Canvas Has White Space At The Bottom And Scrolls Too Far

I'm using this answer https://stackoverflow.com/a/36233727/1350146 to scroll a canvas in a div. I'm also hiding the scrollbar. The problem is it appears to scroll too far, in this

Solution 1:

Make the canvas a block element or use vertical-align:top. By default, canvas is an inline element and it will behave similary to an img; thus you will have the whitespace issue due to vertical alignement (Image inside div has extra space below the image)

var c = document.getElementById("myCanvas");
var ctx = c.getContext("2d");
ctx.fillStyle = '#00aa00'
ctx.fillRect(0, 0, c.width, c.height);
ctx.fillStyle = '#fff'
ctx.font='12pt A'
ctx.fillText("scroll here to see red from screen div", 30, 50);

.screen {
  background: red;
  height: 100px;
  width: 300px;
  overflow: auto;
  border-radius: 20px;
}
canvas {
 display:block;
}

::-webkit-scrollbar {
  width: 0px;
  height: 0px;
}

<divclass="screen"><canvasid="myCanvas"width="300"height="120"></canvas></div>

Solution 2:

Use a negative margin-bottom value for your canvas element. Anything between margin-bottom: -5px; and margin-bottom: -105px; will work for this example.

var c = document.getElementById("myCanvas");
var ctx = c.getContext("2d");
ctx.fillStyle = '#00aa00'
ctx.fillRect(0, 0, c.width, c.height);
ctx.fillStyle = '#fff'
ctx.font='12pt A'
ctx.fillText("scroll here to see red from screen div", 30, 50);

.screen {
  background: red;
  height: 100px;
  width: 300px;
  overflow: auto;
  border-radius: 20px;
  
}

::-webkit-scrollbar {
  width: 0px;
  height: 0px;
}

canvas {
  margin-bottom: -5px;
}

<divclass="screen"><canvasid="myCanvas"width="300"height="120"></canvas></div>