Hover events on element covered by higher z-index?

Question

I have a canvas element (canvas-mouse) that spans the whole screen - its purpose is to draw a 50% opacity circle around the mouse of a certain size (grabsize). Also on the page will be a number of images in divs. I want these images to be clickable/hoverable, but I also want the 50% opacity circle in canvas-mouse to appear on top of them.

Is there any way to accomplish this?

HTML:

<canvas id="canvas-mouse" class="fullscreen"></canvas>
<div class="object die"><img src="images/Die_d6.svg"></div>

CSS:

html, body {
    width:  100%;
    height: 100%;
    margin: 2px;
    overflow: hidden;
    color: #FFFFFF;
    background-color: #2C744C;
}

canvas.fullscreen {
    position: absolute;
    left: 0px;
    top: 0px;
    z-index: -1;
}

.object {
    position: absolute;
}

#canvas-mouse {
    z-index: 10;
}

JavaScript:

CanvasRenderingContext2D.prototype.drawCircle = function(xpos, ypos, radius, linewidth, linecolor, fill) {
    if(typeof(linewidth)==="undefined") {
        linewidth = 1;
    }
    if(typeof(linecolor)==="undefined") {
        linecolor = "#000000";
    }

    this.beginPath();
    this.arc(xpos, ypos, radius, 0, 2*Math.PI, false);
    this.lineWidth = linewidth;
    if(typeof(fill)!=="undefined") {
        this.fillStyle = fill
        this.fill();
    }
    this.strokeStyle = linecolor;
    this.stroke();
}
CanvasRenderingContext2D.prototype.maximize = function() {
    this.canvas.width = window.innerWidth;
    this.canvas.height = window.innerHeight;
}
mousectx = $("#canvas-mouse")[0].getContext("2d");
mousectx.maximize();

//Dice handlers
$(".object.die").hover(function() {
    //Hover event goes here
})
$(".object.die").mousedown(function() {
    //Click event goes here
})

//Mouse movement handler
$(document).mousemove(function(e){
    //Get the mouse positions and put them in {mouse}
    mouse.x = e.pageX;z
    mouse.y = e.pageY;

    //Redraw the grab circle
    mousectx.clearCanvas();
    mousectx.drawCircle(mouse.x,mouse.y,grabsize,1,"#000000","rgba(0,0,255,0.5)");
});

Thanks in advance.

this http://stackoverflow.com/questions/3680429/click-through-a-div-to-underlying-elements might solve the issue.. — T J, Mar 18 '14 at 19:38
Shouldn't canvas-mouse have a relative position for the z-index to function? — Rstew, Mar 18 '14 at 19:41

score 18 · Accepted Answer · answered Mar 18 '14 at 19:41

18

Try using pointer-events: none. This rule tells the browser to ignore an element. Mouse events won't be received by it, but will 'pass through'.

#canvas-mouse {
    z-index: 10;
    pointer-events: none;
}

answered Mar 18 '14 at 19:41

Oscar Paz

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Hover events on element covered by higher z-index?

1 Answers1