Bug 1465424 - Added 3 histograms to test font editor usage assumptions; r=rcaliman
authorPatrick Brosset <pbrosset@mozilla.com>
Thu, 19 Jul 2018 14:29:40 +0200
changeset 821105 b2f2361ee3175a867335952705274d8d08cc086f
parent 821104 b891899b2036de7b47cf96790c581fb704588c78
child 821106 ab6c2651f8eff6b2846ee89732089c9ca62f6a13
push id117018
push userbmo:sfoster@mozilla.com
push dateSat, 21 Jul 2018 04:05:10 +0000
reviewersrcaliman
bugs1465424
milestone63.0a1
Bug 1465424 - Added 3 histograms to test font editor usage assumptions; r=rcaliman MozReview-Commit-ID: BIkqEzp5BNA
devtools/client/inspector/fonts/fonts.js
toolkit/components/telemetry/Histograms.json
--- a/devtools/client/inspector/fonts/fonts.js
+++ b/devtools/client/inspector/fonts/fonts.js
@@ -50,16 +50,20 @@ const REGISTERED_AXES_TO_FONT_PROPERTIES
   "ital": "font-style",
   "opsz": "font-optical-sizing",
   "slnt": "font-style",
   "wdth": "font-stretch",
   "wght": "font-weight",
 };
 const REGISTERED_AXES = Object.keys(REGISTERED_AXES_TO_FONT_PROPERTIES);
 
+const HISTOGRAM_N_FONT_AXES = "DEVTOOLS_FONTEDITOR_N_FONT_AXES";
+const HISTOGRAM_N_FONTS_RENDERED = "DEVTOOLS_FONTEDITOR_N_FONTS_RENDERED";
+const HISTOGRAM_FONT_TYPE_DISPLAYED = "DEVTOOLS_FONTEDITOR_FONT_TYPE_DISPLAYED";
+
 class FontInspector {
   constructor(inspector, window) {
     this.cssProperties = getCssProperties(inspector.toolbox);
     this.document = window.document;
     this.inspector = inspector;
     // Set of unique keyword values supported by designated font properties.
     this.keywordValues = new Set(this.getFontPropertyValueKeywords());
     this.nodeComputedStyle = {};
@@ -597,16 +601,44 @@ class FontInspector {
     return this.inspector &&
            this.inspector.selection.nodeFront &&
            this.inspector.selection.isConnected() &&
            this.inspector.selection.isElementNode() &&
            !this.inspector.selection.isPseudoElementNode();
   }
 
   /**
+   * Upon a new node selection, log some interesting telemetry probes.
+   */
+  logTelemetryProbesOnNewNode() {
+    const { fontData, fontEditor } = this.store.getState();
+    const { telemetry } = this.inspector;
+
+    // Log the number of font faces used to render content of the element.
+    const nbOfFontsRendered = fontData.fonts.length;
+    if (nbOfFontsRendered) {
+      telemetry.getHistogramById(HISTOGRAM_N_FONTS_RENDERED).add(nbOfFontsRendered);
+    }
+
+    // Log data about the currently edited font (if any).
+    // Note that the edited font is always the first one from the fontEditor.fonts array.
+    const editedFont = fontEditor.fonts[0];
+    if (!editedFont) {
+      return;
+    }
+
+    const nbOfAxes = editedFont.variationAxes ? editedFont.variationAxes.length : 0;
+    telemetry.getHistogramById(HISTOGRAM_FONT_TYPE_DISPLAYED).add(
+      !nbOfAxes ? "nonvariable" : "variable");
+    if (nbOfAxes) {
+      telemetry.getHistogramById(HISTOGRAM_N_FONT_AXES).add(nbOfAxes);
+    }
+  }
+
+  /**
    * Sync the Rule view with the latest styles from the page. Called in a debounced way
    * (see constructor) after property changes are applied directly to the CSS style rule
    * on the page circumventing direct TextProperty.setValue() which triggers expensive DOM
    * operations in TextPropertyEditor.update().
    *
    * @param  {String} name
    *         CSS property name
    * @param  {String} value
@@ -681,18 +713,19 @@ class FontInspector {
   }
 
   /**
    * Selection 'new-node' event handler.
    */
   onNewNode() {
     this.ruleView.off("property-value-updated", this.onRulePropertyUpdated);
     if (this.isPanelVisible()) {
-      this.update();
-      this.refreshFontEditor();
+      Promise.all([this.update(), this.refreshFontEditor()]).then(() => {
+        this.logTelemetryProbesOnNewNode();
+      }).catch(e => console.error(e));
     }
   }
 
   /**
    * Handler for change in preview input.
    */
   onPreviewFonts(value) {
     this.store.dispatch(updatePreviewText(value));
--- a/toolkit/components/telemetry/Histograms.json
+++ b/toolkit/components/telemetry/Histograms.json
@@ -10150,16 +10150,48 @@
     "expires_in_version": "never",
     "kind": "linear",
     "high": 30,
     "n_buckets": 29,
     "bug_numbers": [1373483],
     "description": "On page load, record the number of CSS Grid elements present on a page when the DevTools is open",
     "releaseChannelCollection": "opt-out"
   },
+  "DEVTOOLS_FONTEDITOR_N_FONT_AXES": {
+    "record_in_processes": ["main"],
+    "alert_emails": ["dev-developer-tools@lists.mozilla.org", "mbalfanz@mozilla.com"],
+    "expires_in_version": "66",
+    "bug_numbers": [1465424],
+    "description": "Indicates the number of variation axes of the variable fonts that are displayed in the font editor UI",
+    "releaseChannelCollection": "opt-out",
+    "kind": "exponential",
+    "high": 100,
+    "n_buckets": 20
+  },
+  "DEVTOOLS_FONTEDITOR_N_FONTS_RENDERED": {
+    "record_in_processes": ["main"],
+    "alert_emails": ["dev-developer-tools@lists.mozilla.org", "mbalfanz@mozilla.com"],
+    "expires_in_version": "66",
+    "bug_numbers": [1465424],
+    "description": "Indicates how many fonts the font editor displayed as being needed to render the selected element's content",
+    "releaseChannelCollection": "opt-out",
+    "kind": "exponential",
+    "high": 50,
+    "n_buckets": 10
+  },
+  "DEVTOOLS_FONTEDITOR_FONT_TYPE_DISPLAYED": {
+    "record_in_processes": ["main"],
+    "alert_emails": ["dev-developer-tools@lists.mozilla.org", "mbalfanz@mozilla.com"],
+    "expires_in_version": "66",
+    "bug_numbers": [1465424],
+    "description": "Indicates if the font editor displayed its UI for a non-variable font or a variable font",
+    "releaseChannelCollection": "opt-out",
+    "kind": "categorical",
+    "labels": ["variable", "nonvariable"]
+  },
   "BROWSER_IS_USER_DEFAULT": {
     "record_in_processes": ["main"],
     "expires_in_version": "never",
     "kind": "boolean",
     "releaseChannelCollection": "opt-out",
     "description": "The result of the startup default desktop browser check."
   },
   "BROWSER_IS_USER_DEFAULT_ERROR": {