Why Does My Canvas Have Extra White Space and Excessive Scrolling?

Canvas Scroll Issue: White Space at Bottom and Excessive Scrolling

When scrolling a canvas within a div, users may encounter two problems: white space at the bottom of the canvas and excessive scrolling that reveals the underlying div's background. This is primarily due to the canvas's default inline-element status.

Solution: Convert Canvas to Block Element

To resolve these issues, the canvas must be converted to a block element. This can be done through CSS by adding the property "display: block" to the canvas.

Vertical Alignment

Alternatively, if converting the canvas to a block element is not suitable, vertical alignment can be used. Add "vertical-align: top" to the canvas's CSS to ensure it is aligned at the top of the div, eliminating any white space at the bottom.

Revised Code:

The following revised code snippet incorporates the suggested solutions:

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; /* or vertical-align:top; */
}

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

<div class="screen">
  <canvas>

By implementing these modifications, the canvas will now scroll to the end of its content without revealing the underlying div's background.

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