canvas-background-layer.html | Explore in Territory

<!DOCTYPE html>
<html>
  <head>
    <style type="text/css">
      .container {
        width: 60px;
        height: 60px;
        margin: 5px;
      }
      canvas {
        background-color: green;
      }
      #canvas-simple {}
      #canvas-padding { padding: 5px; }
      #canvas-border { border: 5px solid; }
      #canvas-image { background-image: url("../resources/simple_image.png"); }
      #canvas-transparent-background { background-color: rgba(0, 255, 0, 0.5); }
      #canvas-opaque {}
      #canvas-opaque-border { border: 5px solid; }
      #canvas-opaque-box-shadow { box-shadow: 10px 10px 0px red; }
    </style>
    <script>
        if (window.testRunner)
            testRunner.dumpAsText();
        if (window.internals)
            internals.runtimeFlags.accelerated2dCanvasEnabled = true;

        function drawCanvas(canvasID, hasAlpha) {
            var canvas = document.getElementById(canvasID);
            var context = canvas.getContext("2d", {alpha: hasAlpha});
            context.clearRect(0, 0, canvas.width, canvas.height);
        };

        function doTest() {
            // Simple background can be direct-composited with content-layer.
            // The container GraphicsLayer does not paint anything.
            // The content layer should be treated as opaque because the
            // background color is opaque.
            drawCanvas('canvas-simple', true);

            // Padding makes the background-box bigger than content-box.
            // The container GraphicsLayer needs to paint background.
            drawCanvas('canvas-padding', true);

            // Content layer cannot direct-composite any kind of box decoration.
            // The container GraphicsLayer needs to paint box decorations.
            drawCanvas('canvas-border', true);

            // Content layer cannot direct-composite background image.
            // The container GraphicsLayer needs to paint background image.
            drawCanvas('canvas-image', true);

            // Simple background can be direct-composited with content-layer.
            // The container GraphicsLayer does not paint anything.
            // The content layer should not be treated as opaque because the 
            // background color is not opaque.
            drawCanvas('canvas-transparent-background', true);

            // Contents of the canvas are opaque so the background does
            // not need to be painted.
            drawCanvas('canvas-opaque', false);

            // The layer for this canvas is technically opaque because it has
            // opaque contents and an opque border style, but blink does not
            // currently analyze border style opacity, so the layer will be
            // conservatively considered non-opaque.  If a future CL causes
            // this test to fail due to this case being marked as opaque, that
            // would be an improvement.
            drawCanvas('canvas-opaque-border', false);

            // The presence of a of a box shadow makes the canvas's layer
            // non-opaque even though canvas contents are opque.
            drawCanvas('canvas-opaque-box-shadow', false);

            if (window.testRunner && window.internals)
                document.getElementById('layer-tree').innerText = internals.layerTreeAsText(document);
        };
        window.addEventListener('load', doTest, false);
    </script>
  </head>

  <body>
    <div class="container">
      <canvas id="canvas-simple" width="50" height="50"></canvas>
    </div>
    <div class="container">
      <canvas id="canvas-transparent-background" width="50" height="50"></canvas>
    </div>
    <div class="container">
      <canvas id="canvas-padding" width="50" height="50"></canvas>
    </div>
    <div class="container">
      <canvas id="canvas-border" width="50" height="50"></canvas>
    </div>
    <div class="container">
      <canvas id="canvas-image" width="50" height="50"></canvas>
    </div>
    <div class="container">
      <canvas id="canvas-opaque" width="50" height="50"></canvas>
    </div> 
    <div class="container">
      <canvas id="canvas-opaque-border" width="50" height="50"></canvas>
    </div> 
    <div class="container">
      <canvas id="canvas-opaque-box-shadow" width="50" height="50"></canvas>
    </div> 
    <pre id="layer-tree"></pre>
  </body>
</html>
chromium/third_party/blink/web_tests/compositing/draws-content/canvas-background-layer.html
