Source code
<script> var stage, circle; function init() { stage = new createjs.Stage("demoCanvas"); circle = stage.addChild(new createjs.Shape()); circle.graphics.beginFill("red").drawCircle(50,50,50); circle.x = 0; circle.y = 0; // All the same from above as 0.1 createjs.Ticker.addEventListener("tick", tick); // Add a "tick" event so that the function tick(){...} runs periodically } function tick() { circle.alpha = 0.2; if (circle.hitTest(stage.mouseX, stage.mouseY)) { circle.alpha = 1; } // If mouse hits the circle, change the circle colour to solid stage.update(); // Draw on canvas (notice it needs to be updated constantly so we did not draw in init() function cuz it's pointless) } </script> <canvas id="demoCanvas" width="300" height="100"> alternate content </canvas> <script> init(); </script>