<!doctype html>
<html>
<head>
<script src="../../http/tests/inspector/resources/inspector-test.js"></script>
<script>

function addCompositedLayer()
{
    var element = document.createElement("div");
    element.className = "composited";
    element.id = "last-element";
    document.body.appendChild(element);
    
    // Force layout to trigger a layer update.
    document.body.offsetWidth;

    requestAnimationFrame(() => {
        TestPage.dispatchEventToFrontend("TestPageDidAppendChild");
    });
};

function test()
{
    let documentNode = null;

    let suite = InspectorTest.createAsyncSuite("LayerTree.layerTreeDidChange");

    suite.addTestCase({
        name: "LayerTree.layerTreeDidChange.WithRequest",
        description: "Check that layerTreeDidChange is able to be dispatched once LayerTree.commands.layersForNode is called.",
        test(resolve, reject) {
            let layerTreeDidChangeCount = 0;
            let testPageDidAppendChildCount = 0;

            let handleLayerTreeDidChange = null;
            let handleTestPageDidAppendChild = InspectorTest.addEventListener("TestPageDidAppendChild", (event) => {
                ++testPageDidAppendChildCount;

                if (testPageDidAppendChildCount === 2) {
                    WI.layerTreeManager.removeEventListener(WI.LayerTreeManager.Event.LayerTreeDidChange, handleLayerTreeDidChange);
                    InspectorTest.removeEventListener("TestPageDidAppendChild", handleTestPageDidAppendChild);

                    InspectorTest.expectEqual(layerTreeDidChangeCount, 2, "LayerTreeDidChange should fire after layersForNode is called");

                    resolve();
                }
            });

            WI.layerTreeManager.layersForNode(documentNode, (layers) => {
                handleLayerTreeDidChange = WI.layerTreeManager.addEventListener(WI.LayerTreeManager.Event.LayerTreeDidChange, (event) => {
                    ++layerTreeDidChangeCount;

                    InspectorTest.log("Layer tree changed");

                    if (layerTreeDidChangeCount === 1) {
                        WI.layerTreeManager.layersForNode(documentNode, (layers) => {
                            InspectorTest.log("Creating layer...");
                            InspectorTest.evaluateInPage(`addCompositedLayer()`);
                        });
                    }
                });

                InspectorTest.log("Creating layer...");
                InspectorTest.evaluateInPage(`addCompositedLayer()`);
            });
        },
    });

    suite.addTestCase({
        name: "LayerTree.layerTreeDidChange.WithoutRequest",
        description: "Check that layerTreeDidChange doesn't dispatch more than once until LayerTree.commands.layersForNode is called.",
        test(resolve, reject) {
            let layerTreeDidChangeCount = 0;
            let handleLayerTreeDidChange = WI.layerTreeManager.addEventListener(WI.LayerTreeManager.Event.LayerTreeDidChange, (event) => {
                ++layerTreeDidChangeCount;

                InspectorTest.log("Layer tree changed");

                if (layerTreeDidChangeCount === 1) {
                    InspectorTest.log("Creating layer...");
                    InspectorTest.evaluateInPage(`addCompositedLayer()`);
                }
            });

            let testPageDidAppendChildCount = 0;
            let handleTestPageDidAppendChild = InspectorTest.addEventListener("TestPageDidAppendChild", (event) => {
                ++testPageDidAppendChildCount;

                if (testPageDidAppendChildCount === 2) {
                    WI.layerTreeManager.removeEventListener(WI.LayerTreeManager.Event.LayerTreeDidChange, handleLayerTreeDidChange);
                    InspectorTest.removeEventListener("TestPageDidAppendChild", handleTestPageDidAppendChild);

                    InspectorTest.expectEqual(layerTreeDidChangeCount, 1, "LayerTreeDidChange should not fire before layersForNode is called");

                    resolve();
                }
            });

            WI.layerTreeManager.layersForNode(documentNode, (layers) => {
                InspectorTest.log("Creating layer...");
                InspectorTest.evaluateInPage(`addCompositedLayer()`);
            });
        },
    });

    WI.domManager.requestDocument((node) => {
        documentNode = node;
        if (!documentNode) {
            InspectorTest.fail("Missing document node.");
            InspectorTest.completeTest();
            return;
        }

        suite.runTestCasesAndFinish();
    });
}
</script>
<style>
.composited {
    -webkit-transform: translateZ(0);
}
</style>
</head>
<body onload="runTest()">
<p>Tests for LayerTree.event.layerTreeDidChange.</p>
</body>
</html>