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javascripthtmlcsshtml5-canvas

Mouseover only active once I'm on my canvas and not my shape


i'm a beginner using canvas and also javascript and I'm trying to use the mouseover. I got to get it work a bit but it's only when the mouse is on the canvas, I'd like to make my square color change once my mouse is on it.

How can I get it work ?

Here's my code :

  window.onload = function()
    {
        canvasEvent();
    }

    function canvasEvent()
    {
        var c=document.getElementById("canvas");
        var ctx=c.getContext("2d");
        ctx.rect(150, 150, 100, 100);
        ctx.fillStyle = "blue";
        ctx.fill();
        ctx.stroke();   

        c.addEventListener("mouseover", hover, false);
        c.addEventListener("mouseout", hoverOut, false);
    }

    function hover(e)
    {
        var c=document.getElementById("canvas");
        var ctx=c.getContext("2d");
        ctx.fillStyle = 'green';
        ctx.fill();
        ctx.stroke();
    }

    function hoverOut(e)
    {
        var c=document.getElementById("canvas");
        var ctx=c.getContext("2d");
        ctx.fillStyle = 'blue';
        ctx.fill();
    }
canvas#canvas{
    background-color:#DDDDDD;
    display: block;
    margin: 0 auto;
}
<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>TEST</title>
    <script type="text/javascript" src="script.js"></script>
    <link rel="stylesheet" type="text/css" href="style.css">
</head>
<body>
    <center>
        <canvas id="canvas" width="550" height="400"></canvas>
    </center>
</body>
</html>


Solution

  • just check if mouse is on rectangle

    window.onload = function()
    {
        canvasEvent();
    }
    
    function canvasEvent()
    {
        var c=document.getElementById("canvas");
        var ctx=c.getContext("2d");
        ctx.rect(150, 150, 100, 100);
        ctx.fillStyle = "blue";
        ctx.fill();
        ctx.stroke();   
    
        c.addEventListener("mousemove", e => { 
    
          if (
            e.offsetX >=150 && 
            e.offsetX <= 250 && 
            e.offsetY >= 150 && 
            e.offsetY<=250){
              hover();
          }
          else{
          hoverOut();
          }
        });
    }
    
    function hover(e)
    {
        var c=document.getElementById("canvas");
        var ctx=c.getContext("2d");
        ctx.fillStyle = 'green';
        ctx.fill();
        ctx.stroke();
    }
    
    function hoverOut(e)
    {
        var c=document.getElementById("canvas");
        var ctx=c.getContext("2d");
        ctx.fillStyle = 'blue';
        ctx.fill();
    }
    canvas#canvas{
        background-color:#DDDDDD;
        display: block;
        margin: 0 auto;
    }
    <!DOCTYPE html>
    <html>
    <head>
        <meta charset="utf-8">
        <meta name="viewport" content="width=device-width, initial-scale=1">
        <title>TEST</title>
        <script type="text/javascript" src="script.js"></script>
        <link rel="stylesheet" type="text/css" href="style.css">
    </head>
    <body>
        <center>
            <canvas id="canvas" width="550" height="400"></canvas>
        </center>
    </body>
    </html>