After having seen how to apply styles and colors in the previous chapter, we will now have a look at how to draw text onto the canvas.

Drawing text

The canvas rendering context provides two methods to render text:

fillText(text, x, y [, maxWidth])

• Fills a given text at the given (x,y) position. Optionally with a maximum width to draw.

strokeText(text, x, y [, maxWidth])

• Strokes a given text at the given (x,y) position. Optionally with a maximum width to draw.

A fillText example

The text is filled using the current fillStyle.

function draw() {
  var ctx = document.getElementById('canvas').getContext('2d');
  ctx.font = '48px serif';
  ctx.fillText('Hello world', 10, 50);
}

A strokeText example

The text is filled using the current strokeStyle.

function draw() {
  var ctx = document.getElementById('canvas').getContext('2d');
  ctx.font = '48px serif';
  ctx.strokeText('Hello world', 10, 50);
}

Styling text

In the examples above we are already making use of the font property to make the text a bit larger than the default size. There are some more properties which let you adjust the way the text gets displayed on the canvas:

font = value

• The current text style being used when drawing text. This string uses the same syntax as the CSS font property. The default font is 10px sans-serif.

textAlign = value

• Text alignment setting. Possible values:start,end,left,rightorcenter. The default value isstart.

textBaseline = value

• Baseline alignment setting. Possible values: top, hanging, middle, alphabetic, ideographic, bottom. The default value is alphabetic.

direction = value

• Directionality. Possible values:ltr, rtl, inherit. The default value is inherit.

These properties might be familiar to you if you have worked with CSS before.

The following diagram from the WHATWG demonstrates the various baselines supported by the textBaseline property.

Advanced text measurements

In the case you need to obtain more details about the text, the following method allows you to measure it.

measureText()

• Returns a TextMetrics object containing the width, in pixels, that the specified text will be when drawn in the current text style.

The following code snippet shows how you can measure a text and get its width.

function draw() {
  var ctx = document.getElementById('canvas').getContext('2d');
  var text = ctx.measureText('foo'); // TextMetrics object
  text.width; // 16;
}