1 files changed, 69 insertions, 0 deletions
diff --git a/devtools/client/performance/components/waterfall-header.js b/devtools/client/performance/components/waterfall-header.js
new file mode 100644
index 000000000..f3030091b
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+++ b/devtools/client/performance/components/waterfall-header.js
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+/* 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";
+
+/**
+ * The "waterfall ticks" view, a header for the markers displayed in the waterfall.
+ */
+
+const { DOM: dom, PropTypes } = require("devtools/client/shared/vendor/react");
+const { L10N } = require("../modules/global");
+const { TickUtils } = require("../modules/waterfall-ticks");
+
+// ms
+const WATERFALL_HEADER_TICKS_MULTIPLE = 5;
+// px
+const WATERFALL_HEADER_TICKS_SPACING_MIN = 50;
+// px
+const WATERFALL_HEADER_TEXT_PADDING = 3;
+
+function WaterfallHeader(props) {
+  let { startTime, dataScale, sidebarWidth, waterfallWidth } = props;
+
+  let tickInterval = TickUtils.findOptimalTickInterval({
+    ticksMultiple: WATERFALL_HEADER_TICKS_MULTIPLE,
+    ticksSpacingMin: WATERFALL_HEADER_TICKS_SPACING_MIN,
+    dataScale: dataScale
+  });
+
+  let ticks = [];
+  for (let x = 0; x < waterfallWidth; x += tickInterval) {
+    let left = x + WATERFALL_HEADER_TEXT_PADDING;
+    let time = Math.round(x / dataScale + startTime);
+    let label = L10N.getFormatStr("timeline.tick", time);
+
+    let node = dom.div({
+      className: "plain waterfall-header-tick",
+      style: { transform: `translateX(${left}px)` }
+    }, label);
+    ticks.push(node);
+  }
+
+  return dom.div(
+    { className: "waterfall-header" },
+    dom.div(
+      {
+        className: "waterfall-sidebar theme-sidebar waterfall-header-name",
+        style: { width: sidebarWidth + "px" }
+      },
+      L10N.getStr("timeline.records")
+    ),
+    dom.div(
+      { className: "waterfall-header-ticks waterfall-background-ticks" },
+      ticks
+    )
+  );
+}
+
+WaterfallHeader.displayName = "WaterfallHeader";
+
+WaterfallHeader.propTypes = {
+  startTime: PropTypes.number.isRequired,
+  dataScale: PropTypes.number.isRequired,
+  sidebarWidth: PropTypes.number.isRequired,
+  waterfallWidth: PropTypes.number.isRequired,
+};
+
+module.exports = WaterfallHeader;