Slight tweaking of UI code

Author: Brian Vaughn

packages/react-devtools-scheduling-profiler/src/content-views/ReactMeasuresView.js

@@ -242,20 +242,21 @@ export class ReactMeasuresView extends View {
       }
 
       // Render lane labels
-      const labelRect = {
-        origin: {
-          x: visibleArea.origin.x,
-          y: baseY,
-        },
-        size: {
-          width: visibleArea.size.width,
-          height: REACT_LANE_HEIGHT,
-        },
-      };
       const label = this._profilerData.laneToLabelMap.get(lane);
       if (label == null) {
         console.warn(`Could not find label for lane ${lane}.`);
       } else {
+        const labelRect = {
+          origin: {
+            x: visibleArea.origin.x,
+            y: baseY,
+          },
+          size: {
+            width: visibleArea.size.width,
+            height: REACT_LANE_HEIGHT,
+          },
+        };
+
         drawText(label, context, labelRect, visibleArea, {
           fillStyle: COLORS.TEXT_DIM_COLOR,
         });

packages/react-devtools-scheduling-profiler/src/content-views/utils/text.js

@@ -14,6 +14,19 @@ import {COLORS, FONT_SIZE, TEXT_PADDING} from '../constants';
 
 const cachedTextWidths = new Map();
 
+export function getTextWidth(
+  context: CanvasRenderingContext2D,
+  text: string,
+): number {
+  let measuredWidth = cachedTextWidths.get(text);
+  if (measuredWidth == null) {
+    measuredWidth = context.measureText(text).width;
+    cachedTextWidths.set(text, measuredWidth);
+  }
+
+  return ((measuredWidth: any): number);
+}
+
 export function trimText(
   context: CanvasRenderingContext2D,
   text: string,
@@ -22,13 +35,7 @@ export function trimText(
   for (let i = text.length - 1; i >= 0; i--) {
     const trimmedText = i === text.length - 1 ? text : text.substr(0, i) + '…';
 
-    let measuredWidth = cachedTextWidths.get(trimmedText);
-    if (measuredWidth == null) {
-      measuredWidth = context.measureText(trimmedText).width;
-      cachedTextWidths.set(trimmedText, measuredWidth);
-    }
-
-    if (measuredWidth <= width) {
+    if (getTextWidth(context, text) <= width) {
       return trimmedText;
     }
   }