| <!DOCTYPE html> |
| <html> |
| <head> |
| <style> |
| #background { |
| background-color: yellow; |
| display: inline-block; |
| } |
| |
| .container { |
| font-size: 0px; |
| } |
| </style> |
| </head> |
| <body> |
| |
| <div id="background"> |
| <div class="container"> |
| <canvas id ="opaque" width="100" height="100"></canvas> |
| </div> |
| <div class="container"> |
| <canvas id ="nonopaque" width="100" height="100"></canvas> |
| </div> |
| </div> |
| |
| <script> |
| function drawCanvas(canvasID, hasAlpha) { |
| var canvas = document.getElementById(canvasID); |
| var context = canvas.getContext("2d", {alpha: hasAlpha}); |
| context.clearRect(0, 0, canvas.width, canvas.height); |
| context.strokeStyle = 'blue'; |
| context.lineWidth = 4; |
| context.strokeRect(20, 20, 60, 60); |
| }; |
| |
| drawCanvas('opaque', false); |
| drawCanvas('nonopaque', true); |
| |
| </script> |
| </body> |
| </html> |
