[EuiTextTruncate] Performance improvements; Remove non-canvas renderi…

…ng methods (#7210)

src-docs/src/views/text_truncate/performance.tsx

@@ -1,4 +1,4 @@
-import React, { useState, useEffect, useRef } from 'react';
+import React, { useState, useEffect, useRef, useMemo } from 'react';
 import { css } from '@emotion/react';
 import { throttle } from 'lodash';
 import { faker } from '@faker-js/faker';
@@ -15,14 +15,16 @@ import {
   EuiTextTruncate,
 } from '../../../../src';
 
-const text = Array.from({ length: 100 }, () => faker.lorem.lines(5));
-
 export default () => {
   // Testing toggles
-  const [canvasRendering, setCanvasRendering] = useState(true);
-  const measurementRenderAPI = canvasRendering ? 'canvas' : 'dom';
   const [virtualization, setVirtualization] = useState(false);
-  const [throttleMs, setThrottleMs] = useState(100);
+  const [throttleMs, setThrottleMs] = useState(0);
+  const [lineCount, setLineCount] = useState(100);
+
+  // Number of lines of text to render
+  const text = useMemo(() => {
+    return Array.from({ length: lineCount }, () => faker.lorem.lines(5));
+  }, [lineCount]);
 
   // Width resize observer
   const widthRef = useRef<HTMLDivElement | null>(null);
@@ -37,19 +39,25 @@ export default () => {
     }, throttleMs);
 
     const resizeObserver = new ResizeObserver(onObserve);
-    resizeObserver.observe(widthRef.current);
+
+    document.fonts.ready.then(() => {
+      resizeObserver.observe(widthRef.current!);
+    });
 
     () => resizeObserver.disconnect();
   }, [throttleMs]);
 
   return (
     <EuiText>
-      <EuiFlexGroup alignItems="center">
-        <EuiSwitch
-          label="Toggle canvas rendering"
-          checked={canvasRendering}
-          onChange={() => setCanvasRendering(!canvasRendering)}
-        />
+      <EuiFlexGroup alignItems="center" gutterSize="xl">
+        <EuiFormRow label="Lines" display="columnCompressed">
+          <EuiFieldNumber
+            value={lineCount}
+            onChange={(e) => setLineCount(Number(e.target.value))}
+            style={{ width: 100 }}
+            compressed
+          />
+        </EuiFormRow>
         <EuiSwitch
           label="Toggle virtualization"
           checked={virtualization}
@@ -91,7 +99,6 @@ export default () => {
                 text={text[index]}
                 truncation="middle"
                 width={width}
-                measurementRenderAPI={measurementRenderAPI}
               />
             )}
           </FixedSizeList>
@@ -102,7 +109,6 @@ export default () => {
               text={text}
               truncation="middle"
               width={width}
-              measurementRenderAPI={measurementRenderAPI}
             />
           ))
         )}

src-docs/src/views/text_truncate/text_truncate_example.js

@@ -35,10 +35,9 @@ export const TextTruncateExample = {
   intro: (
     <EuiCallOut iconType="beta" title="Beta development" color="warning">
       <strong>EuiTextTruncate</strong> is a beta component that is still
-      undergoing performance investigations. We would particularly caution
-      against repeated usage (over 10 usages per page) with long text (over 100
-      characters) until we've improved{' '}
-      <Link to="#performance">performance</Link>.
+      undergoing <Link to="#performance">performance investigation</Link>. We
+      would particularly caution in high-usage scenarios (e.g. over 500 usages
+      per page).
     </EuiCallOut>
   ),
   sections: [
@@ -234,17 +233,17 @@ export const TextTruncateExample = {
       text: (
         <>
           <p>
-            <strong>EuiTextTruncate</strong> uses an extra DOM element under the
+            <strong>EuiTextTruncate</strong> uses a canvas element under the
             hood to manipulate text and calculate whether the text width fits
             within the available width. Additionally, by default, the component
             will include its own resize observer in order to react to width
             changes.
           </p>
           <p>
             These functionalities can cause performance issues if the component
-            is rendered many times per page, and we would strongly recommend
-            using caution when doing so. Several escape hatches are available
-            for performance improvements:
+            is rendered over hundreds of times per page, and we would strongly
+            recommend using caution when doing so. Several escape hatches are
+            available for performance improvements:
           </p>
           <ol
             css={({ euiTheme }) =>
@@ -259,37 +258,30 @@ export const TextTruncateExample = {
               Pass a <EuiCode>width</EuiCode> prop to skip initializing a resize
               observer for each component instance. For text within a container
               of the same width, we would strongly recommend applying a single
-              resize observer to the parent container and passing down that
-              width to all child <strong>EuiTextTruncate</strong>s.
-            </li>
-            <li>
-              Use the <EuiCode>measurementRenderAPI="canvas"</EuiCode> prop to
-              utilize the Canvas API for text measurement. While this can be
-              significantly more performant at higher iterations, please do note
-              that there are minute pixel to subpixel differences in this
-              rendering method.
+              resize observer to the parent container and passing that width to
+              all child <strong>EuiTextTruncate</strong>s. Additionally, you may
+              want to consider{' '}
+              <EuiLink href="https://lodash.com/docs/#throttle" target="_blank">
+                throttling
+              </EuiLink>{' '}
+              any resize observers or width-based logic.
             </li>
             <li>
-              Strongly consider using{' '}
+              Use{' '}
               <EuiLink
                 href="https://github.com/bvaughn/react-window"
                 target="_blank"
               >
                 virtualization
               </EuiLink>{' '}
               to reduce the number of rendered elements visible at any given
-              time, or{' '}
-              <EuiLink href="https://lodash.com/docs/#throttle" target="_blank">
-                throttling
-              </EuiLink>{' '}
-              any resize observers or width-based logic.
+              time. For over hundreds of instances, this will generally be the
+              most effective solution for performance or rerender issues.
             </li>
             <li>
               If necessary, consider pulling out the underlying{' '}
-              <EuiCode>TruncationUtilsForDOM</EuiCode> and{' '}
-              <EuiCode>TruncationUtilsForCanvas</EuiCode> truncation utils and
-              re-using the same canvas context or DOM node, as opposed to
-              repeatedly creating new ones.
+              <EuiCode>TruncationUtils</EuiCode> and re-using the same canvas
+              context, as opposed to repeatedly creating new ones.
             </li>
           </ol>
         </>
@@ -300,7 +292,6 @@ export const TextTruncateExample = {
       snippet: `<EuiTextTruncate
   text="Hello world"
   width={width}
-  measurementRenderAPI="canvas"
 />`,
     },
   ],

src/components/text_truncate/index.ts

@@ -12,4 +12,4 @@ export type {
 } from './text_truncate';
 export { EuiTextTruncate } from './text_truncate';
 
-export { TruncationUtilsWithDOM, TruncationUtilsWithCanvas } from './utils';
+export { CanvasTextUtils, TruncationUtils } from './utils';

src/components/text_truncate/text_truncate.spec.tsx

@@ -297,7 +297,7 @@ describe('EuiTextTruncate', () => {
             {...props}
             id="text1"
             truncation="startEnd"
-            width={30}
+            width={20}
           />
           <EuiTextTruncate
             {...props}
@@ -336,7 +336,7 @@ describe('EuiTextTruncate', () => {
       getTruncatedText().should('have.text', 'Lorem ipsum dolor sit amet, …');
 
       cy.viewport(100, 50);
-      getTruncatedText().should('have.text', 'Lorem ipsum …');
+      getTruncatedText().should('have.text', 'Lorem ipsum…');
     });
   });
 });

src/components/text_truncate/text_truncate.test.tsx

@@ -13,17 +13,9 @@ import { requiredProps } from '../../test';
 
 // Util mocks
 const mockEarlyReturn = { checkIfTruncationIsNeeded: () => false };
-const mockCleanup = jest.fn();
-jest.mock('./utils', () => {
-  return {
-    TruncationUtilsWithDOM: jest.fn(() => ({
-      ...mockEarlyReturn,
-      cleanup: mockCleanup,
-    })),
-    TruncationUtilsWithCanvas: jest.fn(() => mockEarlyReturn),
-  };
-});
-import { TruncationUtilsWithCanvas } from './utils';
+jest.mock('./utils', () => ({
+  TruncationUtils: jest.fn(() => mockEarlyReturn),
+}));
 
 import { EuiTextTruncate } from './text_truncate';
 
@@ -61,24 +53,5 @@ describe('EuiTextTruncate', () => {
     });
   });
 
-  describe('render API', () => {
-    it('calls the DOM cleanup method after each render', () => {
-      render(<EuiTextTruncate {...props} measurementRenderAPI="dom" />);
-      expect(mockCleanup).toHaveBeenCalledTimes(1);
-    });
-
-    it('allows switching to canvas rendering via `measurementRenderAPI`', () => {
-      render(
-        <EuiTextTruncate
-          width={100}
-          text="Canvas test"
-          measurementRenderAPI="canvas"
-        />
-      );
-      expect(TruncationUtilsWithCanvas).toHaveBeenCalledTimes(1);
-      expect(mockCleanup).not.toHaveBeenCalled();
-    });
-  });
-
   // We can't unit test the actual truncation logic in JSDOM - see Cypress spec tests instead
 });

src/components/text_truncate/text_truncate.tsx

@@ -24,7 +24,7 @@ import {
 } from '../observer/resize_observer';
 import type { CommonProps } from '../common';
 
-import { TruncationUtilsWithDOM, TruncationUtilsWithCanvas } from './utils';
+import { TruncationUtils } from './utils';
 import { euiTextTruncateStyles as styles } from './text_truncate.styles';
 
 const TRUNCATION_TYPES = ['end', 'start', 'startEnd', 'middle'] as const;
@@ -85,16 +85,6 @@ export type EuiTextTruncateProps = Omit<
      * registers a size change. This callback will **not** fire if `width` is passed.
      */
     onResize?: (width: number) => void;
-    /**
-     * By default, EuiTextTruncate will calculate its truncation via DOM manipulation
-     * and measurement, which has the benefit of automatically inheriting font styles.
-     * However, if this approach proves to have a significant performance impact for your
-     * usage, consider using the `canvas` API instead, which is more performant.
-     *
-     * Please note that there are minute pixel to subpixel differences between the
-     * two options due to different rendering engines.
-     */
-    measurementRenderAPI?: 'dom' | 'canvas';
     /**
      * By default, EuiTextTruncate will render the truncated string directly.
      * You can optionally pass a render prop function to the component, which
@@ -129,7 +119,6 @@ const EuiTextTruncateWithWidth: FunctionComponent<
   truncationPosition,
   ellipsis = '…',
   containerRef,
-  measurementRenderAPI = 'dom',
   className,
   ...rest
 }) => {
@@ -160,16 +149,12 @@ const EuiTextTruncateWithWidth: FunctionComponent<
     let truncatedText = '';
     if (!containerEl || !width) return truncatedText;
 
-    const params = {
+    const utils = new TruncationUtils({
       fullText: text,
       ellipsis,
       container: containerEl,
       availableWidth: width,
-    };
-    const utils =
-      measurementRenderAPI === 'canvas'
-        ? new TruncationUtilsWithCanvas(params)
-        : new TruncationUtilsWithDOM(params);
+    });
 
     if (utils.checkIfTruncationIsNeeded() === false) {
       truncatedText = text;
@@ -196,10 +181,6 @@ const EuiTextTruncateWithWidth: FunctionComponent<
           break;
       }
     }
-
-    if (measurementRenderAPI === 'dom') {
-      (utils as TruncationUtilsWithDOM).cleanup();
-    }
     return truncatedText;
   }, [
     width,
@@ -209,7 +190,6 @@ const EuiTextTruncateWithWidth: FunctionComponent<
     truncationPosition,
     ellipsis,
     containerEl,
-    measurementRenderAPI,
   ]);
 
   const isTruncating = truncatedText !== text;