Question

I can’t seem to get this working, what should happen is when the user presses the spacebar ie. event.which=32 it does move but it moves 20 up and 20 over all at once it doesn’t go 1 by 1 every second or 1000 milliseconds

$(function() {

    var canvas = document.getElementById('canvas');
    var ctx = canvas.getContext('2d');
    var x =0;
    var y =100;
    var w =50;
    var h =50;
    var prekey = '';
    ctx.fillStyle = "rgb(200,0,0)";  
    ctx.fillRect (x, y, w, h);
    var i=0; var hi = '';

    $("*").keydown(function(event)  {
        ctx.clearRect (0, 0, 500, 300);

        if (event.which == 37){
            if (x!=0){x=x-1;} prekey=event.which;
        }
        if (event.which == 39){if (x!=450){x=x+1;} prekey=event.which;}
        if (event.which == 32)  {
            if (prekey==39) {
                for(i=0;i<=20;i++) {
                    function jumpBox() {
                        x=x+1;
                        y=y-1;
                        ctx.clearRect (0, 0, 500, 300);
                        ctx.fillRect (x, y, w, h);
                        return 1;
                    }

                    var t = setTimeout(jumpBox, 1000);
                }

            if (prekey==37){}
            }           
        ctx.fillRect (x, y, w, h);
    });

});

Answer 1

You are setting all your setTimeouts at the same time through the for loop. You need to wait before calling the next one.

if (prekey==39) { 
    var count = 0,
    jumpBox;
    jumpBox = function()  {
        x=x+1;
        y=y-1;
        ctx.clearRect (0, 0, 500, 300);
        ctx.fillRect (x, y, w, h);

        if(++count < 20) {
           setTimeout(jumpBox, 1000);
        }    
    }
    var t = setTimeout(jumpBox, 1000);
}