1 files changed, 104 insertions, 0 deletions
diff --git a/devtools/client/inspector/animation/components/graph/ComputedTimingPath.js b/devtools/client/inspector/animation/components/graph/ComputedTimingPath.js
new file mode 100644
index 0000000000..fed25e161e
--- /dev/null
+++ b/devtools/client/inspector/animation/components/graph/ComputedTimingPath.js
@@ -0,0 +1,104 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+const PropTypes = require("resource://devtools/client/shared/vendor/react-prop-types.js");
+const dom = require("resource://devtools/client/shared/vendor/react-dom-factories.js");
+
+const {
+  createSummaryGraphPathStringFunction,
+  SummaryGraphHelper,
+} = require("resource://devtools/client/inspector/animation/utils/graph-helper.js");
+const TimingPath = require("resource://devtools/client/inspector/animation/components/graph/TimingPath.js");
+
+class ComputedTimingPath extends TimingPath {
+  static get propTypes() {
+    return {
+      animation: PropTypes.object.isRequired,
+      durationPerPixel: PropTypes.number.isRequired,
+      keyframes: PropTypes.object.isRequired,
+      offset: PropTypes.number.isRequired,
+      opacity: PropTypes.number.isRequired,
+      simulateAnimation: PropTypes.func.isRequired,
+      totalDuration: PropTypes.number.isRequired,
+    };
+  }
+
+  render() {
+    const {
+      animation,
+      durationPerPixel,
+      keyframes,
+      offset,
+      opacity,
+      simulateAnimation,
+      totalDuration,
+    } = this.props;
+
+    const { state } = animation;
+    const effectTiming = Object.assign({}, state, {
+      iterations: state.iterationCount ? state.iterationCount : Infinity,
+    });
+
+    // Create new keyframes for opacity as computed style.
+    // The reason why we use computed value instead of computed timing progress is to
+    // include the easing in keyframes as well. Although the computed timing progress
+    // is not affected by the easing in keyframes at all, computed value reflects that.
+    const frames = keyframes.map(keyframe => {
+      return {
+        opacity: keyframe.offset,
+        offset: keyframe.offset,
+        easing: keyframe.easing,
+      };
+    });
+
+    const simulatedAnimation = simulateAnimation(frames, effectTiming, true);
+
+    if (!simulatedAnimation) {
+      return null;
+    }
+
+    const simulatedElement = simulatedAnimation.effect.target;
+    const win = simulatedElement.ownerGlobal;
+    const endTime = simulatedAnimation.effect.getComputedTiming().endTime;
+
+    // Set the underlying opacity to zero so that if we sample the animation's output
+    // during the delay phase and it is not filling backwards, we get zero.
+    simulatedElement.style.opacity = 0;
+
+    const getValueFunc = time => {
+      if (time < 0) {
+        return 0;
+      }
+
+      simulatedAnimation.currentTime = time < endTime ? time : endTime;
+      return win.getComputedStyle(simulatedElement).opacity;
+    };
+
+    const toPathStringFunc = createSummaryGraphPathStringFunction(
+      endTime,
+      state.playbackRate
+    );
+    const helper = new SummaryGraphHelper(
+      state,
+      keyframes,
+      totalDuration,
+      durationPerPixel,
+      getValueFunc,
+      toPathStringFunc
+    );
+
+    return dom.g(
+      {
+        className: "animation-computed-timing-path",
+        style: { opacity },
+        transform: `translate(${offset})`,
+      },
+      super.renderGraph(state, helper)
+    );
+  }
+}
+
+module.exports = ComputedTimingPath;