1 files changed, 245 insertions, 0 deletions
diff --git a/devtools/client/inspector/animation/components/keyframes-graph/ComputedStylePath.js b/devtools/client/inspector/animation/components/keyframes-graph/ComputedStylePath.js
new file mode 100644
index 0000000000..1da5c4da96
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+++ b/devtools/client/inspector/animation/components/keyframes-graph/ComputedStylePath.js
@@ -0,0 +1,245 @@
+/* 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 {
+  PureComponent,
+} = require("resource://devtools/client/shared/vendor/react.js");
+const dom = require("resource://devtools/client/shared/vendor/react-dom-factories.js");
+const PropTypes = require("resource://devtools/client/shared/vendor/react-prop-types.js");
+
+const {
+  createPathSegments,
+  DEFAULT_DURATION_RESOLUTION,
+  getPreferredProgressThresholdByKeyframes,
+  toPathString,
+} = require("resource://devtools/client/inspector/animation/utils/graph-helper.js");
+
+/*
+ * This class is an abstraction for computed style path of keyframes.
+ * Subclass of this should implement the following methods:
+ *
+ * getPropertyName()
+ *   Returns property name which will be animated.
+ *   @return {String}
+ *           e.g. opacity
+ *
+ * getPropertyValue(keyframe)
+ *   Returns value which uses as animated keyframe value from given parameter.
+ *   @param {Object} keyframe
+ *   @return {String||Number}
+ *           e.g. 0
+ *
+ * toSegmentValue(computedStyle)
+ *   Convert computed style to segment value of graph.
+ *   @param {String||Number}
+ *          e.g. 0
+ *   @return {Number}
+ *          e.g. 0 (should be 0 - 1.0)
+ */
+class ComputedStylePath extends PureComponent {
+  static get propTypes() {
+    return {
+      componentWidth: PropTypes.number.isRequired,
+      easingHintStrokeWidth: PropTypes.number.isRequired,
+      graphHeight: PropTypes.number.isRequired,
+      keyframes: PropTypes.array.isRequired,
+      simulateAnimation: PropTypes.func.isRequired,
+      totalDuration: PropTypes.number.isRequired,
+    };
+  }
+
+  /**
+   * Return an array containing the path segments between the given start and
+   * end keyframe values.
+   *
+   * @param {Object} startKeyframe
+   *        Starting keyframe.
+   * @param {Object} endKeyframe
+   *        Ending keyframe.
+   * @return {Array}
+   *         Array of path segment.
+   *         [{x: {Number} time, y: {Number} segment value}, ...]
+   */
+  getPathSegments(startKeyframe, endKeyframe) {
+    const { componentWidth, simulateAnimation, totalDuration } = this.props;
+
+    const propertyName = this.getPropertyName();
+    const offsetDistance = endKeyframe.offset - startKeyframe.offset;
+    const duration = offsetDistance * totalDuration;
+
+    const keyframes = [startKeyframe, endKeyframe].map((keyframe, index) => {
+      return {
+        offset: index,
+        easing: keyframe.easing,
+        [getJsPropertyName(propertyName)]: this.getPropertyValue(keyframe),
+      };
+    });
+    const effect = {
+      duration,
+      fill: "forwards",
+    };
+
+    const simulatedAnimation = simulateAnimation(keyframes, effect, true);
+
+    if (!simulatedAnimation) {
+      return null;
+    }
+
+    const simulatedElement = simulatedAnimation.effect.target;
+    const win = simulatedElement.ownerGlobal;
+    const threshold = getPreferredProgressThresholdByKeyframes(keyframes);
+
+    const getSegment = time => {
+      simulatedAnimation.currentTime = time;
+      const computedStyle = win
+        .getComputedStyle(simulatedElement)
+        .getPropertyValue(propertyName);
+
+      return {
+        computedStyle,
+        x: time,
+        y: this.toSegmentValue(computedStyle),
+      };
+    };
+
+    const segments = createPathSegments(
+      0,
+      duration,
+      duration / componentWidth,
+      threshold,
+      DEFAULT_DURATION_RESOLUTION,
+      getSegment
+    );
+    const offset = startKeyframe.offset * totalDuration;
+
+    for (const segment of segments) {
+      segment.x += offset;
+    }
+
+    return segments;
+  }
+
+  /**
+   * Render easing hint from given path segments.
+   *
+   * @param {Array} segments
+   *        Path segments.
+   * @return {Element}
+   *         Element which represents easing hint.
+   */
+  renderEasingHint(segments) {
+    const { easingHintStrokeWidth, keyframes, totalDuration } = this.props;
+
+    const hints = [];
+
+    for (let i = 0, indexOfSegments = 0; i < keyframes.length - 1; i++) {
+      const startKeyframe = keyframes[i];
+      const endKeyframe = keyframes[i + 1];
+      const endTime = endKeyframe.offset * totalDuration;
+      const hintSegments = [];
+
+      for (; indexOfSegments < segments.length; indexOfSegments++) {
+        const segment = segments[indexOfSegments];
+        hintSegments.push(segment);
+
+        if (startKeyframe.offset === endKeyframe.offset) {
+          hintSegments.push(segments[++indexOfSegments]);
+          break;
+        } else if (segment.x === endTime) {
+          break;
+        }
+      }
+
+      const g = dom.g(
+        {
+          className: "hint",
+        },
+        dom.title({}, startKeyframe.easing),
+        dom.path({
+          d:
+            `M${hintSegments[0].x},${hintSegments[0].y} ` +
+            toPathString(hintSegments),
+          style: {
+            "stroke-width": easingHintStrokeWidth,
+          },
+        })
+      );
+
+      hints.push(g);
+    }
+
+    return hints;
+  }
+
+  /**
+   * Render graph. This method returns React dom.
+   *
+   * @return {Element}
+   */
+  renderGraph() {
+    const { keyframes } = this.props;
+
+    const segments = [];
+
+    for (let i = 0; i < keyframes.length - 1; i++) {
+      const startKeyframe = keyframes[i];
+      const endKeyframe = keyframes[i + 1];
+      const keyframesSegments = this.getPathSegments(
+        startKeyframe,
+        endKeyframe
+      );
+
+      if (!keyframesSegments) {
+        return null;
+      }
+
+      segments.push(...keyframesSegments);
+    }
+
+    return [this.renderPathSegments(segments), this.renderEasingHint(segments)];
+  }
+
+  /**
+   * Return react dom fron given path segments.
+   *
+   * @param {Array} segments
+   * @param {Object} style
+   * @return {Element}
+   */
+  renderPathSegments(segments, style) {
+    const { graphHeight } = this.props;
+
+    for (const segment of segments) {
+      segment.y *= graphHeight;
+    }
+
+    let d = `M${segments[0].x},0 `;
+    d += toPathString(segments);
+    d += `L${segments[segments.length - 1].x},0 Z`;
+
+    return dom.path({ d, style });
+  }
+}
+
+/**
+ * Convert given CSS property name to JavaScript CSS name.
+ *
+ * @param {String} cssPropertyName
+ *        CSS property name (e.g. background-color).
+ * @return {String}
+ *         JavaScript CSS property name (e.g. backgroundColor).
+ */
+function getJsPropertyName(cssPropertyName) {
+  if (cssPropertyName == "float") {
+    return "cssFloat";
+  }
+  // https://drafts.csswg.org/cssom/#css-property-to-idl-attribute
+  return cssPropertyName.replace(/-([a-z])/gi, (str, group) => {
+    return group.toUpperCase();
+  });
+}
+
+module.exports = ComputedStylePath;