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The CanvasRenderingContext2D
.textAlign
property of the Canvas 2D API specifies the current text alignment being used when drawing text. Beware that the alignment is base on the x value of the CanvasRenderingContext2D.fillText method. So if textAlign="center", then the text would be drawn at x-50%*width.
Syntax
ctx.textAlign = "left" || "right" || "center" || "start" || "end";
Options
Possible values:
- left
- The text is left-aligned.
- right
- The text is right-aligned.
- center
- The text is centered.
- start
- The text is aligned at the normal start of the line (left-aligned for left-to-right locales, right-aligned for right-to-left locales).
- end
- The text is aligned at the normal end of the line (right-aligned for left-to-right locales, left-aligned for right-to-left locales).
The default value is start
.
Examples
Using the textAlign
property
This is just a simple code snippet using the textAlign
property to set a different text alignment.
HTML
<canvas id="canvas"></canvas>
JavaScript
var canvas = document.getElementById("canvas"); var ctx = canvas.getContext("2d"); ctx.font = "48px serif"; ctx.textAlign = "left"; ctx.strokeText("Hello world", 0, 100);
Edit the code below and see your changes update live in the canvas:
Playable code
<canvas id="canvas" width="400" height="200" class="playable-canvas"></canvas> <div class="playable-buttons"> <input id="edit" type="button" value="Edit" /> <input id="reset" type="button" value="Reset" /> </div> <textarea id="code" class="playable-code"> ctx.font = "48px serif"; ctx.textAlign = "left"; ctx.strokeText("Hello world", 0, 100);</textarea>
var canvas = document.getElementById("canvas"); var ctx = canvas.getContext("2d"); var textarea = document.getElementById("code"); var reset = document.getElementById("reset"); var edit = document.getElementById("edit"); var code = textarea.value; function drawCanvas() { ctx.clearRect(0, 0, canvas.width, canvas.height); eval(textarea.value); } reset.addEventListener("click", function() { textarea.value = code; drawCanvas(); }); edit.addEventListener("click", function() { textarea.focus(); }) textarea.addEventListener("input", drawCanvas); window.addEventListener("load", drawCanvas);
Specifications
Specification | Status | Comment |
---|---|---|
WHATWG HTML Living Standard The definition of 'CanvasRenderingContext2D.textAlign' in that specification. |
Living Standard |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|
Basic support | (Yes) | 3.5 (1.9.1) | 9 | (Yes) | (Yes) |
Feature | Android | Chrome for Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|
Basic support | (Yes) | (Yes) | 1.0 (1.9.1) | (Yes) | (Yes) | (Yes) |
See also
- The interface defining it,
CanvasRenderingContext2D
.
Tag del documento e collaboratori
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