggable. My thought was: Add a black circle and a white circle with a slightly smaller radius, group them. then on dragstart white circle -> drag node, on dragstart black circle -> draw arrow.
The Problem is how to draw an arrow starting from one shape and following the mouse to it's target (which can be another nodegroup => connection to this group or a blank point of the stage => an overlay opens which lets the user choose another node to draw or cancel the drawing).
I hope this is somewhat clear to understand. For more information please feel free to ask me.
Best regards,
Dominik
p.s.: The behaviour seems to be exactly like the behaviour lucidchart (dot com) uses when creating diagrams, so maybe you understand what I want to achieve better looking at their demo here: https://www.lucidchart.com/demo .
First off, for simplicity's sake here is a fiddle on how to draw a basic Line with your mouse and KineticJS: http://jsfiddle.net/projeqht/fF3hh/
Let's say you already have two circles on the stage, and you need to draw a line to connect them.
We can use e.targetNode to select the nodes on each event (mousedown, mouseup), for example:
layer.on("mousedown", function (e) {
var nodeDown = e.targetNode;
}
layer.on("mouseup", function (e) {
var nodeUp = e.targetNode;
}
We need to check if the parent of nodeDown is a Kinetic.Group or something else.
If the target node nodeDown has a Kinetic.Group for a parent, we can use this Group to store the new line, and the 2nd target node nodeUp.
If the target node nodeUp does not have a Kinetic.Group for a parent, we need to see if nodeUp has a Group for a parent. If nodeUp has a Kinetic.Group for a parent, then we can use that Group to store the new line, and the first target node nodeDown.
If neither nodeDown or nodeUp have a group for a parent, then we will need to create a new group for them and add all 3 shapes (2 circles and a line) to that new group.
Use this tutorial to learn how to move shapes from 1 group to another: http://www.html5canvastutorials.com/kineticjs/html5-canvas-move-shape-to-another-container-with-kineticjs/
Also, if you move a shape from one group to another, you may want to remove() or destroy() the extra group if it is no longer needed.
While drawing a Line, you will have to disable dragging the shapes, so that you can drag and draw with a mouse. You can do that by doing something similar to this:
function stopDrag() {
for (var i=0; i<layer.children.length; i++) {
layer.children[i].setDraggable(false);
}
}
function startDrag() {
for (var i=0; i<layer.children.length; i++) {
layer.children[i].setDraggable(true);
}
}
This will make all the children of layer draggable and undraggable, but you might want to limit that by being more specific than select layer.children. A nice trick I liked to use here was to name all groups that were draggable as "draggable_shapes" and then use var draggableArray = stage.get('.draggable_shapes') to select all the groups that are allowed to be dragged, then you could loop through that array and setDraggable().
Another point to note is that the X and Y coordinates of the Line will be a bit tricky to calculate, depending on if it has a Group as a parent or a Layer. If the Line is grouped, line's coordinates will be relative to the Group position, or else the Line's coordinates will be relative to the Stage (top left corner).
This will get you started on connecting a line with two different circles. It's up to you to do the coordinate logic if you want the lines to only connect on the outer rim of the circles.
Maybe you might want to add a transparent rectangle (attribute opacity: 0) behind each circle, so that on mousedown with the rectangle, you will call drawLine() to start drawing a line. Or else if the user clicks the circle, it will drag the group. At least that has similar functionality to the lucid charts application.
Custom Hit Function (http://www.html5canvastutorials.com/kineticjs/html5-canvas-kineticjs-custom-hit-function-tutorial/) would probably be a cleaner way to do this but I'm not 100% on using Custom Hit Functions, someone else might know better.
Let me know if you need further help. Good luck!

I would like to reposition a circle created through Raphael js, and to use it as a letter in a title

I have created a vector graphic using Raphael JS - specifically a circle.
I would now like to use this circle as the letter "O" in a title. It is also a circle that will animate upon click. I would like to know if this is at all possible.
Here is a fiddle to explain better what I'm trying to say.
The html is very simple:
<h2>N<span id="canvas_cont"></span>OTRE APPROCHE :</h2>
Here is the jsfiddle
Basically the circle will act as the second letter in "Notre", and when clicked will move to the right of the screen. Other things will happen after, but this effect is what I'm trying to get....
Placing the Raphael canvas in a span is clever, but at the end of the day I suspect you'll regret mixing native HTML with Raphael in this way. Doing so would probably require a lot of absolute positioning and z-indexes that are better handled and supported in Raphael.
I recommend you simple draw the text in Raphael:
var text = r.set();
text.push(
r.text(10,20,"N"),
r.text(70,20,"TRE APPROCHE :")
);
text.attr({
'text-anchor': 'start',
'font-size':'36px'
});
If the SVG/VML styling is inadequate, you could also just use an image. Again, I would recommend placing that image on the canvas using Raphael (paper.image());
Note that, in the updated fiddle, I made the canvas a div the width of the logo.
Updated fiddle.

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